diff --git a/.editorconfig b/.editorconfig
index 60429d4e0..ec3ffa235 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -21,6 +21,10 @@ indent_size = 4
 indent_style = space
 indent_size = 2
 
+[*.{c,h}]
+indent_style = space
+indent_size = 2
+
 [*.html]
 indent_style = space
 indent_size = 2
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 73ad2c4d6..ef3be8a4b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -275,6 +275,7 @@ jobs:
 
       - name: Compile shared object
         run: make cargo.build crate=medea-jason platform=android targets=x86
+                              args="--features mockable"
 
       - uses: reactivecircus/android-emulator-runner@v2
         with:
diff --git a/Cargo.lock b/Cargo.lock
index 2cef1eb40..6d84bccad 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -140,7 +140,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b4ca8ce00b267af8ccebbd647de0d61e0674b6e61185cc7a592ff88772bed655"
 dependencies = [
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -325,7 +325,7 @@ checksum = "ad26f77093333e0e7c6ffe54ebe3582d908a104e448723eec6d43d08b07143fb"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -336,7 +336,7 @@ checksum = "b95aceadaf327f18f0df5962fedc1bde2f870566a0b9f65c89508a3b1f79334c"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -363,6 +363,24 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "android_log-sys"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85965b6739a430150bdd138e2374a98af0c3ee0d030b3bb7fc3bddff58d0102e"
+
+[[package]]
+name = "android_logger"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9ed09b18365ed295d722d0b5ed59c01b79a826ff2d2a8f73d5ecca8e6fb2f66"
+dependencies = [
+ "android_log-sys",
+ "env_logger",
+ "lazy_static",
+ "log",
+]
+
 [[package]]
 name = "ansi_term"
 version = "0.11.0"
@@ -409,16 +427,16 @@ dependencies = [
 
 [[package]]
 name = "async-executor"
-version = "1.4.0"
+version = "1.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eb877970c7b440ead138f6321a3b5395d6061183af779340b65e20c0fede9146"
+checksum = "871f9bb5e0a22eeb7e8cf16641feb87c9dc67032ccf8ff49e772eb9941d3a965"
 dependencies = [
  "async-task",
  "concurrent-queue",
  "fastrand",
  "futures-lite",
  "once_cell",
- "vec-arena",
+ "slab",
 ]
 
 [[package]]
@@ -439,9 +457,9 @@ dependencies = [
 
 [[package]]
 name = "async-io"
-version = "1.4.0"
+version = "1.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fcb9af4888a70ad78ecb5efcb0ba95d66a3cf54a88b62ae81559954c7588c7a2"
+checksum = "4bbfd5cf2794b1e908ea8457e6c45f8f8f1f6ec5f74617bf4662623f47503c3b"
 dependencies = [
  "concurrent-queue",
  "fastrand",
@@ -451,8 +469,8 @@ dependencies = [
  "once_cell",
  "parking",
  "polling",
+ "slab",
  "socket2 0.4.0",
- "vec-arena",
  "waker-fn",
  "winapi 0.3.9",
 ]
@@ -483,7 +501,7 @@ checksum = "d7d78656ba01f1b93024b7c3a0467f1608e4be67d725749fdcd7d2c7678fd7a2"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -541,7 +559,7 @@ checksum = "25f9db3b38af870bf7e5cc649167533b493928e50744e2c30ae350230b414670"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -552,7 +570,7 @@ checksum = "db134ba52475c060f3329a8ef0f8786d6b872ed01515d4b79c162e5798da1340"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -569,7 +587,7 @@ checksum = "0b98e84bbb4cbcdd97da190ba0c58a1bb0de2c1fdf67d159e192ed766aeca722"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -621,11 +639,12 @@ dependencies = [
 
 [[package]]
 name = "backtrace"
-version = "0.3.57"
+version = "0.3.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "78ed203b9ba68b242c62b3fb7480f589dd49829be1edb3fe8fc8b4ffda2dcb8d"
+checksum = "88fb5a785d6b44fd9d6700935608639af1b8356de1e55d5f7c2740f4faa15d82"
 dependencies = [
  "addr2line",
+ "cc",
  "cfg-if 1.0.0",
  "libc",
  "miniz_oxide",
@@ -989,7 +1008,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5e98e2ad1a782e33928b96fc3948e7c355e5af34ba4de7670fe8bac2a3b2006d"
 dependencies = [
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1027,7 +1046,7 @@ dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
  "regex",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1037,7 +1056,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed431abf442833fd62ad7cc527a3833d969155c803f0dcf7f8a68db8adddc4c5"
 dependencies = [
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1071,7 +1090,7 @@ dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
  "strsim 0.9.3",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1085,7 +1104,7 @@ dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
  "strsim 0.10.0",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1096,7 +1115,7 @@ checksum = "d9b5a2f4ac4969822c62224815d069952656cadc7084fdca9751e6d959189b72"
 dependencies = [
  "darling_core 0.10.2",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1107,9 +1126,15 @@ checksum = "29b5acf0dea37a7f66f7b25d2c5e93fd46f8f6968b1a5d7a3e02e97768afc95a"
 dependencies = [
  "darling_core 0.12.4",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
+[[package]]
+name = "dart-sys"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42fe64308f2072bb94ecd8f7557f9ac01b69d86e6199bac24be0f091ad74b092"
+
 [[package]]
 name = "deadpool"
 version = "0.5.2"
@@ -1147,7 +1172,7 @@ checksum = "fcc3dd5e9e9c0b295d6e1e4d811fb6f157d5ffd784b8d202fc62eac8035a770b"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1160,7 +1185,7 @@ dependencies = [
  "derive_builder_core",
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1172,7 +1197,7 @@ dependencies = [
  "darling 0.10.2",
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1184,7 +1209,7 @@ dependencies = [
  "convert_case",
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1271,7 +1296,17 @@ dependencies = [
  "heck",
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
+]
+
+[[package]]
+name = "env_logger"
+version = "0.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17392a012ea30ef05a610aa97dfb49496e71c9f676b27879922ea5bdf60d9d3f"
+dependencies = [
+ "log",
+ "regex",
 ]
 
 [[package]]
@@ -1298,7 +1333,7 @@ checksum = "aa4da3c766cd7a0db8242e326e9e4e081edd567072893ed320008189715366a4"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
  "synstructure",
 ]
 
@@ -1313,7 +1348,7 @@ dependencies = [
  "futures-core",
  "futures-util",
  "http",
- "hyper 0.14.6",
+ "hyper 0.14.7",
  "hyper-tls",
  "mime",
  "serde 1.0.125",
@@ -1325,9 +1360,9 @@ dependencies = [
 
 [[package]]
 name = "fastrand"
-version = "1.4.0"
+version = "1.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ca5faf057445ce5c9d4329e382b2ce7ca38550ef3b73a5348362d5f24e0c7fe3"
+checksum = "77b705829d1e87f762c2df6da140b26af5839e1033aa84aa5f56bb688e4e1bdb"
 dependencies = [
  "instant",
 ]
@@ -1516,7 +1551,7 @@ dependencies = [
  "proc-macro-hack",
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1616,7 +1651,7 @@ dependencies = [
  "quote 1.0.9",
  "serde 1.0.125",
  "serde_json",
- "syn 1.0.70",
+ "syn 1.0.71",
  "textwrap 0.12.1",
  "thiserror",
  "typed-builder",
@@ -1630,7 +1665,7 @@ checksum = "1a5bcf1bbeab73aa4cf2fde60a846858dc036163c7c33bec309f8d17de785479"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -1867,9 +1902,9 @@ dependencies = [
 
 [[package]]
 name = "hyper"
-version = "0.14.6"
+version = "0.14.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f006b8784cfb01fe7aa9c46f5f5cd4cf5c85a8c612a0653ec97642979062665"
+checksum = "1e5f105c494081baa3bf9e200b279e27ec1623895cd504c7dbef8d0b080fcf54"
 dependencies = [
  "bytes 1.0.1",
  "futures-channel",
@@ -1896,7 +1931,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d6183ddfa99b85da61a140bea0efc93fdf56ceaa041b37d553518030827f9905"
 dependencies = [
  "bytes 1.0.1",
- "hyper 0.14.6",
+ "hyper 0.14.7",
  "native-tls",
  "tokio 1.5.0",
  "tokio-native-tls",
@@ -1981,7 +2016,7 @@ checksum = "75c094e94816723ab936484666968f5b58060492e880f3c8d00489a1e244fa51"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -2090,9 +2125,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.93"
+version = "0.2.94"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9385f66bf6105b241aa65a61cb923ef20efc665cb9f9bb50ac2f0c4b7f378d41"
+checksum = "18794a8ad5b29321f790b55d93dfba91e125cb1a9edbd4f8e3150acc771c1a5e"
 
 [[package]]
 name = "linked-hash-map"
@@ -2183,7 +2218,7 @@ dependencies = [
  "function_name",
  "futures 0.3.14",
  "humantime-serde",
- "hyper 0.14.6",
+ "hyper 0.14.7",
  "lazy_static",
  "medea-client-api-proto 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "medea-control-api-mock",
@@ -2330,16 +2365,21 @@ dependencies = [
 name = "medea-jason"
 version = "0.2.0"
 dependencies = [
+ "android_logger",
  "async-recursion",
  "async-trait",
  "bitflags",
+ "cc",
+ "cfg-if 1.0.0",
  "console_error_panic_hook",
+ "dart-sys",
  "derivative",
  "derive_more",
  "downcast",
  "fragile",
  "futures 0.3.14",
  "js-sys",
+ "libc",
  "log",
  "medea-client-api-proto 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "medea-macro 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2367,7 +2407,7 @@ dependencies = [
  "medea-jason",
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
  "synstructure",
 ]
 
@@ -2380,7 +2420,7 @@ dependencies = [
  "Inflector",
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
  "synstructure",
 ]
 
@@ -2527,7 +2567,7 @@ dependencies = [
  "cfg-if 1.0.0",
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -2649,9 +2689,9 @@ checksum = "624a8340c38c1b80fd549087862da4ba43e08858af025b236e509b6649fc13d5"
 
 [[package]]
 name = "openssl"
-version = "0.10.33"
+version = "0.10.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a61075b62a23fef5a29815de7536d940aa35ce96d18ce0cc5076272db678a577"
+checksum = "6d7830286ad6a3973c0f1d9b73738f69c76b739301d0229c4b96501695cbe4c8"
 dependencies = [
  "bitflags",
  "cfg-if 1.0.0",
@@ -2669,9 +2709,9 @@ checksum = "77af24da69f9d9341038eba93a073b1fdaaa1b788221b00a69bce9e762cb32de"
 
 [[package]]
 name = "openssl-sys"
-version = "0.9.61"
+version = "0.9.62"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "313752393519e876837e09e1fa183ddef0be7735868dced3196f4472d536277f"
+checksum = "fa52160d45fa2e7608d504b7c3a3355afed615e6d8b627a74458634ba21b69bd"
 dependencies = [
  "autocfg",
  "cc",
@@ -2786,7 +2826,7 @@ checksum = "3be26700300be6d9d23264c73211d8190e755b6b5ca7a1b28230025511b52a5e"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -2797,7 +2837,7 @@ checksum = "48c950132583b500556b1efd71d45b319029f2b71518d979fcc208e16b42426f"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -2845,9 +2885,9 @@ checksum = "ac74c624d6b2d21f425f752262f42188365d7b8ff1aff74c82e45136510a4857"
 
 [[package]]
 name = "predicates"
-version = "1.0.7"
+version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eeb433456c1a57cc93554dea3ce40b4c19c4057e41c55d4a0f3d84ea71c325aa"
+checksum = "f49cfaf7fdaa3bfacc6fa3e7054e65148878354a5cfddcf661df4c851f8021df"
 dependencies = [
  "difference",
  "float-cmp",
@@ -2949,7 +2989,7 @@ dependencies = [
  "itertools 0.8.2",
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -2964,9 +3004,9 @@ dependencies = [
 
 [[package]]
 name = "protobuf"
-version = "2.22.1"
+version = "2.23.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1b7f4a129bb3754c25a4e04032a90173c68f85168f77118ac4cb4936e7f06f92"
+checksum = "45604fc7a88158e7d514d8e22e14ac746081e7a70d7690074dd0029ee37458d6"
 
 [[package]]
 name = "quick-error"
@@ -3153,9 +3193,9 @@ dependencies = [
 
 [[package]]
 name = "redox_syscall"
-version = "0.2.6"
+version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8270314b5ccceb518e7e578952f0b72b88222d02e8f77f5ecf7abbb673539041"
+checksum = "85dd92e586f7355c633911e11f77f3d12f04b1b1bd76a198bd34ae3af8341ef2"
 dependencies = [
  "bitflags",
 ]
@@ -3172,9 +3212,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.4.5"
+version = "1.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "957056ecddbeba1b26965114e191d2e8589ce74db242b6ea25fc4062427a5c19"
+checksum = "2a26af418b574bd56588335b3a3659a65725d4e636eb1016c2f9e3b38c7cc759"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -3209,7 +3249,7 @@ dependencies = [
  "futures-util",
  "http",
  "http-body 0.4.1",
- "hyper 0.14.6",
+ "hyper 0.14.7",
  "hyper-tls",
  "ipnet",
  "js-sys",
@@ -3409,7 +3449,7 @@ checksum = "b093b7a2bb58203b5da3056c05b4ec1fed827dcfdb37347a8841695263b3d06d"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -3476,7 +3516,7 @@ dependencies = [
  "darling 0.12.4",
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -3510,7 +3550,7 @@ checksum = "b2acd6defeddb41eb60bb468f8825d0cfd0c2a76bc03bfd235b6a1dc4f6a1ad5"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -3651,7 +3691,7 @@ checksum = "133659a15339456eeeb07572eb02a91c91e9815e9cbc89566944d2c8d3efdbf6"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -3714,7 +3754,7 @@ dependencies = [
  "quote 1.0.9",
  "serde 1.0.125",
  "serde_derive",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -3730,7 +3770,7 @@ dependencies = [
  "serde_derive",
  "serde_json",
  "sha1",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -3776,9 +3816,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.70"
+version = "1.0.71"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9505f307c872bab8eb46f77ae357c8eba1fdacead58ee5a850116b1d7f82883"
+checksum = "ad184cc9470f9117b2ac6817bfe297307418819ba40552f9b3846f05c33d5373"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
@@ -3793,7 +3833,7 @@ checksum = "b834f2d66f734cb897113e34aaff2f1ab4719ca946f9a7358dba8f8064148701"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
  "unicode-xid 0.2.1",
 ]
 
@@ -3883,7 +3923,7 @@ checksum = "7765189610d8241a44529806d6fd1f2e0a08734313a35d5b3a556f92b381f3c0"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -3949,7 +3989,7 @@ dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
  "standback",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -4014,7 +4054,7 @@ checksum = "e44da00bfc73a25f814cd8d7e57a68a5c31b74b3152a0a1d1f590c97ed06265a"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -4025,7 +4065,7 @@ checksum = "caf7b11a536f46a809a8a9f0bb4237020f70ecbf115b842360afb127ea2fda57"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -4115,7 +4155,7 @@ dependencies = [
  "proc-macro2 1.0.26",
  "prost-build",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -4326,7 +4366,7 @@ checksum = "c42e6fa53307c8a17e4ccd4dc81cf5ec38db9209f59b222210375b54ee40d1e2"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -4407,7 +4447,7 @@ checksum = "f85f4270f4f449a3f2c0cf2aecc8415e388a597aeacc7d55fc749c5c968c8533"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
 ]
 
 [[package]]
@@ -4509,12 +4549,6 @@ version = "0.2.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cbdbff6266a24120518560b5dc983096efb98462e51d0d68169895b237be3e5d"
 
-[[package]]
-name = "vec-arena"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34b2f665b594b07095e3ac3f718e13c2197143416fae4c5706cffb7b1af8d7f1"
-
 [[package]]
 name = "vec_map"
 version = "0.8.2"
@@ -4615,7 +4649,7 @@ dependencies = [
  "log",
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
  "wasm-bindgen-shared",
 ]
 
@@ -4649,7 +4683,7 @@ checksum = "d53739ff08c8a68b0fdbcd54c372b8ab800b1449ab3c9d706503bc7dd1621b2c"
 dependencies = [
  "proc-macro2 1.0.26",
  "quote 1.0.9",
- "syn 1.0.70",
+ "syn 1.0.71",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
diff --git a/Makefile b/Makefile
index e3d8d24bb..a3cf11049 100644
--- a/Makefile
+++ b/Makefile
@@ -26,14 +26,10 @@ CHROME_VERSION := 89.0
 FIREFOX_VERSION := 87.0
 
 CARGO_NDK_VER := 2.3.0-ndkr22b-rust$(RUST_VER)
-ANDROID_NDK_TARGETS := arm64-v8a \
-                       armeabi-v7a \
-                       x86 \
-                       x86_64
-ANDROID_RUST_TARGETS := aarch64-linux-android \
-                        armv7-linux-androideabi \
-                        i686-linux-android \
-                        x86_64-linux-android
+ANDROID_TARGETS := aarch64-linux-android \
+                   armv7-linux-androideabi \
+                   i686-linux-android \
+                   x86_64-linux-android
 ANDROID_SDK_COMPILE_VERSION := $(strip \
 	$(shell grep compileSdkVersion jason/flutter/android/build.gradle \
 	        | awk '{print $$2}'))
@@ -232,12 +228,13 @@ cargo:
 #		 | crate=medea-jason [debug=(yes|no)] [dockerized=(no|yes)]
 #		   	[( [platform=web]
 #		   	 | platform=android
-#		   	   	[targets=($(ANDROID_NDK_TARGETS)|<t1>[,<t2>...])] )] )]
+#		   	   	[targets=($(ANDROID_TARGETS)|<t1>[,<t2>...])] )] )]
+# 		[args=<cargo-build-args>]
 
 cargo-build-crate = $(if $(call eq,$(crate),),@all,$(crate))
 cargo-build-platform = $(if $(call eq,$(platform),),web,$(platform))
 cargo-build-targets = $(strip \
-	$(if $(call eq,$(targets),),$(ANDROID_NDK_TARGETS),$(targets)))
+	$(if $(call eq,$(targets),),$(ANDROID_TARGETS),$(targets)))
 
 cargo.build:
 ifeq ($(cargo-build-crate),@all)
@@ -254,7 +251,7 @@ ifeq ($(dockerized),yes)
 			make cargo.build crate=$(cargo-build-crate) \
 			                 debug=$(debug) dockerized=no
 else
-	cargo build --bin medea $(if $(call eq,$(debug),no),--release,)
+	cargo build --bin medea $(if $(call eq,$(debug),no),--release,) $(args)
 endif
 endif
 ifeq ($(cargo-build-crate),medea-jason)
@@ -287,7 +284,9 @@ ifeq ($(pre-install),yes)
 	curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
 endif
 	@rm -rf $(crate-dir)/pkg/
-	wasm-pack build -t web $(crate-dir) $(if $(call eq,$(debug),no),,--dev)
+	wasm-pack build -t web $(crate-dir) \
+		$(if $(call eq,$(debug),no),,--dev) \
+		$(args)
 endif
 ifeq ($(cargo-build-platform),android)
 	$(foreach target,$(subst $(comma), ,$(cargo-build-targets)),\
@@ -295,15 +294,13 @@ ifeq ($(cargo-build-platform),android)
 endif
 endif
 endif
-# TODO: Replace with actual `medea-jason` crate.
 define cargo.build.medea-jason.android
 	$(eval target := $(strip $(1)))
 	$(eval debug := $(strip $(2)))
-	cd jason/jason-dummy/ && \
 	cargo ndk -p $(ANDROID_SDK_COMPILE_VERSION) -t $(target) \
-	          -o ../flutter/android/src/main/jniLibs \
-	          --manifest-path=Cargo.toml \
-		build $(if $(call eq,$(debug),no),--release,)
+	          -o jason/flutter/android/src/main/jniLibs \
+	          --manifest-path=jason/Cargo.toml \
+		build $(if $(call eq,$(debug),no),--release,) $(args)
 endef
 
 
@@ -348,14 +345,13 @@ endif
 #	make cargo.lint
 
 cargo.lint:
-	cargo clippy --all -- -D clippy::pedantic -D warnings
-	$(foreach target,$(subst $(comma), ,$(ANDROID_RUST_TARGETS)),\
+	cargo clippy --workspace -- -D clippy::pedantic -D warnings
+	$(foreach target,$(subst $(comma), ,$(ANDROID_TARGETS)),\
 		$(call cargo.lint.medea-jason.android,$(target)))
-# TODO: Replace with actual `medea-jason` crate.
 define cargo.lint.medea-jason.android
 	$(eval target := $(strip $(1)))
-	cd jason/jason-dummy/ && \
-	cargo clippy --target=$(target) -- -D clippy::pedantic -D warnings
+	cargo clippy --manifest-path jason/Cargo.toml --target=$(target) -- \
+		-D clippy::pedantic -D warnings
 endef
 
 
@@ -374,7 +370,7 @@ cargo.version:
 #	make rustup.android
 
 rustup.android:
-	rustup target add $(ANDROID_RUST_TARGETS)
+	rustup target add $(ANDROID_TARGETS)
 
 
 
diff --git a/jason/Cargo.toml b/jason/Cargo.toml
index da6bf98dd..376f8acfe 100644
--- a/jason/Cargo.toml
+++ b/jason/Cargo.toml
@@ -12,7 +12,7 @@ repository = "https://github.com/instrumentisto/medea/tree/master/jason"
 readme = "README.md"
 keywords = ["medea", "jason", "webrtc", "client", "browser"]
 categories = ["multimedia", "api-bindings", "web-programming", "wasm"]
-exclude = ["/demo/", "/e2e-demo/"]
+exclude = ["/demo/", "/e2e-demo/", "/flutter/"]
 
 [lib]
 crate-type = ["cdylib", "rlib"]
@@ -25,13 +25,12 @@ mockable = ["downcast", "fragile", "mockall", "predicates-tree"]
 async-recursion = "0.3"
 async-trait = "0.1"
 bitflags = "1.2"
-console_error_panic_hook = { version = "0.1", optional = true }
+cfg-if = "1.0"
 derivative = "2.1"
 derive_more = "0.99"
 downcast = { version = "0.10", optional = true }
 fragile = { version = "1.0", optional = true }
 futures = "0.3"
-js-sys = "0.3"
 log = "0.4"
 medea-client-api-proto = { version = "0.3", features = ["jason"] }
 medea-macro = "0.2"
@@ -42,11 +41,20 @@ serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 tracerr = "0.1"
 url = "2.1"
+
+[target.'cfg(target_os = "android")'.dependencies]
+android_logger = "0.10"
+dart-sys = "2.0"
+libc = "0.2"
+
+[target.'cfg(not(target_os = "android"))'.dependencies]
+console_error_panic_hook = { version = "0.1", optional = true }
+js-sys = "0.3"
 wasm-bindgen = { version = "0.2", features = ["serde-serialize"] }
 wasm-bindgen-futures = "0.4"
 wasm-logger = "0.2"
 wee_alloc = { version = "0.4", optional = true }
-[dependencies.web-sys]
+[target.'cfg(not(target_os = "android"))'.dependencies.web-sys]
     version = "0.3.47"
     features = [
         "console",
@@ -78,5 +86,8 @@ wee_alloc = { version = "0.4", optional = true }
         "WebSocket", "Window",
     ]
 
+[build-dependencies]
+cc = "1.0"
+
 [dev-dependencies]
 wasm-bindgen-test = "0.3"
diff --git a/jason/build.rs b/jason/build.rs
new file mode 100644
index 000000000..07c77c14c
--- /dev/null
+++ b/jason/build.rs
@@ -0,0 +1,19 @@
+//! Compiles `trampoline.c` and links it into the final library.
+
+use std::env;
+
+fn main() {
+    println!("cargo:rerun-if-env-changed=CLIPPY_ARGS");
+    if let Ok("cargo-clippy") = env::var("CARGO_CFG_FEATURE").as_deref() {
+        return;
+    }
+
+    if let Ok("wasm32-unknown-unknown") = env::var("TARGET").as_deref() {
+        return;
+    }
+
+    println!("cargo:rerun-if-changed=src/platform/dart/api_dl/trampoline.c");
+    cc::Build::new()
+        .file("src/platform/dart/api_dl/trampoline.c")
+        .compile("trampoline");
+}
diff --git a/jason/flutter/example/integration_test/jason.dart b/jason/flutter/example/integration_test/jason.dart
index 49bc290ab..eb56fc8e2 100644
--- a/jason/flutter/example/integration_test/jason.dart
+++ b/jason/flutter/example/integration_test/jason.dart
@@ -7,7 +7,7 @@ import 'package:medea_jason/connection_handle.dart';
 import 'package:medea_jason/device_video_track_constraints.dart';
 import 'package:medea_jason/display_video_track_constraints.dart';
 import 'package:medea_jason/jason.dart';
-import 'package:medea_jason/kind.dart';
+import 'package:medea_jason/track_kinds.dart';
 import 'package:medea_jason/media_stream_settings.dart';
 import 'package:medea_jason/remote_media_track.dart';
 import 'package:medea_jason/room_close_reason.dart';
@@ -140,7 +140,7 @@ void main() {
 
     var reason = await reasonFut.future.timeout(Duration(seconds: 1));
 
-    expect(reason.reason(), equals('RoomCloseReason.reason'));
+    expect(reason.reason(), equals('RpcClientUnexpectedlyDropped'));
     expect(reason.isClosedByServer(), equals(false));
     expect(reason.isErr(), equals(true));
     reason.free();
diff --git a/jason/flutter/lib/audio_track_constraints.dart b/jason/flutter/lib/audio_track_constraints.dart
index 66f857d9e..20d3e1f41 100644
--- a/jason/flutter/lib/audio_track_constraints.dart
+++ b/jason/flutter/lib/audio_track_constraints.dart
@@ -1,4 +1,5 @@
 import 'dart:ffi';
+
 import 'package:ffi/ffi.dart';
 
 import 'jason.dart';
@@ -22,9 +23,14 @@ final _deviceId = dl.lookupFunction<_deviceId_C, _deviceId_Dart>(
 final _free =
     dl.lookupFunction<_free_C, _free_Dart>('AudioTrackConstraints__free');
 
+/// Constraints applicable to audio tracks.
 class AudioTrackConstraints {
+  /// [Pointer] to the Rust struct backing this object.
   final NullablePointer ptr = NullablePointer(_new());
 
+  /// Sets an exact [`deviceId`][1] constraint.
+  ///
+  /// [1]: https://w3.org/TR/mediacapture-streams#def-constraint-deviceId
   void deviceId(String deviceId) {
     var deviceIdPtr = deviceId.toNativeUtf8();
     try {
@@ -34,6 +40,7 @@ class AudioTrackConstraints {
     }
   }
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/connection_handle.dart b/jason/flutter/lib/connection_handle.dart
index fe1fe8dfb..fde7a08ac 100644
--- a/jason/flutter/lib/connection_handle.dart
+++ b/jason/flutter/lib/connection_handle.dart
@@ -41,29 +41,40 @@ final _onQualityScoreUpdate =
     dl.lookupFunction<_onQualityScoreUpdate_C, _onQualityScoreUpdate_Dart>(
         'ConnectionHandle__on_quality_score_update');
 
+/// External handler to a `Connection` with a remote `Member`.
 class ConnectionHandle {
+  /// [Pointer] to the Rust struct backing this object.
   late NullablePointer ptr;
 
+  /// Constructs a new [ConnectionHandle] backed by a Rust struct behind the
+  /// provided [Pointer].
   ConnectionHandle(this.ptr);
 
+  /// Returns ID of the remote `Member`.
   String getRemoteMemberId() {
     return _getRemoteMemberId(ptr.getInnerPtr()).nativeStringToDartString();
   }
 
+  /// Sets callback, invoked when this `Connection` is closed.
   void onClose(void Function() f) {
     _onClose(ptr.getInnerPtr(), f);
   }
 
+  /// Sets callback, invoked when a new [RemoteMediaTrack] is added to this
+  /// `Connection`.
   void onRemoteTrackAdded(void Function(RemoteMediaTrack) f) {
     _onRemoteTrackAdded(ptr.getInnerPtr(), (t) {
       f(RemoteMediaTrack(NullablePointer(t)));
     });
   }
 
+  /// Sets callback, invoked when a connection quality score is updated by a
+  /// server.
   void onQualityScoreUpdate(void Function(int) f) {
     _onQualityScoreUpdate(ptr.getInnerPtr(), f);
   }
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/device_video_track_constraints.dart b/jason/flutter/lib/device_video_track_constraints.dart
index 91e0e5095..9407ded71 100644
--- a/jason/flutter/lib/device_video_track_constraints.dart
+++ b/jason/flutter/lib/device_video_track_constraints.dart
@@ -1,4 +1,5 @@
 import 'dart:ffi';
+
 import 'package:ffi/ffi.dart';
 
 import 'jason.dart';
@@ -73,16 +74,34 @@ final _widthInRange = dl.lookupFunction<_widthInRange_C, _widthInRange_Dart>(
 final _free =
     dl.lookupFunction<_free_C, _free_Dart>('DeviceVideoTrackConstraints__free');
 
+/// Describes the directions that the camera can face, as seen from a user's
+/// perspective.
+///
+/// Representation of the [`VideoFacingModeEnum`][1].
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#dom-videofacingmodeenum
 enum FacingMode {
+  /// Facing towards the user (a self-view camera).
   User,
+
+  /// Facing away from the user (viewing an environment).
   Environment,
+
+  /// Facing to the left of the user.
   Left,
+
+  /// Facing to the right of the user.
   Right,
 }
 
+/// Constraints applicable to video tracks sourced from some media device.
 class DeviceVideoTrackConstraints {
+  /// [Pointer] to the Rust struct backing this object.
   final NullablePointer ptr = NullablePointer(_new());
 
+  /// Sets an exact [`deviceId`][1] constraint.
+  ///
+  /// [1]: https://w3.org/TR/mediacapture-streams#def-constraint-deviceId
   void deviceId(String deviceId) {
     var deviceIdPtr = deviceId.toNativeUtf8();
     try {
@@ -92,38 +111,63 @@ class DeviceVideoTrackConstraints {
     }
   }
 
+  /// Sets an exact [`facingMode`][1] constraint.
+  ///
+  /// [1]: https://w3.org/TR/mediacapture-streams#dom-constraindomstring
   void exactFacingMode(FacingMode facingMode) {
     _exactFacingMode(ptr.getInnerPtr(), facingMode.index);
   }
 
+  /// Sets an ideal [`facingMode`][1] constraint.
+  ///
+  /// [1]: https://w3.org/TR/mediacapture-streams#dom-constraindomstring
   void idealFacingMode(FacingMode facingMode) {
     _idealFacingMode(ptr.getInnerPtr(), facingMode.index);
   }
 
+  /// Sets an exact [`height`][1] constraint.
+  ///
+  /// [1]: https://tinyurl.com/w3-streams#def-constraint-height
   void exactHeight(int height) {
     _exactHeight(ptr.getInnerPtr(), height);
   }
 
+  /// Sets an ideal [`height`][1] constraint.
+  ///
+  /// [1]: https://tinyurl.com/w3-streams#def-constraint-height
   void idealHeight(int height) {
     _idealHeight(ptr.getInnerPtr(), height);
   }
 
+  /// Sets a range of a [`height`][1] constraint.
+  ///
+  /// [1]: https://tinyurl.com/w3-streams#def-constraint-height
   void heightInRange(int min, int max) {
     _heightInRange(ptr.getInnerPtr(), min, max);
   }
 
+  /// Sets an exact [`width`][1] constraint.
+  ///
+  /// [1]: https://tinyurl.com/w3-streams#def-constraint-width
   void exactWidth(int width) {
     _exactWidth(ptr.getInnerPtr(), width);
   }
 
+  /// Sets an ideal [`width`][1] constraint.
+  ///
+  /// [1]: https://tinyurl.com/w3-streams#def-constraint-width
   void idealWidth(int width) {
     _idealWidth(ptr.getInnerPtr(), width);
   }
 
+  /// Sets a range of a [`width`][1] constraint.
+  ///
+  /// [1]: https://tinyurl.com/w3-streams#def-constraint-width
   void widthInRange(int min, int max) {
     _widthInRange(ptr.getInnerPtr(), min, max);
   }
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/display_video_track_constraints.dart b/jason/flutter/lib/display_video_track_constraints.dart
index 9bf20cea2..2d8322867 100644
--- a/jason/flutter/lib/display_video_track_constraints.dart
+++ b/jason/flutter/lib/display_video_track_constraints.dart
@@ -16,9 +16,12 @@ final _new =
 final _free_Dart _free = dl
     .lookupFunction<_free_C, _free_Dart>('DisplayVideoTrackConstraints__free');
 
+/// Constraints applicable to video tracks sourced from a screen capturing.
 class DisplayVideoTrackConstraints {
+  /// [Pointer] to the Rust struct backing this object.
   final NullablePointer ptr = NullablePointer(_new());
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/input_device_info.dart b/jason/flutter/lib/input_device_info.dart
index 81c6b9a3b..bc440149a 100644
--- a/jason/flutter/lib/input_device_info.dart
+++ b/jason/flutter/lib/input_device_info.dart
@@ -3,7 +3,7 @@ import 'dart:ffi';
 import 'package:ffi/ffi.dart';
 
 import 'jason.dart';
-import 'kind.dart';
+import 'track_kinds.dart';
 import 'util/move_semantic.dart';
 import 'util/nullable_pointer.dart';
 import 'util/native_string.dart';
@@ -36,28 +36,53 @@ final _deviceId = dl
 
 final _free = dl.lookupFunction<_free_C, _free_Dart>('InputDeviceInfo__free');
 
+/// [`MediaDeviceInfo`][1] interface.
+///
+/// [1]: https://w3.org/TR/mediacapture-streams/#device-info
 class InputDeviceInfo {
+  /// [Pointer] to the Rust struct backing this object.
   late NullablePointer ptr;
 
+  /// Constructs a new [InputDeviceInfo] backed by a Rust struct behind the
+  /// provided [Pointer].
   InputDeviceInfo(this.ptr);
 
+  /// Returns an unique identifier of the represented device.
   String deviceId() {
     return _deviceId(ptr.getInnerPtr()).nativeStringToDartString();
   }
 
+  /// Returns label describing the represented device (for example "External USB
+  /// Webcam").
+  ///
+  /// If the device has no associated label, then returns an empty string.
   String label() {
     return _label(ptr.getInnerPtr()).nativeStringToDartString();
   }
 
+  /// Returns kind of the represented device.
+  ///
+  /// This representation of a [`MediaDeviceInfo`][1] is ONLY for input devices.
+  ///
+  /// [1]: https://w3.org/TR/mediacapture-streams/#device-info
   MediaKind kind() {
     var index = _kind(ptr.getInnerPtr());
     return MediaKind.values[index];
   }
 
+  /// Returns a group identifier of the represented device.
+  ///
+  /// Two devices have the same group identifier if they belong to the same
+  /// physical device. For example, the audio input and output devices
+  /// representing the speaker and microphone of the same headset have the
+  /// same [`groupId`][1].
+  ///
+  /// [1]: https://w3.org/TR/mediacapture-streams/#dom-mediadeviceinfo-groupid
   String groupId() {
     return _nativeGroupId(ptr.getInnerPtr()).nativeStringToDartString();
   }
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/jason.dart b/jason/flutter/lib/jason.dart
index 938e51287..07c5cd39e 100644
--- a/jason/flutter/lib/jason.dart
+++ b/jason/flutter/lib/jason.dart
@@ -50,7 +50,7 @@ DynamicLibrary _dl_load() {
     throw 'You are running unsupported NativeApi version.';
   }
 
-  var dl = DynamicLibrary.open('libjason.so');
+  var dl = DynamicLibrary.open('libmedea_jason.so');
 
   var initResult = dl.lookupFunction<
       IntPtr Function(Pointer<Void>),
@@ -65,22 +65,32 @@ DynamicLibrary _dl_load() {
   return dl;
 }
 
+/// General library interface.
+///
+/// Responsible for managing shared transports, local media and room
+/// initialization.
 class Jason {
+  /// [Pointer] to the Rust struct backing this object.
   final NullablePointer ptr = NullablePointer(_new());
 
-  MediaManager mediaManager() {
-    return MediaManager(NullablePointer(_media_manager(ptr.getInnerPtr())));
+  /// Returns a [MediaManagerHandle] to the `MediaManager` of this [Jason].
+  MediaManagerHandle mediaManager() {
+    return MediaManagerHandle(
+        NullablePointer(_media_manager(ptr.getInnerPtr())));
   }
 
+  /// Creates a new `Room` and returns its [RoomHandle].
   RoomHandle initRoom() {
     return RoomHandle(NullablePointer(_initRoom(ptr.getInnerPtr())));
   }
 
+  /// Closes the `Room` by the provided [RoomHandle].
   void closeRoom(@moveSemantics RoomHandle room) {
     _close_room(ptr.getInnerPtr(), room.ptr.getInnerPtr());
     room.ptr.free();
   }
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/kind.dart b/jason/flutter/lib/kind.dart
deleted file mode 100644
index 4467dd03f..000000000
--- a/jason/flutter/lib/kind.dart
+++ /dev/null
@@ -1,9 +0,0 @@
-enum MediaKind {
-  Audio,
-  Video,
-}
-
-enum MediaSourceKind {
-  Device,
-  Display,
-}
diff --git a/jason/flutter/lib/local_media_track.dart b/jason/flutter/lib/local_media_track.dart
index e39f3c0ad..6c2a2ae7a 100644
--- a/jason/flutter/lib/local_media_track.dart
+++ b/jason/flutter/lib/local_media_track.dart
@@ -1,7 +1,7 @@
 import 'dart:ffi';
 
 import 'jason.dart';
-import 'kind.dart';
+import 'track_kinds.dart';
 import 'util/move_semantic.dart';
 import 'util/nullable_pointer.dart';
 
@@ -22,21 +22,41 @@ final _sourceKind =
 
 final _free = dl.lookupFunction<_free_C, _free_Dart>('LocalMediaTrack__free');
 
+/// Strongly referenced media track received from a
+/// [`getUserMedia()`][1]/[`getDisplayMedia()`][2] request.
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#dom-mediadevices-getusermedia
+/// [2]: https://w3.org/TR/screen-capture/#dom-mediadevices-getdisplaymedia
 class LocalMediaTrack {
+  /// [Pointer] to the Rust struct backing this object.
   late NullablePointer ptr;
 
+  /// Constructs a new [LocalMediaTrack] backed by the Rust struct behind the
+  /// provided [Pointer].
   LocalMediaTrack(this.ptr);
 
+  /// Returns the [MediaKind.Audio] if this [LocalMediaTrack] represents an
+  /// audio track, or the [MediaKind.Video] if it represents a video track.
   MediaKind kind() {
     var index = _kind(ptr.getInnerPtr());
     return MediaKind.values[index];
   }
 
+  /// Returns the [MediaSourceKind.Device] if this [LocalMediaTrack] is sourced
+  /// from some device (webcam/microphone), or the [MediaSourceKind.Display]
+  /// if it's captured via [`MediaDevices.getDisplayMedia()`][1].
+  ///
+  /// [1]: https://w3.org/TR/screen-capture/#dom-mediadevices-getdisplaymedia
   MediaSourceKind mediaSourceKind() {
     var index = _sourceKind(ptr.getInnerPtr());
     return MediaSourceKind.values[index];
   }
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
+  ///
+  /// Note, that this is a strong reference, so freeing it will stop underlying
+  /// track if there are no other strong references (i.e., not used in local
+  /// peer's senders).
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/media_manager.dart b/jason/flutter/lib/media_manager.dart
index 691d2c313..2ef2fbbf3 100644
--- a/jason/flutter/lib/media_manager.dart
+++ b/jason/flutter/lib/media_manager.dart
@@ -28,11 +28,24 @@ final _enumerateDevices =
 final _free =
     dl.lookupFunction<_free_C, _free_Dart>('MediaManagerHandle__free');
 
-class MediaManager {
+/// External handle to a `MediaManager`.
+///
+/// `MediaManager` performs all media acquisition requests
+/// ([`getUserMedia()`][1]/[`getDisplayMedia()`][2]) and stores all received
+/// tracks for further re-usage.
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#dom-mediadevices-getusermedia
+/// [2]: https://w3.org/TR/screen-capture/#dom-mediadevices-getdisplaymedia
+class MediaManagerHandle {
+  /// [Pointer] to the Rust struct backing this object.
   late NullablePointer ptr;
 
-  MediaManager(this.ptr);
+  /// Creates a new [MediaManagerHandle] backed by the Rust struct behind the
+  /// provided [Pointer].
+  MediaManagerHandle(this.ptr);
 
+  /// Obtains [LocalMediaTrack]s objects from local media devices (or screen
+  /// capture) basing on the provided [MediaStreamSettings].
   List<LocalMediaTrack> initLocalTracks(MediaStreamSettings caps) {
     return _initLocalTracks(ptr.getInnerPtr(), caps.ptr.getInnerPtr())
         .intoPointerList()
@@ -40,6 +53,8 @@ class MediaManager {
         .toList();
   }
 
+  /// Returns a list of [InputDeviceInfo] objects representing available media
+  /// input devices, such as microphones, cameras, and so forth.
   List<InputDeviceInfo> enumerateDevices() {
     return _enumerateDevices(ptr.getInnerPtr())
         .intoPointerList()
@@ -47,6 +62,7 @@ class MediaManager {
         .toList();
   }
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/media_stream_settings.dart b/jason/flutter/lib/media_stream_settings.dart
index 8fc29f5c4..868e7d5c7 100644
--- a/jason/flutter/lib/media_stream_settings.dart
+++ b/jason/flutter/lib/media_stream_settings.dart
@@ -36,24 +36,32 @@ final _displayVideo = dl.lookupFunction<_displayVideo_C, _displayVideo_Dart>(
 final _free =
     dl.lookupFunction<_free_C, _free_Dart>('MediaStreamSettings__free');
 
+/// Representation of [`MediaStreamConstraints`][1].
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#dom-mediastreamconstraints
 class MediaStreamSettings {
+  /// [Pointer] to the Rust struct backing this object.
   final NullablePointer ptr = NullablePointer(_new());
 
+  /// Specifies a nature and settings of the audio `LocalMediaTrack`.
   void audio(@moveSemantics AudioTrackConstraints constraints) {
     _audio(ptr.getInnerPtr(), constraints.ptr.getInnerPtr());
     constraints.ptr.free();
   }
 
+  /// Sets constraints for obtaining a local video, sourced from a media device.
   void deviceVideo(@moveSemantics DeviceVideoTrackConstraints constraints) {
     _deviceVideo(ptr.getInnerPtr(), constraints.ptr.getInnerPtr());
     constraints.ptr.free();
   }
 
+  /// Set constraints for capturing a local video from user's display.
   void displayVideo(@moveSemantics DisplayVideoTrackConstraints constraints) {
     _displayVideo(ptr.getInnerPtr(), constraints.ptr.getInnerPtr());
     constraints.ptr.free();
   }
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/reconnect_handle.dart b/jason/flutter/lib/reconnect_handle.dart
index f8b8d4c2d..380bb787c 100644
--- a/jason/flutter/lib/reconnect_handle.dart
+++ b/jason/flutter/lib/reconnect_handle.dart
@@ -9,11 +9,18 @@ typedef _free_Dart = void Function(Pointer);
 
 final _free = dl.lookupFunction<_free_C, _free_Dart>('ReconnectHandle__free');
 
+/// External handle used to reconnect to a media server when connection is lost.
+///
+/// This handle is passed to the `RoomHandle.onConnectionLoss()` callback.
 class ReconnectHandle {
+  /// [Pointer] to the Rust struct backing this object.
   late NullablePointer ptr;
 
+  /// Constructs a new [ReconnectHandle] backed by the Rust struct behind the
+  /// provided [Pointer].
   ReconnectHandle(this.ptr);
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/remote_media_track.dart b/jason/flutter/lib/remote_media_track.dart
index 222bc1324..718cc8bb0 100644
--- a/jason/flutter/lib/remote_media_track.dart
+++ b/jason/flutter/lib/remote_media_track.dart
@@ -1,7 +1,7 @@
 import 'dart:ffi';
 
 import 'jason.dart';
-import 'kind.dart';
+import 'track_kinds.dart';
 import 'util/move_semantic.dart';
 import 'util/nullable_pointer.dart';
 
@@ -64,49 +64,65 @@ final _onStopped = dl.lookupFunction<_onStopped_C, _onStopped_Dart>(
 
 final _free = dl.lookupFunction<_free_C, _free_Dart>('RemoteMediaTrack__free');
 
+/// Representation of a received remote [`MediaStreamTrack`][1].
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#dom-mediastreamtrack
 class RemoteMediaTrack {
+  /// [Pointer] to the Rust struct that backing this object.
   late NullablePointer ptr;
 
+  /// Constructs a new [RemoteMediaTrack] backed by the Rust struct behind the
+  /// provided [Pointer].
   RemoteMediaTrack(this.ptr);
 
+  /// Indicates whether this [RemoteMediaTrack] is enabled.
   bool enabled() {
     return _enabled(ptr.getInnerPtr()) > 0;
   }
 
+  /// Indicate whether this [RemoteMediaTrack] is muted.
   bool muted() {
     return _muted(ptr.getInnerPtr()) > 0;
   }
 
+  /// Returns this [RemoteMediaTrack]'s kind (audio/video).
   MediaKind kind() {
     var index = _kind(ptr.getInnerPtr());
     return MediaKind.values[index];
   }
 
+  /// Returns this [RemoteMediaTrack]'s media source kind (device/display).
   MediaSourceKind mediaSourceKind() {
     var index = _mediaSourceKind(ptr.getInnerPtr());
     return MediaSourceKind.values[index];
   }
 
+  /// Sets callback, invoked when this [RemoteMediaTrack] is enabled.
   void onEnabled(void Function() f) {
     _onEnabled(ptr.getInnerPtr(), f);
   }
 
+  /// Sets callback, invoked when this [RemoteMediaTrack] is disabled.
   void onDisabled(void Function() f) {
     _onDisabled(ptr.getInnerPtr(), f);
   }
 
+  /// Sets callback to invoke when this [RemoteMediaTrack] is muted.
   void onMuted(void Function() f) {
     _onMuted(ptr.getInnerPtr(), f);
   }
 
+  /// Sets callback to invoke when this [RemoteMediaTrack] is unmuted.
   void onUnmuted(void Function() f) {
     _onUnmuted(ptr.getInnerPtr(), f);
   }
 
+  /// Sets callback to invoke when this [RemoteMediaTrack] is stopped.
   void onStopped(void Function() f) {
     _onStopped(ptr.getInnerPtr(), f);
   }
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/room_close_reason.dart b/jason/flutter/lib/room_close_reason.dart
index 3f5d9f9ff..7bc85343e 100644
--- a/jason/flutter/lib/room_close_reason.dart
+++ b/jason/flutter/lib/room_close_reason.dart
@@ -30,23 +30,33 @@ final _isErr =
 
 final _free = dl.lookupFunction<_free_C, _free_Dart>('RoomCloseReason__free');
 
+/// Reason of why a `Room` has been closed.
+///
+/// This struct is passed into the `RoomHandle.onClose()` callback.
 class RoomCloseReason {
+  /// [Pointer] to the Rust struct that backing this object.
   late NullablePointer ptr;
 
+  /// Constructs a new [RoomCloseReason] backed by the Rust struct behind the
+  /// provided [Pointer].
   RoomCloseReason(this.ptr);
 
+  /// Returns a close reason of the `Room`.
   String reason() {
     return _reason(ptr.getInnerPtr()).nativeStringToDartString();
   }
 
+  /// Indicates whether the `Room` was closed by server.
   bool isClosedByServer() {
     return _isClosedByServer(ptr.getInnerPtr()) > 0;
   }
 
+  /// Indicates whether the `Room`'s close reason is considered as an error.
   bool isErr() {
     return _isErr(ptr.getInnerPtr()) > 0;
   }
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/room_handle.dart b/jason/flutter/lib/room_handle.dart
index b2f012bda..823f98753 100644
--- a/jason/flutter/lib/room_handle.dart
+++ b/jason/flutter/lib/room_handle.dart
@@ -1,13 +1,12 @@
 import 'dart:ffi';
 
-import 'package:medea_jason/local_media_track.dart';
-import 'package:medea_jason/util/nullable_pointer.dart';
-
 import 'connection_handle.dart';
 import 'jason.dart';
+import 'local_media_track.dart';
 import 'reconnect_handle.dart';
 import 'room_close_reason.dart';
 import 'util/move_semantic.dart';
+import 'util/nullable_pointer.dart';
 
 typedef _free_C = Void Function(Pointer);
 typedef _free_Dart = void Function(Pointer);
@@ -40,35 +39,54 @@ final _onConnectionLoss =
     dl.lookupFunction<_onConnectionLoss_C, _onConnectionLoss_Dart>(
         'RoomHandle__on_connection_loss');
 
+/// External handle to a `Room`.
 class RoomHandle {
+  /// [Pointer] to the Rust struct that backing this object.
   late NullablePointer ptr;
 
+  /// Constructs a new [RoomHandle] backed by the Rust struct behind the
+  /// provided [Pointer].
   RoomHandle(this.ptr);
 
+  /// Sets callback, invoked when a new `Connection` with some remote `Peer`
+  /// is established.
   void onNewConnection(void Function(ConnectionHandle) f) {
     _onNewConnection(ptr.getInnerPtr(), (t) {
       f(ConnectionHandle(NullablePointer(t)));
     });
   }
 
+  /// Sets callback, invoked when this `Room` is closed, providing a
+  /// [RoomCloseReason].
   void onClose(void Function(RoomCloseReason) f) {
     _onClose(ptr.getInnerPtr(), (t) {
       f(RoomCloseReason(NullablePointer(t)));
     });
   }
 
+  /// Sets callback, invoked when a new [LocalMediaTrack] is added to this
+  /// `Room`.
+  ///
+  /// This might happen in the following cases:
+  /// 1. Media server initiates a media request.
+  /// 2. [RoomHandle.enableAudio()]/[RoomHandle.enableVideo()] is called.
+  /// 3. [MediaStreamSettings] were updated via
+  ///    [RoomHandle.setLocalMediaSettings()] method.
   void onLocalTrack(void Function(LocalMediaTrack) f) {
     _onLocalTrack(ptr.getInnerPtr(), (t) {
       f(LocalMediaTrack(NullablePointer(t)));
     });
   }
 
+  /// Sets callback, invoked when a connection with a media server is lost,
+  /// providing a [ReconnectHandle].
   void onConnectionLoss(void Function(ReconnectHandle) f) {
     _onConnectionLoss(ptr.getInnerPtr(), (t) {
       f(ReconnectHandle(NullablePointer(t)));
     });
   }
 
+  /// Drops the associated Rust struct and nulls the local [Pointer] to it.
   @moveSemantics
   void free() {
     _free(ptr.getInnerPtr());
diff --git a/jason/flutter/lib/track_kinds.dart b/jason/flutter/lib/track_kinds.dart
new file mode 100644
index 000000000..72875620d
--- /dev/null
+++ b/jason/flutter/lib/track_kinds.dart
@@ -0,0 +1,19 @@
+/// Representation of a [`MediaStreamTrack.kind`][1].
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#dom-mediastreamtrack-kind
+enum MediaKind {
+  /// Audio track.
+  Audio,
+
+  /// Video track.
+  Video,
+}
+
+/// Media source type.
+enum MediaSourceKind {
+  /// Media is sourced from some media device (webcam or microphone).
+  Device,
+
+  /// Media is obtained via screen capturing.
+  Display,
+}
diff --git a/jason/flutter/lib/util/move_semantic.dart b/jason/flutter/lib/util/move_semantic.dart
index 910e99b15..6180c2fd4 100644
--- a/jason/flutter/lib/util/move_semantic.dart
+++ b/jason/flutter/lib/util/move_semantic.dart
@@ -1,5 +1,15 @@
-class MoveSemantics {
-  const MoveSemantics();
+class _MoveSemantics {
+  const _MoveSemantics();
 }
 
-const MoveSemantics moveSemantics = MoveSemantics();
+/// Marker annotation signalling that current operation on an item (it's applied
+/// to) has move semantics.
+///
+/// Move semantics means that the item will be moved and can not be used after.
+///
+/// When applied to an object method, means that the object should not be used
+/// after that method is called.
+///
+/// When applied to method arguments, means that the argument is moved into that
+/// method.
+const _MoveSemantics moveSemantics = _MoveSemantics();
diff --git a/jason/flutter/lib/util/native_string.dart b/jason/flutter/lib/util/native_string.dart
index ba9b219b8..fcba90455 100644
--- a/jason/flutter/lib/util/native_string.dart
+++ b/jason/flutter/lib/util/native_string.dart
@@ -3,13 +3,17 @@ import 'dart:ffi';
 import 'package:ffi/ffi.dart';
 import 'package:medea_jason/jason.dart';
 
+import 'move_semantic.dart';
+
 typedef _free_C = Void Function(Pointer<Utf8>);
 typedef _free_Dart = void Function(Pointer<Utf8>);
 
+/// Frees [String] returned from Rust.
 final _free = dl.lookupFunction<_free_C, _free_Dart>('String_free');
 
 extension RustStringPointer on Pointer<Utf8> {
-  /// Frees an underlying native memory, so it can only be called once.
+  /// Converts this [RustStringPointer] to a Dart's [String].
+  @moveSemantics
   String nativeStringToDartString() {
     try {
       return toDartString();
diff --git a/jason/flutter/lib/util/nullable_pointer.dart b/jason/flutter/lib/util/nullable_pointer.dart
index e641fdd53..67591c433 100644
--- a/jason/flutter/lib/util/nullable_pointer.dart
+++ b/jason/flutter/lib/util/nullable_pointer.dart
@@ -1,8 +1,15 @@
 import 'dart:ffi';
 
+/// Wrapper around a [Pointer] that can be null when its pointed memory is
+/// freed.
+///
+/// Accessing the pointer after it's freed will throw [StateError].
 class NullablePointer {
   Pointer? _ptr;
 
+  /// Constructs [NullablePointer] from the provided [Pointer].
+  ///
+  /// Provided [Pointer] should not have a zero address.
   NullablePointer(Pointer ptr) {
     if (ptr.address == 0) {
       throw ArgumentError.notNull('ptr');
@@ -10,6 +17,9 @@ class NullablePointer {
     _ptr = ptr;
   }
 
+  /// Returns the underlying [Pointer].
+  ///
+  /// Throws [StateError] if the underlying [Pointer] has been freed.
   Pointer getInnerPtr() {
     if (_ptr == null) {
       throw StateError('NullablePointer cannot be used after free.');
@@ -18,6 +28,10 @@ class NullablePointer {
     }
   }
 
+  /// Nulls the underlying [Pointer].
+  ///
+  /// This doesn't affect the pointed memory, but Dart won't be able to access
+  /// it, so it's expected that native memory has been freed at this point.
   void free() {
     _ptr = null;
   }
diff --git a/jason/flutter/lib/util/ptrarray.dart b/jason/flutter/lib/util/ptrarray.dart
index 9ba21156c..5ef36567d 100644
--- a/jason/flutter/lib/util/ptrarray.dart
+++ b/jason/flutter/lib/util/ptrarray.dart
@@ -1,19 +1,26 @@
 import 'dart:ffi';
 
 import '../jason.dart';
+import 'move_semantic.dart';
 
 typedef _free_C = Void Function(PtrArray);
 typedef _free_Dart = void Function(PtrArray);
 
+/// Frees [PtrArray] returned from Rust.
 final _free_Dart _free =
     dl.lookupFunction<_free_C, _free_Dart>('PtrArray_free');
 
+/// Array of [Pointer]s to Rust objects.
 class PtrArray extends Struct {
+  /// [Pointer] to the first array element.
   external Pointer<Pointer> _ptr;
+
+  /// Length of this [PtrArray].
   @Uint64()
   external int _len;
 
-  /// Frees an underlying native memory, so it can only be called once.
+  /// Converts this [PtrArray] to a Dart's [List] of [Pointer]s.
+  @moveSemantics
   List<Pointer> intoPointerList() {
     try {
       var out = List<Pointer>.empty(growable: true);
diff --git a/jason/jason-dummy/.editorconfig b/jason/jason-dummy/.editorconfig
deleted file mode 100644
index 7f9845bb1..000000000
--- a/jason/jason-dummy/.editorconfig
+++ /dev/null
@@ -1,3 +0,0 @@
-[*.{c,h}]
-indent_style = space
-indent_size = 2
diff --git a/jason/jason-dummy/.gitignore b/jason/jason-dummy/.gitignore
deleted file mode 100644
index 042776aad..000000000
--- a/jason/jason-dummy/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-/Cargo.lock
-/target/
diff --git a/jason/jason-dummy/Cargo.toml b/jason/jason-dummy/Cargo.toml
deleted file mode 100644
index 625e175a4..000000000
--- a/jason/jason-dummy/Cargo.toml
+++ /dev/null
@@ -1,18 +0,0 @@
-[package]
-name = "jason-dummy"
-version = "0.0.1"
-edition = "2018"
-description = "Temp crate to help us bootstrap flutter + rust builds"
-
-[lib]
-name = "jason"
-crate-type = ["staticlib", "cdylib"]
-
-[dependencies]
-dart-sys = "2.0"
-libc = "0.2"
-
-[build-dependencies]
-cc = "1.0"
-
-[workspace]
diff --git a/jason/jason-dummy/build.rs b/jason/jason-dummy/build.rs
deleted file mode 100644
index 6b5f4d771..000000000
--- a/jason/jason-dummy/build.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-//! Compiles `trampoline.c` and links it into the final library.
-
-fn main() {
-    println!("cargo:rerun-if-env-changed=CLIPPY_ARGS");
-    if let Ok("cargo-clippy") = std::env::var("CARGO_CFG_FEATURE").as_deref() {
-        return;
-    }
-
-    println!("cargo:rerun-if-changed=src/dart_api_dl/trampoline.c");
-    cc::Build::new()
-        .file("src/dart_api_dl/trampoline.c")
-        .compile("trampoline");
-}
diff --git a/jason/jason-dummy/src/audio_track_constraints.rs b/jason/jason-dummy/src/audio_track_constraints.rs
deleted file mode 100644
index 6f78584da..000000000
--- a/jason/jason-dummy/src/audio_track_constraints.rs
+++ /dev/null
@@ -1,35 +0,0 @@
-use crate::{utils::c_str_into_string, ForeignClass};
-
-pub struct AudioTrackConstraints;
-
-impl ForeignClass for AudioTrackConstraints {}
-
-impl AudioTrackConstraints {
-    pub fn new() -> Self {
-        Self
-    }
-
-    pub fn device_id(&mut self, _: String) {}
-}
-
-#[no_mangle]
-pub extern "C" fn AudioTrackConstraints__new() -> *const AudioTrackConstraints {
-    AudioTrackConstraints::new().into_ptr()
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn AudioTrackConstraints__device_id(
-    this: *mut AudioTrackConstraints,
-    device_id: *const libc::c_char,
-) {
-    let this = this.as_mut().unwrap();
-
-    this.device_id(c_str_into_string(device_id))
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn AudioTrackConstraints__free(
-    this: *mut AudioTrackConstraints,
-) {
-    AudioTrackConstraints::from_ptr(this);
-}
diff --git a/jason/jason-dummy/src/connection_handle.rs b/jason/jason-dummy/src/connection_handle.rs
deleted file mode 100644
index 020b05e02..000000000
--- a/jason/jason-dummy/src/connection_handle.rs
+++ /dev/null
@@ -1,74 +0,0 @@
-use dart_sys::Dart_Handle;
-
-use crate::{
-    remote_media_track::RemoteMediaTrack,
-    utils::{string_into_c_str, DartClosure},
-    ForeignClass,
-};
-
-pub struct ConnectionHandle;
-
-impl ForeignClass for ConnectionHandle {}
-
-impl ConnectionHandle {
-    pub fn get_remote_member_id(&self) -> String {
-        //  Result<String, JasonError>
-        String::from("ConnectionHandle.get_remote_member_id")
-    }
-
-    pub fn on_close(&self, f: DartClosure<()>) {
-        // Result<(), JasonError>
-        f.call0();
-    }
-
-    pub fn on_remote_track_added(&self, f: DartClosure<RemoteMediaTrack>) {
-        // Result<(), JasonError>
-        f.call1(RemoteMediaTrack);
-    }
-
-    pub fn on_quality_score_update(&self, f: DartClosure<u8>) {
-        // Result<(), JasonError>
-        f.call1(4);
-    }
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn ConnectionHandle__on_close(
-    this: *const ConnectionHandle,
-    f: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_close(DartClosure::new(f));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn ConnectionHandle__on_remote_track_added(
-    this: *const ConnectionHandle,
-    f: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_remote_track_added(DartClosure::new(f));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn ConnectionHandle__on_quality_score_update(
-    this: *const ConnectionHandle,
-    f: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_quality_score_update(DartClosure::new(f));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn ConnectionHandle__get_remote_member_id(
-    this: *const ConnectionHandle,
-) -> *const libc::c_char {
-    let this = this.as_ref().unwrap();
-
-    string_into_c_str(this.get_remote_member_id())
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn ConnectionHandle__free(this: *mut ConnectionHandle) {
-    ConnectionHandle::from_ptr(this);
-}
diff --git a/jason/jason-dummy/src/display_video_track_constraints.rs b/jason/jason-dummy/src/display_video_track_constraints.rs
deleted file mode 100644
index e2c5c21ca..000000000
--- a/jason/jason-dummy/src/display_video_track_constraints.rs
+++ /dev/null
@@ -1,24 +0,0 @@
-use crate::ForeignClass;
-
-pub struct DisplayVideoTrackConstraints;
-
-impl ForeignClass for DisplayVideoTrackConstraints {}
-
-impl DisplayVideoTrackConstraints {
-    fn new() -> Self {
-        Self
-    }
-}
-
-#[no_mangle]
-pub extern "C" fn DisplayVideoTrackConstraints__new(
-) -> *const DisplayVideoTrackConstraints {
-    DisplayVideoTrackConstraints::new().into_ptr()
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn DisplayVideoTrackConstraints__free(
-    this: *mut DisplayVideoTrackConstraints,
-) {
-    DisplayVideoTrackConstraints::from_ptr(this);
-}
diff --git a/jason/jason-dummy/src/input_device_info.rs b/jason/jason-dummy/src/input_device_info.rs
deleted file mode 100644
index f552f1032..000000000
--- a/jason/jason-dummy/src/input_device_info.rs
+++ /dev/null
@@ -1,64 +0,0 @@
-use crate::{utils::string_into_c_str, ForeignClass, MediaKind};
-
-pub struct InputDeviceInfo {}
-
-impl ForeignClass for InputDeviceInfo {}
-
-impl InputDeviceInfo {
-    pub fn device_id(&self) -> String {
-        String::from("InputDeviceInfo.device_id")
-    }
-
-    pub fn kind(&self) -> MediaKind {
-        MediaKind::Audio
-    }
-
-    pub fn label(&self) -> String {
-        String::from("InputDeviceInfo.label")
-    }
-
-    pub fn group_id(&self) -> String {
-        String::from("InputDeviceInfo.group_id")
-    }
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn InputDeviceInfo__device_id(
-    this: *const InputDeviceInfo,
-) -> *const libc::c_char {
-    let this = this.as_ref().unwrap();
-
-    string_into_c_str(this.device_id())
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn InputDeviceInfo__kind(
-    this: *const InputDeviceInfo,
-) -> u8 {
-    let this = this.as_ref().unwrap();
-
-    this.kind() as u8
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn InputDeviceInfo__label(
-    this: *const InputDeviceInfo,
-) -> *const libc::c_char {
-    let this = this.as_ref().unwrap();
-
-    string_into_c_str(this.label())
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn InputDeviceInfo__group_id(
-    this: *const InputDeviceInfo,
-) -> *const libc::c_char {
-    let this = this.as_ref().unwrap();
-
-    string_into_c_str(this.group_id())
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn InputDeviceInfo__free(this: *mut InputDeviceInfo) {
-    InputDeviceInfo::from_ptr(this);
-}
diff --git a/jason/jason-dummy/src/jason.rs b/jason/jason-dummy/src/jason.rs
deleted file mode 100644
index 7225cbe53..000000000
--- a/jason/jason-dummy/src/jason.rs
+++ /dev/null
@@ -1,61 +0,0 @@
-use crate::{
-    media_manager::MediaManagerHandle, room_handle::RoomHandle, ForeignClass,
-};
-
-pub struct Jason;
-
-impl ForeignClass for Jason {}
-
-impl Jason {
-    pub fn new() -> Self {
-        Self
-    }
-
-    pub fn init_room(&self) -> RoomHandle {
-        RoomHandle
-    }
-
-    pub fn media_manager(&self) -> MediaManagerHandle {
-        MediaManagerHandle
-    }
-
-    pub fn close_room(&self, _: RoomHandle) {}
-}
-
-#[no_mangle]
-pub extern "C" fn Jason__new() -> *const Jason {
-    Jason::new().into_ptr()
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn Jason__init_room(
-    this: *const Jason,
-) -> *const RoomHandle {
-    let this = this.as_ref().unwrap();
-
-    this.init_room().into_ptr()
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn Jason__media_manager(
-    this: *const Jason,
-) -> *const MediaManagerHandle {
-    let this = this.as_ref().unwrap();
-
-    this.media_manager().into_ptr()
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn Jason__close_room(
-    this: *const Jason,
-    room_to_delete: *mut RoomHandle,
-) {
-    let this = this.as_ref().unwrap();
-
-    this.close_room(RoomHandle::from_ptr(room_to_delete));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn Jason__free(this: *mut Jason) {
-    Jason::from_ptr(this);
-}
diff --git a/jason/jason-dummy/src/lib.rs b/jason/jason-dummy/src/lib.rs
deleted file mode 100644
index 69432a3ae..000000000
--- a/jason/jason-dummy/src/lib.rs
+++ /dev/null
@@ -1,55 +0,0 @@
-#![allow(
-    clippy::module_name_repetitions,
-    clippy::unused_self,
-    clippy::needless_pass_by_value,
-    clippy::missing_safety_doc,
-    clippy::must_use_candidate,
-    clippy::missing_panics_doc,
-    clippy::new_without_default
-)]
-
-pub mod audio_track_constraints;
-pub mod connection_handle;
-pub mod device_video_track_constraints;
-pub mod display_video_track_constraints;
-pub mod input_device_info;
-pub mod jason;
-pub mod local_media_track;
-pub mod media_manager;
-pub mod media_stream_settings;
-pub mod reconnect_handle;
-pub mod remote_media_track;
-pub mod room_close_reason;
-pub mod room_handle;
-mod unimplemented;
-pub mod utils;
-
-/// Rust structure that has wrapper class in Dart. Such structures are passed
-/// through FFI boundaries as thin pointers.
-pub trait ForeignClass {
-    /// Consumes `Self` returning a wrapped raw pointer via [`Box::into_raw`].
-    fn into_ptr(self) -> *const Self
-    where
-        Self: Sized,
-    {
-        Box::into_raw(Box::new(self))
-    }
-
-    /// Constructs `Self` from a raw pointer via [`Box::from_raw`].
-    unsafe fn from_ptr(this: *mut Self) -> Self
-    where
-        Self: Sized,
-    {
-        *Box::from_raw(this)
-    }
-}
-
-pub enum MediaKind {
-    Audio = 0,
-    Video = 1,
-}
-
-pub enum MediaSourceKind {
-    Device = 0,
-    Display = 1,
-}
diff --git a/jason/jason-dummy/src/local_media_track.rs b/jason/jason-dummy/src/local_media_track.rs
deleted file mode 100644
index 7417e4796..000000000
--- a/jason/jason-dummy/src/local_media_track.rs
+++ /dev/null
@@ -1,40 +0,0 @@
-use crate::{ForeignClass, MediaKind, MediaSourceKind};
-
-pub struct LocalMediaTrack;
-
-impl ForeignClass for LocalMediaTrack {}
-
-impl LocalMediaTrack {
-    pub fn kind(&self) -> MediaKind {
-        MediaKind::Video
-    }
-
-    pub fn media_source_kind(&self) -> MediaSourceKind {
-        MediaSourceKind::Display
-    }
-
-    // pub fn get_track(&self) -> sys::MediaStreamTrack
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn LocalMediaTrack__kind(
-    this: *const LocalMediaTrack,
-) -> u8 {
-    let this = this.as_ref().unwrap();
-
-    this.kind() as u8
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn LocalMediaTrack__media_source_kind(
-    this: *const LocalMediaTrack,
-) -> u8 {
-    let this = this.as_ref().unwrap();
-
-    this.media_source_kind() as u8
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn LocalMediaTrack__free(this: *mut LocalMediaTrack) {
-    LocalMediaTrack::from_ptr(this);
-}
diff --git a/jason/jason-dummy/src/media_manager.rs b/jason/jason-dummy/src/media_manager.rs
deleted file mode 100644
index 91a66b794..000000000
--- a/jason/jason-dummy/src/media_manager.rs
+++ /dev/null
@@ -1,50 +0,0 @@
-use crate::{
-    input_device_info::InputDeviceInfo, local_media_track::LocalMediaTrack,
-    media_stream_settings::MediaStreamSettings, utils::PtrArray, ForeignClass,
-};
-
-pub struct MediaManagerHandle;
-
-impl ForeignClass for MediaManagerHandle {}
-
-impl MediaManagerHandle {
-    pub fn enumerate_devices(&self) -> Vec<InputDeviceInfo> {
-        // async && Result
-        vec![InputDeviceInfo {}, InputDeviceInfo {}, InputDeviceInfo {}]
-    }
-
-    pub fn init_local_tracks(
-        &self,
-        _caps: &MediaStreamSettings,
-    ) -> Vec<LocalMediaTrack> {
-        // async && Result
-        vec![LocalMediaTrack {}, LocalMediaTrack {}, LocalMediaTrack {}]
-    }
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn MediaManagerHandle__init_local_tracks(
-    this: *const MediaManagerHandle,
-    caps: *const MediaStreamSettings,
-) -> PtrArray<LocalMediaTrack> {
-    let this = this.as_ref().unwrap();
-    let caps = caps.as_ref().unwrap();
-
-    PtrArray::new(this.init_local_tracks(caps))
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn MediaManagerHandle__enumerate_devices(
-    this: *const MediaManagerHandle,
-) -> PtrArray<InputDeviceInfo> {
-    let this = this.as_ref().unwrap();
-
-    PtrArray::new(this.enumerate_devices())
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn MediaManagerHandle__free(
-    this: *mut MediaManagerHandle,
-) {
-    MediaManagerHandle::from_ptr(this);
-}
diff --git a/jason/jason-dummy/src/reconnect_handle.rs b/jason/jason-dummy/src/reconnect_handle.rs
deleted file mode 100644
index 9ab59531e..000000000
--- a/jason/jason-dummy/src/reconnect_handle.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-use crate::ForeignClass;
-
-pub struct ReconnectHandle;
-
-impl ForeignClass for ReconnectHandle {}
-
-impl ReconnectHandle {
-    // pub async fn reconnect_with_delay(&self, delay_ms: u32) -> Result<(),
-    // JasonError> pub async fn reconnect_with_backoff(&self,
-    // starting_delay_ms: u32, multiplier: f32,  max_delay: u32) -> Result<(),
-    // JasonError>
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn ReconnectHandle__free(this: *mut ReconnectHandle) {
-    ReconnectHandle::from_ptr(this);
-}
diff --git a/jason/jason-dummy/src/remote_media_track.rs b/jason/jason-dummy/src/remote_media_track.rs
deleted file mode 100644
index f571c6bae..000000000
--- a/jason/jason-dummy/src/remote_media_track.rs
+++ /dev/null
@@ -1,133 +0,0 @@
-use dart_sys::Dart_Handle;
-
-use crate::{utils::DartClosure, ForeignClass, MediaKind, MediaSourceKind};
-
-pub struct RemoteMediaTrack;
-
-impl ForeignClass for RemoteMediaTrack {}
-
-impl RemoteMediaTrack {
-    pub fn enabled(&self) -> bool {
-        true
-    }
-
-    pub fn kind(&self) -> MediaKind {
-        MediaKind::Video
-    }
-
-    pub fn media_source_kind(&self) -> MediaSourceKind {
-        MediaSourceKind::Device
-    }
-
-    pub fn muted(&self) -> bool {
-        false
-    }
-
-    // pub fn get_track(&self) -> sys::MediaStreamTrack
-
-    pub fn on_enabled(&self, cb: DartClosure<()>) {
-        cb.call0();
-    }
-
-    pub fn on_disabled(&self, cb: DartClosure<()>) {
-        cb.call0();
-    }
-
-    pub fn on_muted(&self, cb: DartClosure<()>) {
-        cb.call0();
-    }
-
-    pub fn on_unmuted(&self, cb: DartClosure<()>) {
-        cb.call0();
-    }
-
-    pub fn on_stopped(&self, cb: DartClosure<()>) {
-        cb.call0();
-    }
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RemoteMediaTrack__on_enabled(
-    this: *const RemoteMediaTrack,
-    f: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_enabled(DartClosure::new(f));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RemoteMediaTrack__on_disabled(
-    this: *const RemoteMediaTrack,
-    f: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_disabled(DartClosure::new(f));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RemoteMediaTrack__on_muted(
-    this: *const RemoteMediaTrack,
-    f: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_muted(DartClosure::new(f));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RemoteMediaTrack__on_unmuted(
-    this: *const RemoteMediaTrack,
-    f: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_unmuted(DartClosure::new(f));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RemoteMediaTrack__on_stopped(
-    this: *const RemoteMediaTrack,
-    f: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_stopped(DartClosure::new(f));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RemoteMediaTrack__enabled(
-    this: *const RemoteMediaTrack,
-) -> u8 {
-    let this = this.as_ref().unwrap();
-
-    this.enabled() as u8
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RemoteMediaTrack__muted(
-    this: *const RemoteMediaTrack,
-) -> u8 {
-    let this = this.as_ref().unwrap();
-
-    this.muted() as u8
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RemoteMediaTrack__kind(
-    this: *const RemoteMediaTrack,
-) -> u8 {
-    let this = this.as_ref().unwrap();
-
-    this.kind() as u8
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RemoteMediaTrack__media_source_kind(
-    this: *const RemoteMediaTrack,
-) -> u8 {
-    let this = this.as_ref().unwrap();
-
-    this.media_source_kind() as u8
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RemoteMediaTrack__free(this: *mut RemoteMediaTrack) {
-    RemoteMediaTrack::from_ptr(this);
-}
diff --git a/jason/jason-dummy/src/room_handle.rs b/jason/jason-dummy/src/room_handle.rs
deleted file mode 100644
index 5f05b1021..000000000
--- a/jason/jason-dummy/src/room_handle.rs
+++ /dev/null
@@ -1,98 +0,0 @@
-use dart_sys::Dart_Handle;
-
-use crate::{
-    connection_handle::ConnectionHandle, local_media_track::LocalMediaTrack,
-    reconnect_handle::ReconnectHandle, room_close_reason::RoomCloseReason,
-    utils::DartClosure, ForeignClass,
-};
-
-pub struct RoomHandle;
-
-impl ForeignClass for RoomHandle {}
-
-impl RoomHandle {
-    pub fn on_new_connection(&self, cb: DartClosure<ConnectionHandle>) {
-        // Result<(), JasonError>
-        cb.call1(ConnectionHandle);
-    }
-
-    pub fn on_close(&self, cb: DartClosure<RoomCloseReason>) {
-        // Result<(), JasonError>
-        cb.call1(RoomCloseReason);
-    }
-
-    pub fn on_local_track(&self, cb: DartClosure<LocalMediaTrack>) {
-        // Result<(), JasonError>
-        cb.call1(LocalMediaTrack);
-    }
-
-    pub fn on_connection_loss(&self, cb: DartClosure<ReconnectHandle>) {
-        // Result<(), JasonError>
-        cb.call1(ReconnectHandle);
-    }
-
-    // pub async fn join(&self, token: String) -> Result<(), JasonError>
-    // pub fn on_failed_local_media(
-    //     &self,
-    //     f: Callback<JasonError>,
-    // ) -> Result<(), JasonError> {
-    // }
-    // pub async fn set_local_media_settings(&self,
-    // settings: &MediaStreamSettings, stop_first: bool, rollback_on_fail: bool)
-    // -> Result<(), ConstraintsUpdateException> pub async fn
-    // mute_audio(&self) -> Result<(), JasonError> pub async fn
-    // unmute_audio(&self) -> Result<(), JasonError> pub async fn
-    // mute_video(&self, source_kind: Option<MediaSourceKind>) -> Result<(),
-    // JasonError> pub async fn unmute_video(&self, source_kind:
-    // Option<MediaSourceKind>) -> Result<(), JasonError> pub async fn
-    // disable_audio(&self) -> Result<(), JasonError> pub async fn
-    // enable_audio(&self) -> Result<(), JasonError> pub async fn
-    // disable_video(&self, source_kind: Option<MediaSourceKind>) -> Result<(),
-    // JasonError> pub async fn enable_video(&self,source_kind:
-    // Option<MediaSourceKind>) -> Result<(), JasonError> pub async fn
-    // disable_remote_audio(&self) -> Result<(), JasonError> pub async fn
-    // disable_remote_video(&self) -> Result<(), JasonError> pub async fn
-    // enable_remote_audio(&self) -> Result<(), JasonError> pub async fn
-    // enable_remote_video(&self) -> Result<(), JasonError>
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RoomHandle__on_new_connection(
-    this: *mut RoomHandle,
-    cb: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_new_connection(DartClosure::new(cb));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RoomHandle__on_close(
-    this: *mut RoomHandle,
-    cb: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_close(DartClosure::new(cb));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RoomHandle__on_local_track(
-    this: *mut RoomHandle,
-    cb: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_local_track(DartClosure::new(cb));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RoomHandle__on_connection_loss(
-    this: *mut RoomHandle,
-    cb: Dart_Handle,
-) {
-    let this = this.as_ref().unwrap();
-    this.on_connection_loss(DartClosure::new(cb));
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn RoomHandle__free(this: *mut RoomHandle) {
-    RoomHandle::from_ptr(this);
-}
diff --git a/jason/jason-dummy/src/utils/string.rs b/jason/jason-dummy/src/utils/string.rs
deleted file mode 100644
index 7835cef03..000000000
--- a/jason/jason-dummy/src/utils/string.rs
+++ /dev/null
@@ -1,14 +0,0 @@
-use std::ffi::{CStr, CString};
-
-pub unsafe fn c_str_into_string(string: *const libc::c_char) -> String {
-    CStr::from_ptr(string).to_str().unwrap().to_owned()
-}
-
-pub unsafe fn string_into_c_str(string: String) -> *const libc::c_char {
-    CString::new(string).unwrap().into_raw()
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn String_free(s: *mut libc::c_char) {
-    CString::from_raw(s);
-}
diff --git a/jason/src/api/dart/audio_track_constraints.rs b/jason/src/api/dart/audio_track_constraints.rs
new file mode 100644
index 000000000..df75c1f7c
--- /dev/null
+++ b/jason/src/api/dart/audio_track_constraints.rs
@@ -0,0 +1,41 @@
+//! Constraints applicable to audio tracks.
+
+use std::os::raw::c_char;
+
+use super::{utils::c_str_into_string, ForeignClass};
+
+pub use crate::media::AudioTrackConstraints;
+
+impl ForeignClass for AudioTrackConstraints {}
+
+/// Creates new [`AudioTrackConstraints`] with none constraints configured.
+#[no_mangle]
+pub extern "C" fn AudioTrackConstraints__new() -> *const AudioTrackConstraints {
+    AudioTrackConstraints::new().into_ptr()
+}
+
+/// Sets an exact [deviceId][1] constraint.
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#def-constraint-deviceId
+#[no_mangle]
+pub unsafe extern "C" fn AudioTrackConstraints__device_id(
+    this: *mut AudioTrackConstraints,
+    device_id: *const c_char,
+) {
+    let this = this.as_mut().unwrap();
+
+    this.device_id(c_str_into_string(device_id))
+}
+
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
+#[no_mangle]
+pub unsafe extern "C" fn AudioTrackConstraints__free(
+    this: *mut AudioTrackConstraints,
+) {
+    let _ = AudioTrackConstraints::from_ptr(this);
+}
diff --git a/jason/src/api/dart/connection_handle.rs b/jason/src/api/dart/connection_handle.rs
new file mode 100644
index 000000000..10d2f7dec
--- /dev/null
+++ b/jason/src/api/dart/connection_handle.rs
@@ -0,0 +1,124 @@
+use std::os::raw::c_char;
+
+use dart_sys::Dart_Handle;
+
+use crate::platform;
+
+use super::{utils::string_into_c_str, ForeignClass};
+
+#[cfg(feature = "mockable")]
+pub use self::mock::ConnectionHandle;
+#[cfg(not(feature = "mockable"))]
+pub use crate::connection::ConnectionHandle;
+
+impl ForeignClass for ConnectionHandle {}
+
+/// Sets callback, invoked when this `Connection` will close.
+#[no_mangle]
+pub unsafe extern "C" fn ConnectionHandle__on_close(
+    this: *const ConnectionHandle,
+    f: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+
+    // TODO: Remove unwrap when propagating errors from Rust to Dart is
+    //       implemented.
+    this.on_close(platform::Function::new(f)).unwrap();
+}
+
+/// Sets callback, invoked when a new [`remote::Track`] is added to this
+/// [`Connection`].
+///
+/// [`remote::Track`]: crate::media::track::remote::Track
+/// [`Connection`]: crate::connection::Connection
+#[no_mangle]
+pub unsafe extern "C" fn ConnectionHandle__on_remote_track_added(
+    this: *const ConnectionHandle,
+    f: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+
+    // TODO: Remove unwrap when propagating errors from Rust to Dart is
+    //       implemented.
+    this.on_remote_track_added(platform::Function::new(f))
+        .unwrap();
+}
+
+/// Sets callback, invoked when a connection quality score is updated by
+/// a server.
+#[no_mangle]
+pub unsafe extern "C" fn ConnectionHandle__on_quality_score_update(
+    this: *const ConnectionHandle,
+    f: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+
+    // TODO: Remove unwrap when propagating errors from Rust to Dart is
+    //       implemented.
+    this.on_quality_score_update(platform::Function::new(f))
+        .unwrap();
+}
+
+/// Returns remote `Member` ID.
+#[no_mangle]
+pub unsafe extern "C" fn ConnectionHandle__get_remote_member_id(
+    this: *const ConnectionHandle,
+) -> *const c_char {
+    let this = this.as_ref().unwrap();
+
+    // TODO: Remove unwrap when propagating errors from Rust to Dart is
+    //       implemented.
+    string_into_c_str(this.get_remote_member_id().unwrap())
+}
+
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
+#[no_mangle]
+pub unsafe extern "C" fn ConnectionHandle__free(this: *mut ConnectionHandle) {
+    let _ = ConnectionHandle::from_ptr(this);
+}
+
+#[cfg(feature = "mockable")]
+mod mock {
+    use crate::{
+        api::{JasonError, RemoteMediaTrack},
+        platform,
+    };
+
+    pub struct ConnectionHandle;
+
+    #[allow(clippy::missing_errors_doc)]
+    impl ConnectionHandle {
+        pub fn get_remote_member_id(&self) -> Result<String, JasonError> {
+            Ok(String::from("ConnectionHandle.get_remote_member_id"))
+        }
+
+        pub fn on_close(
+            &self,
+            f: platform::Function<()>,
+        ) -> Result<(), JasonError> {
+            f.call0();
+            Ok(())
+        }
+
+        pub fn on_remote_track_added(
+            &self,
+            f: platform::Function<RemoteMediaTrack>,
+        ) -> Result<(), JasonError> {
+            f.call1(RemoteMediaTrack);
+            Ok(())
+        }
+
+        pub fn on_quality_score_update(
+            &self,
+            f: platform::Function<u8>,
+        ) -> Result<(), JasonError> {
+            f.call1(4);
+            Ok(())
+        }
+    }
+}
diff --git a/jason/jason-dummy/src/device_video_track_constraints.rs b/jason/src/api/dart/device_video_track_constraints.rs
similarity index 63%
rename from jason/jason-dummy/src/device_video_track_constraints.rs
rename to jason/src/api/dart/device_video_track_constraints.rs
index 1f981b193..da181aec8 100644
--- a/jason/jason-dummy/src/device_video_track_constraints.rs
+++ b/jason/src/api/dart/device_video_track_constraints.rs
@@ -1,41 +1,12 @@
-use std::convert::TryFrom;
+use std::{convert::TryFrom, os::raw::c_char};
 
-use crate::{utils::c_str_into_string, ForeignClass};
+use crate::media::FacingMode;
 
-pub struct DeviceVideoTrackConstraints;
+use super::{utils::c_str_into_string, ForeignClass};
 
-impl ForeignClass for DeviceVideoTrackConstraints {}
-
-impl DeviceVideoTrackConstraints {
-    pub fn new() -> Self {
-        Self
-    }
-
-    pub fn device_id(&mut self, _device_id: String) {}
-
-    pub fn exact_facing_mode(&mut self, _facing_mode: FacingMode) {}
-
-    pub fn ideal_facing_mode(&mut self, _facing_mode: FacingMode) {}
-
-    pub fn exact_height(&mut self, _height: u32) {}
-
-    pub fn ideal_height(&mut self, _height: u32) {}
+pub use crate::media::DeviceVideoTrackConstraints;
 
-    pub fn height_in_range(&mut self, _min: u32, _max: u32) {}
-
-    pub fn exact_width(&mut self, _width: u32) {}
-
-    pub fn ideal_width(&mut self, _width: u32) {}
-
-    pub fn width_in_range(&mut self, _min: u32, _max: u32) {}
-}
-
-pub enum FacingMode {
-    User,
-    Environment,
-    Left,
-    Right,
-}
+impl ForeignClass for DeviceVideoTrackConstraints {}
 
 impl From<u8> for FacingMode {
     fn from(value: u8) -> Self {
@@ -51,22 +22,30 @@ impl From<u8> for FacingMode {
     }
 }
 
+/// Creates new [`DeviceVideoTrackConstraints`] with none constraints
+/// configured.
 #[no_mangle]
 pub extern "C" fn DeviceVideoTrackConstraints__new(
 ) -> *const DeviceVideoTrackConstraints {
     DeviceVideoTrackConstraints::new().into_ptr()
 }
 
+/// Sets an exact [deviceId][1] constraint.
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#def-constraint-deviceId
 #[no_mangle]
 pub unsafe extern "C" fn DeviceVideoTrackConstraints__device_id(
     this: *mut DeviceVideoTrackConstraints,
-    device_id: *const libc::c_char,
+    device_id: *const c_char,
 ) {
     let this = this.as_mut().unwrap();
 
     this.device_id(c_str_into_string(device_id));
 }
 
+/// Sets an exact [facingMode][1] constraint.
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#dom-constraindomstring
 #[no_mangle]
 pub unsafe extern "C" fn DeviceVideoTrackConstraints__exact_facing_mode(
     this: *mut DeviceVideoTrackConstraints,
@@ -77,6 +56,9 @@ pub unsafe extern "C" fn DeviceVideoTrackConstraints__exact_facing_mode(
     this.exact_facing_mode(FacingMode::try_from(facing_mode).unwrap());
 }
 
+/// Sets an ideal [facingMode][1] constraint.
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#dom-constraindomstring
 #[no_mangle]
 pub unsafe extern "C" fn DeviceVideoTrackConstraints__ideal_facing_mode(
     this: *mut DeviceVideoTrackConstraints,
@@ -87,6 +69,9 @@ pub unsafe extern "C" fn DeviceVideoTrackConstraints__ideal_facing_mode(
     this.ideal_facing_mode(FacingMode::try_from(facing_mode).unwrap());
 }
 
+/// Sets an exact [height][1] constraint.
+///
+/// [1]: https://tinyurl.com/w3-streams#def-constraint-height
 #[no_mangle]
 pub unsafe extern "C" fn DeviceVideoTrackConstraints__exact_height(
     this: *mut DeviceVideoTrackConstraints,
@@ -97,6 +82,9 @@ pub unsafe extern "C" fn DeviceVideoTrackConstraints__exact_height(
     this.exact_height(height);
 }
 
+/// Sets an ideal [height][1] constraint.
+///
+/// [1]: https://tinyurl.com/w3-streams#def-constraint-height
 #[no_mangle]
 pub unsafe extern "C" fn DeviceVideoTrackConstraints__ideal_height(
     this: *mut DeviceVideoTrackConstraints,
@@ -107,6 +95,9 @@ pub unsafe extern "C" fn DeviceVideoTrackConstraints__ideal_height(
     this.ideal_height(height);
 }
 
+/// Sets a range of a [height][1] constraint.
+///
+/// [1]: https://tinyurl.com/w3-streams#def-constraint-height
 #[no_mangle]
 pub unsafe extern "C" fn DeviceVideoTrackConstraints__height_in_range(
     this: *mut DeviceVideoTrackConstraints,
@@ -118,6 +109,9 @@ pub unsafe extern "C" fn DeviceVideoTrackConstraints__height_in_range(
     this.height_in_range(min, max);
 }
 
+/// Sets an exact [width][1] constraint.
+///
+/// [1]: https://tinyurl.com/w3-streams#def-constraint-width
 #[no_mangle]
 pub unsafe extern "C" fn DeviceVideoTrackConstraints__exact_width(
     this: *mut DeviceVideoTrackConstraints,
@@ -128,6 +122,9 @@ pub unsafe extern "C" fn DeviceVideoTrackConstraints__exact_width(
     this.exact_width(width);
 }
 
+/// Sets an ideal [width][1] constraint.
+///
+/// [1]: https://tinyurl.com/w3-streams#def-constraint-width
 #[no_mangle]
 pub unsafe extern "C" fn DeviceVideoTrackConstraints__ideal_width(
     this: *mut DeviceVideoTrackConstraints,
@@ -138,6 +135,9 @@ pub unsafe extern "C" fn DeviceVideoTrackConstraints__ideal_width(
     this.ideal_width(width);
 }
 
+/// Sets a range of a [width][1] constraint.
+///
+/// [1]: https://tinyurl.com/w3-streams#def-constraint-width
 #[no_mangle]
 pub unsafe extern "C" fn DeviceVideoTrackConstraints__width_in_range(
     this: *mut DeviceVideoTrackConstraints,
@@ -149,9 +149,15 @@ pub unsafe extern "C" fn DeviceVideoTrackConstraints__width_in_range(
     this.width_in_range(min, max);
 }
 
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
 #[no_mangle]
 pub unsafe extern "C" fn DeviceVideoTrackConstraints__free(
     this: *mut DeviceVideoTrackConstraints,
 ) {
-    DeviceVideoTrackConstraints::from_ptr(this);
+    let _ = DeviceVideoTrackConstraints::from_ptr(this);
 }
diff --git a/jason/src/api/dart/display_video_track_constraints.rs b/jason/src/api/dart/display_video_track_constraints.rs
new file mode 100644
index 000000000..25f4f925b
--- /dev/null
+++ b/jason/src/api/dart/display_video_track_constraints.rs
@@ -0,0 +1,26 @@
+use super::ForeignClass;
+
+pub use crate::media::DisplayVideoTrackConstraints;
+
+impl ForeignClass for DisplayVideoTrackConstraints {}
+
+/// Creates new [`DisplayVideoTrackConstraints`] with none constraints
+/// configured.
+#[no_mangle]
+pub extern "C" fn DisplayVideoTrackConstraints__new(
+) -> *const DisplayVideoTrackConstraints {
+    DisplayVideoTrackConstraints::new().into_ptr()
+}
+
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
+#[no_mangle]
+pub unsafe extern "C" fn DisplayVideoTrackConstraints__free(
+    this: *mut DisplayVideoTrackConstraints,
+) {
+    let _ = DisplayVideoTrackConstraints::from_ptr(this);
+}
diff --git a/jason/src/api/dart/input_device_info.rs b/jason/src/api/dart/input_device_info.rs
new file mode 100644
index 000000000..a294eaa29
--- /dev/null
+++ b/jason/src/api/dart/input_device_info.rs
@@ -0,0 +1,100 @@
+use std::os::raw::c_char;
+
+use super::{utils::string_into_c_str, ForeignClass};
+
+#[cfg(feature = "mockable")]
+pub use self::mock::InputDeviceInfo;
+#[cfg(not(feature = "mockable"))]
+pub use crate::platform::InputDeviceInfo;
+
+impl ForeignClass for InputDeviceInfo {}
+
+/// Returns unique identifier of the represented device.
+#[no_mangle]
+pub unsafe extern "C" fn InputDeviceInfo__device_id(
+    this: *const InputDeviceInfo,
+) -> *const c_char {
+    let this = this.as_ref().unwrap();
+
+    string_into_c_str(this.device_id())
+}
+
+/// Returns kind of the represented device.
+///
+/// This representation of [MediaDeviceInfo][1] ONLY for input device.
+///
+/// [1]: https://w3.org/TR/mediacapture-streams/#device-info
+#[no_mangle]
+pub unsafe extern "C" fn InputDeviceInfo__kind(
+    this: *const InputDeviceInfo,
+) -> u8 {
+    let this = this.as_ref().unwrap();
+
+    this.kind() as u8 // TODO: .into()
+}
+
+/// Returns label describing the represented device (for example "External USB
+/// Webcam").
+///
+/// If the device has no associated label, then returns an empty string.
+#[no_mangle]
+pub unsafe extern "C" fn InputDeviceInfo__label(
+    this: *const InputDeviceInfo,
+) -> *const c_char {
+    let this = this.as_ref().unwrap();
+
+    string_into_c_str(this.label())
+}
+
+/// Returns group identifier of the represented device.
+///
+/// Two devices have the same group identifier if they belong to the same
+/// physical device. For example, the audio input and output devices
+/// representing the speaker and microphone of the same headset have the
+/// same [groupId][1].
+///
+/// [1]: https://w3.org/TR/mediacapture-streams/#dom-mediadeviceinfo-groupid
+#[no_mangle]
+pub unsafe extern "C" fn InputDeviceInfo__group_id(
+    this: *const InputDeviceInfo,
+) -> *const c_char {
+    let this = this.as_ref().unwrap();
+
+    string_into_c_str(this.group_id())
+}
+
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
+#[no_mangle]
+pub unsafe extern "C" fn InputDeviceInfo__free(this: *mut InputDeviceInfo) {
+    let _ = InputDeviceInfo::from_ptr(this);
+}
+
+#[cfg(feature = "mockable")]
+mod mock {
+    use crate::media::MediaKind;
+
+    pub struct InputDeviceInfo;
+
+    impl InputDeviceInfo {
+        pub fn device_id(&self) -> String {
+            String::from("InputDeviceInfo.device_id")
+        }
+
+        pub fn kind(&self) -> MediaKind {
+            MediaKind::Audio
+        }
+
+        pub fn label(&self) -> String {
+            String::from("InputDeviceInfo.label")
+        }
+
+        pub fn group_id(&self) -> String {
+            String::from("InputDeviceInfo.group_id")
+        }
+    }
+}
diff --git a/jason/src/api/dart/jason.rs b/jason/src/api/dart/jason.rs
new file mode 100644
index 000000000..677569589
--- /dev/null
+++ b/jason/src/api/dart/jason.rs
@@ -0,0 +1,85 @@
+use super::{
+    media_manager_handle::MediaManagerHandle, room_handle::RoomHandle,
+    ForeignClass,
+};
+
+#[cfg(feature = "mockable")]
+pub use self::mock::Jason;
+#[cfg(not(feature = "mockable"))]
+pub use crate::jason::Jason;
+
+impl ForeignClass for Jason {}
+
+/// Instantiates a new [`Jason`] interface to interact with this library.
+#[no_mangle]
+pub extern "C" fn Jason__new() -> *const Jason {
+    Jason::new().into_ptr()
+}
+
+/// Creates a new [`Room`] and returns its [`RoomHandle`].
+///
+/// [`Room`]: crate::room::Room
+#[no_mangle]
+pub unsafe extern "C" fn Jason__init_room(
+    this: *const Jason,
+) -> *const RoomHandle {
+    let this = this.as_ref().unwrap();
+
+    this.init_room().into_ptr()
+}
+
+/// Returns a [`MediaManagerHandle`].
+#[no_mangle]
+pub unsafe extern "C" fn Jason__media_manager(
+    this: *const Jason,
+) -> *const MediaManagerHandle {
+    let this = this.as_ref().unwrap();
+
+    this.media_manager().into_ptr()
+}
+
+/// Closes the provided [`RoomHandle`].
+#[no_mangle]
+pub unsafe extern "C" fn Jason__close_room(
+    this: *const Jason,
+    room_to_delete: *mut RoomHandle,
+) {
+    let this = this.as_ref().unwrap();
+
+    this.close_room(RoomHandle::from_ptr(room_to_delete));
+}
+
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
+#[no_mangle]
+pub unsafe extern "C" fn Jason__free(this: *mut Jason) {
+    let _ = Jason::from_ptr(this);
+}
+
+#[cfg(feature = "mockable")]
+mod mock {
+    use crate::api::{MediaManagerHandle, RoomHandle};
+
+    pub struct Jason;
+
+    impl Jason {
+        pub fn new() -> Self {
+            crate::platform::init_logger();
+            Self
+        }
+
+        pub fn init_room(&self) -> RoomHandle {
+            RoomHandle
+        }
+
+        pub fn media_manager(&self) -> MediaManagerHandle {
+            MediaManagerHandle
+        }
+
+        pub fn close_room(&self, _: RoomHandle) {}
+    }
+}
diff --git a/jason/src/api/dart/jason_error.rs b/jason/src/api/dart/jason_error.rs
new file mode 100644
index 000000000..a6219b96e
--- /dev/null
+++ b/jason/src/api/dart/jason_error.rs
@@ -0,0 +1,54 @@
+//! App error exported to JS side.
+// TODO: This is just a copy of wasm version, Rust to Dart error propagation
+//       will be implemented later.
+
+use std::fmt::{Debug, Display};
+
+use derive_more::{Display, From};
+use tracerr::{Trace, Traced};
+
+use crate::{platform, utils::JsCaused};
+
+/// Representation of an app error exported to JS side.
+///
+/// Contains JS side error if it's the cause, and a trace information.
+#[derive(From, Clone, Debug, Display)]
+#[display(fmt = "{}: {}\n{}", name, message, trace)]
+pub struct JasonError {
+    /// Name of this [`JasonError`].
+    name: &'static str,
+
+    /// Message describing this [`JasonError`].
+    message: String,
+
+    /// [`Trace`] information of this [`JasonError`].
+    trace: Trace,
+
+    /// Optional cause of this [`JasonError`] as a JS side error.
+    source: Option<platform::Error>,
+}
+
+impl<E: JsCaused + Display> From<(E, Trace)> for JasonError
+where
+    E::Error: Into<platform::Error>,
+{
+    #[inline]
+    fn from((err, trace): (E, Trace)) -> Self {
+        Self {
+            name: err.name(),
+            message: err.to_string(),
+            trace,
+            source: err.js_cause().map(Into::into),
+        }
+    }
+}
+
+impl<E: JsCaused + Display> From<Traced<E>> for JasonError
+where
+    E::Error: Into<platform::Error>,
+{
+    #[inline]
+    fn from(traced: Traced<E>) -> Self {
+        Self::from(traced.into_parts())
+    }
+}
diff --git a/jason/src/api/dart/local_media_track.rs b/jason/src/api/dart/local_media_track.rs
new file mode 100644
index 000000000..34baf0bd0
--- /dev/null
+++ b/jason/src/api/dart/local_media_track.rs
@@ -0,0 +1,69 @@
+use super::ForeignClass;
+
+#[cfg(feature = "mockable")]
+pub use self::mock::LocalMediaTrack;
+#[cfg(not(feature = "mockable"))]
+pub use crate::media::track::local::LocalMediaTrack;
+
+impl ForeignClass for LocalMediaTrack {}
+
+/// Returns a [`MediaKind::Audio`] if this [`LocalMediaTrack`] represents an
+/// audio track, or a [`MediaKind::Video`] if it represents a video track.
+///
+/// [`MediaKind::Audio`]: crate::media::MediaKind::Audio
+/// [`MediaKind::Video`]: crate::media::MediaKind::Video
+#[no_mangle]
+pub unsafe extern "C" fn LocalMediaTrack__kind(
+    this: *const LocalMediaTrack,
+) -> u8 {
+    let this = this.as_ref().unwrap();
+
+    this.kind() as u8
+}
+
+/// Returns a [`MediaSourceKind::Device`] if this [`LocalMediaTrack`] is
+/// sourced from some device (webcam/microphone), or a
+/// [`MediaSourceKind::Display`] if it's captured via
+/// [MediaDevices.getDisplayMedia()][1].
+///
+/// [1]: https://w3.org/TR/screen-capture/#dom-mediadevices-getdisplaymedia
+/// [`MediaSourceKind::Device`]: crate::media::MediaSourceKind::Device
+/// [`MediaSourceKind::Display`]: crate::media::MediaSourceKind::Display
+#[no_mangle]
+pub unsafe extern "C" fn LocalMediaTrack__media_source_kind(
+    this: *const LocalMediaTrack,
+) -> u8 {
+    let this = this.as_ref().unwrap();
+
+    this.media_source_kind() as u8
+}
+
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
+#[no_mangle]
+pub unsafe extern "C" fn LocalMediaTrack__free(this: *mut LocalMediaTrack) {
+    let _ = LocalMediaTrack::from_ptr(this);
+}
+
+#[cfg(feature = "mockable")]
+mod mock {
+    use crate::media::{MediaKind, MediaSourceKind};
+
+    pub struct LocalMediaTrack;
+
+    impl LocalMediaTrack {
+        pub fn kind(&self) -> MediaKind {
+            MediaKind::Video
+        }
+
+        pub fn media_source_kind(&self) -> MediaSourceKind {
+            MediaSourceKind::Display
+        }
+
+        // pub fn get_track(&self) -> sys::MediaStreamTrack
+    }
+}
diff --git a/jason/src/api/dart/media_manager_handle.rs b/jason/src/api/dart/media_manager_handle.rs
new file mode 100644
index 000000000..e17e0656d
--- /dev/null
+++ b/jason/src/api/dart/media_manager_handle.rs
@@ -0,0 +1,94 @@
+use futures::FutureExt as _;
+
+use super::{
+    input_device_info::InputDeviceInfo, local_media_track::LocalMediaTrack,
+    media_stream_settings::MediaStreamSettings, utils::PtrArray, ForeignClass,
+};
+
+#[cfg(feature = "mockable")]
+pub use self::mock::MediaManagerHandle;
+#[cfg(not(feature = "mockable"))]
+pub use crate::media::MediaManagerHandle;
+
+impl ForeignClass for MediaManagerHandle {}
+
+/// Returns [`LocalMediaTrack`]s objects, built from the provided
+/// [`MediaStreamSettings`].
+#[no_mangle]
+pub unsafe extern "C" fn MediaManagerHandle__init_local_tracks(
+    this: *const MediaManagerHandle,
+    caps: *const MediaStreamSettings,
+) -> PtrArray<LocalMediaTrack> {
+    let this = this.as_ref().unwrap();
+    let caps = caps.as_ref().unwrap();
+
+    // TODO: Remove now_or_never when polling from Dart is implemented.
+    //       Remove unwrap when propagating errors from Rust to Dart is
+    //       implemented.
+    PtrArray::new(
+        this.init_local_tracks(caps.clone())
+            .now_or_never()
+            .unwrap()
+            .unwrap(),
+    )
+}
+
+/// Returns a list of [`InputDeviceInfo`] objects representing available media
+/// input and devices, such as microphones, cameras, and so forth.
+#[no_mangle]
+pub unsafe extern "C" fn MediaManagerHandle__enumerate_devices(
+    this: *const MediaManagerHandle,
+) -> PtrArray<InputDeviceInfo> {
+    let this = this.as_ref().unwrap();
+
+    // TODO: Remove now_or_never when polling from Dart is implemented.
+    //       Remove unwrap when propagating errors from Rust to Dart is
+    //       implemented.
+    PtrArray::new(this.enumerate_devices().now_or_never().unwrap().unwrap())
+}
+
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
+#[no_mangle]
+pub unsafe extern "C" fn MediaManagerHandle__free(
+    this: *mut MediaManagerHandle,
+) {
+    let _ = MediaManagerHandle::from_ptr(this);
+}
+
+#[cfg(feature = "mockable")]
+mod mock {
+    use crate::api::{
+        InputDeviceInfo, JasonError, LocalMediaTrack, MediaStreamSettings,
+    };
+
+    pub struct MediaManagerHandle;
+
+    #[allow(clippy::missing_errors_doc)]
+    impl MediaManagerHandle {
+        pub async fn enumerate_devices(
+            &self,
+        ) -> Result<Vec<InputDeviceInfo>, JasonError> {
+            Ok(vec![
+                InputDeviceInfo {},
+                InputDeviceInfo {},
+                InputDeviceInfo {},
+            ])
+        }
+
+        pub async fn init_local_tracks(
+            &self,
+            _caps: MediaStreamSettings,
+        ) -> Result<Vec<LocalMediaTrack>, JasonError> {
+            Ok(vec![
+                LocalMediaTrack {},
+                LocalMediaTrack {},
+                LocalMediaTrack {},
+            ])
+        }
+    }
+}
diff --git a/jason/jason-dummy/src/media_stream_settings.rs b/jason/src/api/dart/media_stream_settings.rs
similarity index 66%
rename from jason/jason-dummy/src/media_stream_settings.rs
rename to jason/src/api/dart/media_stream_settings.rs
index befcaad39..1689a6035 100644
--- a/jason/jason-dummy/src/media_stream_settings.rs
+++ b/jason/src/api/dart/media_stream_settings.rs
@@ -1,31 +1,23 @@
-use crate::{
+use super::{
     audio_track_constraints::AudioTrackConstraints,
     device_video_track_constraints::DeviceVideoTrackConstraints,
     display_video_track_constraints::DisplayVideoTrackConstraints,
     ForeignClass,
 };
 
-pub struct MediaStreamSettings;
+pub use crate::media::MediaStreamSettings;
 
 impl ForeignClass for MediaStreamSettings {}
 
-impl MediaStreamSettings {
-    pub fn new() -> Self {
-        Self
-    }
-
-    pub fn audio(&mut self, _: AudioTrackConstraints) {}
-
-    pub fn device_video(&mut self, _: DeviceVideoTrackConstraints) {}
-
-    pub fn display_video(&mut self, _: DisplayVideoTrackConstraints) {}
-}
-
+/// Creates new [`MediaStreamSettings`] with none constraints configured.
 #[no_mangle]
 pub extern "C" fn MediaStreamSettings__new() -> *const MediaStreamSettings {
     MediaStreamSettings::new().into_ptr()
 }
 
+/// Specifies a nature and settings of an audio [`MediaStreamTrack`].
+///
+/// [`MediaStreamTrack`]: crate::platform::MediaStreamTrack
 #[no_mangle]
 pub unsafe extern "C" fn MediaStreamSettings__audio(
     this: *mut MediaStreamSettings,
@@ -36,6 +28,7 @@ pub unsafe extern "C" fn MediaStreamSettings__audio(
     this.audio(AudioTrackConstraints::from_ptr(constraints));
 }
 
+/// Set constraints for obtaining a local video sourced from a media device.
 #[no_mangle]
 pub unsafe extern "C" fn MediaStreamSettings__device_video(
     this: *mut MediaStreamSettings,
@@ -46,6 +39,7 @@ pub unsafe extern "C" fn MediaStreamSettings__device_video(
     this.device_video(DeviceVideoTrackConstraints::from_ptr(constraints));
 }
 
+/// Set constraints for capturing a local video from user's display.
 #[no_mangle]
 pub unsafe extern "C" fn MediaStreamSettings__display_video(
     this: *mut MediaStreamSettings,
@@ -56,9 +50,15 @@ pub unsafe extern "C" fn MediaStreamSettings__display_video(
     this.display_video(DisplayVideoTrackConstraints::from_ptr(constraints));
 }
 
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
 #[no_mangle]
 pub unsafe extern "C" fn MediaStreamSettings__free(
     this: *mut MediaStreamSettings,
 ) {
-    MediaStreamSettings::from_ptr(this);
+    let _ = MediaStreamSettings::from_ptr(this);
 }
diff --git a/jason/src/api/dart/mod.rs b/jason/src/api/dart/mod.rs
new file mode 100644
index 000000000..0f39f6c5b
--- /dev/null
+++ b/jason/src/api/dart/mod.rs
@@ -0,0 +1,63 @@
+//! External [`Jason`] API exposing functions that can be called via FFI and
+//! designed to be integrated into a [Flutter] plugin.
+//!
+//! [`Jason`]: crate::api::Jason
+//! [Flutter]: https://flutter.dev
+
+// TODO: Improve documentation in this module.
+#![allow(clippy::missing_safety_doc, clippy::missing_panics_doc, missing_docs)]
+
+pub mod audio_track_constraints;
+pub mod connection_handle;
+pub mod device_video_track_constraints;
+pub mod display_video_track_constraints;
+pub mod input_device_info;
+pub mod jason;
+pub mod jason_error;
+pub mod local_media_track;
+pub mod media_manager_handle;
+pub mod media_stream_settings;
+pub mod reconnect_handle;
+pub mod remote_media_track;
+pub mod room_close_reason;
+pub mod room_handle;
+mod unimplemented;
+pub mod utils;
+
+pub use self::{
+    audio_track_constraints::AudioTrackConstraints,
+    connection_handle::ConnectionHandle,
+    device_video_track_constraints::DeviceVideoTrackConstraints,
+    display_video_track_constraints::DisplayVideoTrackConstraints,
+    input_device_info::InputDeviceInfo, jason::Jason, jason_error::JasonError,
+    local_media_track::LocalMediaTrack,
+    media_manager_handle::MediaManagerHandle,
+    media_stream_settings::MediaStreamSettings,
+    reconnect_handle::ReconnectHandle, remote_media_track::RemoteMediaTrack,
+    room_close_reason::RoomCloseReason, room_handle::RoomHandle,
+};
+
+/// Rust structure having wrapper class in Dart.
+///
+/// Intended to be passed through FFI boundaries as thin pointers.
+pub trait ForeignClass: Sized {
+    /// Consumes itself returning a wrapped raw pointer obtained via
+    /// [`Box::into_raw()`].
+    #[inline]
+    #[must_use]
+    fn into_ptr(self) -> *const Self {
+        Box::into_raw(Box::new(self))
+    }
+
+    /// Constructs a [`ForeignClass`] from the given raw pointer via
+    /// [`Box::from_raw()`].
+    ///
+    /// # Safety
+    ///
+    /// Same as for [`Box::from_raw()`].
+    #[inline]
+    #[must_use]
+    unsafe fn from_ptr(this: *mut Self) -> Self {
+        *Box::from_raw(this)
+    }
+}
diff --git a/jason/src/api/dart/reconnect_handle.rs b/jason/src/api/dart/reconnect_handle.rs
new file mode 100644
index 000000000..9c2b65192
--- /dev/null
+++ b/jason/src/api/dart/reconnect_handle.rs
@@ -0,0 +1,31 @@
+use super::ForeignClass;
+
+#[cfg(feature = "mockable")]
+pub use self::mock::ReconnectHandle;
+#[cfg(not(feature = "mockable"))]
+pub use crate::rpc::ReconnectHandle;
+
+impl ForeignClass for ReconnectHandle {}
+
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
+#[no_mangle]
+pub unsafe extern "C" fn ReconnectHandle__free(this: *mut ReconnectHandle) {
+    let _ = ReconnectHandle::from_ptr(this);
+}
+
+#[cfg(feature = "mockable")]
+mod mock {
+    pub struct ReconnectHandle;
+
+    impl ReconnectHandle {
+        // pub async fn reconnect_with_delay(&self, delay_ms: u32) -> Result<(),
+        // JasonError> pub async fn reconnect_with_backoff(&self,
+        // starting_delay_ms: u32, multiplier: f32,  max_delay: u32) ->
+        // Result<(), JasonError>
+    }
+}
diff --git a/jason/src/api/dart/remote_media_track.rs b/jason/src/api/dart/remote_media_track.rs
new file mode 100644
index 000000000..f9052e0da
--- /dev/null
+++ b/jason/src/api/dart/remote_media_track.rs
@@ -0,0 +1,163 @@
+use dart_sys::Dart_Handle;
+
+use crate::platform;
+
+use super::ForeignClass;
+
+#[cfg(feature = "mockable")]
+pub use self::mock::RemoteMediaTrack;
+#[cfg(not(feature = "mockable"))]
+pub use crate::media::track::remote::Track as RemoteMediaTrack;
+
+impl ForeignClass for RemoteMediaTrack {}
+
+/// Sets callback, invoked when this [`RemoteMediaTrack`] is enabled.
+#[no_mangle]
+pub unsafe extern "C" fn RemoteMediaTrack__on_enabled(
+    this: *const RemoteMediaTrack,
+    f: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+    this.on_enabled(platform::Function::new(f));
+}
+
+/// Sets callback, invoked when this [`RemoteMediaTrack`] is disabled.
+#[no_mangle]
+pub unsafe extern "C" fn RemoteMediaTrack__on_disabled(
+    this: *const RemoteMediaTrack,
+    f: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+    this.on_disabled(platform::Function::new(f));
+}
+
+/// Sets callback to invoke when this [`RemoteMediaTrack`] is muted.
+#[no_mangle]
+pub unsafe extern "C" fn RemoteMediaTrack__on_muted(
+    this: *const RemoteMediaTrack,
+    f: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+    this.on_muted(platform::Function::new(f));
+}
+
+/// Sets callback to invoke when this [`RemoteMediaTrack`] is unmuted.
+#[no_mangle]
+pub unsafe extern "C" fn RemoteMediaTrack__on_unmuted(
+    this: *const RemoteMediaTrack,
+    f: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+    this.on_unmuted(platform::Function::new(f));
+}
+
+/// Sets callback to invoke when this [`RemoteMediaTrack`] is stopped.
+#[no_mangle]
+pub unsafe extern "C" fn RemoteMediaTrack__on_stopped(
+    this: *const RemoteMediaTrack,
+    f: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+    this.on_stopped(platform::Function::new(f));
+}
+
+/// Indicates whether this [`RemoteMediaTrack`] is enabled.
+#[no_mangle]
+pub unsafe extern "C" fn RemoteMediaTrack__enabled(
+    this: *const RemoteMediaTrack,
+) -> u8 {
+    let this = this.as_ref().unwrap();
+
+    this.enabled() as u8
+}
+
+/// Indicate whether this [`RemoteMediaTrack`] is muted.
+#[no_mangle]
+pub unsafe extern "C" fn RemoteMediaTrack__muted(
+    this: *const RemoteMediaTrack,
+) -> u8 {
+    let this = this.as_ref().unwrap();
+
+    this.muted() as u8
+}
+
+/// Returns this [`RemoteMediaTrack`]'s kind (audio/video).
+#[no_mangle]
+pub unsafe extern "C" fn RemoteMediaTrack__kind(
+    this: *const RemoteMediaTrack,
+) -> u8 {
+    let this = this.as_ref().unwrap();
+
+    this.kind() as u8
+}
+
+/// Returns this [`RemoteMediaTrack`]'s media source kind.
+#[no_mangle]
+pub unsafe extern "C" fn RemoteMediaTrack__media_source_kind(
+    this: *const RemoteMediaTrack,
+) -> u8 {
+    let this = this.as_ref().unwrap();
+
+    this.media_source_kind() as u8
+}
+
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
+#[no_mangle]
+pub unsafe extern "C" fn RemoteMediaTrack__free(this: *mut RemoteMediaTrack) {
+    let _ = RemoteMediaTrack::from_ptr(this);
+}
+
+#[cfg(feature = "mockable")]
+mod mock {
+    use crate::{
+        media::{MediaKind, MediaSourceKind},
+        platform,
+    };
+
+    pub struct RemoteMediaTrack;
+
+    impl RemoteMediaTrack {
+        pub fn enabled(&self) -> bool {
+            true
+        }
+
+        pub fn kind(&self) -> MediaKind {
+            MediaKind::Video
+        }
+
+        pub fn media_source_kind(&self) -> MediaSourceKind {
+            MediaSourceKind::Device
+        }
+
+        pub fn muted(&self) -> bool {
+            false
+        }
+
+        // pub fn get_track(&self) -> sys::MediaStreamTrack
+
+        pub fn on_enabled(&self, cb: platform::Function<()>) {
+            cb.call0();
+        }
+
+        pub fn on_disabled(&self, cb: platform::Function<()>) {
+            cb.call0();
+        }
+
+        pub fn on_muted(&self, cb: platform::Function<()>) {
+            cb.call0();
+        }
+
+        pub fn on_unmuted(&self, cb: platform::Function<()>) {
+            cb.call0();
+        }
+
+        pub fn on_stopped(&self, cb: platform::Function<()>) {
+            cb.call0();
+        }
+    }
+}
diff --git a/jason/jason-dummy/src/room_close_reason.rs b/jason/src/api/dart/room_close_reason.rs
similarity index 50%
rename from jason/jason-dummy/src/room_close_reason.rs
rename to jason/src/api/dart/room_close_reason.rs
index 29a9eb355..9ca8469fa 100644
--- a/jason/jason-dummy/src/room_close_reason.rs
+++ b/jason/src/api/dart/room_close_reason.rs
@@ -1,32 +1,26 @@
-use crate::{utils::string_into_c_str, ForeignClass};
+use std::os::raw::c_char;
 
-pub struct RoomCloseReason;
+use super::{utils::string_into_c_str, ForeignClass};
 
-impl ForeignClass for RoomCloseReason {}
-
-impl RoomCloseReason {
-    pub fn reason(&self) -> String {
-        String::from("RoomCloseReason.reason")
-    }
-
-    pub fn is_closed_by_server(&self) -> bool {
-        false
-    }
+pub use crate::room::RoomCloseReason;
 
-    pub fn is_err(&self) -> bool {
-        true
-    }
-}
+impl ForeignClass for RoomCloseReason {}
 
+/// Returns a close reason of a [`Room`].
+///
+/// [`Room`]: crate::room::Room
 #[no_mangle]
 pub unsafe extern "C" fn RoomCloseReason__reason(
     this: *const RoomCloseReason,
-) -> *const libc::c_char {
+) -> *const c_char {
     let this = this.as_ref().unwrap();
 
     string_into_c_str(this.reason())
 }
 
+/// Indicates whether a [`Room`] was closed by server.
+///
+/// [`Room`]: crate::room::Room
 #[no_mangle]
 pub unsafe extern "C" fn RoomCloseReason__is_closed_by_server(
     this: *const RoomCloseReason,
@@ -36,6 +30,9 @@ pub unsafe extern "C" fn RoomCloseReason__is_closed_by_server(
     this.is_closed_by_server() as u8
 }
 
+/// Indicates whether a [`Room`]'s close reason is considered as an error.
+///
+/// [`Room`]: crate::room::Room
 #[no_mangle]
 pub unsafe extern "C" fn RoomCloseReason__is_err(
     this: *const RoomCloseReason,
@@ -45,7 +42,13 @@ pub unsafe extern "C" fn RoomCloseReason__is_err(
     this.is_err() as u8
 }
 
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
 #[no_mangle]
 pub unsafe extern "C" fn RoomCloseReason__free(this: *mut RoomCloseReason) {
-    RoomCloseReason::from_ptr(this);
+    let _ = RoomCloseReason::from_ptr(this);
 }
diff --git a/jason/src/api/dart/room_handle.rs b/jason/src/api/dart/room_handle.rs
new file mode 100644
index 000000000..599919323
--- /dev/null
+++ b/jason/src/api/dart/room_handle.rs
@@ -0,0 +1,166 @@
+use dart_sys::Dart_Handle;
+
+use crate::{api::dart::ForeignClass, platform};
+
+#[cfg(feature = "mockable")]
+pub use self::mock::RoomHandle;
+#[cfg(not(feature = "mockable"))]
+pub use crate::room::RoomHandle;
+
+impl ForeignClass for RoomHandle {}
+
+/// Sets callback, invoked when a new [`Connection`] with some remote `Peer`
+/// is established.
+///
+/// [`Connection`]: crate::connection::Connection
+#[no_mangle]
+pub unsafe extern "C" fn RoomHandle__on_new_connection(
+    this: *mut RoomHandle,
+    cb: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+
+    // TODO: Remove unwrap when propagating errors from Rust to Dart is
+    //       implemented.
+    this.on_new_connection(platform::Function::new(cb)).unwrap();
+}
+
+/// Sets callback, invoked on this [`Room`] close, providing a
+/// [`RoomCloseReason`].
+///
+/// [`Room`]: crate::room::Room
+/// [`RoomCloseReason`]: crate::room::RoomCloseReason
+#[no_mangle]
+pub unsafe extern "C" fn RoomHandle__on_close(
+    this: *mut RoomHandle,
+    cb: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+
+    // TODO: Remove unwrap when propagating errors from Rust to Dart is
+    //       implemented.
+    this.on_close(platform::Function::new(cb)).unwrap();
+}
+
+/// Sets callback, invoked when a new [`LocalMediaTrack`] is added to this
+/// [`Room`].
+///
+/// This might happen in such cases:
+/// 1. Media server initiates a media request.
+/// 2. `enable_audio`/`enable_video` is called.
+/// 3. [`MediaStreamSettings`] updated via `set_local_media_settings`.
+///
+/// [`Room`]: crate::room::Room
+/// [`MediaStreamSettings`]: crate::media::MediaStreamSettings
+/// [`LocalMediaTrack`]: crate::media::track::local::LocalMediaTrack
+#[no_mangle]
+pub unsafe extern "C" fn RoomHandle__on_local_track(
+    this: *mut RoomHandle,
+    cb: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+
+    // TODO: Remove unwrap when propagating errors from Rust to Dart is
+    //       implemented.
+    this.on_local_track(platform::Function::new(cb)).unwrap();
+}
+
+/// Sets callback, invoked when a connection with server is lost.
+#[no_mangle]
+pub unsafe extern "C" fn RoomHandle__on_connection_loss(
+    this: *mut RoomHandle,
+    cb: Dart_Handle,
+) {
+    let this = this.as_ref().unwrap();
+
+    // TODO: Remove unwrap when propagating errors from Rust to Dart is
+    //       implemented.
+    this.on_connection_loss(platform::Function::new(cb))
+        .unwrap();
+}
+
+/// Frees the data behind the provided pointer.
+///
+/// # Safety
+///
+/// Should be called when object is no longer needed. Calling this more than
+/// once for the same pointer is equivalent to double free.
+#[no_mangle]
+pub unsafe extern "C" fn RoomHandle__free(this: *mut RoomHandle) {
+    let _ = RoomHandle::from_ptr(this);
+}
+
+#[cfg(feature = "mockable")]
+mod mock {
+    use crate::{
+        api::{ConnectionHandle, JasonError, LocalMediaTrack, ReconnectHandle},
+        platform,
+        room::RoomCloseReason,
+        rpc::{ClientDisconnect, CloseReason},
+    };
+
+    pub struct RoomHandle;
+
+    #[allow(clippy::missing_errors_doc)]
+    impl RoomHandle {
+        pub fn on_new_connection(
+            &self,
+            cb: platform::Function<ConnectionHandle>,
+        ) -> Result<(), JasonError> {
+            cb.call1(ConnectionHandle);
+            Ok(())
+        }
+
+        pub fn on_close(
+            &self,
+            cb: platform::Function<RoomCloseReason>,
+        ) -> Result<(), JasonError> {
+            cb.call1(RoomCloseReason::new(CloseReason::ByClient {
+                is_err: true,
+                reason: ClientDisconnect::RpcClientUnexpectedlyDropped,
+            }));
+            Ok(())
+        }
+
+        pub fn on_local_track(
+            &self,
+            cb: platform::Function<LocalMediaTrack>,
+        ) -> Result<(), JasonError> {
+            cb.call1(LocalMediaTrack);
+            Ok(())
+        }
+
+        pub fn on_connection_loss(
+            &self,
+            cb: platform::Function<ReconnectHandle>,
+        ) -> Result<(), JasonError> {
+            cb.call1(ReconnectHandle);
+            Ok(())
+        }
+
+        // pub async fn join(&self, token: String) -> Result<(), JasonError>
+        // pub fn on_failed_local_media(
+        //     &self,
+        //     f: Callback<JasonError>,
+        // ) -> Result<(), JasonError> {
+        // }
+        // pub async fn set_local_media_settings(&self,
+        // settings: &MediaStreamSettings, stop_first: bool, rollback_on_fail:
+        // bool) -> Result<(), ConstraintsUpdateException> pub async fn
+        // mute_audio(&self) -> Result<(), JasonError> pub async fn
+        // unmute_audio(&self) -> Result<(), JasonError> pub async fn
+        // mute_video(&self, source_kind: Option<MediaSourceKind>) -> Result<(),
+        // JasonError> pub async fn unmute_video(&self, source_kind:
+        // Option<MediaSourceKind>) -> Result<(), JasonError> pub async fn
+        // disable_audio(&self) -> Result<(), JasonError> pub async fn
+        // enable_audio(&self) -> Result<(), JasonError> pub async fn
+        // disable_video(&self, source_kind: Option<MediaSourceKind>) ->
+        // Result<(), JasonError> pub async fn
+        // enable_video(&self,source_kind: Option<MediaSourceKind>) ->
+        // Result<(), JasonError> pub async fn disable_remote_audio(&
+        // self) -> Result<(), JasonError> pub async fn
+        // disable_remote_video(&self) -> Result<(), JasonError> pub async fn
+        // enable_remote_audio(&self) -> Result<(), JasonError> pub async fn
+        // enable_remote_video(&self) -> Result<(), JasonError>
+    }
+}
diff --git a/jason/jason-dummy/src/unimplemented.rs b/jason/src/api/dart/unimplemented.rs
similarity index 100%
rename from jason/jason-dummy/src/unimplemented.rs
rename to jason/src/api/dart/unimplemented.rs
diff --git a/jason/jason-dummy/src/utils/arrays.rs b/jason/src/api/dart/utils/arrays.rs
similarity index 98%
rename from jason/jason-dummy/src/utils/arrays.rs
rename to jason/src/api/dart/utils/arrays.rs
index 51246b0ef..d864304d0 100644
--- a/jason/jason-dummy/src/utils/arrays.rs
+++ b/jason/src/api/dart/utils/arrays.rs
@@ -2,7 +2,7 @@
 
 use std::{ffi::c_void, marker::PhantomData, slice};
 
-use crate::ForeignClass;
+use crate::api::ForeignClass;
 
 /// Array of pointers to [`ForeignClass`] structs.
 ///
diff --git a/jason/jason-dummy/src/utils/mod.rs b/jason/src/api/dart/utils/mod.rs
similarity index 69%
rename from jason/jason-dummy/src/utils/mod.rs
rename to jason/src/api/dart/utils/mod.rs
index fee318f0c..a340ca232 100644
--- a/jason/jason-dummy/src/utils/mod.rs
+++ b/jason/src/api/dart/utils/mod.rs
@@ -1,10 +1,7 @@
 mod arrays;
-mod closure;
-mod dart_api;
 mod string;
 
 pub use self::{
     arrays::PtrArray,
-    closure::DartClosure,
     string::{c_str_into_string, string_into_c_str},
 };
diff --git a/jason/src/api/dart/utils/string.rs b/jason/src/api/dart/utils/string.rs
new file mode 100644
index 000000000..c292bac84
--- /dev/null
+++ b/jason/src/api/dart/utils/string.rs
@@ -0,0 +1,47 @@
+//! Helper functionality for passing [`String`]s through FFI boundaries.
+
+use std::{
+    ffi::{CStr, CString},
+    os::raw::c_char,
+};
+
+/// Constructs a Rust [`String`] from the provided raw C string.
+///
+/// # Panics
+///
+/// If the provided C string UTF-8 validation fails.
+///
+/// # Safety
+///
+/// Same as for [`CStr::from_ptr()`].
+#[inline]
+#[must_use]
+pub unsafe fn c_str_into_string(string: *const c_char) -> String {
+    CStr::from_ptr(string).to_str().unwrap().to_owned()
+}
+
+/// Leaks the given [`String`] returning a raw C string that can be passed
+/// through FFI boundaries.
+///
+/// The pointer (returned by this function) must be returned to Rust and
+/// reconstituted via [`CString::from_raw()`] for proper deallocating.
+///
+/// # Panics
+///
+/// If the provided [`String`] contains an internal `0x0` byte.
+#[inline]
+#[must_use]
+pub fn string_into_c_str(string: String) -> *const c_char {
+    CString::new(string).unwrap().into_raw()
+}
+
+/// Retakes ownership over a [`CString`] previously transferred to Dart via
+/// [`CString::into_raw()`].
+///
+/// # Safety
+///
+/// Same as for [`CString::from_raw()`].
+#[no_mangle]
+pub unsafe extern "C" fn String_free(s: *mut c_char) {
+    CString::from_raw(s);
+}
diff --git a/jason/src/api/mod.rs b/jason/src/api/mod.rs
index bed53b2c7..7a8d3b5dc 100644
--- a/jason/src/api/mod.rs
+++ b/jason/src/api/mod.rs
@@ -1,88 +1,11 @@
 //! External [`Jason`] API.
 
-pub mod wasm;
-
-use crate::media;
-
-pub use self::wasm::{
-    connection_handle::ConnectionHandle,
-    constraints_update_exception::ConstraintsUpdateException,
-    input_device_info::InputDeviceInfo,
-    jason::Jason,
-    jason_error::JasonError,
-    local_media_track::LocalMediaTrack,
-    media_manager_handle::MediaManagerHandle,
-    media_stream_settings::{
-        AudioTrackConstraints, DeviceVideoTrackConstraints,
-        DisplayVideoTrackConstraints, MediaStreamSettings,
-    },
-    reconnect_handle::ReconnectHandle,
-    remote_media_track::RemoteMediaTrack,
-    room_close_reason::RoomCloseReason,
-    room_handle::RoomHandle,
-    FacingMode, MediaKind, MediaSourceKind,
-};
-
-impl From<media::MediaKind> for MediaKind {
-    #[inline]
-    fn from(that: media::MediaKind) -> Self {
-        match that {
-            media::MediaKind::Audio => Self::Audio,
-            media::MediaKind::Video => Self::Video,
-        }
-    }
-}
-
-impl From<MediaKind> for media::MediaKind {
-    #[inline]
-    fn from(that: MediaKind) -> Self {
-        match that {
-            MediaKind::Audio => Self::Audio,
-            MediaKind::Video => Self::Video,
-        }
-    }
-}
-
-impl From<media::MediaSourceKind> for MediaSourceKind {
-    #[inline]
-    fn from(that: media::MediaSourceKind) -> Self {
-        match that {
-            media::MediaSourceKind::Device => Self::Device,
-            media::MediaSourceKind::Display => Self::Display,
-        }
-    }
-}
-
-impl From<MediaSourceKind> for media::MediaSourceKind {
-    #[inline]
-    fn from(that: MediaSourceKind) -> Self {
-        match that {
-            MediaSourceKind::Device => Self::Device,
-            MediaSourceKind::Display => Self::Display,
-        }
-    }
-}
-
-impl From<media::FacingMode> for FacingMode {
-    #[inline]
-    fn from(that: media::FacingMode) -> Self {
-        match that {
-            media::FacingMode::User => Self::User,
-            media::FacingMode::Environment => Self::Environment,
-            media::FacingMode::Left => Self::Left,
-            media::FacingMode::Right => Self::Right,
-        }
-    }
-}
-
-impl From<FacingMode> for media::FacingMode {
-    #[inline]
-    fn from(val: FacingMode) -> Self {
-        match val {
-            FacingMode::User => Self::User,
-            FacingMode::Environment => Self::Environment,
-            FacingMode::Left => Self::Left,
-            FacingMode::Right => Self::Right,
-        }
+cfg_if::cfg_if! {
+    if #[cfg(target_os = "android")] {
+        mod dart;
+        pub use self::dart::*;
+    } else {
+        mod wasm;
+        pub use self::wasm::*;
     }
 }
diff --git a/jason/src/api/wasm/mod.rs b/jason/src/api/wasm/mod.rs
index 3867a498a..d3c2f72bd 100644
--- a/jason/src/api/wasm/mod.rs
+++ b/jason/src/api/wasm/mod.rs
@@ -19,7 +19,25 @@ pub mod room_handle;
 use derive_more::Display;
 use wasm_bindgen::prelude::*;
 
-pub use self::jason_error::JasonError;
+use crate::media;
+
+pub use self::{
+    connection_handle::ConnectionHandle,
+    constraints_update_exception::ConstraintsUpdateException,
+    input_device_info::InputDeviceInfo,
+    jason::Jason,
+    jason_error::JasonError,
+    local_media_track::LocalMediaTrack,
+    media_manager_handle::MediaManagerHandle,
+    media_stream_settings::{
+        AudioTrackConstraints, DeviceVideoTrackConstraints,
+        DisplayVideoTrackConstraints, MediaStreamSettings,
+    },
+    reconnect_handle::ReconnectHandle,
+    remote_media_track::RemoteMediaTrack,
+    room_close_reason::RoomCloseReason,
+    room_handle::RoomHandle,
+};
 
 /// [MediaStreamTrack.kind][1] representation.
 ///
@@ -64,3 +82,67 @@ pub enum FacingMode {
     /// Facing to the right of a user.
     Right,
 }
+
+impl From<media::MediaKind> for MediaKind {
+    #[inline]
+    fn from(that: media::MediaKind) -> Self {
+        match that {
+            media::MediaKind::Audio => Self::Audio,
+            media::MediaKind::Video => Self::Video,
+        }
+    }
+}
+
+impl From<MediaKind> for media::MediaKind {
+    #[inline]
+    fn from(that: MediaKind) -> Self {
+        match that {
+            MediaKind::Audio => Self::Audio,
+            MediaKind::Video => Self::Video,
+        }
+    }
+}
+
+impl From<media::MediaSourceKind> for MediaSourceKind {
+    #[inline]
+    fn from(that: media::MediaSourceKind) -> Self {
+        match that {
+            media::MediaSourceKind::Device => Self::Device,
+            media::MediaSourceKind::Display => Self::Display,
+        }
+    }
+}
+
+impl From<MediaSourceKind> for media::MediaSourceKind {
+    #[inline]
+    fn from(that: MediaSourceKind) -> Self {
+        match that {
+            MediaSourceKind::Device => Self::Device,
+            MediaSourceKind::Display => Self::Display,
+        }
+    }
+}
+
+impl From<media::FacingMode> for FacingMode {
+    #[inline]
+    fn from(that: media::FacingMode) -> Self {
+        match that {
+            media::FacingMode::User => Self::User,
+            media::FacingMode::Environment => Self::Environment,
+            media::FacingMode::Left => Self::Left,
+            media::FacingMode::Right => Self::Right,
+        }
+    }
+}
+
+impl From<FacingMode> for media::FacingMode {
+    #[inline]
+    fn from(val: FacingMode) -> Self {
+        match val {
+            FacingMode::User => Self::User,
+            FacingMode::Environment => Self::Environment,
+            FacingMode::Left => Self::Left,
+            FacingMode::Right => Self::Right,
+        }
+    }
+}
diff --git a/jason/src/api/wasm/room_handle.rs b/jason/src/api/wasm/room_handle.rs
index 76cd2069d..1dc7678c2 100644
--- a/jason/src/api/wasm/room_handle.rs
+++ b/jason/src/api/wasm/room_handle.rs
@@ -84,7 +84,7 @@ impl RoomHandle {
     ///
     /// This might happen in such cases:
     /// 1. Media server initiates a media request.
-    /// 2. `disable_audio`/`enable_video` is called.
+    /// 2. `enable_audio`/`enable_video` is called.
     /// 3. [`MediaStreamSettings`] is updated via `set_local_media_settings`.
     ///
     /// [`Room`]: room::Room
diff --git a/jason/src/connection.rs b/jason/src/connection.rs
index 2568c1d16..76568201e 100644
--- a/jason/src/connection.rs
+++ b/jason/src/connection.rs
@@ -148,8 +148,8 @@ impl ConnectionHandle {
             .map(|inner| inner.remote_id.0.clone())
     }
 
-    /// Sets callback, invoked when a new [`remote::Track`] will is added to
-    /// this [`Connection`].
+    /// Sets callback, invoked when a new [`remote::Track`] is added to this
+    /// [`Connection`].
     ///
     /// # Errors
     ///
diff --git a/jason/src/media/manager.rs b/jason/src/media/manager.rs
index 9ae49903d..fd166214f 100644
--- a/jason/src/media/manager.rs
+++ b/jason/src/media/manager.rs
@@ -322,8 +322,8 @@ pub struct MediaManagerHandle(Weak<InnerMediaManager>);
 #[allow(clippy::unused_self)]
 impl MediaManagerHandle {
     /// Returns a list of [`platform::InputDeviceInfo`] objects representing
-    /// available media input and output devices, such as microphones, cameras,
-    /// and so forth.
+    /// available media input and devices, such as microphones, cameras, and so
+    /// forth.
     ///
     /// # Errors
     ///
diff --git a/jason/src/peer/media/mod.rs b/jason/src/peer/media/mod.rs
index 694bd6927..82b4df6da 100644
--- a/jason/src/peer/media/mod.rs
+++ b/jason/src/peer/media/mod.rs
@@ -370,7 +370,7 @@ impl InnerMediaConnections {
         kind: MediaKind,
         direction: platform::TransceiverDirection,
     ) -> platform::Transceiver {
-        platform::Transceiver::from(self.peer.add_transceiver(kind, direction))
+        self.peer.add_transceiver(kind, direction)
     }
 
     /// Lookups a [`platform::Transceiver`] by the provided [`mid`].
@@ -380,9 +380,7 @@ impl InnerMediaConnections {
         &self,
         mid: &str,
     ) -> Option<platform::Transceiver> {
-        self.peer
-            .get_transceiver_by_mid(mid)
-            .map(platform::Transceiver::from)
+        self.peer.get_transceiver_by_mid(mid)
     }
 }
 
@@ -394,6 +392,7 @@ impl MediaConnections {
     /// Instantiates a new [`MediaConnections`] storage for the given
     /// [`platform::RtcPeerConnection`].
     #[inline]
+    #[must_use]
     pub fn new(
         peer: Rc<platform::RtcPeerConnection>,
         peer_events_sender: mpsc::UnboundedSender<PeerEvent>,
@@ -708,7 +707,7 @@ impl MediaConnections {
         {
             if let Some(mid) = receiver.mid() {
                 if let Some(trnscvr) = inner.peer.get_transceiver_by_mid(&mid) {
-                    receiver.replace_transceiver(trnscvr.into())
+                    receiver.replace_transceiver(trnscvr)
                 }
             }
         }
diff --git a/jason/src/peer/media/sender/mod.rs b/jason/src/peer/media/sender/mod.rs
index 29474b9cb..6525d0163 100644
--- a/jason/src/peer/media/sender/mod.rs
+++ b/jason/src/peer/media/sender/mod.rs
@@ -6,7 +6,6 @@ use std::{cell::Cell, rc::Rc};
 
 use futures::channel::mpsc;
 use medea_client_api_proto::TrackId;
-use wasm_bindgen_futures::spawn_local;
 
 use crate::{
     media::{
@@ -177,7 +176,6 @@ impl Sender {
         self.transceiver
             .set_send_track(Rc::new(new_track))
             .await
-            .map_err(Into::into)
             .map_err(MediaConnectionsError::CouldNotInsertLocalTrack)
             .map_err(tracerr::wrap!())?;
 
@@ -270,7 +268,7 @@ impl Drop for Sender {
         if !self.transceiver.is_stopped() {
             self.transceiver
                 .sub_direction(platform::TransceiverDirection::SEND);
-            spawn_local(self.transceiver.drop_send_track());
+            platform::spawn(self.transceiver.drop_send_track());
         }
     }
 }
diff --git a/jason/jason-dummy/src/dart_api_dl/README.md b/jason/src/platform/dart/api_dl/README.md
similarity index 100%
rename from jason/jason-dummy/src/dart_api_dl/README.md
rename to jason/src/platform/dart/api_dl/README.md
diff --git a/jason/jason-dummy/src/dart_api_dl/include/bin/dart_io_api.h b/jason/src/platform/dart/api_dl/include/bin/dart_io_api.h
similarity index 100%
rename from jason/jason-dummy/src/dart_api_dl/include/bin/dart_io_api.h
rename to jason/src/platform/dart/api_dl/include/bin/dart_io_api.h
diff --git a/jason/jason-dummy/src/dart_api_dl/include/dart_api.h b/jason/src/platform/dart/api_dl/include/dart_api.h
similarity index 100%
rename from jason/jason-dummy/src/dart_api_dl/include/dart_api.h
rename to jason/src/platform/dart/api_dl/include/dart_api.h
diff --git a/jason/jason-dummy/src/dart_api_dl/include/dart_api_dl.c b/jason/src/platform/dart/api_dl/include/dart_api_dl.c
similarity index 100%
rename from jason/jason-dummy/src/dart_api_dl/include/dart_api_dl.c
rename to jason/src/platform/dart/api_dl/include/dart_api_dl.c
diff --git a/jason/jason-dummy/src/dart_api_dl/include/dart_api_dl.h b/jason/src/platform/dart/api_dl/include/dart_api_dl.h
similarity index 100%
rename from jason/jason-dummy/src/dart_api_dl/include/dart_api_dl.h
rename to jason/src/platform/dart/api_dl/include/dart_api_dl.h
diff --git a/jason/jason-dummy/src/dart_api_dl/include/dart_embedder_api.h b/jason/src/platform/dart/api_dl/include/dart_embedder_api.h
similarity index 100%
rename from jason/jason-dummy/src/dart_api_dl/include/dart_embedder_api.h
rename to jason/src/platform/dart/api_dl/include/dart_embedder_api.h
diff --git a/jason/jason-dummy/src/dart_api_dl/include/dart_native_api.h b/jason/src/platform/dart/api_dl/include/dart_native_api.h
similarity index 100%
rename from jason/jason-dummy/src/dart_api_dl/include/dart_native_api.h
rename to jason/src/platform/dart/api_dl/include/dart_native_api.h
diff --git a/jason/jason-dummy/src/dart_api_dl/include/dart_tools_api.h b/jason/src/platform/dart/api_dl/include/dart_tools_api.h
similarity index 100%
rename from jason/jason-dummy/src/dart_api_dl/include/dart_tools_api.h
rename to jason/src/platform/dart/api_dl/include/dart_tools_api.h
diff --git a/jason/jason-dummy/src/dart_api_dl/include/dart_version.h b/jason/src/platform/dart/api_dl/include/dart_version.h
similarity index 100%
rename from jason/jason-dummy/src/dart_api_dl/include/dart_version.h
rename to jason/src/platform/dart/api_dl/include/dart_version.h
diff --git a/jason/jason-dummy/src/dart_api_dl/include/internal/dart_api_dl_impl.h b/jason/src/platform/dart/api_dl/include/internal/dart_api_dl_impl.h
similarity index 100%
rename from jason/jason-dummy/src/dart_api_dl/include/internal/dart_api_dl_impl.h
rename to jason/src/platform/dart/api_dl/include/internal/dart_api_dl_impl.h
diff --git a/jason/jason-dummy/src/dart_api_dl/trampoline.c b/jason/src/platform/dart/api_dl/trampoline.c
similarity index 100%
rename from jason/jason-dummy/src/dart_api_dl/trampoline.c
rename to jason/src/platform/dart/api_dl/trampoline.c
diff --git a/jason/src/platform/dart/constraints.rs b/jason/src/platform/dart/constraints.rs
new file mode 100644
index 000000000..cbf7cf9cb
--- /dev/null
+++ b/jason/src/platform/dart/constraints.rs
@@ -0,0 +1,78 @@
+//! Media tracks and streams constraints functionality.
+
+use derive_more::{AsRef, Into};
+
+use crate::media::{
+    AudioTrackConstraints, DeviceVideoTrackConstraints,
+    DisplayVideoTrackConstraints,
+};
+
+/// [MediaStreamConstraints][1] wrapper.
+///
+/// [1]: https://w3.org/TR/mediacapture-streams/#dom-mediastreamconstraints
+#[derive(AsRef, Debug, Into)]
+pub struct MediaStreamConstraints;
+
+impl MediaStreamConstraints {
+    /// Creates a new [`MediaStreamConstraints`] with none constraints
+    /// configured.
+    #[inline]
+    #[must_use]
+    pub fn new() -> Self {
+        unimplemented!()
+    }
+
+    /// Specifies the nature and settings of the `audio` [MediaStreamTrack][1].
+    ///
+    /// [1]: https://w3.org/TR/mediacapture-streams/#mediastreamtrack
+    #[inline]
+    pub fn audio(&mut self, audio: AudioTrackConstraints) {
+        unimplemented!()
+    }
+
+    /// Specifies the nature and settings of the `video` [MediaStreamTrack][1].
+    ///
+    /// [1]: https://w3.org/TR/mediacapture-streams/#mediastreamtrack
+    #[inline]
+    pub fn video(&mut self, video: DeviceVideoTrackConstraints) {
+        unimplemented!()
+    }
+}
+
+impl Default for MediaStreamConstraints {
+    #[inline]
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+/// [DisplayMediaStreamConstraints][1] wrapper.
+///
+/// [1]: https://w3.org/TR/screen-capture/#dom-displaymediastreamconstraints
+#[derive(AsRef, Debug, Into)]
+pub struct DisplayMediaStreamConstraints();
+
+impl Default for DisplayMediaStreamConstraints {
+    #[inline]
+    fn default() -> Self {
+        unimplemented!()
+    }
+}
+
+impl DisplayMediaStreamConstraints {
+    /// Creates a new [`DisplayMediaStreamConstraints`] with none constraints
+    /// configured.
+    #[inline]
+    #[must_use]
+    pub fn new() -> Self {
+        unimplemented!()
+    }
+
+    /// Specifies the nature and settings of the `video` [MediaStreamTrack][1].
+    ///
+    /// [1]: https://w3.org/TR/mediacapture-streams/#mediastreamtrack
+    #[inline]
+    pub fn video(&mut self, video: DisplayVideoTrackConstraints) {
+        unimplemented!()
+    }
+}
diff --git a/jason/src/platform/dart/error.rs b/jason/src/platform/dart/error.rs
new file mode 100644
index 000000000..9cf0fffc7
--- /dev/null
+++ b/jason/src/platform/dart/error.rs
@@ -0,0 +1,7 @@
+//! Wrapper for Dart exceptions.
+
+use derive_more::Display;
+
+/// Wrapper for Dart exception thrown when calling Dart code.
+#[derive(Clone, Debug, Display, PartialEq)]
+pub struct Error;
diff --git a/jason/src/platform/dart/ice_server.rs b/jason/src/platform/dart/ice_server.rs
new file mode 100644
index 000000000..81288b7d4
--- /dev/null
+++ b/jason/src/platform/dart/ice_server.rs
@@ -0,0 +1,20 @@
+//! Collection of [`RtcIceServer`][1]s.
+//!
+//! [1]: https://w3.org/TR/webrtc/#rtciceserver-dictionary
+
+use medea_client_api_proto::IceServer;
+
+/// Collection of [RTCIceServer][1]s.
+///
+/// [1]: https://w3.org/TR/webrtc/#rtciceserver-dictionary
+#[derive(Debug)]
+pub struct RtcIceServers;
+
+impl<I> From<I> for RtcIceServers
+where
+    I: IntoIterator<Item = IceServer>,
+{
+    fn from(servers: I) -> Self {
+        unimplemented!()
+    }
+}
diff --git a/jason/src/platform/dart/input_device_info.rs b/jason/src/platform/dart/input_device_info.rs
new file mode 100644
index 000000000..a0b459bef
--- /dev/null
+++ b/jason/src/platform/dart/input_device_info.rs
@@ -0,0 +1,65 @@
+//! [MediaDeviceInfo][1] related objects.
+//!
+//! [1]: https://w3.org/TR/mediacapture-streams/#device-info
+
+use derive_more::Display;
+
+use crate::media::MediaKind;
+
+/// Errors that may occur when parsing [MediaDeviceInfo][1].
+///
+/// [1]: https://w3.org/TR/mediacapture-streams/#device-info
+#[derive(Debug, Display)]
+pub enum Error {
+    /// Occurs when kind of media device is not an input device.
+    #[display(fmt = "Not an input device")]
+    NotInputDevice,
+}
+
+/// Representation of [MediaDeviceInfo][1].
+///
+/// [1]: https://w3.org/TR/mediacapture-streams/#device-info
+pub struct InputDeviceInfo;
+
+impl InputDeviceInfo {
+    /// Returns unique identifier for the represented device.
+    #[inline]
+    #[must_use]
+    pub fn device_id(&self) -> String {
+        unimplemented!()
+    }
+
+    /// Returns kind of the represented device.
+    ///
+    /// This representation of [MediaDeviceInfo][1] ONLY for input device.
+    ///
+    /// [1]: https://w3.org/TR/mediacapture-streams/#device-info
+    #[inline]
+    #[must_use]
+    pub fn kind(&self) -> MediaKind {
+        unimplemented!()
+    }
+
+    /// Returns label describing the represented device (for example
+    /// "External USB Webcam").
+    /// If the device has no associated label, then returns an empty string.
+    #[inline]
+    #[must_use]
+    pub fn label(&self) -> String {
+        unimplemented!()
+    }
+
+    /// Returns group identifier of the represented device.
+    ///
+    /// Two devices have the same group identifier if they belong to the same
+    /// physical device. For example, the audio input and output devices
+    /// representing the speaker and microphone of the same headset have the
+    /// same [groupId][1].
+    ///
+    /// [1]: https://w3.org/TR/mediacapture-streams/#dom-mediadeviceinfo-groupid
+    #[inline]
+    #[must_use]
+    pub fn group_id(&self) -> String {
+        unimplemented!()
+    }
+}
diff --git a/jason/src/platform/dart/media_devices.rs b/jason/src/platform/dart/media_devices.rs
new file mode 100644
index 000000000..c4546c0fc
--- /dev/null
+++ b/jason/src/platform/dart/media_devices.rs
@@ -0,0 +1,75 @@
+//! [MediaDevices][1] functionality.
+//!
+//! [1]: https://w3.org/TR/mediacapture-streams#mediadevices
+
+use tracerr::Traced;
+
+use crate::{
+    media::MediaManagerError,
+    platform::{
+        DisplayMediaStreamConstraints, InputDeviceInfo, MediaStreamConstraints,
+        MediaStreamTrack,
+    },
+};
+
+/// Collects information about the User Agent's available media input devices.
+///
+/// Adapter for a [MediaDevices.enumerateDevices()][1] function.
+///
+/// # Errors
+///
+/// With [`MediaManagerError::CouldNotGetMediaDevices`] if couldn't get
+/// [MediaDevices][2].
+///
+/// With [`MediaManagerError::EnumerateDevicesFailed`] if
+/// [MediaDevices.enumerateDevices()][1] returns error.
+///
+/// [1]: https://tinyurl.com/w3-streams#dom-mediadevices-enumeratedevices
+/// [2]: https://w3.org/TR/mediacapture-streams#mediadevices
+pub async fn enumerate_devices(
+) -> Result<Vec<InputDeviceInfo>, Traced<MediaManagerError>> {
+    unimplemented!()
+}
+
+/// Prompts a user for a permission to use a media input which produces vector
+/// of [`MediaStreamTrack`]s containing the requested types of media.
+///
+/// Adapter for a [MediaDevices.getUserMedia()][1] function.
+///
+/// # Errors
+///
+/// With [`MediaManagerError::CouldNotGetMediaDevices`] if couldn't get
+/// [MediaDevices][2].
+///
+/// With [`MediaManagerError::GetUserMediaFailed`] if
+/// [MediaDevices.getUserMedia()][1] returns error.
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#dom-mediadevices-getusermedia
+/// [2]: https://w3.org/TR/mediacapture-streams#mediadevices
+pub async fn get_user_media(
+    caps: MediaStreamConstraints,
+) -> Result<Vec<MediaStreamTrack>, Traced<MediaManagerError>> {
+    unimplemented!()
+}
+
+/// Prompts a user to select and grant a permission to capture contents of a
+/// display or portion thereof (such as a single window) as vector of
+/// [`MediaStreamTrack`].
+///
+/// Adapter for a [MediaDevices.getDisplayMedia()][1] function.
+///
+/// # Errors
+///
+/// With [`MediaManagerError::CouldNotGetMediaDevices`] if couldn't get
+/// [MediaDevices][2].
+///
+/// With [`MediaManagerError::GetUserMediaFailed`] if
+/// [MediaDevices.getDisplayMedia()][1] returns error.
+///
+/// [1]: https://w3.org/TR/screen-capture/#dom-mediadevices-getdisplaymedia
+/// [2]: https://w3.org/TR/mediacapture-streams#mediadevices
+pub async fn get_display_media(
+    caps: DisplayMediaStreamConstraints,
+) -> Result<Vec<MediaStreamTrack>, Traced<MediaManagerError>> {
+    unimplemented!()
+}
diff --git a/jason/src/platform/dart/media_track.rs b/jason/src/platform/dart/media_track.rs
new file mode 100644
index 000000000..7c2d15087
--- /dev/null
+++ b/jason/src/platform/dart/media_track.rs
@@ -0,0 +1,150 @@
+//! Wrapper around [MediaStreamTrack][1].
+//!
+//! [1]: https://w3.org/TR/mediacapture-streams#mediastreamtrack
+
+use derive_more::AsRef;
+
+use crate::media::{track::MediaStreamTrackState, FacingMode, MediaKind};
+
+/// Wrapper around [MediaStreamTrack][1] received from a
+/// [getUserMedia()][2]/[getDisplayMedia()][3] request.
+///
+/// [1]: https://w3.org/TR/mediacapture-streams#mediastreamtrack
+/// [2]: https://w3.org/TR/mediacapture-streams#dom-mediadevices-getusermedia
+/// [3]: https://w3.org/TR/screen-capture/#dom-mediadevices-getdisplaymedia
+#[derive(AsRef, Debug)]
+pub struct MediaStreamTrack;
+
+impl MediaStreamTrack {
+    /// Returns [`id`] of the underlying [MediaStreamTrack][2].
+    ///
+    /// [`id`]: https://w3.org/TR/mediacapture-streams#dom-mediastreamtrack-id
+    /// [2]: https://w3.org/TR/mediacapture-streams#mediastreamtrack
+    #[inline]
+    #[must_use]
+    pub fn id(&self) -> String {
+        unimplemented!()
+    }
+
+    /// Returns this [`MediaStreamTrack`]'s kind (audio/video).
+    #[inline]
+    #[must_use]
+    pub fn kind(&self) -> MediaKind {
+        unimplemented!()
+    }
+
+    /// Returns [MediaStreamTrackState][1] of the underlying
+    /// [MediaStreamTrack][2].
+    ///
+    /// [1]: https://w3.org/TR/mediacapture-streams#dom-mediastreamtrackstate
+    /// [2]: https://w3.org/TR/mediacapture-streams#mediastreamtrack
+    #[must_use]
+    pub fn ready_state(&self) -> MediaStreamTrackState {
+        unimplemented!()
+    }
+
+    /// Returns a [`deviceId`][1] of the underlying [MediaStreamTrack][2].
+    ///
+    /// [1]: https://tinyurl.com/w3-streams#dom-mediatracksettings-deviceid
+    /// [2]: https://w3.org/TR/mediacapture-streams#mediastreamtrack
+    #[inline]
+    #[must_use]
+    pub fn device_id(&self) -> Option<String> {
+        unimplemented!()
+    }
+
+    /// Return a [`facingMode`][1] of the underlying [MediaStreamTrack][2].
+    ///
+    /// [1]: https://tinyurl.com/w3-streams#dom-mediatracksettings-facingmode
+    /// [2]: https://w3.org/TR/mediacapture-streams#mediastreamtrack
+    #[must_use]
+    pub fn facing_mode(&self) -> Option<FacingMode> {
+        unimplemented!()
+    }
+
+    /// Returns a [`height`][1] of the underlying [MediaStreamTrack][2].
+    ///
+    /// [1]: https://tinyurl.com/w3-streams#dom-mediatracksettings-height
+    /// [2]: https://w3.org/TR/mediacapture-streams#mediastreamtrack
+    #[inline]
+    #[must_use]
+    pub fn height(&self) -> Option<u32> {
+        unimplemented!()
+    }
+
+    /// Return a [`width`][1] of the underlying [MediaStreamTrack][2].
+    ///
+    /// [1]: https://w3.org/TR/mediacapture-streams#dom-mediatracksettings-width
+    /// [2]: https://w3.org/TR/mediacapture-streams#mediastreamtrack
+    #[inline]
+    #[must_use]
+    pub fn width(&self) -> Option<u32> {
+        unimplemented!()
+    }
+
+    /// Changes an [`enabled`][1] attribute in the underlying
+    /// [MediaStreamTrack][2].
+    ///
+    /// [1]: https://w3.org/TR/mediacapture-streams#dom-mediastreamtrack-enabled
+    /// [2]: https://w3.org/TR/mediacapture-streams#mediastreamtrack
+    #[inline]
+    pub fn set_enabled(&self, enabled: bool) {
+        unimplemented!()
+    }
+
+    /// Changes a [`readyState`][1] attribute in the underlying
+    /// [MediaStreamTrack][2] to [`ended`][3].
+    ///
+    /// [1]: https://tinyurl.com/w3-streams#dom-mediastreamtrack-readystate
+    /// [2]: https://w3.org/TR/mediacapture-streams#mediastreamtrack
+    /// [3]: https://tinyurl.com/w3-streams#idl-def-MediaStreamTrackState.ended
+    #[inline]
+    pub fn stop(&self) {
+        unimplemented!()
+    }
+
+    /// Returns an [`enabled`][1] attribute of the underlying
+    /// [MediaStreamTrack][2].
+    ///
+    /// [1]: https://w3.org/TR/mediacapture-streams#dom-mediastreamtrack-enabled
+    /// [2]: https://w3.org/TR/mediacapture-streams#mediastreamtrack
+    #[inline]
+    #[must_use]
+    pub fn enabled(&self) -> bool {
+        unimplemented!()
+    }
+
+    /// Detects whether a video track captured from display searching
+    /// [specific fields][1] in its settings.
+    ///
+    /// Only works in Chrome browser at the moment.
+    ///
+    /// [1]: https://w3.org/TR/screen-capture/#extensions-to-mediatracksettings
+    #[must_use]
+    pub fn guess_is_from_display(&self) -> bool {
+        unimplemented!()
+    }
+
+    /// Forks this [`MediaStreamTrack`].
+    ///
+    /// Creates a new [`MediaStreamTrack`] from this [`MediaStreamTrack`] using
+    /// a [`clone()`][1] method. It won't clone current [`MediaStreamTrack`]'s
+    /// callbacks.
+    ///
+    /// [1]: https://w3.org/TR/mediacapture-streams#dom-mediastreamtrack-clone
+    #[must_use]
+    pub fn fork(&self) -> Self {
+        unimplemented!()
+    }
+
+    /// Sets handler for the [`ended`][1] event.
+    ///
+    /// [1]: https://tinyurl.com/w3-streams#event-mediastreamtrack-ended
+    #[allow(clippy::unused_self, clippy::needless_pass_by_value)]
+    pub fn on_ended<F>(&self, f: Option<F>)
+    where
+        F: 'static + FnOnce(),
+    {
+        unimplemented!()
+    }
+}
diff --git a/jason/src/platform/dart/mod.rs b/jason/src/platform/dart/mod.rs
new file mode 100644
index 000000000..317c51dac
--- /dev/null
+++ b/jason/src/platform/dart/mod.rs
@@ -0,0 +1,67 @@
+//! Multiplatform Dart runtime specific functionality.
+
+// TODO: Remove allows when implementing platform code.
+#![allow(
+    unused_variables,
+    clippy::missing_panics_doc,
+    clippy::unused_self,
+    clippy::needless_pass_by_value
+)]
+
+pub mod constraints;
+pub mod error;
+pub mod ice_server;
+pub mod input_device_info;
+pub mod media_devices;
+pub mod media_track;
+pub mod peer_connection;
+pub mod rtc_stats;
+pub mod transceiver;
+pub mod transport;
+pub mod utils;
+
+use std::time::Duration;
+
+use futures::Future;
+
+pub use self::{
+    constraints::{DisplayMediaStreamConstraints, MediaStreamConstraints},
+    error::Error,
+    input_device_info::InputDeviceInfo,
+    media_devices::{enumerate_devices, get_display_media, get_user_media},
+    media_track::MediaStreamTrack,
+    peer_connection::RtcPeerConnection,
+    rtc_stats::RtcStats,
+    transceiver::{Transceiver, TransceiverDirection},
+    transport::WebSocketRpcTransport,
+    utils::{Callback, Function},
+};
+
+/// TODO: Implement panic hook.
+pub fn set_panic_hook() {}
+
+/// Initialize [`android_logger`] as default application logger with min log
+/// level set to [`log::Level::Debug`].
+///
+/// [`android_logger`]: https://docs.rs/android_logger
+pub fn init_logger() {
+    android_logger::init_once(
+        android_logger::Config::default().with_min_level(log::Level::Debug),
+    );
+}
+
+/// Runs a Rust [`Future`] on the current thread.
+#[inline]
+pub fn spawn<F>(task: F)
+where
+    F: Future<Output = ()> + 'static,
+{
+    unimplemented!()
+}
+
+/// [`Future`] which resolves after the provided [`Duration`].
+///
+/// [`Future`]: std::future::Future
+pub async fn delay_for(delay: Duration) {
+    unimplemented!()
+}
diff --git a/jason/src/platform/dart/peer_connection.rs b/jason/src/platform/dart/peer_connection.rs
new file mode 100644
index 000000000..f173e89ec
--- /dev/null
+++ b/jason/src/platform/dart/peer_connection.rs
@@ -0,0 +1,256 @@
+//! Wrapper around [RTCPeerConnection][1].
+//!
+//! [1]: https://w3.org/TR/webrtc/#dom-rtcpeerconnection
+
+use medea_client_api_proto::{
+    IceConnectionState, IceServer, PeerConnectionState,
+};
+use tracerr::Traced;
+
+use crate::{
+    media::{MediaKind, TrackConstraints},
+    platform::{
+        IceCandidate, MediaStreamTrack, RtcPeerConnectionError, RtcStats,
+        SdpType, Transceiver, TransceiverDirection,
+    },
+};
+
+impl From<&TrackConstraints> for MediaKind {
+    fn from(media_type: &TrackConstraints) -> Self {
+        match media_type {
+            TrackConstraints::Audio(_) => Self::Audio,
+            TrackConstraints::Video(_) => Self::Video,
+        }
+    }
+}
+
+type Result<T> = std::result::Result<T, Traced<RtcPeerConnectionError>>;
+
+/// Representation of [RTCPeerConnection][1].
+///
+/// [1]: https://w3.org/TR/webrtc/#dom-rtcpeerconnection
+pub struct RtcPeerConnection;
+
+impl RtcPeerConnection {
+    /// Instantiates new [`RtcPeerConnection`].
+    ///
+    /// # Errors
+    ///
+    /// Errors with [`RtcPeerConnectionError::PeerCreationError`] if
+    /// [`RtcPeerConnection`] creation fails.
+    pub fn new<I>(ice_servers: I, is_force_relayed: bool) -> Result<Self>
+    where
+        I: IntoIterator<Item = IceServer>,
+    {
+        unimplemented!()
+    }
+
+    /// Returns [`RtcStats`] of this [`RtcPeerConnection`].
+    ///
+    /// # Errors
+    ///
+    /// Errors with [`RtcPeerConnectionError::RtcStatsError`] if getting or
+    /// parsing of [`RtcStats`] fails.
+    ///
+    /// Errors with [`RtcPeerConnectionError::GetStatsException`] when
+    /// [PeerConnection.getStats][1] promise throws exception.
+    ///
+    /// [1]: https://tinyurl.com/w6hmt5f
+    pub async fn get_stats(&self) -> Result<RtcStats> {
+        unimplemented!()
+    }
+
+    /// Sets handler for a [RTCTrackEvent][1] (see [`ontrack` callback][2]).
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#rtctrackevent
+    /// [2]: https://w3.org/TR/webrtc/#dom-rtcpeerconnection-ontrack
+    pub fn on_track<F>(&self, f: Option<F>)
+    where
+        F: 'static + FnMut(MediaStreamTrack, Transceiver),
+    {
+        unimplemented!()
+    }
+
+    /// Sets handler for a [RTCPeerConnectionIceEvent][1] (see
+    /// [`onicecandidate` callback][2]).
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#dom-rtcpeerconnectioniceevent
+    /// [2]: https://w3.org/TR/webrtc/#dom-rtcpeerconnection-onicecandidate
+    pub fn on_ice_candidate<F>(&self, f: Option<F>)
+    where
+        F: 'static + FnMut(IceCandidate),
+    {
+        unimplemented!()
+    }
+
+    /// Returns [`IceConnectionState`] of this [`RtcPeerConnection`].
+    #[inline]
+    #[must_use]
+    pub fn ice_connection_state(&self) -> IceConnectionState {
+        unimplemented!()
+    }
+
+    /// Returns [`PeerConnectionState`] of this [`RtcPeerConnection`].
+    ///
+    /// Returns [`None`] if failed to parse a [`PeerConnectionState`].
+    #[inline]
+    #[must_use]
+    pub fn connection_state(&self) -> Option<PeerConnectionState> {
+        unimplemented!()
+    }
+
+    /// Sets handler for an [`iceconnectionstatechange`][1] event.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#event-iceconnectionstatechange
+    pub fn on_ice_connection_state_change<F>(&self, f: Option<F>)
+    where
+        F: 'static + FnMut(IceConnectionState),
+    {
+        unimplemented!()
+    }
+
+    /// Sets handler for a [`connectionstatechange`][1] event.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#event-connectionstatechange
+    pub fn on_connection_state_change<F>(&self, f: Option<F>)
+    where
+        F: 'static + FnMut(PeerConnectionState),
+    {
+        unimplemented!()
+    }
+
+    /// Adds remote [RTCPeerConnection][1]'s [ICE candidate][2] to this
+    /// [`RtcPeerConnection`].
+    ///
+    /// # Errors
+    ///
+    /// With [`RtcPeerConnectionError::AddIceCandidateFailed`] if
+    /// [RtcPeerConnection.addIceCandidate()][3] fails.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#rtcpeerconnection-interface
+    /// [2]: https://tools.ietf.org/html/rfc5245#section-2
+    /// [3]: https://w3.org/TR/webrtc/#dom-peerconnection-addicecandidate
+    pub async fn add_ice_candidate(
+        &self,
+        candidate: &str,
+        sdp_m_line_index: Option<u16>,
+        sdp_mid: &Option<String>,
+    ) -> Result<()> {
+        unimplemented!()
+    }
+
+    /// Marks [`RtcPeerConnection`] to trigger ICE restart.
+    ///
+    /// After this function returns, the offer returned by the next call to
+    /// [`RtcPeerConnection::create_offer`] is automatically configured
+    /// to trigger ICE restart.
+    #[inline]
+    pub fn restart_ice(&self) {
+        unimplemented!()
+    }
+
+    /// Sets provided [SDP offer][`SdpType::Offer`] as local description.
+    ///
+    /// # Errors
+    ///
+    /// With [`RtcPeerConnectionError::SetLocalDescriptionFailed`] if
+    /// [RtcPeerConnection.setLocalDescription()][1] fails.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#dom-peerconnection-setlocaldescription
+    pub async fn set_offer(&self, offer: &str) -> Result<()> {
+        unimplemented!()
+    }
+
+    /// Sets provided [SDP answer][`SdpType::Answer`] as local description.
+    ///
+    /// # Errors
+    ///
+    /// With [`RtcPeerConnectionError::SetLocalDescriptionFailed`] if
+    /// [RtcPeerConnection.setLocalDescription()][1] fails.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#dom-peerconnection-setlocaldescription
+    pub async fn set_answer(&self, answer: &str) -> Result<()> {
+        unimplemented!()
+    }
+
+    /// Obtains [SDP answer][`SdpType::Answer`] from the [`RtcPeerConnection`].
+    ///
+    /// Should be called whenever remote description has been changed.
+    ///
+    /// # Errors
+    ///
+    /// With [`RtcPeerConnectionError::CreateAnswerFailed`] if
+    /// [RtcPeerConnection.createAnswer()][1] fails.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#dom-rtcpeerconnection-createanswer
+    pub async fn create_answer(&self) -> Result<String> {
+        unimplemented!()
+    }
+
+    /// Rollbacks the [`RtcPeerConnection`] to the previous stable state.
+    ///
+    /// # Errors
+    ///
+    /// With [`RtcPeerConnectionError::SetLocalDescriptionFailed`] if
+    /// [RtcPeerConnection.setLocalDescription()][1] fails.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#dom-peerconnection-setlocaldescription
+    pub async fn rollback(&self) -> Result<()> {
+        unimplemented!()
+    }
+
+    /// Obtains [SDP offer][`SdpType::Offer`] from the [`RtcPeerConnection`].
+    ///
+    /// Should be called after local tracks changes, which require
+    /// (re)negotiation.
+    ///
+    /// # Errors
+    ///
+    /// With [`RtcPeerConnectionError::CreateOfferFailed`] if
+    /// [RtcPeerConnection.createOffer()][1] fails.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#dom-rtcpeerconnection-createoffer
+    pub async fn create_offer(&self) -> Result<String> {
+        unimplemented!()
+    }
+
+    /// Instructs the [`RtcPeerConnection`] to apply the supplied
+    /// [SDP][`SdpType`] as the remote [offer][`SdpType::Offer`] or
+    /// [answer][`SdpType::Answer`].
+    ///
+    /// Changes the local media state.
+    ///
+    /// # Errors
+    ///
+    /// With [`RtcPeerConnectionError::SetRemoteDescriptionFailed`] if
+    /// [RTCPeerConnection.setRemoteDescription()][1] fails.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#dom-peerconnection-setremotedescription
+    pub async fn set_remote_description(&self, sdp: SdpType) -> Result<()> {
+        unimplemented!()
+    }
+
+    /// Creates a new [`Transceiver`] (see [RTCRtpTransceiver][1]) and adds it
+    /// to the [set of this RTCPeerConnection's transceivers][2].
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#dom-rtcrtptransceiver
+    /// [2]: https://w3.org/TR/webrtc/#transceivers-set
+    #[must_use]
+    pub fn add_transceiver(
+        &self,
+        kind: MediaKind,
+        direction: TransceiverDirection,
+    ) -> Transceiver {
+        unimplemented!()
+    }
+
+    /// Returns [`Transceiver`] (see [RTCRtpTransceiver][1]) from a
+    /// [set of this RTCPeerConnection's transceivers][2] by provided `mid`.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#dom-rtcrtptransceiver
+    /// [2]: https://w3.org/TR/webrtc/#transceivers-set
+    #[must_use]
+    pub fn get_transceiver_by_mid(&self, mid: &str) -> Option<Transceiver> {
+        unimplemented!()
+    }
+}
diff --git a/jason/src/platform/dart/rtc_stats.rs b/jason/src/platform/dart/rtc_stats.rs
new file mode 100644
index 000000000..da3459f4c
--- /dev/null
+++ b/jason/src/platform/dart/rtc_stats.rs
@@ -0,0 +1,10 @@
+//! Deserialization of [`RtcStats`].
+
+use medea_client_api_proto::stats::RtcStat;
+
+/// All available [`RtcStatsType`]s of a [`RtcPeerConnection`].
+///
+/// [`RtcStatsType`]: medea_client_api_proto::stats::RtcStatsType
+/// [`RtcPeerConnection`]: crate::platform::RtcPeerConnection
+#[derive(Clone, Debug)]
+pub struct RtcStats(pub Vec<RtcStat>);
diff --git a/jason/src/platform/dart/transceiver.rs b/jason/src/platform/dart/transceiver.rs
new file mode 100644
index 000000000..0fcd5073b
--- /dev/null
+++ b/jason/src/platform/dart/transceiver.rs
@@ -0,0 +1,127 @@
+//! [RTCRtpTransceiver] wrapper.
+//!
+//! [RTCRtpTransceiver]: https://w3.org/TR/webrtc/#dom-rtcrtptransceiver
+
+use std::rc::Rc;
+
+use bitflags::bitflags;
+use futures::future::LocalBoxFuture;
+
+use crate::{media::track::local, platform::Error};
+
+/// Wrapper around [RTCRtpTransceiver] which provides handy methods for
+/// direction changes.
+///
+/// [RTCRtpTransceiver]: https://w3.org/TR/webrtc/#dom-rtcrtptransceiver
+#[derive(Clone)]
+pub struct Transceiver;
+
+impl Transceiver {
+    /// Disables provided [`TransceiverDirection`] of this [`Transceiver`].
+    #[inline]
+    pub fn sub_direction(&self, disabled_direction: TransceiverDirection) {
+        unimplemented!()
+    }
+
+    /// Enables provided [`TransceiverDirection`] of this [`Transceiver`].
+    #[inline]
+    pub fn add_direction(&self, enabled_direction: TransceiverDirection) {
+        unimplemented!()
+    }
+
+    /// Indicates whether the provided [`TransceiverDirection`] is enabled for
+    /// this [`Transceiver`].
+    #[inline]
+    #[must_use]
+    pub fn has_direction(&self, direction: TransceiverDirection) -> bool {
+        unimplemented!()
+    }
+
+    /// Replaces [`TransceiverDirection::SEND`] [`local::Track`] of this
+    /// [`Transceiver`].
+    ///
+    /// # Errors
+    ///
+    /// Errors with [`Error`] if the underlying [`replaceTrack`][1] call fails.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#dom-rtcrtpsender-replacetrack
+    pub async fn set_send_track(
+        &self,
+        new_track: Rc<local::Track>,
+    ) -> Result<(), Error> {
+        unimplemented!()
+    }
+
+    /// Sets a [`TransceiverDirection::SEND`] [`local::Track`] of this
+    /// [`Transceiver`] to [`None`].
+    #[must_use]
+    pub fn drop_send_track(&self) -> LocalBoxFuture<'static, ()> {
+        unimplemented!()
+    }
+
+    /// Returns [`mid`] of this [`Transceiver`].
+    ///
+    /// [`mid`]: https://w3.org/TR/webrtc/#dom-rtptransceiver-mid
+    #[inline]
+    #[must_use]
+    pub fn mid(&self) -> Option<String> {
+        unimplemented!()
+    }
+
+    /// Returns [`local::Track`] that is being send to remote, if any.
+    #[inline]
+    #[must_use]
+    pub fn send_track(&self) -> Option<Rc<local::Track>> {
+        unimplemented!()
+    }
+
+    /// Indicates whether this [`Transceiver`] has [`local::Track`].
+    #[inline]
+    #[must_use]
+    pub fn has_send_track(&self) -> bool {
+        unimplemented!()
+    }
+
+    /// Sets the underlying [`local::Track`]'s `enabled` field to the provided
+    /// value, if any.
+    #[inline]
+    pub fn set_send_track_enabled(&self, enabled: bool) {
+        unimplemented!()
+    }
+
+    /// Indicates whether the underlying [RTCRtpTransceiver] is stopped.
+    ///
+    /// [RTCRtpTransceiver]: https://w3.org/TR/webrtc/#dom-rtcrtptransceiver
+    #[inline]
+    #[must_use]
+    pub fn is_stopped(&self) -> bool {
+        unimplemented!()
+    }
+}
+
+// TODO: Probably should be shared between `wasm` and `dart` platforms.
+bitflags! {
+    /// Representation of [RTCRtpTransceiverDirection][1].
+    ///
+    /// [`sendrecv` direction][2] is represented by a
+    /// [`TransceiverDirection::all`] bitflag.
+    ///
+    /// [1]: https://w3.org/TR/webrtc/#dom-rtcrtptransceiverdirection
+    /// [2]: https://w3.org/TR/webrtc/#dom-rtcrtptransceiverdirection-sendrecv
+    pub struct TransceiverDirection: u8 {
+        /// [`inactive` direction][1] of transceiver.
+        ///
+        /// [1]: https://tinyurl.com/y2zslyw2
+        const INACTIVE = 0b00;
+
+        /// [`sendonly` direction][1] of transceiver.
+        ///
+        /// [1]: https://tinyurl.com/y6y2ye97
+        const SEND = 0b01;
+
+        /// [`recvonly` direction][1] of transceiver.
+        ///
+        /// [1]: https://tinyurl.com/y2nlxpzf
+        const RECV = 0b10;
+    }
+}
diff --git a/jason/src/platform/dart/transport.rs b/jason/src/platform/dart/transport.rs
new file mode 100644
index 000000000..92c031092
--- /dev/null
+++ b/jason/src/platform/dart/transport.rs
@@ -0,0 +1,68 @@
+//! [WebSocket] transport wrapper.
+//!
+//! [WebSocket]: https://developer.mozilla.org/docs/WebSockets
+
+use futures::stream::LocalBoxStream;
+use medea_client_api_proto::{ClientMsg, ServerMsg};
+use tracerr::Traced;
+
+use crate::{
+    platform::transport::{RpcTransport, TransportError, TransportState},
+    rpc::{websocket::ClientDisconnect, ApiUrl},
+};
+
+type Result<T, E = Traced<TransportError>> = std::result::Result<T, E>;
+
+/// [WebSocket] [`RpcTransport`] between a client and a server.
+///
+/// # Drop
+///
+/// This structure has __cyclic references__, which are freed in its [`Drop`]
+/// implementation.
+///
+/// If you're adding new cyclic dependencies, then don't forget to drop them in
+/// the [`Drop`].
+///
+/// [WebSocket]: https://developer.mozilla.org/docs/WebSockets
+pub struct WebSocketRpcTransport;
+
+impl WebSocketRpcTransport {
+    /// Initiates a new [WebSocket] connection. Resolves only once an underlying
+    /// connection becomes active.
+    ///
+    /// # Errors
+    ///
+    /// With [`TransportError::CreateSocket`] if cannot establish [WebSocket] to
+    /// specified URL.
+    ///
+    /// With [`TransportError::InitSocket`] if [WebSocket.onclose][1] callback
+    /// fired before [WebSocket.onopen][2] callback.
+    ///
+    /// [WebSocket]: https://developer.mozilla.org/docs/WebSockets
+    /// [1]: https://developer.mozilla.org/docs/Web/API/WebSocket/onclose
+    /// [2]: https://developer.mozilla.org/docs/Web/API/WebSocket/onopen
+    pub async fn new(url: ApiUrl) -> Result<Self> {
+        unimplemented!()
+    }
+}
+
+impl RpcTransport for WebSocketRpcTransport {
+    #[inline]
+    fn on_message(&self) -> LocalBoxStream<'static, ServerMsg> {
+        unimplemented!()
+    }
+
+    #[inline]
+    fn set_close_reason(&self, close_reason: ClientDisconnect) {
+        unimplemented!()
+    }
+
+    fn send(&self, msg: &ClientMsg) -> Result<()> {
+        unimplemented!()
+    }
+
+    #[inline]
+    fn on_state_change(&self) -> LocalBoxStream<'static, TransportState> {
+        unimplemented!()
+    }
+}
diff --git a/jason/jason-dummy/src/utils/closure.rs b/jason/src/platform/dart/utils/callback.rs
similarity index 70%
rename from jason/jason-dummy/src/utils/closure.rs
rename to jason/src/platform/dart/utils/callback.rs
index fbfa4a65e..512a72a76 100644
--- a/jason/jason-dummy/src/utils/closure.rs
+++ b/jason/src/platform/dart/utils/callback.rs
@@ -10,11 +10,11 @@
 //! initialization phase: after Dart DL API is initialized and before any other
 //! exported Rust function is called.
 
-use std::{ffi::c_void, marker::PhantomData};
+use std::{cell::RefCell, ffi::c_void, marker::PhantomData};
 
 use dart_sys::{Dart_Handle, Dart_PersistentHandle};
 
-use crate::ForeignClass;
+use crate::api::ForeignClass;
 
 use super::dart_api::{
     Dart_DeletePersistentHandle_DL_Trampolined,
@@ -76,47 +76,95 @@ pub unsafe extern "C" fn register_int_arg_fn_caller(f: IntArgFnCaller) {
     INT_ARG_FN_CALLER = Some(f);
 }
 
+// TODO: Probably should be shared between `wasm` and `dart` platforms.
+/// Wrapper for a single argument Dart callback function.
+pub struct Callback<A>(RefCell<Option<Function<A>>>);
+
+impl<A> Callback<A> {
+    /// Sets the inner [`Function`].
+    #[inline]
+    pub fn set_func(&self, f: Function<A>) {
+        self.0.borrow_mut().replace(f);
+    }
+
+    /// Indicates whether this [`Callback`]'s inner [`Function`] is set.
+    #[inline]
+    #[must_use]
+    pub fn is_set(&self) -> bool {
+        self.0.borrow().as_ref().is_some()
+    }
+}
+
+impl Callback<()> {
+    /// Invokes the underlying [`Function`] (if any) passing no arguments to it.
+    #[inline]
+    pub fn call0(&self) {
+        if let Some(f) = self.0.borrow().as_ref() {
+            f.call0()
+        };
+    }
+}
+
+impl<A> Default for Callback<A> {
+    #[inline]
+    fn default() -> Self {
+        Self(RefCell::new(None))
+    }
+}
+
+impl<A> Callback<A> {
+    /// Invokes the underlying [`Function`] (if any) passing the single provided
+    /// argument to it.
+    #[inline]
+    pub fn call1<T>(&self, arg: T) {
+        unimplemented!()
+    }
+}
+
 // TODO: Print exception if Dart closure throws.
 /// Dart closure that can be called from Rust.
-pub struct DartClosure<T> {
+pub struct Function<T> {
     /// [`Dart_PersistentHandle`] to the Dart closure that should be called.
-    cb: Dart_PersistentHandle,
+    dart_fn: Dart_PersistentHandle,
 
     /// Type of this closure argument.
     _arg: PhantomData<T>,
 }
 
-impl<T> DartClosure<T> {
-    /// Creates a new [`DartClosure`] from the provided [`Dart_Handle`] to a
-    /// Dart closure, and persists the provided [`Dart_Handle`] so it won't be
-    /// moved by the Dart VM GC.
+impl<T> Function<T> {
+    /// Creates a new [`Function`] from the provided [`Dart_Handle`] to a Dart
+    /// closure, and persists the provided [`Dart_Handle`] so it won't be moved
+    /// by the Dart VM GC.
     #[inline]
+    #[must_use]
     pub fn new(cb: Dart_Handle) -> Self {
         Self {
-            cb: unsafe { Dart_NewPersistentHandle_DL_Trampolined(cb) },
+            dart_fn: unsafe { Dart_NewPersistentHandle_DL_Trampolined(cb) },
             _arg: PhantomData,
         }
     }
 }
 
-impl DartClosure<()> {
+impl Function<()> {
     /// Calls the underlying Dart closure.
     #[inline]
     pub fn call0(&self) {
         unsafe {
-            let fn_handle = Dart_HandleFromPersistent_DL_Trampolined(self.cb);
+            let fn_handle =
+                Dart_HandleFromPersistent_DL_Trampolined(self.dart_fn);
             NO_ARGS_FN_CALLER.unwrap()(fn_handle);
         }
     }
 }
 
-impl<T: ForeignClass> DartClosure<T> {
+impl<T: ForeignClass> Function<T> {
     /// Calls the underlying Dart closure with the provided [`ForeignClass`]
     /// argument.
     #[inline]
     pub fn call1(&self, arg: T) {
         unsafe {
-            let fn_handle = Dart_HandleFromPersistent_DL_Trampolined(self.cb);
+            let fn_handle =
+                Dart_HandleFromPersistent_DL_Trampolined(self.dart_fn);
             PTR_ARG_FN_CALLER.unwrap()(
                 fn_handle,
                 arg.into_ptr().cast::<c_void>(),
@@ -129,12 +177,12 @@ impl<T: ForeignClass> DartClosure<T> {
 /// called for all integer types that fit into `2^63`.
 macro_rules! impl_dart_closure_for_int {
     ($arg:ty) => {
-        impl DartClosure<$arg> {
+        impl Function<$arg> {
             /// Calls the underlying Dart closure with the provided argument.
             pub fn call1(&self, arg: $arg) {
                 unsafe {
                     let fn_handle =
-                        Dart_HandleFromPersistent_DL_Trampolined(self.cb);
+                        Dart_HandleFromPersistent_DL_Trampolined(self.dart_fn);
                     INT_ARG_FN_CALLER.unwrap()(fn_handle, arg as i64);
                 }
             }
@@ -152,9 +200,9 @@ impl_dart_closure_for_int!(u16);
 impl_dart_closure_for_int!(u32);
 impl_dart_closure_for_int!(bool);
 
-impl<T> Drop for DartClosure<T> {
+impl<T> Drop for Function<T> {
     /// Manually deallocates saved [`Dart_PersistentHandle`] so it won't leak.
     fn drop(&mut self) {
-        unsafe { Dart_DeletePersistentHandle_DL_Trampolined(self.cb) };
+        unsafe { Dart_DeletePersistentHandle_DL_Trampolined(self.dart_fn) };
     }
 }
diff --git a/jason/jason-dummy/src/utils/dart_api.rs b/jason/src/platform/dart/utils/dart_api.rs
similarity index 90%
rename from jason/jason-dummy/src/utils/dart_api.rs
rename to jason/src/platform/dart/utils/dart_api.rs
index cf43fb141..4ddec3a1e 100644
--- a/jason/jason-dummy/src/utils/dart_api.rs
+++ b/jason/src/platform/dart/utils/dart_api.rs
@@ -2,6 +2,8 @@
 //!
 //! [`Dart DL API`]: https://tinyurl.com/32e7fudh
 
+use std::ffi::c_void;
+
 use dart_sys::{Dart_Handle, Dart_PersistentHandle};
 
 #[link(name = "trampoline")]
@@ -11,7 +13,7 @@ extern "C" {
     /// code. Must be called before calling any other Dart API method.
     ///
     /// [1]: https://api.dart.dev/dart-ffi/NativeApi/initializeApiDLData.html
-    pub fn Dart_InitializeApiDL(obj: *mut libc::c_void) -> libc::intptr_t;
+    pub fn Dart_InitializeApiDL(obj: *mut c_void) -> libc::intptr_t;
 
     /// Allocates a [`Dart_PersistentHandle`] for provided [`Dart_Handle`].
     ///
@@ -44,8 +46,6 @@ extern "C" {
 ///
 /// [1]: https://api.dart.dev/dart-ffi/NativeApi/initializeApiDLData.html
 #[no_mangle]
-pub unsafe extern "C" fn init_dart_api_dl(
-    obj: *mut libc::c_void,
-) -> libc::intptr_t {
+pub unsafe extern "C" fn init_dart_api_dl(obj: *mut c_void) -> libc::intptr_t {
     Dart_InitializeApiDL(obj)
 }
diff --git a/jason/src/platform/dart/utils/event_listener.rs b/jason/src/platform/dart/utils/event_listener.rs
new file mode 100644
index 000000000..e3ffe9652
--- /dev/null
+++ b/jason/src/platform/dart/utils/event_listener.rs
@@ -0,0 +1,52 @@
+use std::{marker::PhantomData, rc::Rc};
+
+use derive_more::{Display, From};
+use tracerr::Traced;
+
+use crate::{platform, utils::JsCaused};
+
+/// Failure to bind a listener to some event.
+#[derive(Clone, Debug, Display, From, JsCaused, PartialEq)]
+#[js(error = "platform::Error")]
+pub struct EventListenerBindError(platform::Error);
+
+/// Wrapper for the closure that handles some event.
+#[derive(Debug)]
+pub struct EventListener<T, A> {
+    t: PhantomData<T>,
+    a: PhantomData<A>,
+}
+
+impl<T, A> EventListener<T, A> {
+    /// Creates a new [`EventListener`] from the given [`FnMut`] `closure`.
+    ///
+    /// # Errors
+    ///
+    /// Errors if [`EventListener`] bound fails.
+    pub fn new_mut<F>(
+        target: Rc<T>,
+        event_name: &'static str,
+        closure: F,
+    ) -> Result<Self, Traced<EventListenerBindError>>
+    where
+        F: FnMut(A) + 'static,
+    {
+        unimplemented!()
+    }
+
+    /// Creates a new [`EventListener`] from the given [`FnOnce`] `closure`.
+    ///
+    /// # Errors
+    ///
+    /// Errors if [`EventListener`] bound fails.
+    pub fn new_once<F>(
+        target: Rc<T>,
+        event_name: &'static str,
+        closure: F,
+    ) -> Result<Self, Traced<EventListenerBindError>>
+    where
+        F: FnOnce(A) + 'static,
+    {
+        unimplemented!()
+    }
+}
diff --git a/jason/src/platform/dart/utils/mod.rs b/jason/src/platform/dart/utils/mod.rs
new file mode 100644
index 000000000..9598e0293
--- /dev/null
+++ b/jason/src/platform/dart/utils/mod.rs
@@ -0,0 +1,11 @@
+//! Multiplatform Dart runtime specific utility structs and functions.
+
+mod callback;
+pub mod dart_api;
+mod event_listener;
+
+#[doc(inline)]
+pub use self::{
+    callback::{Callback, Function},
+    event_listener::{EventListener, EventListenerBindError},
+};
diff --git a/jason/src/platform/mod.rs b/jason/src/platform/mod.rs
index 3bddbe95e..b0eb61c54 100644
--- a/jason/src/platform/mod.rs
+++ b/jason/src/platform/mod.rs
@@ -3,28 +3,21 @@
 pub mod peer_connection;
 pub mod rtc_stats;
 pub mod transport;
-pub mod wasm;
+
+cfg_if::cfg_if! {
+    if #[cfg(target_os = "android")] {
+        mod dart;
+        pub use self::dart::*;
+    } else {
+        mod wasm;
+        pub use self::wasm::*;
+    }
+}
 
 pub use self::{
     peer_connection::{IceCandidate, RtcPeerConnectionError, SdpType},
     rtc_stats::RtcStatsError,
-    transport::{
-        RpcTransport, TransportError, TransportState, WebSocketRpcTransport,
-    },
-    wasm::{
-        constraints::{DisplayMediaStreamConstraints, MediaStreamConstraints},
-        delay_for,
-        error::Error,
-        get_property_by_name, init_logger,
-        input_device_info::InputDeviceInfo,
-        media_devices::{enumerate_devices, get_display_media, get_user_media},
-        media_track::MediaStreamTrack,
-        peer_connection::RtcPeerConnection,
-        rtc_stats::RtcStats,
-        set_panic_hook, spawn,
-        transceiver::{Transceiver, TransceiverDirection},
-        utils::{Callback, Function},
-    },
+    transport::{RpcTransport, TransportError, TransportState},
 };
 
 #[cfg(feature = "mockable")]
diff --git a/jason/src/platform/transport.rs b/jason/src/platform/transport.rs
index e08229921..e8dd9cee7 100644
--- a/jason/src/platform/transport.rs
+++ b/jason/src/platform/transport.rs
@@ -11,8 +11,6 @@ use crate::{
     utils::{JsCaused, JsonParseError},
 };
 
-pub use super::wasm::transport::WebSocketRpcTransport;
-
 /// Possible states of a [`RpcTransport`].
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum TransportState {
diff --git a/jason/src/platform/wasm/media_track.rs b/jason/src/platform/wasm/media_track.rs
index 3aaad04d4..07b086761 100644
--- a/jason/src/platform/wasm/media_track.rs
+++ b/jason/src/platform/wasm/media_track.rs
@@ -8,7 +8,7 @@ use derive_more::AsRef;
 
 use crate::{
     media::{track::MediaStreamTrackState, FacingMode, MediaKind},
-    platform::{get_property_by_name, wasm::utils::EventListener},
+    platform::wasm::{get_property_by_name, utils::EventListener},
 };
 
 /// Wrapper around [MediaStreamTrack][1] received from a
diff --git a/jason/src/platform/wasm/mod.rs b/jason/src/platform/wasm/mod.rs
index a6b3f2c39..7b30a6816 100644
--- a/jason/src/platform/wasm/mod.rs
+++ b/jason/src/platform/wasm/mod.rs
@@ -1,7 +1,5 @@
 //! `wasm32`-platform-specific functionality.
 
-use std::{convert::TryInto as _, time::Duration};
-
 pub mod constraints;
 pub mod error;
 pub mod ice_server;
@@ -14,24 +12,39 @@ pub mod transceiver;
 pub mod transport;
 pub mod utils;
 
+use std::{convert::TryInto as _, time::Duration};
+
 use futures::Future;
 use js_sys::{Promise, Reflect};
 use wasm_bindgen::JsValue;
 use wasm_bindgen_futures::JsFuture;
 use web_sys::Window;
 
+pub use self::{
+    constraints::{DisplayMediaStreamConstraints, MediaStreamConstraints},
+    error::Error,
+    input_device_info::InputDeviceInfo,
+    media_devices::{enumerate_devices, get_display_media, get_user_media},
+    media_track::MediaStreamTrack,
+    peer_connection::RtcPeerConnection,
+    rtc_stats::RtcStats,
+    transceiver::{Transceiver, TransceiverDirection},
+    transport::WebSocketRpcTransport,
+    utils::{Callback, Function},
+};
+
 // When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
 // allocator.
 #[cfg(feature = "wee_alloc")]
 #[global_allocator]
 static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
 
-// When the `console_error_panic_hook` feature is enabled, we can call the
-// `set_panic_hook` function at least once during initialization, and then
-// we will get better error messages if our code ever panics.
-//
-// For more details see:
-// https://github.com/rustwasm/console_error_panic_hook#readme
+/// When the `console_error_panic_hook` feature is enabled, we can call the
+/// `set_panic_hook` function at least once during initialization, and then
+/// we will get better error messages if our code ever panics.
+///
+/// For more details see:
+/// <https://github.com/rustwasm/console_error_panic_hook#readme>
 #[cfg(feature = "console_error_panic_hook")]
 pub use console_error_panic_hook::set_once as set_panic_hook;
 
diff --git a/jason/src/platform/wasm/peer_connection.rs b/jason/src/platform/wasm/peer_connection.rs
index 63b241edf..7a88d0e06 100644
--- a/jason/src/platform/wasm/peer_connection.rs
+++ b/jason/src/platform/wasm/peer_connection.rs
@@ -24,9 +24,10 @@ use web_sys::{
 use crate::{
     media::{MediaKind, TrackConstraints},
     platform::{
-        self, get_property_by_name, wasm::utils::EventListener, IceCandidate,
-        MediaStreamTrack, RtcPeerConnectionError, RtcStats, SdpType,
-        Transceiver, TransceiverDirection,
+        self,
+        wasm::{get_property_by_name, utils::EventListener},
+        IceCandidate, MediaStreamTrack, RtcPeerConnectionError, RtcStats,
+        SdpType, Transceiver, TransceiverDirection,
     },
 };
 
@@ -577,11 +578,13 @@ impl RtcPeerConnection {
         &self,
         kind: MediaKind,
         direction: TransceiverDirection,
-    ) -> RtcRtpTransceiver {
+    ) -> Transceiver {
         let mut init = RtcRtpTransceiverInit::new();
         init.direction(direction.into());
-        self.peer
-            .add_transceiver_with_str_and_init(kind.as_str(), &init)
+        let transceiver = self
+            .peer
+            .add_transceiver_with_str_and_init(kind.as_str(), &init);
+        Transceiver::from(transceiver)
     }
 
     /// Returns [`RtcRtpTransceiver`] (see [RTCRtpTransceiver][1]) from a
@@ -594,10 +597,7 @@ impl RtcPeerConnection {
     ///
     /// [1]: https://w3.org/TR/webrtc/#dom-rtcrtptransceiver
     /// [2]: https://w3.org/TR/webrtc/#transceivers-set
-    pub fn get_transceiver_by_mid(
-        &self,
-        mid: &str,
-    ) -> Option<RtcRtpTransceiver> {
+    pub fn get_transceiver_by_mid(&self, mid: &str) -> Option<Transceiver> {
         let mut transceiver = None;
 
         let transceivers = js_sys::try_iter(&self.peer.get_transceivers())
@@ -613,7 +613,7 @@ impl RtcPeerConnection {
             }
         }
 
-        transceiver
+        transceiver.map(Transceiver::from)
     }
 }
 
diff --git a/jason/src/platform/wasm/rtc_stats.rs b/jason/src/platform/wasm/rtc_stats.rs
index 2151c92f0..088740fbb 100644
--- a/jason/src/platform/wasm/rtc_stats.rs
+++ b/jason/src/platform/wasm/rtc_stats.rs
@@ -11,7 +11,7 @@ use medea_client_api_proto::stats::{RtcStat, RtcStatsType};
 use tracerr::Traced;
 use wasm_bindgen::{prelude::*, JsCast};
 
-use crate::platform::{self, get_property_by_name, RtcStatsError};
+use crate::platform::{self, wasm::get_property_by_name, RtcStatsError};
 
 /// All available [`RtcStatsType`]s of a [`platform::RtcPeerConnection`].
 #[derive(Clone, Debug)]
diff --git a/jason/src/platform/wasm/transceiver.rs b/jason/src/platform/wasm/transceiver.rs
index b553e90e2..7f99e5956 100644
--- a/jason/src/platform/wasm/transceiver.rs
+++ b/jason/src/platform/wasm/transceiver.rs
@@ -5,11 +5,10 @@ use std::{cell::RefCell, rc::Rc};
 use bitflags::bitflags;
 use futures::future::LocalBoxFuture;
 use medea_client_api_proto::Direction as DirectionProto;
-use wasm_bindgen::JsValue;
 use wasm_bindgen_futures::JsFuture;
 use web_sys::{RtcRtpTransceiver, RtcRtpTransceiverDirection};
 
-use crate::media::track::local;
+use crate::{media::track::local, platform::Error};
 
 /// Wrapper around [`RtcRtpTransceiver`] which provides handy methods for
 /// direction changes.
@@ -62,7 +61,7 @@ impl Transceiver {
     pub async fn set_send_track(
         &self,
         new_track: Rc<local::Track>,
-    ) -> Result<(), JsValue> {
+    ) -> Result<(), Error> {
         let sys_track: &web_sys::MediaStreamTrack =
             (*new_track).as_ref().as_ref();
         JsFuture::from(
diff --git a/jason/src/room.rs b/jason/src/room.rs
index abf80115a..5894567e4 100644
--- a/jason/src/room.rs
+++ b/jason/src/room.rs
@@ -355,7 +355,7 @@ impl RoomHandle {
     ///
     /// This might happen in such cases:
     /// 1. Media server initiates a media request.
-    /// 2. `disable_audio`/`enable_video` is called.
+    /// 2. `enable_audio`/`enable_video` is called.
     /// 3. [`MediaStreamSettings`] updated via `set_local_media_settings`.
     ///
     /// # Errors