From 801f62fa491952254d2926d6eed489b6f8fd4c9e Mon Sep 17 00:00:00 2001
From: Aman Mangal <aman@dgraph.io>
Date: Tue, 23 May 2023 03:31:28 -0400
Subject: [PATCH] feat(graphql): adds @default directive to graphql (#8017)

---
 .../schema/apollo_service_response.graphql    |   5 +
 graphql/e2e/schema/generatedSchema.graphql    |   5 +
 graphql/resolve/add_mutation_test.yaml        | 513 ++++++++++++++++
 graphql/resolve/mutation_rewriter.go          |  15 +
 graphql/resolve/schema.graphql                |  26 +
 graphql/resolve/update_mutation_test.yaml     | 553 ++++++++++++++++++
 graphql/schema/gqlschema.go                   |  23 +-
 graphql/schema/gqlschema_test.yml             | 122 +++-
 graphql/schema/rules.go                       |  82 +++
 .../output/auth-directive.graphql             |   5 +
 .../output/custom-directive.graphql           |   5 +
 .../output/extended-types.graphql             |   5 +
 .../output/generate-directive.graphql         |   5 +
 .../output/single-extended-type.graphql       |   5 +
 .../input/created-updated-directives.graphql  |  13 +
 .../output/apollo-federation.graphql          |   5 +
 .../output/auth-on-interfaces.graphql         |   5 +
 .../schemagen/output/authorization.graphql    |   5 +
 .../output/comments-and-descriptions.graphql  |   5 +
 .../output/created-updated-directives.graphql | 483 +++++++++++++++
 ...custom-dql-query-with-subscription.graphql |   5 +
 .../schemagen/output/custom-mutation.graphql  |   5 +
 .../output/custom-nested-types.graphql        |   5 +
 .../output/custom-query-mixed-types.graphql   |   5 +
 .../custom-query-not-dgraph-type.graphql      |   5 +
 .../custom-query-with-dgraph-type.graphql     |   5 +
 .../schemagen/output/deprecated.graphql       |   5 +
 ...e-on-concrete-type-with-interfaces.graphql |   5 +
 ...-reverse-directive-with-interfaces.graphql |   5 +
 .../output/field-with-id-directive.graphql    |   5 +
 .../field-with-multiple-@id-fields.graphql    |   5 +
 ...erse-predicate-in-dgraph-directive.graphql |   5 +
 .../filter-cleanSchema-all-empty.graphql      |   5 +
 .../filter-cleanSchema-circular.graphql       |   5 +
 ...filter-cleanSchema-custom-mutation.graphql |   5 +
 .../filter-cleanSchema-directLink.graphql     |   5 +
 .../output/generate-directive.graphql         |   5 +
 .../schemagen/output/geo-type.graphql         |   5 +
 ...se-with-interface-having-directive.graphql |   5 +
 .../output/hasInverse-with-interface.graphql  |   5 +
 ...Inverse-with-type-having-directive.graphql |   5 +
 .../schemagen/output/hasInverse.graphql       |   5 +
 .../hasInverse_withSubscription.graphql       |   5 +
 .../schemagen/output/hasfilter.graphql        |   5 +
 .../ignore-unsupported-directive.graphql      |   5 +
 .../output/interface-with-dgraph-pred.graphql |   5 +
 .../interface-with-id-directive.graphql       |   5 +
 .../output/interface-with-no-ids.graphql      |   5 +
 ...interfaces-with-types-and-password.graphql |   5 +
 .../output/interfaces-with-types.graphql      |   5 +
 .../schemagen/output/lambda-directive.graphql |   5 +
 .../schemagen/output/language-tags.graphql    |   6 +
 .../no-id-field-with-searchables.graphql      |   5 +
 .../schemagen/output/no-id-field.graphql      |   5 +
 .../schemagen/output/password-type.graphql    |   5 +
 .../testdata/schemagen/output/random.graphql  |   5 +
 .../output/searchables-references.graphql     |   5 +
 .../schemagen/output/searchables.graphql      |   5 +
 .../output/single-type-with-enum.graphql      |   5 +
 .../schemagen/output/single-type.graphql      |   5 +
 ...ype-implements-multiple-interfaces.graphql |   5 +
 .../schemagen/output/type-reference.graphql   |   5 +
 .../type-with-arguments-on-field.graphql      |   5 +
 ...e-with-custom-field-on-dgraph-type.graphql |   5 +
 ...-with-custom-fields-on-remote-type.graphql |   5 +
 .../output/type-without-orderables.graphql    |   5 +
 .../testdata/schemagen/output/union.graphql   |   5 +
 graphql/schema/wrappers.go                    |  39 +-
 68 files changed, 2154 insertions(+), 6 deletions(-)
 create mode 100644 graphql/schema/testdata/schemagen/input/created-updated-directives.graphql
 create mode 100644 graphql/schema/testdata/schemagen/output/created-updated-directives.graphql

diff --git a/graphql/e2e/schema/apollo_service_response.graphql b/graphql/e2e/schema/apollo_service_response.graphql
index c0383cdeec5..fa8f1a6300e 100644
--- a/graphql/e2e/schema/apollo_service_response.graphql
+++ b/graphql/e2e/schema/apollo_service_response.graphql
@@ -117,6 +117,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -199,6 +203,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @remote on OBJECT | INTERFACE | UNION | INPUT_OBJECT | ENUM
diff --git a/graphql/e2e/schema/generatedSchema.graphql b/graphql/e2e/schema/generatedSchema.graphql
index 6b9c37d5f31..7effc173194 100644
--- a/graphql/e2e/schema/generatedSchema.graphql
+++ b/graphql/e2e/schema/generatedSchema.graphql
@@ -98,6 +98,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -180,6 +184,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/resolve/add_mutation_test.yaml b/graphql/resolve/add_mutation_test.yaml
index 1f85a553e98..5883be087a1 100644
--- a/graphql/resolve/add_mutation_test.yaml
+++ b/graphql/resolve/add_mutation_test.yaml
@@ -5204,3 +5204,516 @@
           "dgraph.type": ["Person"],
           "uid": "_:Person_1"
         }
+
+-
+  name: "2-level add mutation with nullable @id fields "
+  explaination: "bookId in Book and PenName in author are @id and nullable field,
+   we can skip them while doing add mutation. Nested object author doesn't exist, so we
+   add it and link it to book"
+  gqlmutation: |
+    mutation addBook($input: [AddBookInput!]!) {
+      addBook(input: $input, upsert: false) {
+        book {
+          title
+        }
+      }
+    }
+  gqlvariables: |
+    { "input":
+      [
+        {
+          "title": "Sapiens",
+          "ISBN": "B02",
+          "publisher": "penguin",
+          "author": {
+             "name": "Alice",
+             "authorId": "A02"
+          }
+        }
+      ]
+    }
+  dgquery: |-
+    query {
+      Book_1(func: eq(Book.ISBN, "B02")) {
+        uid
+        dgraph.type
+      }
+      Book_2(func: eq(Book.title, "Sapiens")) {
+        uid
+        dgraph.type
+      }
+      author_3(func: eq(author.authorId, "A02")) {
+        uid
+        dgraph.type
+      }
+    }
+  dgmutations:
+    - setjson: |
+        {
+            "Book.title": "Sapiens",
+            "Book.ISBN": "B02",
+            "Book.publisher": "penguin",
+            "dgraph.type": [
+                "Book"
+            ],
+            "Book.author": {
+                "author.authorId":"A02",
+                "author.book": [
+                    {
+                        "uid": "_:Book_2"
+                    }
+                ],
+                "author.name": "Alice",
+                "dgraph.type": [
+                    "author"
+                ],
+                "uid": "_:author_3"
+            },
+            "uid": "_:Book_2"
+        }
+
+-
+  name: "2- level add mutation with upsert and nullable @id fields "
+  explaination: "bookId in @id,penName in author are nullable @id fields and we can skip them.
+  title,ISBN in Book are @id fields,so also added in set Json, because @id fields will also be updated by upserts.
+  Both book and author already exist so we just link new author to book and delete old reference from book to author,
+  if there is any"
+  gqlmutation: |
+    mutation addBook($input: [AddBookInput!]!) {
+      addBook(input: $input, upsert: true) {
+        book {
+          title
+        }
+      }
+    }
+  gqlvariables: |
+    { "input":
+      [
+        {
+          "title": "Sapiens",
+          "ISBN": "B01",
+          "publisher": "penguin",
+          "author": {
+             "name": "Alice",
+             "authorId": "A01"
+          }
+        }
+      ]
+    }
+  dgquery: |-
+    query {
+      Book_1(func: eq(Book.ISBN, "B01")) {
+        uid
+        dgraph.type
+      }
+      Book_2(func: eq(Book.title, "Sapiens")) {
+        uid
+        dgraph.type
+      }
+      author_3(func: eq(author.authorId, "A01")) {
+        uid
+        dgraph.type
+      }
+    }
+  qnametouid: |
+    {
+       "Book_2":"0x11",
+       "author_3": "0x12"
+    }
+  dgquerysec: |-
+    query {
+      Book_2 as Book_2(func: uid(0x11)) @filter(type(Book)) {
+        uid
+      }
+      var(func: uid(Book_2)) {
+        author_4 as Book.author @filter(NOT (uid(0x12)))
+      }
+    }
+  dgmutations:
+    - setjson: |
+        {
+            "Book.ISBN": "B01",
+            "Book.author": {
+                "author.book": [
+                    {
+                        "uid": "uid(Book_2)"
+                    }
+                ],
+                "uid": "0x12"
+            },
+            "Book.publisher": "penguin",
+            "Book.title": "Sapiens",
+            "uid": "uid(Book_2)"
+        }
+      deletejson: |
+        [{
+           "author.book": [
+              {
+                  "uid": "uid(Book_2)"
+              }
+          ],
+          "uid": "uid(author_4)"
+        }]
+      cond: "@if(gt(len(Book_2), 0))"
+
+-
+  name: "add mutation with upsert gives error when multiple nodes are found for existence queries"
+  explaination: "Two different books exist for title and Sapiens @id fields, We can't do upsert mutation "
+  gqlmutation: |
+    mutation addBook($input: [AddBookInput!]!) {
+      addBook(input: $input, upsert: true) {
+        book {
+          title
+        }
+      }
+    }
+  gqlvariables: |
+    { "input":
+      [
+        {
+          "title": "Sapiens",
+          "ISBN": "B01",
+          "publisher": "penguin"
+        }
+      ]
+    }
+  dgquery: |-
+    query {
+      Book_1(func: eq(Book.ISBN, "B01")) {
+        uid
+        dgraph.type
+      }
+      Book_2(func: eq(Book.title, "Sapiens")) {
+        uid
+        dgraph.type
+      }
+    }
+  qnametouid: |
+    {
+       "Book_1":"0x11",
+       "Book_2": "0x12"
+    }
+  error2:
+    {
+      "message": "failed to rewrite mutation payload because multiple nodes found
+       for given xid values, updation not possible"
+    }
+
+-
+  name: "add mutation with upsert at nested level gives error when multiple nodes are found
+   for existence queries"
+  explaination: "Two different author exist for penName and authorId @id fields inside author,
+   We can't link author to both books "
+  gqlmutation: |
+    mutation addBook($input: [AddBookInput!]!) {
+      addBook(input: $input, upsert: true) {
+        book {
+          title
+        }
+      }
+    }
+  gqlvariables: |
+    { "input":
+      [
+        {
+          "title": "Sapiens",
+          "ISBN": "B01",
+          "publisher": "penguin",
+          "author": {
+             "penName": "Alice",
+             "authorId": "A01"
+          }
+        }
+      ]
+    }
+  dgquery: |-
+    query {
+      Book_1(func: eq(Book.ISBN, "B01")) {
+        uid
+        dgraph.type
+      }
+      Book_2(func: eq(Book.title, "Sapiens")) {
+        uid
+        dgraph.type
+      }
+      author_3(func: eq(author.authorId, "A01")) {
+        uid
+        dgraph.type
+      }
+      author_4(func: eq(author.penName, "Alice")) {
+        uid
+        dgraph.type
+      }
+    }
+  qnametouid: |
+    {
+       "author_3":"0x11",
+       "author_4": "0x12"
+    }
+  error2:
+    {
+      "message": "failed to rewrite mutation payload because multiple nodes
+       found for given xid values, updation not possible"
+    }
+
+-
+  name: "No xid present for add mutation with upsert"
+  explaination: "If none of the xid field is given in upsert mutation then there will be no existence queries,
+   and it will behave as simple add mutation,i.e. create new node with all the given fields"
+  gqlmutation: |
+    mutation addBook($input: [AddBookInput!]!) {
+      addBook(input: $input, upsert: true) {
+        book {
+          title
+        }
+      }
+    }
+  gqlvariables: |
+    { "input":
+      [
+        {
+          "publisher": "penguin"
+        }
+      ]
+    }
+  dgmutations:
+    - setjson: |
+        {
+            "Book.publisher": "penguin",
+            "dgraph.type": [
+                    "Book"
+                ],
+             "uid":"_:Book_1"
+        }
+
+-
+  name: "Non-nullable xid should be present in add Mutation for nested field"
+  explaination: "non-nullable @id field id in comment1 type not provided. As no reference is
+   provided for comment, we treat it as new node, and return error for missing xid."
+  gqlmutation: |
+    mutation addPost1($input: [AddPost1Input!]!) {
+      addPost1(input: $input, upsert: false) {
+        post1 {
+          content
+        }
+      }
+    }
+  gqlvariables: |
+    { "input":
+      [
+        {
+          "id": "P01",
+          "content":"Intro to GraphQL",
+          "comments":[{
+             "message":"Nice Intro! Love GraphQl"
+          }]
+        }
+      ]
+    }
+  dgquery: |-
+    query {
+      Post1_1(func: eq(Post1.id, "P01")) {
+        uid
+        dgraph.type
+      }
+    }
+  error2:
+    {
+      "message": "failed to rewrite mutation payload because field id cannot be empty"
+    }
+
+-
+  name: "Add Mutation referencing same XID in different types"
+  gqlmutation: |
+    mutation($input: [AddT1Input!]!) {
+      addT1(input: $input) {
+        t1 {
+          name
+          name1
+          name2
+          link {
+            name
+            name1
+            name3
+          }
+        }
+      }
+    }
+  gqlvariables: |
+    {
+      "input": [
+        {
+          "name": "Bob",
+          "name1": "Bob11",
+          "name2": "Bob2",
+          "link": {
+            "name": "Bob"
+          }
+        }
+      ]
+    }
+  explanation: "As the link and top level object contain the same XID, Bob, this should throw an error"
+  error:
+    {
+      "message":
+        "failed to rewrite mutation payload because using duplicate XID value: Bob for XID: name for two different
+         implementing types of same interfaces: T1 and T2"
+    }
+
+-
+  name: "Add mutation with @default directive"
+  gqlmutation: |
+    mutation($input: [AddBookingInput!]!) {
+      addBooking(input: $input) {
+        booking {
+          name
+          created
+          updated
+        }
+      }
+    }
+  gqlvariables: |
+    {
+      "input": [
+        {
+          "name": "Holiday to Bermuda"
+        }
+      ]
+    }
+  explanation: "As booking has @default fields and is being added, these should be set to the default add value"
+  dgmutations:
+    - setjson: |
+        {
+            "Booking.created": "2000-01-01T00:00:00.00Z",
+            "Booking.active": "false",
+            "Booking.count": "1",
+            "Booking.hotel": "add",
+            "Booking.length": "1.1",
+            "Booking.status": "ACTIVE",
+            "Booking.name": "Holiday to Bermuda",
+            "Booking.updated": "2000-01-01T00:00:00.00Z",
+            "dgraph.type": [
+                    "Booking"
+                ],
+            "uid":"_:Booking_1"
+        }
+
+-
+  name: "Add mutation with @default directive uses provided values"
+  gqlmutation: |
+    mutation($input: [AddBookingInput!]!) {
+      addBooking(input: $input) {
+        booking {
+          name
+          created
+          updated
+        }
+      }
+    }
+  gqlvariables: |
+    {
+      "input": [
+        {
+          "name": "Holiday to Bermuda",
+          "created": "2022-10-12T07:20:50.52Z",
+          "updated": "2023-10-12T07:20:50.52Z",
+          "active": false,
+          "length": 12.3,
+          "status": "INACTIVE",
+          "hotel": "provided"
+        }
+      ]
+    }
+  explanation: "Fields with @default(add) should use input values if provided (note that count is still using default)"
+  dgmutations:
+    - setjson: |
+        {
+            "Booking.name": "Holiday to Bermuda",
+            "Booking.created": "2022-10-12T07:20:50.52Z",
+            "Booking.updated": "2023-10-12T07:20:50.52Z",
+            "Booking.active": false,
+            "Booking.count": "1",
+            "Booking.hotel": "provided",
+            "Booking.length": 12.3,
+            "Booking.status": "INACTIVE",
+            "dgraph.type": [
+                    "Booking"
+                ],
+            "uid":"_:Booking_1"
+        }
+
+-
+  name: "Upsert mutation with @default directives where only one of the nodes exists"
+  explanation: "Booking1 should only have updated timestamp as it exists, Booking2 should have created and updated timestamps"
+  gqlmutation: |
+    mutation addBookingXID($input: [AddBookingXIDInput!]!) {
+      addBookingXID(input: $input, upsert: true) {
+        bookingXID {
+          name
+        }
+      }
+    }
+  gqlvariables: |
+    { "input":
+      [
+        {
+          "id": "Booking1",
+          "name": "Trip to Bermuda"
+        },
+        {
+          "id": "Booking2",
+          "name": "Trip to Antigua"
+        }
+      ]
+    }
+  dgquery: |-
+    query {
+      BookingXID_1(func: eq(BookingXID.id, "Booking1")) {
+        uid
+        dgraph.type
+      }
+      BookingXID_2(func: eq(BookingXID.id, "Booking2")) {
+        uid
+        dgraph.type
+      }
+    }
+  qnametouid: |-
+    {
+      "BookingXID_1": "0x11"
+    }
+  dgquerysec: |-
+    query {
+      BookingXID_1 as BookingXID_1(func: uid(0x11)) @filter(type(BookingXID)) {
+        uid
+      }
+    }
+  dgmutations:
+    - setjson: |
+        {
+          "uid" : "uid(BookingXID_1)",
+          "BookingXID.id": "Booking1",
+          "BookingXID.name": "Trip to Bermuda",
+          "BookingXID.updated": "2000-01-01T00:00:00.00Z",
+          "BookingXID.active": "true",
+          "BookingXID.count": "2",
+          "BookingXID.length": "1.2",
+          "BookingXID.status": "INACTIVE",
+          "BookingXID.hotel": "update"
+        }
+      cond: "@if(gt(len(BookingXID_1), 0))"
+    - setjson: |
+        {
+          "uid": "_:BookingXID_2",
+          "BookingXID.id": "Booking2",
+          "BookingXID.name": "Trip to Antigua",
+          "BookingXID.created": "2000-01-01T00:00:00.00Z",
+          "BookingXID.updated": "2000-01-01T00:00:00.00Z",
+          "BookingXID.active": "false",
+          "BookingXID.count": "1",
+          "BookingXID.length": "1.1",
+          "BookingXID.status": "ACTIVE",
+          "BookingXID.hotel": "add",
+          "dgraph.type": [
+            "BookingXID"
+          ]
+        }
diff --git a/graphql/resolve/mutation_rewriter.go b/graphql/resolve/mutation_rewriter.go
index deb00d61e40..084cb523fbc 100644
--- a/graphql/resolve/mutation_rewriter.go
+++ b/graphql/resolve/mutation_rewriter.go
@@ -1570,6 +1570,8 @@ func rewriteObject(
 		}
 	}
 
+	action := "update"
+
 	// This is not an XID reference. This is also not a UID reference.
 	// This is definitely a new node.
 	// Create new node
@@ -1618,6 +1620,19 @@ func rewriteObject(
 		// "_:Project2" . myUID will store the variable generated to reference this node.
 		newObj["dgraph.type"] = dgraphTypes
 		newObj["uid"] = myUID
+		action = "add"
+	}
+
+	// Now we know whether this is a new node or not, we can set @default(add/update) fields
+	for _, field := range typ.Fields() {
+		var pred = field.DgraphPredicate()
+		if newObj[pred] != nil {
+			continue
+		}
+		var value = field.GetDefaultValue(action)
+		if value != nil {
+			newObj[pred] = value
+		}
 	}
 
 	// Add Inverse Link if necessary
diff --git a/graphql/resolve/schema.graphql b/graphql/resolve/schema.graphql
index fe94fd0cbef..ba1e3347e08 100644
--- a/graphql/resolve/schema.graphql
+++ b/graphql/resolve/schema.graphql
@@ -175,6 +175,32 @@ type Student implements People {
     taughtBy: [Teacher] @hasInverse(field: "teaches")
 }
 
+# For testing default values
+type Booking {
+    id: ID!
+    name: String!
+    created: DateTime! @default(add: {value: "$now"})
+    updated: DateTime! @default(add: {value: "$now"}, update: {value: "$now"})
+    count: Int! @default(add: {value: "1"}, update: {value: "2"})
+    length: Float! @default(add: {value: "1.1"}, update: {value: "1.2"})
+    hotel: String! @default(add: {value: "add"}, update: {value: "update"})
+    active: Boolean! @default(add: {value: "false"}, update: {value: "true"})
+    status: Status! @default(add: {value: "ACTIVE"}, update: {value: "INACTIVE"})
+}
+
+# For testing default values with upserts
+type BookingXID {
+    id: String! @id
+    name: String!
+    created: DateTime! @default(add: {value: "$now"})
+    updated: DateTime! @default(add: {value: "$now"}, update: {value: "$now"})
+    count: Int! @default(add: {value: "1"}, update: {value: "2"})
+    length: Float! @default(add: {value: "1.1"}, update: {value: "1.2"})
+    hotel: String! @default(add: {value: "add"}, update: {value: "update"})
+    active: Boolean! @default(add: {value: "false"}, update: {value: "true"})
+    status: Status! @default(add: {value: "ACTIVE"}, update: {value: "INACTIVE"})
+}
+
 type Comment {
     id: ID!
     author: String!
diff --git a/graphql/resolve/update_mutation_test.yaml b/graphql/resolve/update_mutation_test.yaml
index d4335ceebaa..bf434c04f7f 100644
--- a/graphql/resolve/update_mutation_test.yaml
+++ b/graphql/resolve/update_mutation_test.yaml
@@ -1979,3 +1979,556 @@
           "Author.name": "Alice"
         }
       cond: "@if(gt(len(x), 0))"
+
+-
+  name: "Updating @id field when given values for @id fields doesn't exists"
+  explaination: "We are giving two @id fields title and ISBN in set part of update mutation,
+  and will generate two existence queries for both of them. As none of the @id field is present,we
+  update the values successfully "
+  gqlmutation: |
+    mutation update($patch: UpdateBookInput!) {
+      updateBook(input: $patch) {
+        book {
+          title
+          ISBN
+          publisher
+        }
+      }
+    }
+  gqlvariables: |
+    {
+        "patch": {
+            "filter": {
+                "or": [
+                    {
+                        "title": {
+                            "in": "Sapiens"
+                        }
+                    },
+                    {
+                        "ISBN": {
+                            "in": "2QSAT"
+                        }
+                    }
+                ]
+            },
+            "set": {
+                "title": "History of Humans",
+                "ISBN": "I001",
+                "publisher": "penguin"
+            }
+        }
+    }
+  dgquery: |-
+    query {
+      Book_1(func: eq(Book.ISBN, "I001")) {
+        uid
+        dgraph.type
+      }
+      Book_2(func: eq(Book.title, "History of Humans")) {
+        uid
+        dgraph.type
+      }
+    }
+  dgquerysec: |-
+    query {
+      x as updateBook(func: type(Book)) @filter((eq(Book.title, "Sapiens") OR eq(Book.ISBN, "2QSAT"))) {
+        uid
+      }
+    }
+  dgmutations:
+    - setjson: |
+        { "uid" : "uid(x)",
+          "Book.ISBN": "I001",
+          "Book.publisher": "penguin",
+          "Book.title": "History of Humans"
+        }
+      cond: "@if(gt(len(x), 0))"
+-
+  name: "Updating @id field when given value for @id fields exist in some node"
+  explaination: "We are giving two @id fields title and ISBN in set part of update mutation,
+  and will generate two existence queries for both of them.As we already have node with title
+   Sapiens, we will return error in this case "
+  gqlmutation: |
+    mutation update($patch: UpdateBookInput!) {
+      updateBook(input: $patch) {
+        book {
+          title
+          ISBN
+          publisher
+        }
+      }
+    }
+  gqlvariables: |
+    {
+        "patch": {
+            "filter": {
+                "or": [
+                    {
+                        "title": {
+                            "in": "Sapiens"
+                        }
+                    },
+                    {
+                        "ISBN": {
+                            "in": "2QSAT"
+                        }
+                    }
+                ]
+            },
+            "set": {
+                "title": "History of Humans",
+                "ISBN": "I001",
+                "publisher": "penguin"
+            }
+        }
+    }
+  dgquery: |-
+    query {
+      Book_1(func: eq(Book.ISBN, "I001")) {
+        uid
+        dgraph.type
+      }
+      Book_2(func: eq(Book.title, "History of Humans")) {
+        uid
+        dgraph.type
+      }
+    }
+  qnametouid: |-
+    {
+      "Book_2": "0x123"
+    }
+  error2:
+    { "message":
+        "failed to rewrite mutation payload because id History of Humans already exists for field title inside type Book"
+    }
+
+-
+  name: "skipping nullable @id values while Updating link to non-existent nested object"
+  explaination: "when we update link to nested field, we check if that node already exists or not,
+   In this case nested object doesn't exists and update mutation create it and link it to root object.
+   while creating nested object it skip @id nullable fields which don't exists in nested object, in this case
+     it skips commentId in nested type Comment1"
+  gqlmutation: |
+    mutation update($patch: UpdatePost1Input!) {
+      updatePost1(input: $patch) {
+        post1 {
+          id
+        }
+      }
+    }
+  gqlvariables: |
+    {
+        "patch": {
+            "filter": {
+                "id": {
+                    "in": "P02"
+                }
+            },
+            "set": {
+                "id": "P01",
+                "content": "intro to graphql",
+                "comments": {
+                    "id": "C01",
+                    "message": "nice intro!"
+                }
+            }
+        }
+    }
+  dgquery: |-
+    query {
+      Post1_1(func: eq(Post1.id, "P01")) {
+        uid
+        dgraph.type
+      }
+      Comment1_2(func: eq(Comment1.id, "C01")) {
+        uid
+        dgraph.type
+      }
+    }
+  dgquerysec: |-
+    query {
+      x as updatePost1(func: type(Post1)) @filter(eq(Post1.id, "P02")) {
+        uid
+      }
+    }
+  dgmutations:
+    - setjson: |
+        {
+            "Post1.comments": [
+                {
+                    "Comment1.id": "C01",
+                    "Comment1.message": "nice intro!",
+                    "dgraph.type": [
+                        "Comment1"
+                    ],
+                    "uid": "_:Comment1_2"
+                }
+            ],
+            "Post1.content": "intro to graphql",
+            "Post1.id": "P01",
+            "uid": "uid(x)"
+        }
+      cond: "@if(gt(len(x), 0))"
+
+-
+  name: "Updating link to nested field require all the non-null id's to be present in nested field"
+  explaination: "when we update link to nested field then we check if that already exist or not,
+   In this case since @id field is not present in nested field, so we assume it to be a new node.
+   update mutation tries to create it but failed because non-nullable id field is required to add new
+   node."
+  gqlmutation: |
+    mutation update($patch: UpdatePost1Input!) {
+      updatePost1(input: $patch) {
+        post1 {
+          id
+        }
+      }
+    }
+  gqlvariables: |
+    {
+        "patch": {
+            "filter": {
+                        "id": {
+                            "in": "P02"
+                        }
+            },
+            "set": {
+                "id": "P01",
+                "content": "intro to graphql",
+                "comments":{
+                  "message":"nice intro!"
+               }
+            }
+        }
+    }
+  dgquery: |-
+    query {
+      Post1_1(func: eq(Post1.id, "P01")) {
+        uid
+        dgraph.type
+      }
+    }
+  error2:
+    { "message":
+        "failed to rewrite mutation payload because field id cannot be empty"
+    }
+
+-
+  name: "Updating inherited @id field with interface arg -1 "
+  explaination: "For this case we will generate one more existence query for inherited @id field refID which have
+  interface arg set. No node with given refID exist in same or other implementing type of interface so we will
+  successfully update node in this case"
+  gqlmutation: |
+    mutation update($patch: UpdateLibraryMemberInput!) {
+      updateLibraryMember(input: $patch) {
+        libraryMember {
+          refID
+        }
+      }
+    }
+  gqlvariables: |
+    {
+            "patch": {
+                "filter": {
+                            "refID": {
+                                "in": "101"
+                            }
+                },
+                "set": {
+                    "refID": "102",
+                    "name": "Alice",
+                    "readHours": "3d2hr"
+                }
+            }
+    }
+
+  dgquery: |-
+    query {
+      LibraryMember_1(func: eq(Member.name, "Alice")) {
+        uid
+        dgraph.type
+      }
+      LibraryMember_2(func: eq(Member.refID, "102")) {
+        uid
+        dgraph.type
+      }
+      LibraryMember_3(func: eq(Member.refID, "102")) {
+        uid
+        dgraph.type
+      }
+    }
+  dgquerysec: |-
+    query {
+      x as updateLibraryMember(func: type(LibraryMember)) @filter(eq(Member.refID, "101")) {
+        uid
+      }
+    }
+  dgmutations:
+  - setjson: |
+        {
+            "LibraryMember.readHours":"3d2hr",
+            "Member.name":"Alice",
+            "Member.refID":"102",
+            "uid":"uid(x)"
+        }
+    cond: "@if(gt(len(x), 0))"
+
+-
+  name: "Updating inherited @id field with interface arg -2 "
+  explaination: "For this case we will generate one more existence query for inherited @id field refID.
+  There already exist node with refID in other implementing type of interface so we will generate error for this case"
+  gqlmutation: |
+    mutation update($patch: UpdateLibraryMemberInput!) {
+      updateLibraryMember(input: $patch) {
+        libraryMember {
+          refID
+        }
+      }
+    }
+  gqlvariables: |
+    {
+            "patch": {
+                "filter": {
+                            "refID": {
+                                "in": "101"
+                            }
+                },
+                "set": {
+                    "refID": "102",
+                    "name": "Alice",
+                    "readHours": "3d2hr"
+                }
+            }
+    }
+  dgquery: |-
+    query {
+      LibraryMember_1(func: eq(Member.name, "Alice")) {
+        uid
+        dgraph.type
+      }
+      LibraryMember_2(func: eq(Member.refID, "102")) {
+        uid
+        dgraph.type
+      }
+      LibraryMember_3(func: eq(Member.refID, "102")) {
+        uid
+        dgraph.type
+      }
+    }
+  qnametouid: |-
+    {
+      "LibraryMember_3": "0x123"
+    }
+  error2:
+    {
+      "message": "failed to rewrite mutation payload because id 102 already exists for field refID
+         in some other implementing type of interface Member"
+    }
+
+-
+  name: "Updating link to nested object inheriting @id field with interface argument-1"
+  explaination: "If nested object have inherited @id field which have interface argument set, and that
+   field already exist in some other implementing type than we returns error.In below mutation manages
+  is of type LibraryMember but node with given refID already exist in some other
+   type than than LibraryMember"
+  gqlmutation: |
+    mutation update($patch: UpdateLibraryManagerInput!) {
+      updateLibraryManager(input: $patch) {
+        libraryManager {
+          name
+        }
+      }
+    }
+  gqlvariables: |
+    {
+            "patch": {
+                "filter": {
+                            "name": {
+                                "in": "Alice"
+                            }
+                },
+                "set": {
+                    "name": "Bob",
+                    "manages": {
+                       "refID":"101"
+                  }
+                }
+            }
+    }
+  dgquery: |-
+    query {
+      LibraryManager_1(func: eq(LibraryManager.name, "Bob")) {
+        uid
+        dgraph.type
+      }
+      LibraryMember_2(func: eq(Member.refID, "101")) {
+        uid
+        dgraph.type
+      }
+      LibraryMember_3(func: eq(Member.refID, "101")) {
+        uid
+        dgraph.type
+      }
+    }
+  qnametouid: |-
+    {
+      "LibraryMember_3": "0x123"
+    }
+  error2:
+    {
+      "message": "failed to rewrite mutation payload because id 101 already exists for field refID
+         in some other implementing type of interface Member"
+    }
+
+-
+  name: "Updating link to nested object inheriting @id field with interface argument-2"
+  explaination: "In below mutation manages is of type LibraryMember and node of type LibraryMember already
+   existed with given refID, so we link that correctly"
+  gqlmutation: |
+    mutation update($patch: UpdateLibraryManagerInput!) {
+      updateLibraryManager(input: $patch) {
+        libraryManager {
+          name
+        }
+      }
+    }
+  gqlvariables: |
+    {
+            "patch": {
+                "filter": {
+                            "name": {
+                                "in": "Alice"
+                            }
+                },
+                "set": {
+                    "name": "Bob",
+                    "manages": {
+                       "refID":"101"
+                  }
+                }
+            }
+    }
+  dgquery: |-
+    query {
+      LibraryManager_1(func: eq(LibraryManager.name, "Bob")) {
+        uid
+        dgraph.type
+      }
+      LibraryMember_2(func: eq(Member.refID, "101")) {
+        uid
+        dgraph.type
+      }
+      LibraryMember_3(func: eq(Member.refID, "101")) {
+        uid
+        dgraph.type
+      }
+    }
+  qnametouid: |-
+    {
+      "LibraryMember_2": "0x123",
+      "LibraryMember_3": "0x124"
+    }
+  dgquerysec: |-
+    query {
+      x as updateLibraryManager(func: type(LibraryManager)) @filter(eq(LibraryManager.name, "Alice")) {
+        uid
+      }
+    }
+  dgmutations:
+  - setjson: |
+       {
+         "LibraryManager.manages": [
+           {
+             "uid": "0x123"
+           }
+         ],
+         "LibraryManager.name": "Bob",
+         "uid": "uid(x)"
+       }
+    cond: "@if(gt(len(x), 0))"
+
+-
+  name: "Update with @default directive"
+  gqlmutation: |
+    mutation updateBooking($patch: UpdateBookingInput!) {
+      updateBooking(input: $patch) {
+        booking {
+          id
+        }
+      }
+    }
+  gqlvariables: |
+    { "patch":
+      { "filter": {
+          "id": ["0x123", "0x124"]
+        },
+        "set": {
+          "name": "Flight to Antigua"
+        }
+      }
+    }
+  explanation: "The update patch should include default values on the fields with the @default(update:) directive"
+  dgquerysec: |-
+    query {
+      x as updateBooking(func: uid(0x123, 0x124)) @filter(type(Booking)) {
+        uid
+      }
+    }
+  dgmutations:
+    - setjson: |
+        { "uid" : "uid(x)",
+          "Booking.name": "Flight to Antigua",
+          "Booking.updated": "2000-01-01T00:00:00.00Z",
+          "Booking.active": "true",
+          "Booking.count": "2",
+          "Booking.length": "1.2",
+          "Booking.status": "INACTIVE",
+          "Booking.hotel": "update"
+        }
+      cond: "@if(gt(len(x), 0))"
+
+-
+  name: "Update with @default directive uses provided values"
+  gqlmutation: |
+    mutation updateBooking($patch: UpdateBookingInput!) {
+      updateBooking(input: $patch) {
+        booking {
+          id
+        }
+      }
+    }
+  gqlvariables: |
+    { "patch":
+      { "filter": {
+          "id": ["0x123", "0x124"]
+        },
+        "set": {
+          "name": "Flight to Antigua",
+          "updated": "2022-10-12T07:20:50.52Z",
+          "active": false,
+          "length": 12.3,
+          "status": "ACTIVE",
+          "hotel": "provided"
+        }
+      }
+    }
+  explanation: "Fields with @default(update) should use input values if provided (note that count is still using default)"
+  dgquerysec: |-
+    query {
+      x as updateBooking(func: uid(0x123, 0x124)) @filter(type(Booking)) {
+        uid
+      }
+    }
+  dgmutations:
+    - setjson: |
+        { "uid" : "uid(x)",
+          "Booking.name": "Flight to Antigua",
+          "Booking.updated": "2022-10-12T07:20:50.52Z",
+          "Booking.active": false,
+          "Booking.count": "2",
+          "Booking.length": 12.3,
+          "Booking.status": "ACTIVE",
+          "Booking.hotel": "provided"
+        }
+      cond: "@if(gt(len(x), 0))"
diff --git a/graphql/schema/gqlschema.go b/graphql/schema/gqlschema.go
index 185611e50be..d4bc3bc734b 100644
--- a/graphql/schema/gqlschema.go
+++ b/graphql/schema/gqlschema.go
@@ -48,6 +48,7 @@ const (
 	remoteResponseDirective = "remoteResponse"
 	lambdaDirective         = "lambda"
 	lambdaOnMutateDirective = "lambdaOnMutate"
+	defaultDirective        = "default"
 
 	generateDirective       = "generate"
 	generateQueryArg        = "query"
@@ -195,6 +196,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -278,6 +283,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
@@ -309,6 +315,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @remote on OBJECT | INTERFACE | UNION | INPUT_OBJECT | ENUM
@@ -570,6 +577,7 @@ var directiveValidators = map[string]directiveValidator{
 	remoteDirective:         ValidatorNoOp,
 	deprecatedDirective:     ValidatorNoOp,
 	lambdaDirective:         lambdaDirectiveValidation,
+	defaultDirective:        defaultDirectiveValidation,
 	lambdaOnMutateDirective: ValidatorNoOp,
 	generateDirective:       ValidatorNoOp,
 	apolloKeyDirective:      ValidatorNoOp,
@@ -1289,7 +1297,7 @@ func addPatchType(schema *ast.Schema, defn *ast.Definition, providesTypeMap map[
 		return
 	}
 
-	nonIDFields := getNonIDFields(schema, defn, providesTypeMap)
+	nonIDFields := getPatchFields(schema, defn, providesTypeMap)
 	if len(nonIDFields) == 0 {
 		// The user might just have an external id field and nothing else. We don't generate patch
 		// type in that case.
@@ -2233,7 +2241,7 @@ func createField(schema *ast.Schema, fld *ast.FieldDefinition) *ast.FieldDefinit
 	return &newFld
 }
 
-func getNonIDFields(schema *ast.Schema, defn *ast.Definition, providesTypeMap map[string]bool) ast.FieldList {
+func getPatchFields(schema *ast.Schema, defn *ast.Definition, providesTypeMap map[string]bool) ast.FieldList {
 	fldList := make([]*ast.FieldDefinition, 0)
 	for _, fld := range defn.Fields {
 		if isIDField(defn, fld) || hasIDDirective(fld) {
@@ -2315,12 +2323,19 @@ func getFieldsWithoutIDType(schema *ast.Schema, defn *ast.Definition,
 			continue
 		}
 
-		// see also comment in getNonIDFields
+		// see also comment in getPatchFields
 		if schema.Types[fld.Type.Name()].Kind == ast.Interface &&
 			(!hasID(schema.Types[fld.Type.Name()]) && !hasXID(schema.Types[fld.Type.Name()])) {
 			continue
 		}
-		fldList = append(fldList, createField(schema, fld))
+
+		// if the field has a @default(add) value it is optional in add input
+		var field = createField(schema, fld)
+		if getDefaultValue(fld, "add") != nil {
+			field.Type.NonNull = false
+		}
+
+		fldList = append(fldList, field)
 	}
 
 	pd := getPasswordField(defn)
diff --git a/graphql/schema/gqlschema_test.yml b/graphql/schema/gqlschema_test.yml
index b31b6e86705..dd36ca09cb5 100644
--- a/graphql/schema/gqlschema_test.yml
+++ b/graphql/schema/gqlschema_test.yml
@@ -2743,7 +2743,7 @@ invalid_schemas:
           review: String!
       }
     errlist: [
-      {"message": "Type Product; @remote directive cannot be defined with @key directive", "locations": [ { "line": 174, "column": 12} ] },
+      {"message": "Type Product; @remote directive cannot be defined with @key directive", "locations": [ { "line": 179, "column": 12} ] },
     ]
 
   - name: "directives defined on @external fields that are not @key."
@@ -2944,6 +2944,7 @@ invalid_schemas:
       { "message": "Type Person; Field nameHi: `*` language tag not supported in GraphQL",
         "locations": [ { "line": 3, "column": 19 } ] },
     ]
+
   - name: "@id field can't have interface argument when it's defined inside a type"
     input: |
       type Person  {
@@ -2956,6 +2957,125 @@ invalid_schemas:
         "locations": [ { "line": 2, "column": 18 } ] },
     ]
 
+  - name: "@default validates field type for value $now"
+    input: |
+      type X {
+        field: String @default(add:{value:"$now"})
+      }
+    errlist: [
+      {"message": "Type X; Field field: @default directive provides value \"$now\" which cannot be used with String",
+      "locations":[{"line":2, "column":18}]}
+      ]
+
+  - name: "@default validates value for Int"
+    input: |
+      type X {
+        field: Int @default(add:{value:"apple"})
+      }
+    errlist: [
+      {"message": "Type X; Field field: @default directive provides value \"apple\" which cannot be used with Int",
+      "locations":[{"line":2, "column":15}]}
+      ]
+
+  - name: "@default validates value for Float"
+    input: |
+      type X {
+        field: Float @default(add:{value:"apple"})
+      }
+    errlist: [
+      {"message": "Type X; Field field: @default directive provides value \"apple\" which cannot be used with Float",
+      "locations":[{"line":2, "column":17}]}
+      ]
+
+  - name: "@default validates value for Boolean"
+    input: |
+      type X {
+        field: Boolean @default(add:{value:"apple"})
+      }
+    errlist: [
+      {"message": "Type X; Field field: @default directive provides value \"apple\" which cannot be used with Boolean",
+      "locations":[{"line":2, "column":19}]}
+      ]
+
+  - name: "@default validates type is not @remote"
+    input: |
+      type X @remote {
+        field: Int @default(add:{value:"1"})
+      }
+    errlist: [
+      {"message": "Type X; Field field: cannot use @default directive on a @remote type",
+      "locations":[{"line":2, "column":15}]}
+      ]
+
+  - name: "@default validates field type is scalar"
+    input: |
+      type X {
+        field: Y @default(add:{value:"1"})
+      }
+      type Y {
+        field: String
+      }
+    errlist: [
+      {"message": "Type X; Field field: cannot use @default directive on field with non-scalar type Y",
+      "locations":[{"line":2, "column":13}]}
+      ]
+
+  - name: "@default validates field type is not list"
+    input: |
+      type X {
+        field: [String] @default(add:{value:"1"})
+      }
+    errlist: [
+      {"message": "Type X; Field field: cannot use @default directive on field with list type [String]",
+      "locations":[{"line":2, "column":20}]}
+      ]
+
+  - name: "@default validates field type is not @id"
+    input: |
+      type X {
+        field: String! @id @default(add:{value:"foo"})
+      }
+    errlist: [
+      {"message": "Type X; Field field: cannot use @default directive on field with @id directive",
+      "locations":[{"line":2, "column":23}]}
+      ]
+
+  - name: "@default validates field type is not ID"
+    input: |
+      type X {
+        id: ID! @default(add:{value:"foo"})
+        field: String
+      }
+    errlist: [
+      {"message": "Type X; Field id: cannot use @default directive on field with type ID",
+      "locations":[{"line":2, "column":12}]}
+      ]
+
+  - name: "@default validates field type is not @custom"
+    input: |
+      type X {
+        id: String! @id
+        field: String! @default(add:{value:"foo"}) @custom(http: {
+          url: "http://blah.com",
+          method: "GET"
+        })
+      }
+    errlist: [
+      {"message": "Type X; Field field: cannot use @default directive on field with @custom directive",
+      "locations":[{"line":3, "column":19}]}
+      ]
+
+  - name: "@default validates field type is not @lambda"
+    input: |
+      type X {
+        id: String! @id
+        field: String! @default(add:{value:"foo"}) @lambda
+      }
+    errlist: [
+      {"message": "Type X; Field field: cannot use @default directive on field with @lambda directive",
+      "locations":[{"line":3, "column":19}]}
+      ]
+
 valid_schemas:
   - name: "Multiple fields with @id directive should be allowed"
     input: |
diff --git a/graphql/schema/rules.go b/graphql/schema/rules.go
index 1647911ba65..175b14e4fb9 100644
--- a/graphql/schema/rules.go
+++ b/graphql/schema/rules.go
@@ -1301,6 +1301,88 @@ func lambdaDirectiveValidation(sch *ast.Schema,
 	return errs
 }
 
+func defaultDirectiveValidation(sch *ast.Schema,
+	typ *ast.Definition,
+	field *ast.FieldDefinition,
+	dir *ast.Directive,
+	secrets map[string]x.Sensitive) gqlerror.List {
+	if typ.Directives.ForName(remoteDirective) != nil {
+		return []*gqlerror.Error{gqlerror.ErrorPosf(
+			dir.Position,
+			"Type %s; Field %s: cannot use @default directive on a @remote type",
+			typ.Name, field.Name)}
+	}
+	if !isScalar(field.Type.Name()) && sch.Types[field.Type.Name()].Kind != ast.Enum {
+		return []*gqlerror.Error{gqlerror.ErrorPosf(
+			dir.Position,
+			"Type %s; Field %s: cannot use @default directive on field with non-scalar type %s",
+			typ.Name, field.Name, field.Type.Name())}
+	}
+	if field.Type.Elem != nil {
+		return []*gqlerror.Error{gqlerror.ErrorPosf(
+			dir.Position,
+			"Type %s; Field %s: cannot use @default directive on field with list type [%s]",
+			typ.Name, field.Name, field.Type.Name())}
+	}
+	if field.Directives.ForName(idDirective) != nil {
+		return []*gqlerror.Error{gqlerror.ErrorPosf(
+			dir.Position,
+			"Type %s; Field %s: cannot use @default directive on field with @id directive",
+			typ.Name, field.Name)}
+	}
+	if isID(field) {
+		return []*gqlerror.Error{gqlerror.ErrorPosf(
+			dir.Position,
+			"Type %s; Field %s: cannot use @default directive on field with type ID",
+			typ.Name, field.Name)}
+	}
+	if field.Directives.ForName(customDirective) != nil {
+		return []*gqlerror.Error{gqlerror.ErrorPosf(
+			dir.Position,
+			"Type %s; Field %s: cannot use @default directive on field with @custom directive",
+			typ.Name, field.Name)}
+	}
+	if field.Directives.ForName(lambdaDirective) != nil {
+		return []*gqlerror.Error{gqlerror.ErrorPosf(
+			dir.Position,
+			"Type %s; Field %s: cannot use @default directive on field with @lambda directive",
+			typ.Name, field.Name)}
+	}
+	for _, arg := range dir.Arguments {
+		fieldType := field.Type.Name()
+		value := arg.Value.Children.ForName("value").Raw
+		if value == "$now" && fieldType != "DateTime" {
+			return []*gqlerror.Error{gqlerror.ErrorPosf(
+				dir.Position,
+				"Type %s; Field %s: @default directive provides value \"%s\" which cannot be used with %s",
+				typ.Name, field.Name, value, fieldType)}
+		}
+		if fieldType == "Int" {
+			if _, err := strconv.ParseInt(value, 10, 64); err != nil {
+				return []*gqlerror.Error{gqlerror.ErrorPosf(
+					dir.Position,
+					"Type %s; Field %s: @default directive provides value \"%s\" which cannot be used with %s",
+					typ.Name, field.Name, value, fieldType)}
+			}
+		}
+		if fieldType == "Float" {
+			if _, err := strconv.ParseFloat(value, 64); err != nil {
+				return []*gqlerror.Error{gqlerror.ErrorPosf(
+					dir.Position,
+					"Type %s; Field %s: @default directive provides value \"%s\" which cannot be used with %s",
+					typ.Name, field.Name, value, fieldType)}
+			}
+		}
+		if fieldType == "Boolean" && value != "true" && value != "false" {
+			return []*gqlerror.Error{gqlerror.ErrorPosf(
+				dir.Position,
+				"Type %s; Field %s: @default directive provides value \"%s\" which cannot be used with %s",
+				typ.Name, field.Name, value, fieldType)}
+		}
+	}
+	return nil
+}
+
 func lambdaOnMutateValidation(sch *ast.Schema, typ *ast.Definition) gqlerror.List {
 	dir := typ.Directives.ForName(lambdaOnMutateDirective)
 	if dir == nil {
diff --git a/graphql/schema/testdata/apolloservice/output/auth-directive.graphql b/graphql/schema/testdata/apolloservice/output/auth-directive.graphql
index 1d3488c0b27..c91fb7c1471 100644
--- a/graphql/schema/testdata/apolloservice/output/auth-directive.graphql
+++ b/graphql/schema/testdata/apolloservice/output/auth-directive.graphql
@@ -111,6 +111,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -193,6 +197,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @remote on OBJECT | INTERFACE | UNION | INPUT_OBJECT | ENUM
diff --git a/graphql/schema/testdata/apolloservice/output/custom-directive.graphql b/graphql/schema/testdata/apolloservice/output/custom-directive.graphql
index 0ffe521b151..a39876c07d4 100644
--- a/graphql/schema/testdata/apolloservice/output/custom-directive.graphql
+++ b/graphql/schema/testdata/apolloservice/output/custom-directive.graphql
@@ -103,6 +103,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -185,6 +189,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @remote on OBJECT | INTERFACE | UNION | INPUT_OBJECT | ENUM
diff --git a/graphql/schema/testdata/apolloservice/output/extended-types.graphql b/graphql/schema/testdata/apolloservice/output/extended-types.graphql
index 31024cd9323..c1295d8a145 100644
--- a/graphql/schema/testdata/apolloservice/output/extended-types.graphql
+++ b/graphql/schema/testdata/apolloservice/output/extended-types.graphql
@@ -117,6 +117,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -199,6 +203,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @remote on OBJECT | INTERFACE | UNION | INPUT_OBJECT | ENUM
diff --git a/graphql/schema/testdata/apolloservice/output/generate-directive.graphql b/graphql/schema/testdata/apolloservice/output/generate-directive.graphql
index fd38dab07b9..069a312e111 100644
--- a/graphql/schema/testdata/apolloservice/output/generate-directive.graphql
+++ b/graphql/schema/testdata/apolloservice/output/generate-directive.graphql
@@ -113,6 +113,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -195,6 +199,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @remote on OBJECT | INTERFACE | UNION | INPUT_OBJECT | ENUM
diff --git a/graphql/schema/testdata/apolloservice/output/single-extended-type.graphql b/graphql/schema/testdata/apolloservice/output/single-extended-type.graphql
index 0704e8fd6f3..07081021b4f 100644
--- a/graphql/schema/testdata/apolloservice/output/single-extended-type.graphql
+++ b/graphql/schema/testdata/apolloservice/output/single-extended-type.graphql
@@ -98,6 +98,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -180,6 +184,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @remote on OBJECT | INTERFACE | UNION | INPUT_OBJECT | ENUM
diff --git a/graphql/schema/testdata/schemagen/input/created-updated-directives.graphql b/graphql/schema/testdata/schemagen/input/created-updated-directives.graphql
new file mode 100644
index 00000000000..a25ed3a9228
--- /dev/null
+++ b/graphql/schema/testdata/schemagen/input/created-updated-directives.graphql
@@ -0,0 +1,13 @@
+type Booking {
+    id: ID!
+    name: String!
+    created: DateTime! @default(add: {value:"$now"})
+    updated: DateTime! @default(add: {value:"$now"}, update: {value:"$now"})
+}
+
+type BookingXID {
+    id: String! @id
+    name: String!
+    created: DateTime! @default(add: {value:"$now"})
+    updated: DateTime! @default(add: {value:"$now"}, update: {value:"$now"})
+}
diff --git a/graphql/schema/testdata/schemagen/output/apollo-federation.graphql b/graphql/schema/testdata/schemagen/output/apollo-federation.graphql
index 91642aebb01..80c9cb5be09 100644
--- a/graphql/schema/testdata/schemagen/output/apollo-federation.graphql
+++ b/graphql/schema/testdata/schemagen/output/apollo-federation.graphql
@@ -133,6 +133,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -215,6 +219,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/auth-on-interfaces.graphql b/graphql/schema/testdata/schemagen/output/auth-on-interfaces.graphql
index ea87104b74f..ce7c9f93a6c 100644
--- a/graphql/schema/testdata/schemagen/output/auth-on-interfaces.graphql
+++ b/graphql/schema/testdata/schemagen/output/auth-on-interfaces.graphql
@@ -115,6 +115,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -197,6 +201,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/authorization.graphql b/graphql/schema/testdata/schemagen/output/authorization.graphql
index 8d8a2da3d46..b75d733d116 100644
--- a/graphql/schema/testdata/schemagen/output/authorization.graphql
+++ b/graphql/schema/testdata/schemagen/output/authorization.graphql
@@ -111,6 +111,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -193,6 +197,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/comments-and-descriptions.graphql b/graphql/schema/testdata/schemagen/output/comments-and-descriptions.graphql
index cf11ecc3856..7e8823dcb3f 100755
--- a/graphql/schema/testdata/schemagen/output/comments-and-descriptions.graphql
+++ b/graphql/schema/testdata/schemagen/output/comments-and-descriptions.graphql
@@ -124,6 +124,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -206,6 +210,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/created-updated-directives.graphql b/graphql/schema/testdata/schemagen/output/created-updated-directives.graphql
new file mode 100644
index 00000000000..e54a114aa5e
--- /dev/null
+++ b/graphql/schema/testdata/schemagen/output/created-updated-directives.graphql
@@ -0,0 +1,483 @@
+#######################
+# Input Schema
+#######################
+
+type Booking {
+	id: ID!
+	name: String!
+	created: DateTime! @default(add: {value:"$now"})
+	updated: DateTime! @default(add: {value:"$now"}, update: {value:"$now"})
+}
+
+type BookingXID {
+	id: String! @id
+	name: String!
+	created: DateTime! @default(add: {value:"$now"})
+	updated: DateTime! @default(add: {value:"$now"}, update: {value:"$now"})
+}
+
+#######################
+# Extended Definitions
+#######################
+
+"""
+The Int64 scalar type represents a signed 64‐bit numeric non‐fractional value.
+Int64 can represent values in range [-(2^63),(2^63 - 1)].
+"""
+scalar Int64
+
+"""
+The DateTime scalar type represents date and time as a string in RFC3339 format.
+For example: "1985-04-12T23:20:50.52Z" represents 20 minutes and 50.52 seconds after the 23rd hour of April 12th, 1985 in UTC.
+"""
+scalar DateTime
+
+input IntRange{
+	min: Int!
+	max: Int!
+}
+
+input FloatRange{
+	min: Float!
+	max: Float!
+}
+
+input Int64Range{
+	min: Int64!
+	max: Int64!
+}
+
+input DateTimeRange{
+	min: DateTime!
+	max: DateTime!
+}
+
+input StringRange{
+	min: String!
+	max: String!
+}
+
+enum DgraphIndex {
+	int
+	int64
+	float
+	bool
+	hash
+	exact
+	term
+	fulltext
+	trigram
+	regexp
+	year
+	month
+	day
+	hour
+	geo
+}
+
+input AuthRule {
+	and: [AuthRule]
+	or: [AuthRule]
+	not: AuthRule
+	rule: String
+}
+
+enum HTTPMethod {
+	GET
+	POST
+	PUT
+	PATCH
+	DELETE
+}
+
+enum Mode {
+	BATCH
+	SINGLE
+}
+
+input CustomHTTP {
+	url: String!
+	method: HTTPMethod!
+	body: String
+	graphql: String
+	mode: Mode
+	forwardHeaders: [String!]
+	secretHeaders: [String!]
+	introspectionHeaders: [String!]
+	skipIntrospection: Boolean
+}
+
+input DgraphDefault {
+	value: String
+}
+
+type Point {
+	longitude: Float!
+	latitude: Float!
+}
+
+input PointRef {
+	longitude: Float!
+	latitude: Float!
+}
+
+input NearFilter {
+	distance: Float!
+	coordinate: PointRef!
+}
+
+input PointGeoFilter {
+	near: NearFilter
+	within: WithinFilter
+}
+
+type PointList {
+	points: [Point!]!
+}
+
+input PointListRef {
+	points: [PointRef!]!
+}
+
+type Polygon {
+	coordinates: [PointList!]!
+}
+
+input PolygonRef {
+	coordinates: [PointListRef!]!
+}
+
+type MultiPolygon {
+	polygons: [Polygon!]!
+}
+
+input MultiPolygonRef {
+	polygons: [PolygonRef!]!
+}
+
+input WithinFilter {
+	polygon: PolygonRef!
+}
+
+input ContainsFilter {
+	point: PointRef
+	polygon: PolygonRef
+}
+
+input IntersectsFilter {
+	polygon: PolygonRef
+	multiPolygon: MultiPolygonRef
+}
+
+input PolygonGeoFilter {
+	near: NearFilter
+	within: WithinFilter
+	contains: ContainsFilter
+	intersects: IntersectsFilter
+}
+
+input GenerateQueryParams {
+	get: Boolean
+	query: Boolean
+	password: Boolean
+	aggregate: Boolean
+}
+
+input GenerateMutationParams {
+	add: Boolean
+	update: Boolean
+	delete: Boolean
+}
+
+directive @hasInverse(field: String!) on FIELD_DEFINITION
+directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
+directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
+directive @id on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
+directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
+directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
+directive @auth(
+	password: AuthRule
+	query: AuthRule,
+	add: AuthRule,
+	update: AuthRule,
+	delete: AuthRule) on OBJECT | INTERFACE
+directive @custom(http: CustomHTTP, dql: String) on FIELD_DEFINITION
+directive @remote on OBJECT | INTERFACE | UNION | INPUT_OBJECT | ENUM
+directive @remoteResponse(name: String) on FIELD_DEFINITION
+directive @cascade(fields: [String]) on FIELD
+directive @lambda on FIELD_DEFINITION
+directive @lambdaOnMutate(add: Boolean, update: Boolean, delete: Boolean) on OBJECT | INTERFACE
+directive @cacheControl(maxAge: Int!) on QUERY
+directive @generate(
+	query: GenerateQueryParams,
+	mutation: GenerateMutationParams,
+	subscription: Boolean) on OBJECT | INTERFACE
+
+input IntFilter {
+	eq: Int
+	in: [Int]
+	le: Int
+	lt: Int
+	ge: Int
+	gt: Int
+	between: IntRange
+}
+
+input Int64Filter {
+	eq: Int64
+	in: [Int64]
+	le: Int64
+	lt: Int64
+	ge: Int64
+	gt: Int64
+	between: Int64Range
+}
+
+input FloatFilter {
+	eq: Float
+	in: [Float]
+	le: Float
+	lt: Float
+	ge: Float
+	gt: Float
+	between: FloatRange
+}
+
+input DateTimeFilter {
+	eq: DateTime
+	in: [DateTime]
+	le: DateTime
+	lt: DateTime
+	ge: DateTime
+	gt: DateTime
+	between: DateTimeRange
+}
+
+input StringTermFilter {
+	allofterms: String
+	anyofterms: String
+}
+
+input StringRegExpFilter {
+	regexp: String
+}
+
+input StringFullTextFilter {
+	alloftext: String
+	anyoftext: String
+}
+
+input StringExactFilter {
+	eq: String
+	in: [String]
+	le: String
+	lt: String
+	ge: String
+	gt: String
+	between: StringRange
+}
+
+input StringHashFilter {
+	eq: String
+	in: [String]
+}
+
+#######################
+# Generated Types
+#######################
+
+type AddBookingPayload {
+	booking(filter: BookingFilter, order: BookingOrder, first: Int, offset: Int): [Booking]
+	numUids: Int
+}
+
+type AddBookingXIDPayload {
+	bookingXID(filter: BookingXIDFilter, order: BookingXIDOrder, first: Int, offset: Int): [BookingXID]
+	numUids: Int
+}
+
+type BookingAggregateResult {
+	count: Int
+	nameMin: String
+	nameMax: String
+	createdMin: DateTime
+	createdMax: DateTime
+	updatedMin: DateTime
+	updatedMax: DateTime
+}
+
+type BookingXIDAggregateResult {
+	count: Int
+	idMin: String
+	idMax: String
+	nameMin: String
+	nameMax: String
+	createdMin: DateTime
+	createdMax: DateTime
+	updatedMin: DateTime
+	updatedMax: DateTime
+}
+
+type DeleteBookingPayload {
+	booking(filter: BookingFilter, order: BookingOrder, first: Int, offset: Int): [Booking]
+	msg: String
+	numUids: Int
+}
+
+type DeleteBookingXIDPayload {
+	bookingXID(filter: BookingXIDFilter, order: BookingXIDOrder, first: Int, offset: Int): [BookingXID]
+	msg: String
+	numUids: Int
+}
+
+type UpdateBookingPayload {
+	booking(filter: BookingFilter, order: BookingOrder, first: Int, offset: Int): [Booking]
+	numUids: Int
+}
+
+type UpdateBookingXIDPayload {
+	bookingXID(filter: BookingXIDFilter, order: BookingXIDOrder, first: Int, offset: Int): [BookingXID]
+	numUids: Int
+}
+
+#######################
+# Generated Enums
+#######################
+
+enum BookingHasFilter {
+	name
+	created
+	updated
+}
+
+enum BookingOrderable {
+	name
+	created
+	updated
+}
+
+enum BookingXIDHasFilter {
+	id
+	name
+	created
+	updated
+}
+
+enum BookingXIDOrderable {
+	id
+	name
+	created
+	updated
+}
+
+#######################
+# Generated Inputs
+#######################
+
+input AddBookingInput {
+	name: String!
+	created: DateTime
+	updated: DateTime
+}
+
+input AddBookingXIDInput {
+	id: String!
+	name: String!
+	created: DateTime
+	updated: DateTime
+}
+
+input BookingFilter {
+	id: [ID!]
+	has: [BookingHasFilter]
+	and: [BookingFilter]
+	or: [BookingFilter]
+	not: BookingFilter
+}
+
+input BookingOrder {
+	asc: BookingOrderable
+	desc: BookingOrderable
+	then: BookingOrder
+}
+
+input BookingPatch {
+	name: String
+	created: DateTime
+	updated: DateTime
+}
+
+input BookingRef {
+	id: ID
+	name: String
+	created: DateTime
+	updated: DateTime
+}
+
+input BookingXIDFilter {
+	id: StringHashFilter
+	has: [BookingXIDHasFilter]
+	and: [BookingXIDFilter]
+	or: [BookingXIDFilter]
+	not: BookingXIDFilter
+}
+
+input BookingXIDOrder {
+	asc: BookingXIDOrderable
+	desc: BookingXIDOrderable
+	then: BookingXIDOrder
+}
+
+input BookingXIDPatch {
+	id: String
+	name: String
+	created: DateTime
+	updated: DateTime
+}
+
+input BookingXIDRef {
+	id: String
+	name: String
+	created: DateTime
+	updated: DateTime
+}
+
+input UpdateBookingInput {
+	filter: BookingFilter!
+	set: BookingPatch
+	remove: BookingPatch
+}
+
+input UpdateBookingXIDInput {
+	filter: BookingXIDFilter!
+	set: BookingXIDPatch
+	remove: BookingXIDPatch
+}
+
+#######################
+# Generated Query
+#######################
+
+type Query {
+	getBooking(id: ID!): Booking
+	queryBooking(filter: BookingFilter, order: BookingOrder, first: Int, offset: Int): [Booking]
+	aggregateBooking(filter: BookingFilter): BookingAggregateResult
+	getBookingXID(id: String!): BookingXID
+	queryBookingXID(filter: BookingXIDFilter, order: BookingXIDOrder, first: Int, offset: Int): [BookingXID]
+	aggregateBookingXID(filter: BookingXIDFilter): BookingXIDAggregateResult
+}
+
+#######################
+# Generated Mutations
+#######################
+
+type Mutation {
+	addBooking(input: [AddBookingInput!]!): AddBookingPayload
+	updateBooking(input: UpdateBookingInput!): UpdateBookingPayload
+	deleteBooking(filter: BookingFilter!): DeleteBookingPayload
+	addBookingXID(input: [AddBookingXIDInput!]!, upsert: Boolean): AddBookingXIDPayload
+	updateBookingXID(input: UpdateBookingXIDInput!): UpdateBookingXIDPayload
+	deleteBookingXID(filter: BookingXIDFilter!): DeleteBookingXIDPayload
+}
+
diff --git a/graphql/schema/testdata/schemagen/output/custom-dql-query-with-subscription.graphql b/graphql/schema/testdata/schemagen/output/custom-dql-query-with-subscription.graphql
index a6c89246ef5..1a9ea6d0433 100755
--- a/graphql/schema/testdata/schemagen/output/custom-dql-query-with-subscription.graphql
+++ b/graphql/schema/testdata/schemagen/output/custom-dql-query-with-subscription.graphql
@@ -112,6 +112,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -194,6 +198,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/custom-mutation.graphql b/graphql/schema/testdata/schemagen/output/custom-mutation.graphql
index 1b48735de16..b1491d50143 100644
--- a/graphql/schema/testdata/schemagen/output/custom-mutation.graphql
+++ b/graphql/schema/testdata/schemagen/output/custom-mutation.graphql
@@ -102,6 +102,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -184,6 +188,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/custom-nested-types.graphql b/graphql/schema/testdata/schemagen/output/custom-nested-types.graphql
index 7184d90e5a8..e5ef0f6ce6c 100755
--- a/graphql/schema/testdata/schemagen/output/custom-nested-types.graphql
+++ b/graphql/schema/testdata/schemagen/output/custom-nested-types.graphql
@@ -119,6 +119,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -201,6 +205,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/custom-query-mixed-types.graphql b/graphql/schema/testdata/schemagen/output/custom-query-mixed-types.graphql
index d441721cf27..56869daf11e 100644
--- a/graphql/schema/testdata/schemagen/output/custom-query-mixed-types.graphql
+++ b/graphql/schema/testdata/schemagen/output/custom-query-mixed-types.graphql
@@ -103,6 +103,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -185,6 +189,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/custom-query-not-dgraph-type.graphql b/graphql/schema/testdata/schemagen/output/custom-query-not-dgraph-type.graphql
index bbc666a87e1..88be19f9679 100755
--- a/graphql/schema/testdata/schemagen/output/custom-query-not-dgraph-type.graphql
+++ b/graphql/schema/testdata/schemagen/output/custom-query-not-dgraph-type.graphql
@@ -102,6 +102,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -184,6 +188,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/custom-query-with-dgraph-type.graphql b/graphql/schema/testdata/schemagen/output/custom-query-with-dgraph-type.graphql
index a38c50561d8..cafa431e847 100755
--- a/graphql/schema/testdata/schemagen/output/custom-query-with-dgraph-type.graphql
+++ b/graphql/schema/testdata/schemagen/output/custom-query-with-dgraph-type.graphql
@@ -98,6 +98,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -180,6 +184,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/deprecated.graphql b/graphql/schema/testdata/schemagen/output/deprecated.graphql
index 52cb4ea15d4..d7c47708cf2 100755
--- a/graphql/schema/testdata/schemagen/output/deprecated.graphql
+++ b/graphql/schema/testdata/schemagen/output/deprecated.graphql
@@ -98,6 +98,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -180,6 +184,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/dgraph-reverse-directive-on-concrete-type-with-interfaces.graphql b/graphql/schema/testdata/schemagen/output/dgraph-reverse-directive-on-concrete-type-with-interfaces.graphql
index b1af0955121..c701b754382 100755
--- a/graphql/schema/testdata/schemagen/output/dgraph-reverse-directive-on-concrete-type-with-interfaces.graphql
+++ b/graphql/schema/testdata/schemagen/output/dgraph-reverse-directive-on-concrete-type-with-interfaces.graphql
@@ -115,6 +115,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -197,6 +201,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/dgraph-reverse-directive-with-interfaces.graphql b/graphql/schema/testdata/schemagen/output/dgraph-reverse-directive-with-interfaces.graphql
index 44da4eec782..ce781cc3796 100755
--- a/graphql/schema/testdata/schemagen/output/dgraph-reverse-directive-with-interfaces.graphql
+++ b/graphql/schema/testdata/schemagen/output/dgraph-reverse-directive-with-interfaces.graphql
@@ -115,6 +115,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -197,6 +201,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/field-with-id-directive.graphql b/graphql/schema/testdata/schemagen/output/field-with-id-directive.graphql
index 47653c74222..96fc5b69fde 100755
--- a/graphql/schema/testdata/schemagen/output/field-with-id-directive.graphql
+++ b/graphql/schema/testdata/schemagen/output/field-with-id-directive.graphql
@@ -112,6 +112,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -194,6 +198,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/field-with-multiple-@id-fields.graphql b/graphql/schema/testdata/schemagen/output/field-with-multiple-@id-fields.graphql
index d8b93ef7b08..9747d771ad2 100755
--- a/graphql/schema/testdata/schemagen/output/field-with-multiple-@id-fields.graphql
+++ b/graphql/schema/testdata/schemagen/output/field-with-multiple-@id-fields.graphql
@@ -112,6 +112,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -194,6 +198,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/field-with-reverse-predicate-in-dgraph-directive.graphql b/graphql/schema/testdata/schemagen/output/field-with-reverse-predicate-in-dgraph-directive.graphql
index f2145184ee6..a3c7b81057e 100755
--- a/graphql/schema/testdata/schemagen/output/field-with-reverse-predicate-in-dgraph-directive.graphql
+++ b/graphql/schema/testdata/schemagen/output/field-with-reverse-predicate-in-dgraph-directive.graphql
@@ -107,6 +107,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -189,6 +193,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/filter-cleanSchema-all-empty.graphql b/graphql/schema/testdata/schemagen/output/filter-cleanSchema-all-empty.graphql
index 64d88e15dd9..0990e50ec03 100644
--- a/graphql/schema/testdata/schemagen/output/filter-cleanSchema-all-empty.graphql
+++ b/graphql/schema/testdata/schemagen/output/filter-cleanSchema-all-empty.graphql
@@ -110,6 +110,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -192,6 +196,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/filter-cleanSchema-circular.graphql b/graphql/schema/testdata/schemagen/output/filter-cleanSchema-circular.graphql
index fd2ae029d78..f8c12e3718e 100644
--- a/graphql/schema/testdata/schemagen/output/filter-cleanSchema-circular.graphql
+++ b/graphql/schema/testdata/schemagen/output/filter-cleanSchema-circular.graphql
@@ -114,6 +114,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -196,6 +200,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/filter-cleanSchema-custom-mutation.graphql b/graphql/schema/testdata/schemagen/output/filter-cleanSchema-custom-mutation.graphql
index 480d42cc906..b945880374b 100644
--- a/graphql/schema/testdata/schemagen/output/filter-cleanSchema-custom-mutation.graphql
+++ b/graphql/schema/testdata/schemagen/output/filter-cleanSchema-custom-mutation.graphql
@@ -102,6 +102,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -184,6 +188,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/filter-cleanSchema-directLink.graphql b/graphql/schema/testdata/schemagen/output/filter-cleanSchema-directLink.graphql
index ce22f674d5a..eb34687aeef 100644
--- a/graphql/schema/testdata/schemagen/output/filter-cleanSchema-directLink.graphql
+++ b/graphql/schema/testdata/schemagen/output/filter-cleanSchema-directLink.graphql
@@ -112,6 +112,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -194,6 +198,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/generate-directive.graphql b/graphql/schema/testdata/schemagen/output/generate-directive.graphql
index 046c376fd08..1a4e9a7a725 100644
--- a/graphql/schema/testdata/schemagen/output/generate-directive.graphql
+++ b/graphql/schema/testdata/schemagen/output/generate-directive.graphql
@@ -113,6 +113,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -195,6 +199,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/geo-type.graphql b/graphql/schema/testdata/schemagen/output/geo-type.graphql
index 7b007dbea08..071120217c4 100644
--- a/graphql/schema/testdata/schemagen/output/geo-type.graphql
+++ b/graphql/schema/testdata/schemagen/output/geo-type.graphql
@@ -104,6 +104,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -186,6 +190,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/hasInverse-with-interface-having-directive.graphql b/graphql/schema/testdata/schemagen/output/hasInverse-with-interface-having-directive.graphql
index 2a6e74d672c..5529d051f3a 100755
--- a/graphql/schema/testdata/schemagen/output/hasInverse-with-interface-having-directive.graphql
+++ b/graphql/schema/testdata/schemagen/output/hasInverse-with-interface-having-directive.graphql
@@ -123,6 +123,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -205,6 +209,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/hasInverse-with-interface.graphql b/graphql/schema/testdata/schemagen/output/hasInverse-with-interface.graphql
index 7262833b462..07d3a978165 100755
--- a/graphql/schema/testdata/schemagen/output/hasInverse-with-interface.graphql
+++ b/graphql/schema/testdata/schemagen/output/hasInverse-with-interface.graphql
@@ -125,6 +125,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -207,6 +211,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/hasInverse-with-type-having-directive.graphql b/graphql/schema/testdata/schemagen/output/hasInverse-with-type-having-directive.graphql
index 2a6e74d672c..5529d051f3a 100755
--- a/graphql/schema/testdata/schemagen/output/hasInverse-with-type-having-directive.graphql
+++ b/graphql/schema/testdata/schemagen/output/hasInverse-with-type-having-directive.graphql
@@ -123,6 +123,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -205,6 +209,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/hasInverse.graphql b/graphql/schema/testdata/schemagen/output/hasInverse.graphql
index e550998e55a..2e1b4087111 100755
--- a/graphql/schema/testdata/schemagen/output/hasInverse.graphql
+++ b/graphql/schema/testdata/schemagen/output/hasInverse.graphql
@@ -104,6 +104,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -186,6 +190,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/hasInverse_withSubscription.graphql b/graphql/schema/testdata/schemagen/output/hasInverse_withSubscription.graphql
index 08cebd56299..177f12530f2 100755
--- a/graphql/schema/testdata/schemagen/output/hasInverse_withSubscription.graphql
+++ b/graphql/schema/testdata/schemagen/output/hasInverse_withSubscription.graphql
@@ -104,6 +104,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -186,6 +190,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/hasfilter.graphql b/graphql/schema/testdata/schemagen/output/hasfilter.graphql
index e5adcc1acc6..69bfb06206a 100644
--- a/graphql/schema/testdata/schemagen/output/hasfilter.graphql
+++ b/graphql/schema/testdata/schemagen/output/hasfilter.graphql
@@ -106,6 +106,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -188,6 +192,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/ignore-unsupported-directive.graphql b/graphql/schema/testdata/schemagen/output/ignore-unsupported-directive.graphql
index 0d50f4fcb38..c1ab841a763 100755
--- a/graphql/schema/testdata/schemagen/output/ignore-unsupported-directive.graphql
+++ b/graphql/schema/testdata/schemagen/output/ignore-unsupported-directive.graphql
@@ -105,6 +105,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -187,6 +191,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/interface-with-dgraph-pred.graphql b/graphql/schema/testdata/schemagen/output/interface-with-dgraph-pred.graphql
index a604dd070c5..46511cf0a48 100644
--- a/graphql/schema/testdata/schemagen/output/interface-with-dgraph-pred.graphql
+++ b/graphql/schema/testdata/schemagen/output/interface-with-dgraph-pred.graphql
@@ -114,6 +114,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -196,6 +200,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/interface-with-id-directive.graphql b/graphql/schema/testdata/schemagen/output/interface-with-id-directive.graphql
index db2e3d3be50..0f11c74abee 100755
--- a/graphql/schema/testdata/schemagen/output/interface-with-id-directive.graphql
+++ b/graphql/schema/testdata/schemagen/output/interface-with-id-directive.graphql
@@ -110,6 +110,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -192,6 +196,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/interface-with-no-ids.graphql b/graphql/schema/testdata/schemagen/output/interface-with-no-ids.graphql
index 90161b27860..95bf2aed056 100755
--- a/graphql/schema/testdata/schemagen/output/interface-with-no-ids.graphql
+++ b/graphql/schema/testdata/schemagen/output/interface-with-no-ids.graphql
@@ -108,6 +108,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -190,6 +194,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/interfaces-with-types-and-password.graphql b/graphql/schema/testdata/schemagen/output/interfaces-with-types-and-password.graphql
index 2314846daa9..baee5257b8f 100755
--- a/graphql/schema/testdata/schemagen/output/interfaces-with-types-and-password.graphql
+++ b/graphql/schema/testdata/schemagen/output/interfaces-with-types-and-password.graphql
@@ -133,6 +133,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -215,6 +219,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/interfaces-with-types.graphql b/graphql/schema/testdata/schemagen/output/interfaces-with-types.graphql
index 53da87263b2..0b6f623356c 100755
--- a/graphql/schema/testdata/schemagen/output/interfaces-with-types.graphql
+++ b/graphql/schema/testdata/schemagen/output/interfaces-with-types.graphql
@@ -133,6 +133,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -215,6 +219,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/lambda-directive.graphql b/graphql/schema/testdata/schemagen/output/lambda-directive.graphql
index 8df251f64a7..13dc614cc54 100644
--- a/graphql/schema/testdata/schemagen/output/lambda-directive.graphql
+++ b/graphql/schema/testdata/schemagen/output/lambda-directive.graphql
@@ -100,6 +100,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -182,6 +186,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/language-tags.graphql b/graphql/schema/testdata/schemagen/output/language-tags.graphql
index 09bbce78f52..b67526feee5 100755
--- a/graphql/schema/testdata/schemagen/output/language-tags.graphql
+++ b/graphql/schema/testdata/schemagen/output/language-tags.graphql
@@ -113,6 +113,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -195,6 +199,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
@@ -447,6 +452,7 @@ input PersonPatch {
 	f1Hi: String
 	f2: String
 	f3: String
+	name: String
 	nameHi: String
 	nameEn: String
 	address: String
diff --git a/graphql/schema/testdata/schemagen/output/no-id-field-with-searchables.graphql b/graphql/schema/testdata/schemagen/output/no-id-field-with-searchables.graphql
index 5430dbf9e17..5c976fe960e 100755
--- a/graphql/schema/testdata/schemagen/output/no-id-field-with-searchables.graphql
+++ b/graphql/schema/testdata/schemagen/output/no-id-field-with-searchables.graphql
@@ -97,6 +97,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -179,6 +183,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/no-id-field.graphql b/graphql/schema/testdata/schemagen/output/no-id-field.graphql
index 1976d50b845..bc720948cbf 100755
--- a/graphql/schema/testdata/schemagen/output/no-id-field.graphql
+++ b/graphql/schema/testdata/schemagen/output/no-id-field.graphql
@@ -110,6 +110,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -192,6 +196,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/password-type.graphql b/graphql/schema/testdata/schemagen/output/password-type.graphql
index cba6c170459..ffcd13110cd 100755
--- a/graphql/schema/testdata/schemagen/output/password-type.graphql
+++ b/graphql/schema/testdata/schemagen/output/password-type.graphql
@@ -98,6 +98,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -180,6 +184,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/random.graphql b/graphql/schema/testdata/schemagen/output/random.graphql
index 117b334faef..77a1cbc61ec 100644
--- a/graphql/schema/testdata/schemagen/output/random.graphql
+++ b/graphql/schema/testdata/schemagen/output/random.graphql
@@ -116,6 +116,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -198,6 +202,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @remote on OBJECT | INTERFACE | UNION | INPUT_OBJECT | ENUM
diff --git a/graphql/schema/testdata/schemagen/output/searchables-references.graphql b/graphql/schema/testdata/schemagen/output/searchables-references.graphql
index a1d33610f5a..405e5facd32 100755
--- a/graphql/schema/testdata/schemagen/output/searchables-references.graphql
+++ b/graphql/schema/testdata/schemagen/output/searchables-references.graphql
@@ -108,6 +108,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -190,6 +194,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/searchables.graphql b/graphql/schema/testdata/schemagen/output/searchables.graphql
index 8e21af2ddcd..21bb0df8902 100755
--- a/graphql/schema/testdata/schemagen/output/searchables.graphql
+++ b/graphql/schema/testdata/schemagen/output/searchables.graphql
@@ -128,6 +128,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -210,6 +214,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/single-type-with-enum.graphql b/graphql/schema/testdata/schemagen/output/single-type-with-enum.graphql
index dc67bd55967..20445ad0497 100755
--- a/graphql/schema/testdata/schemagen/output/single-type-with-enum.graphql
+++ b/graphql/schema/testdata/schemagen/output/single-type-with-enum.graphql
@@ -106,6 +106,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -188,6 +192,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/single-type.graphql b/graphql/schema/testdata/schemagen/output/single-type.graphql
index ffd93575abf..524aaa18295 100755
--- a/graphql/schema/testdata/schemagen/output/single-type.graphql
+++ b/graphql/schema/testdata/schemagen/output/single-type.graphql
@@ -101,6 +101,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -183,6 +187,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/type-implements-multiple-interfaces.graphql b/graphql/schema/testdata/schemagen/output/type-implements-multiple-interfaces.graphql
index b789d8551f7..ecbd5db1b2c 100755
--- a/graphql/schema/testdata/schemagen/output/type-implements-multiple-interfaces.graphql
+++ b/graphql/schema/testdata/schemagen/output/type-implements-multiple-interfaces.graphql
@@ -115,6 +115,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -197,6 +201,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/type-reference.graphql b/graphql/schema/testdata/schemagen/output/type-reference.graphql
index 721497a18fd..20811f0a341 100755
--- a/graphql/schema/testdata/schemagen/output/type-reference.graphql
+++ b/graphql/schema/testdata/schemagen/output/type-reference.graphql
@@ -105,6 +105,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -187,6 +191,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/type-with-arguments-on-field.graphql b/graphql/schema/testdata/schemagen/output/type-with-arguments-on-field.graphql
index 192482c12fa..b98d068a640 100644
--- a/graphql/schema/testdata/schemagen/output/type-with-arguments-on-field.graphql
+++ b/graphql/schema/testdata/schemagen/output/type-with-arguments-on-field.graphql
@@ -106,6 +106,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -188,6 +192,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/type-with-custom-field-on-dgraph-type.graphql b/graphql/schema/testdata/schemagen/output/type-with-custom-field-on-dgraph-type.graphql
index 7e4c71914f7..d3336134634 100644
--- a/graphql/schema/testdata/schemagen/output/type-with-custom-field-on-dgraph-type.graphql
+++ b/graphql/schema/testdata/schemagen/output/type-with-custom-field-on-dgraph-type.graphql
@@ -105,6 +105,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -187,6 +191,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/type-with-custom-fields-on-remote-type.graphql b/graphql/schema/testdata/schemagen/output/type-with-custom-fields-on-remote-type.graphql
index e85ea68b041..6db0f218446 100644
--- a/graphql/schema/testdata/schemagen/output/type-with-custom-fields-on-remote-type.graphql
+++ b/graphql/schema/testdata/schemagen/output/type-with-custom-fields-on-remote-type.graphql
@@ -105,6 +105,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -187,6 +191,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/type-without-orderables.graphql b/graphql/schema/testdata/schemagen/output/type-without-orderables.graphql
index ff78a20fbb1..fac1447b75d 100644
--- a/graphql/schema/testdata/schemagen/output/type-without-orderables.graphql
+++ b/graphql/schema/testdata/schemagen/output/type-without-orderables.graphql
@@ -100,6 +100,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -182,6 +186,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/testdata/schemagen/output/union.graphql b/graphql/schema/testdata/schemagen/output/union.graphql
index 33eaa4c6c54..7d8d32ed3ad 100644
--- a/graphql/schema/testdata/schemagen/output/union.graphql
+++ b/graphql/schema/testdata/schemagen/output/union.graphql
@@ -147,6 +147,10 @@ input CustomHTTP {
 	skipIntrospection: Boolean
 }
 
+input DgraphDefault {
+	value: String
+}
+
 type Point {
 	longitude: Float!
 	latitude: Float!
@@ -229,6 +233,7 @@ directive @hasInverse(field: String!) on FIELD_DEFINITION
 directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
+directive @default(add: DgraphDefault, update: DgraphDefault) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @secret(field: String!, pred: String) on OBJECT | INTERFACE
 directive @auth(
diff --git a/graphql/schema/wrappers.go b/graphql/schema/wrappers.go
index 40239982a55..056f5e12d1b 100644
--- a/graphql/schema/wrappers.go
+++ b/graphql/schema/wrappers.go
@@ -19,12 +19,14 @@ package schema
 import (
 	"bytes"
 	"encoding/json"
+	"flag"
 	"fmt"
 	"net/http"
 	"net/url"
 	"sort"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/pkg/errors"
 
@@ -270,6 +272,7 @@ type FieldDefinition interface {
 	IsExternal() bool
 	HasIDDirective() bool
 	HasInterfaceArg() bool
+	GetDefaultValue(action string) interface{}
 	Inverse() FieldDefinition
 	WithMemberType(string) FieldDefinition
 	// TODO - It might be possible to get rid of ForwardEdge and just use Inverse() always.
@@ -2313,6 +2316,36 @@ func (fd *fieldDefinition) IsID() bool {
 	return isID(fd.fieldDef)
 }
 
+func (fd *fieldDefinition) GetDefaultValue(action string) interface{} {
+	if fd.fieldDef == nil {
+		return nil
+	}
+	return getDefaultValue(fd.fieldDef, action)
+}
+
+func getDefaultValue(fd *ast.FieldDefinition, action string) interface{} {
+	dir := fd.Directives.ForName(defaultDirective)
+	if dir == nil {
+		return nil
+	}
+	arg := dir.Arguments.ForName(action)
+	if arg == nil {
+		return nil
+	}
+	value := arg.Value.Children.ForName("value")
+	if value == nil {
+		return nil
+	}
+	if value.Raw == "$now" {
+		if flag.Lookup("test.v") == nil {
+			return time.Now().Format(time.RFC3339)
+		} else {
+			return "2000-01-01T00:00:00.00Z"
+		}
+	}
+	return value.Raw
+}
+
 func (fd *fieldDefinition) HasIDDirective() bool {
 	if fd.fieldDef == nil {
 		return false
@@ -2353,6 +2386,10 @@ func isID(fd *ast.FieldDefinition) bool {
 	return fd.Type.Name() == "ID"
 }
 
+func hasDefault(fd *ast.FieldDefinition) bool {
+	return fd.Directives.ForName(defaultDirective) != nil
+}
+
 func (fd *fieldDefinition) Type() Type {
 	return &astType{
 		typ:             fd.fieldDef.Type,
@@ -2717,7 +2754,7 @@ func (t *astType) ImplementingTypes() []Type {
 // satisfy a valid post.
 func (t *astType) EnsureNonNulls(obj map[string]interface{}, exclusion string) error {
 	for _, fld := range t.inSchema.schema.Types[t.Name()].Fields {
-		if fld.Type.NonNull && !isID(fld) && fld.Name != exclusion &&
+		if fld.Type.NonNull && !isID(fld) && !hasDefault(fld) && fld.Name != exclusion &&
 			t.inSchema.customDirectives[t.Name()][fld.Name] == nil {
 			if val, ok := obj[fld.Name]; !ok || val == nil {
 				return errors.Errorf(