feat: add beacon api schema

packages/api/download-beacon-api-schema.ts

@@ -0,0 +1,28 @@
+/* eslint-disable no-console */
+import fs from "node:fs";
+import path from "node:path";
+import url from "node:url";
+
+import {version} from "./src/schema/version.js";
+
+// eslint-disable-next-line @typescript-eslint/naming-convention
+const __dirname = path.dirname(url.fileURLToPath(import.meta.url));
+
+async function downloadBeaconApiSchema(): Promise<void> {
+  const url = `https://github.com/ethereum/beacon-APIs/releases/download/${version}/beacon-node-oapi.json`;
+  const filepath = path.join(__dirname, "./src/schema/beacon-node-oapi.json");
+  console.log(`Downloading oapi file from ${url}`);
+  let openApiStr = await fetch(url).then((res) => res.text());
+
+  // Parse before writting to ensure it's proper JSON
+  try {
+    openApiStr = JSON.stringify(JSON.parse(openApiStr));
+  } catch (e) {
+    console.log(openApiStr);
+    throw e;
+  }
+
+  fs.writeFileSync(filepath, openApiStr);
+}
+
+await downloadBeaconApiSchema();

packages/api/package.json

@@ -61,6 +61,7 @@
     "check-build": "node -e \"(async function() { await import('./lib/index.js') })()\"",
     "check-types": "tsc",
     "coverage": "codecov -F lodestar-api",
+    "download-beacon-api-schema": "node --loader ts-node/esm download-beacon-api-schema.ts",
     "lint": "eslint --color --ext .ts src/ test/",
     "lint:fix": "yarn run lint --fix",
     "pretest": "yarn run check-types",

packages/api/src/schema/index.ts

@@ -0,0 +1,5 @@
+import schemaJson from "./beacon-node-oapi.json" assert {type: "json"};
+import {version} from "./version.js";
+
+export const schema = schemaJson;
+export const version = version;

packages/api/src/schema/version.ts

@@ -0,0 +1,6 @@
+/**
+ * This is the currently-targeted version of the Beacon-API
+ *
+ * https://github.com/ethereum/beacon-apis
+ */
+export const version = "v2.3.0";