[hey-research-lab]

Problem

Codex.parseConfig merges the caller's config over the defaults with Object.assign({}, defaultConfig, config). Object.assign copies keys whose value is undefined, so an option that is present but undefined replaces its default. The examples in examples/simple/ construct the SDK as

const sdk = new Codex(process.env.CODEX_API_KEY || "", {
  apiUrl: process.env.CODEX_API_URL,
});

and the examples README only asks for CODEX_API_KEY. With CODEX_API_URL unset, apiUrl becomes undefined and every query and mutation fails:

const sdk = new Codex("key", { apiUrl: process.env.CODEX_API_URL, ws: false });
await sdk.send("query { getNetworks { id } }");
// TypeError: Only absolute URLs are supported   (the request goes to "undefined")

The same happens to apiRealtimeUrl, and ws: undefined turns the websocket off.

Fix

parseConfig drops options whose value is undefined before merging, so they keep their defaults. Explicit values (including ws: false) behave as before, and updateConfig goes through the same function.

Validation

• Added a test in src/sdk/index.test.ts that passes apiUrl, apiRealtimeUrl and ws as undefined with a stub fetch: on main the request goes to "undefined" (test fails); with the fix it goes to https://graph.codex.io/graphql and the websocket client gets the default URL with ws: true.
• pnpm test (build:types + jest): 4 suites, 93 tests pass.
• eslint and prettier --check on the changed files: no errors.