From 48a286946413e84a67b6ed07d022bb3426655086 Mon Sep 17 00:00:00 2001
From: HEY Research Lab <327801004+hey-research-lab@users.noreply.github.com>
Date: Thu, 22 Oct 2026 16:45:29 +0800
Subject: [PATCH] fix: keep default config for options passed as undefined

new Codex(key, { apiUrl: process.env.CODEX_API_URL }) with the variable
unset replaced the default apiUrl with undefined, so every query and
mutation failed with "Only absolute URLs are supported". The same held
for apiRealtimeUrl and ws.
---
 src/sdk/index.test.ts | 32 ++++++++++++++++++++++++++++++++
 src/sdk/index.ts      |  7 ++++++-
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/src/sdk/index.test.ts b/src/sdk/index.test.ts
index e8a664c..4a21f9d 100644
--- a/src/sdk/index.test.ts
+++ b/src/sdk/index.test.ts
@@ -100,6 +100,38 @@ describe("Codex", () => {
       createGraphQLClientSpy.mockRestore();
       createWebsocketClientSpy.mockRestore();
     });
+    it("should keep the defaults for options passed as undefined", async () => {
+      const urls: string[] = [];
+      const fetchStub = jest.fn(async (input: RequestInfo | URL) => {
+        urls.push(String(input));
+        return new Response(JSON.stringify({ data: { getNetworks: [] } }), {
+          headers: { "content-type": "application/json" },
+        });
+      });
+      const createWebsocketClientSpy = jest.spyOn(
+        Codex.prototype as any,
+        "createWebsocketClient",
+      );
+
+      const sdkInstance = new Codex("test-key", {
+        apiUrl: undefined,
+        apiRealtimeUrl: undefined,
+        ws: undefined,
+        fetch: fetchStub,
+      });
+      await sdkInstance.send(getNetworksString);
+
+      expect(urls).toEqual(["https://graph.codex.io/graphql"]);
+      expect(createWebsocketClientSpy).toHaveBeenCalledWith(
+        expect.objectContaining({
+          apiRealtimeUrl: "wss://graph.codex.io/graphql",
+          ws: true,
+        }),
+      );
+
+      createWebsocketClientSpy.mockRestore();
+      await sdkInstance.dispose();
+    });
   });
 
   describe("updateConfig", () => {
diff --git a/src/sdk/index.ts b/src/sdk/index.ts
index 4fa2ffd..5c6e7f6 100644
--- a/src/sdk/index.ts
+++ b/src/sdk/index.ts
@@ -85,7 +85,12 @@ export class Codex {
 
   private parseConfig(config: Partial<ApiConfig>) {
     invariant(this.apiKey, "apiKey must be defined");
-    return Object.assign({}, defaultConfig, config);
+    // An option passed as undefined (e.g. `apiUrl: process.env.CODEX_API_URL`
+    // with the variable unset) keeps its default instead of replacing it.
+    const defined = Object.fromEntries(
+      Object.entries(config).filter(([, value]) => value !== undefined),
+    );
+    return Object.assign({}, defaultConfig, defined) as ApiConfig;
   }
 
   private createGraphQLClient(config: ApiConfig) {