diff --git a/src/host/extension-catalog.ts b/src/host/extension-catalog.ts
index 53fc46a..87dacbb 100644
--- a/src/host/extension-catalog.ts
+++ b/src/host/extension-catalog.ts
@@ -6,10 +6,19 @@ export type OfficialExtension = {
   manifestUrl: string;
 };
 
-export const OFFICIAL_EXTENSIONS: readonly OfficialExtension[] = [{
-  id: "scheduler",
-  name: "Scheduler",
-  description: "Create normal ZCode tasks from timezone-aware cron schedules while ZCode is open.",
-  repositoryUrl: "https://github.com/notmike101/zcode-scheduler",
-  manifestUrl: "https://github.com/notmike101/zcode-scheduler/releases/latest/download/extension-update.json",
-}];
+export const OFFICIAL_EXTENSIONS: readonly OfficialExtension[] = [
+  {
+    id: "scheduler",
+    name: "Scheduler",
+    description: "Create normal ZCode tasks from timezone-aware cron schedules while ZCode is open.",
+    repositoryUrl: "https://github.com/notmike101/zcode-scheduler",
+    manifestUrl: "https://github.com/notmike101/zcode-scheduler/releases/latest/download/extension-update.json",
+  },
+  {
+    id: "zcode-tps",
+    name: "Token Speed",
+    description: "Show live estimates and exact provider-reported token throughput for ZCode sessions.",
+    repositoryUrl: "https://github.com/notmike101/zcode-tps-extension",
+    manifestUrl: "https://github.com/notmike101/zcode-tps-extension/releases/latest/download/extension-update.json",
+  },
+];
diff --git a/tests/extension-catalog.test.ts b/tests/extension-catalog.test.ts
new file mode 100644
index 0000000..8229694
--- /dev/null
+++ b/tests/extension-catalog.test.ts
@@ -0,0 +1,27 @@
+import {describe, expect, test} from "bun:test";
+import {OFFICIAL_EXTENSIONS} from "../src/host/extension-catalog.ts";
+
+describe("official extension catalog", () => {
+  test("uses unique ids and immutable HTTPS release-feed locations", () => {
+    expect(new Set(OFFICIAL_EXTENSIONS.map(({id}) => id)).size).toBe(OFFICIAL_EXTENSIONS.length);
+    for (const extension of OFFICIAL_EXTENSIONS) {
+      const repository = new URL(extension.repositoryUrl);
+      const manifest = new URL(extension.manifestUrl);
+      expect(repository.protocol).toBe("https:");
+      expect(repository.hostname).toBe("github.com");
+      expect(manifest.protocol).toBe("https:");
+      expect(manifest.hostname).toBe("github.com");
+      expect(manifest.pathname).toBe(`/${repository.pathname.slice(1)}/releases/latest/download/extension-update.json`);
+    }
+  });
+
+  test("lists Token Speed by its public release feed", () => {
+    expect(OFFICIAL_EXTENSIONS).toContainEqual({
+      id: "zcode-tps",
+      name: "Token Speed",
+      description: "Show live estimates and exact provider-reported token throughput for ZCode sessions.",
+      repositoryUrl: "https://github.com/notmike101/zcode-tps-extension",
+      manifestUrl: "https://github.com/notmike101/zcode-tps-extension/releases/latest/download/extension-update.json",
+    });
+  });
+});