feat(threads): production child threads in Agents panel plus threads MCP toolkit (#8)

GLOSSARY.md

@@ -3,11 +3,11 @@
 Canonical terms for the toolboxmd fork. Names follow the Lightbringer series
 by Brent Weeks, the source of the company name.
 
-| Term | Meaning | Avoid |
-| --- | --- | --- |
-| Luxin | The company; also the work agents produce (code, PRs). | |
-| Chromeria | This app: the gateway where the user directs every agent across harnesses, with more interfaces (such as the OpenBot mode) over time. Built from the T3 Code fork. | T3 Code Fork, Bridge |
-| Drafter | An agent working for the user on one harness and model. | bot (reserved for OpenBot's named Bots) |
-| Prism | Planned product name for Model Router: splits work across models and balances capacity. Not renamed yet. | |
-| Toolbox | Planned name for the user's own future harness. | |
-| T3 Code | The upstream project this fork tracks (`pingdotgg/t3code`). | |
+| Term      | Meaning                                                                                                                                                            | Avoid                                   |
+| --------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------ | --------------------------------------- |
+| Luxin     | The company; also the work agents produce (code, PRs).                                                                                                             |                                         |
+| Chromeria | This app: the gateway where the user directs every agent across harnesses, with more interfaces (such as the OpenBot mode) over time. Built from the T3 Code fork. | T3 Code Fork, Bridge                    |
+| Drafter   | An agent working for the user on one harness and model.                                                                                                            | bot (reserved for OpenBot's named Bots) |
+| Prism     | Planned product name for Model Router: splits work across models and balances capacity. Not renamed yet.                                                           |                                         |
+| Toolbox   | Planned name for the user's own future harness.                                                                                                                    |                                         |
+| T3 Code   | The upstream project this fork tracks (`pingdotgg/t3code`).                                                                                                        |                                         |

apps/server/src/entrypoint.test.ts

@@ -48,7 +48,10 @@ describe("isEntrypoint", () => {
   it.skipIf(!symlinksSupported)(
     "matches through a symlinked entrypoint, as npm and npx install it",
     () => {
-      const dir = makeTempDir();
+      // Node reports the entry module URL fully resolved, so resolve the
+      // fixture dir too: under a symlinked TMPDIR (macOS /var -> /private/var)
+      // an unresolved dir would test a URL Node never produces.
+      const dir = NodeFS.realpathSync(makeTempDir());
       const real = NodePath.join(dir, "bin.mjs");
       const link = NodePath.join(dir, "t3");
       NodeFS.writeFileSync(real, "");

apps/server/src/mcp/McpHttpServer.ts

@@ -31,6 +31,8 @@ import {
 } from "./toolkits/preview/tools.ts";
 import { PullRequestsToolkitHandlersLive } from "./toolkits/pullRequests/handlers.ts";
 import { PullRequestsToolkit } from "./toolkits/pullRequests/tools.ts";
+import { ThreadsToolkitHandlersLive } from "./toolkits/threads/handlers.ts";
+import { ThreadsToolkit } from "./toolkits/threads/tools.ts";
 import {
   DeviceScreenshotToolkitHandlersLive,
   DeviceStandardToolkitHandlersLive,
@@ -608,6 +610,10 @@ export const PullRequestsToolkitRegistrationLive = McpServer.toolkit(PullRequest
   Layer.provide(PullRequestsToolkitHandlersLive),
 );
 
+export const ThreadsToolkitRegistrationLive = McpServer.toolkit(ThreadsToolkit).pipe(
+  Layer.provide(ThreadsToolkitHandlersLive),
+);
+
 const DeviceStandardToolkitRegistrationLive = McpServer.toolkit(DeviceStandardToolkit).pipe(
   Layer.provide(DeviceStandardToolkitHandlersLive),
 );
@@ -631,5 +637,6 @@ const McpTransportLive = McpServer.layerHttp({
 export const layer = Layer.mergeAll(
   PreviewToolkitRegistrationLive,
   PullRequestsToolkitRegistrationLive,
+  ThreadsToolkitRegistrationLive,
   DeviceToolkitRegistrationLive,
 ).pipe(Layer.provideMerge(McpTransportLive));

apps/server/src/mcp/toolkits/threads/childThreads.test.ts

@@ -0,0 +1,52 @@
+import { describe, expect, it } from "vite-plus/test";
+
+import { deliveryOf, effortOptionId, subagentStatusOf } from "./handlers.ts";
+
+const session = (status: string) =>
+  ({
+    status,
+    providerInstanceId: "codex",
+    activeTurnId: null,
+    lastError: null,
+  }) as unknown as Parameters<typeof subagentStatusOf>[0];
+
+describe("child thread status vocabulary", () => {
+  it("maps a missing session to starting so the message guard holds", () => {
+    expect(subagentStatusOf(null)).toBe("starting");
+  });
+
+  it("collapses provider session states onto the toolkit vocabulary", () => {
+    expect(subagentStatusOf(session("starting"))).toBe("starting");
+    expect(subagentStatusOf(session("running"))).toBe("running");
+    expect(subagentStatusOf(session("idle"))).toBe("idle");
+    expect(subagentStatusOf(session("ready"))).toBe("idle");
+    expect(subagentStatusOf(session("error"))).toBe("failed");
+    expect(subagentStatusOf(session("interrupted"))).toBe("stopped");
+    expect(subagentStatusOf(session("stopped"))).toBe("stopped");
+  });
+});
+
+describe("child thread effort routing", () => {
+  it("uses each driver's advertised reasoning-effort option", () => {
+    expect(effortOptionId("codex")).toBe("reasoningEffort");
+    expect(effortOptionId("grok")).toBe("reasoningEffort");
+    expect(effortOptionId("opencode")).toBe("variant");
+  });
+
+  it("falls back to effort for Claude, Cursor and Antigravity", () => {
+    expect(effortOptionId("claudeAgent")).toBe("effort");
+    expect(effortOptionId("cursor")).toBe("effort");
+    expect(effortOptionId("antigravity")).toBe("effort");
+  });
+});
+
+describe("child thread message delivery", () => {
+  it("steers a running child and opens a turn everywhere else", () => {
+    expect(deliveryOf("running")).toBe("steer");
+    expect(deliveryOf("idle")).toBe("new-turn");
+    expect(deliveryOf("failed")).toBe("new-turn");
+    expect(deliveryOf("stopped")).toBe("new-turn");
+    // starting never reaches deliveryOf: the message tool refuses it first.
+    expect(deliveryOf("starting")).toBe("new-turn");
+  });
+});