fix(server): include thread titles in MCP links

apps/server/src/mcp/McpInvocationContext.ts

@@ -136,14 +136,18 @@ export interface McpInvocationScope {
 /**
  * T3 Code renders `t3-thread://` links as thread chips. Other MCP clients cannot open them, so
  * they get the hosted link Copy thread copies, which opens the thread in either app or a browser.
+ * A known `title` labels the chip for clients that cannot load this environment's threads.
  */
 export const threadLinkFor = (
   scope: Pick<McpInvocationScope, "environmentId" | "client">,
   threadId: ThreadId,
+  title?: string,
 ): string => {
   const hostedAppUrl = scope.client?.hostedAppUrl;
   const ref = { environmentId: scope.environmentId, threadId };
-  return hostedAppUrl === undefined ? formatThreadLink(ref) : hostedThreadLink(ref, hostedAppUrl);
+  return hostedAppUrl === undefined
+    ? formatThreadLink(ref, title)
+    : hostedThreadLink(ref, hostedAppUrl);
 };
 
 export class McpInvocationContext extends Context.Service<

apps/server/src/mcp/OrchestratorMcpService.ts

@@ -805,7 +805,7 @@ function listItemFromShell(
     threadId: shell.id,
     projectId: shell.projectId,
     title: shell.title,
-    link: threadLinkFor(scope, shell.id),
+    link: threadLinkFor(scope, shell.id, shell.title),
     createdBy: shell.createdBy,
     creationSource: shell.creationSource,
     status: shell.activityRunStatus ?? shell.status,
@@ -839,7 +839,7 @@ function threadDetail(
     threadId: projection.thread.id,
     projectId: projection.thread.projectId,
     title: projection.thread.title,
-    link: threadLinkFor(scope, projection.thread.id),
+    link: threadLinkFor(scope, projection.thread.id, projection.thread.title),
     createdBy: projection.thread.createdBy,
     creationSource: projection.thread.creationSource,
     status: active?.status ?? latest?.status ?? "idle",
@@ -1630,10 +1630,10 @@ const make = Effect.gen(function* () {
     const result = {
       taskId: task.id,
       childThreadId: task.childThreadId,
-      link: formatThreadLink({
-        environmentId: scope.environmentId,
-        threadId: task.childThreadId,
-      }),
+      link: formatThreadLink(
+        { environmentId: scope.environmentId, threadId: task.childThreadId },
+        childControls.thread.title,
+      ),
       childRunId: childRun?.id ?? null,
       childNodeId: task.id,
       status,
@@ -1804,7 +1804,10 @@ const make = Effect.gen(function* () {
       childThreadId: null,
       ...(task.remoteChild === undefined
         ? {}
-        : { remoteChild: task.remoteChild, link: formatThreadLink(task.remoteChild) }),
+        : {
+            remoteChild: task.remoteChild,
+            link: formatThreadLink(task.remoteChild, task.remoteChild.title),
+          }),
       childRunId: null,
       childNodeId: task.id,
       status,
@@ -2992,7 +2995,10 @@ const make = Effect.gen(function* () {
                 );
               return {
                 threadId,
-                link: formatThreadLink({ environmentId: scope.environmentId, threadId }),
+                link: formatThreadLink(
+                  { environmentId: scope.environmentId, threadId },
+                  projection.thread.title,
+                ),
                 runId: run?.id ?? null,
                 status: run?.status ?? "idle",
                 title: projection.thread.title,
@@ -3209,7 +3215,7 @@ const make = Effect.gen(function* () {
         );
       return {
         threadId: input.threadId,
-        link: threadLinkFor(scope, input.threadId),
+        link: threadLinkFor(scope, input.threadId, target.thread.title),
         messageId,
         runId: result.run.id,
         ...(result.run.delegatedTaskId === undefined ? {} : { taskId: result.run.delegatedTaskId }),

apps/server/src/mcp/toolkits/project/handlers.test.ts

@@ -221,7 +221,7 @@ it.effect(
       expect(belowCeiling.result).toMatchObject({
         projectId: belowCeiling.projectId,
         modelSelection: belowCeiling.modelSelection,
-        link: `<t3-thread://v2/environment/${belowCeiling.launched[0]?.threadId}>`,
+        link: `[Fix](t3-thread://v2/environment/${belowCeiling.launched[0]?.threadId})`,
       });
       expect(belowCeiling.launched[0]?.runtimeMode).toBe("approval-required");
       expect(belowCeiling.launched[0]?.initialMessage?.senderThreadId).toBeUndefined();

apps/server/src/mcp/toolkits/project/handlers.ts

@@ -277,7 +277,7 @@ export const layer = McpToolAccess.toLayer(ProjectToolkit, {
         const run = result.projection.runs.find((run) => run.userMessageId === messageId);
         return {
           threadId: thread.id,
-          link: McpInvocationContext.threadLinkFor(scope, thread.id),
+          link: McpInvocationContext.threadLinkFor(scope, thread.id, thread.title),
           projectId: thread.projectId,
           modelSelection: thread.modelSelection,
           runId: run?.id ?? null,

apps/server/src/mcp/toolkits/thread/handlers.ts

@@ -134,7 +134,7 @@ export const layer = McpToolAccess.toLayer(ThreadToolkit, {
       return {
         matches: matches.map((match) => ({
           ...match,
-          link: McpInvocationContext.threadLinkFor(scope, match.threadId),
+          link: McpInvocationContext.threadLinkFor(scope, match.threadId, match.title),
         })),
       };
     }),

apps/server/src/peer/RemoteDelegation.test.ts

@@ -827,7 +827,7 @@ it.effect("a task delegated to the box wakes the laptop's parent when it ends th
       expect(yield* Ref.get(thread.launched)).toBe(delegated.remoteChild.threadId);
       // Its link opens the thread there, so the parent can mention it like any other.
       expect(delegated.link).toBe(
-        `<t3-thread://v2/${box.environmentId}/${delegated.remoteChild.threadId}>`,
+        `[Laptop parent](t3-thread://v2/${box.environmentId}/${delegated.remoteChild.threadId})`,
       );
       // ...naming the parent here, so the thread there links back to it.
       expect(yield* Ref.get(thread.delegatedFrom)).toEqual({

apps/server/src/peer/RemoteDelegation.ts

@@ -260,13 +260,14 @@ const make = Effect.gen(function* () {
       // the forwarder scopes the launch's, and the record's names it.
       const key = input.clientRequestId ?? (yield* random.uuidV4());
       const task = taskPrompt(input);
+      const title = input.title ?? parent.thread.title;
       const launched = yield* forwarding.call(
         scope,
         ProjectToolkit.tools.t3_thread_launch,
         target.environmentId,
         {
           projectId,
-          title: input.title ?? parent.thread.title,
+          title,
           modelSelection: { instanceId, model, ...(options === undefined ? {} : { options }) },
           ...(runtimeMode === undefined ? {} : { runtimeMode }),
           ...(interactionMode === undefined ? {} : { interactionMode }),
@@ -291,6 +292,7 @@ const make = Effect.gen(function* () {
         environmentId: target.environmentId,
         threadId: launched.threadId,
         label: link?.label ?? target.environmentId,
+        title,
         ...(launched.runId === null ? {} : { runId: launched.runId }),
       };
       const recorded = yield* threads