fix(bridge): accept null project values in umbrella handshakes

packages/extension/src/protocol/stdio.ts

@@ -6,7 +6,7 @@ import type { StdioMessage } from './types.ts'
 const openObject = { additionalProperties: true } as const
 const bridgeInfoSchema = Type.Object(
   {
-    project: Type.Optional(Type.String()),
+    project: Type.Optional(Type.Union([Type.String(), Type.Null()])),
     version: Type.Optional(Type.String()),
     build: Type.Optional(Type.String()),
     protocol: Type.Optional(Type.Number()),

packages/extension/src/protocol/types.ts

@@ -21,7 +21,7 @@ export interface PendingToolCall {
 }
 
 export interface BridgeInfo {
-  project?: string
+  project?: string | null
   version?: string
   build?: string
   protocol?: number

packages/extension/test/integration/extension-stdio-smoke.test.ts

@@ -1,5 +1,6 @@
 import { execSync } from 'node:child_process'
 import * as fs from 'node:fs'
+import { tmpdir } from 'node:os'
 import path from 'node:path'
 
 import { getUnavailableReason } from '#src/connection/status.ts'
@@ -134,6 +135,34 @@ describe.skipIf(!elixirAvailable || !projectAvailable)(
       expect(info?.plugins?.map((plugin) => plugin.name)).toContain('DemoPlugin')
     })
 
+    it('starts an umbrella bridge and serves AST requests without an application name', async () => {
+      const cwd = fs.mkdtempSync(path.join(tmpdir(), 'pi-elixir-umbrella-'))
+
+      try {
+        fs.mkdirSync(path.join(cwd, 'apps'))
+        fs.writeFileSync(
+          path.join(cwd, 'mix.exs'),
+          'defmodule Umbrella.MixProject do\n  use Mix.Project\n  def project, do: [apps_path: "apps"]\nend\n'
+        )
+        fs.copyFileSync(path.join(cwd, 'mix.exs'), path.join(cwd, 'fixture.ex'))
+        startEmbeddedInBackground(cwd)
+        await waitForReady(cwd)
+
+        expect(getBridgeInfo(cwd)?.project).toBeNull()
+        const result = await callEmbeddedTool(cwd, 'ex_ast_search', {
+          pattern: 'defmodule _ do _ end',
+          path: 'fixture.ex'
+        })
+
+        expect(result.isError).toBe(false)
+        expect(structuredPayload(result).kind).toBe('ast_search')
+        expect(result.text).toContain('Umbrella.MixProject')
+      } finally {
+        stopEmbedded(cwd)
+        fs.rmSync(cwd, { recursive: true, force: true })
+      }
+    })
+
     it('routes Pi.LLM.complete through the extension request handler', async () => {
       const result = await callEmbeddedTool(PROJECT_DIR, 'project_eval', {
         target: 'bridge',

packages/extension/test/protocol-stdio.test.ts

@@ -22,7 +22,14 @@ describe('decodeStdioMessage', () => {
     })
   })
 
+  it('accepts a ready message without an umbrella application name', () => {
+    const message = { type: 'ready', info: { project: null } }
+
+    expect(decodeStdioMessage(message)).toEqual(message)
+  })
+
   it('rejects malformed known messages instead of casting them', () => {
+    expect(decodeStdioMessage({ type: 'ready', info: { project: 42 } })).toBeNull()
     expect(decodeStdioMessage({ type: 'result', id: '1', text: '42', isError: false })).toBeNull()
     expect(
       decodeStdioMessage({