Claude Agent tool bridge removes isolated MCP conversation before tools/call, causing MCP error -32603 Conversation not found

[simonmoss49]

Summary
Claude Agent mode exposes Xcode-native tools successfully, but tool execution fails because the MCP conversation is removed before /tools/call requests arrive.
The agent can start a response, list available tools, and request Xcode-native tools such as XcodeRead / XcodeGrep, but every bridge tool call then fails with:
McpError: MCP error -32603: Conversation not found
This appears to be a lifecycle/race issue in the Claude Agent tool bridge, specifically around isolated conversations.
Environment

• macOS: Apple Silicon Mac
• Xcode: 26.3
• xcode-copilot-server: 5.0.1
• Node: v24.16.0
• npm: 11.13.0
• Auth: GitHub CLI auth, authenticated successfully as a Copilot user
• Server installed as LaunchAgent
• Proxy mode: auto
• Log level: debug
• • Working directory: /Users//example-ios-app
    Running process:
    /usr/local/bin/node /Users//.npm-global/lib/node_modules/xcode-copilot-server/dist/index.js --launchd --port 8080 --log-level debug --cwd /Users//example-ios-app --auto-patch --idle-timeout 60
    What works
    The server starts correctly and returns models:
    curl --max-time 10 -s
    -H 'User-Agent: Xcode/26.0'
    http://127.0.0.1:8080/v1/models
    returns the expected Copilot model list, including:
    auto
    claude-sonnet-4.6
    claude-haiku-4.5
    claude-opus-4.6
    gpt-5.4
    gpt-5.3-codex
    gpt-5.4-mini
    gpt-5-mini
    Claude Agent also routes through the proxy correctly:
    POST /v1/messages?beta=true
    The agent sees Xcode-native tools and reports them as available, including tools such as:
    XcodeLS
    XcodeGlob
    XcodeGrep
    XcodeRead
    XcodeWrite
    XcodeUpdate
    BuildProject
    GetBuildLog
    RunAllTests
    RunSomeTests
    XcodeListNavigatorIssues
    DocumentationSearch
    What fails
    When Claude Agent tries to use Xcode-native tools, the MCP conversation has already been removed.
    Relevant log excerpt:
    2026-06-10T10:01:17.580Z · DEBUG Created conversation eefcd40f-252f-4c10-9dd6-3b4138f4dab4 (primary=false)
    2026-06-10T10:01:17.581Z ● INFO New conversation eefcd40f-252f-4c10-9dd6-3b4138f4dab4
    2026-06-10T10:01:18.771Z ● INFO Streaming response for conversation eefcd40f-252f-4c10-9dd6-3b4138f4dab4
    2026-06-10T10:01:18.780Z · DEBUG MCP eefcd40f-252f-4c10-9dd6-3b4138f4dab4: SSE stream opened
    2026-06-10T10:01:18.830Z · DEBUG MCP eefcd40f-252f-4c10-9dd6-3b4138f4dab4: method="tools/list", id=1
    2026-06-10T10:01:18.831Z · DEBUG MCP eefcd40f-252f-4c10-9dd6-3b4138f4dab4 tools/list: 36 tools
    2026-06-10T10:01:27.174Z · DEBUG Conversation eefcd40f-252f-4c10-9dd6-3b4138f4dab4 session ended, removing
    2026-06-10T10:01:27.179Z · DEBUG MCP eefcd40f-252f-4c10-9dd6-3b4138f4dab4: method="tools/call", id=2
    2026-06-10T10:01:27.180Z · DEBUG MCP eefcd40f-252f-4c10-9dd6-3b4138f4dab4: method="tools/call", id=3
    The corresponding tool failures:
    xcode-bridge-XcodeRead done (success=false, MCP server 'xcode-bridge': McpError: MCP error -32603: Conversation not found)
    xcode-bridge-XcodeGrep done (success=false, MCP server 'xcode-bridge': McpError: MCP error -32603: Conversation not found)
    After that, every subsequent tool call against the same MCP conversation fails the same way:
    MCP eefcd40f-252f-4c10-9dd6-3b4138f4dab4: method="tools/call"
    xcode-bridge-XcodeRead done (success=false, MCP server 'xcode-bridge': McpError: MCP error -32603: Conversation not found)
    Pattern observed
    Xcode / Claude Agent appears to send overlapping requests. The tool-capable request is placed into an isolated conversation:
    Primary d0af5908-a120-4e61-aa87-ce28c0f708a5 is busy, creating isolated conversation
    Created conversation eefcd40f-252f-4c10-9dd6-3b4138f4dab4 (primary=false)
    Tools in request: 36
    Tool bridge active (in-process MCP)
    The isolated conversation successfully exposes tools via tools/list, but is removed before real tools/call messages are handled.
    Expected behaviour
    The MCP conversation/session should remain available at least until pending or subsequent /mcp//tools/call requests have completed.
    Expected sequence:
    tools/list: 36 tools
    Tool request: XcodeRead
    /mcp/ tools/call
    xcode-bridge-XcodeRead done (success=true)
    Actual behaviour
    Actual sequence:
    tools/list: 36 tools
    Conversation session ended, removing
    /mcp/ tools/call
    MCP error -32603: Conversation not found
    Reproduction steps

1. Install and run xcode-copilot-server as LaunchAgent in auto mode:
   xcode-copilot-server install-agent
   --cwd "$HOME/example-ios-app"
   --log-level debug
2. Confirm local model list works:
   curl --max-time 10 -s
   -H 'User-Agent: Xcode/26.0'
   http://127.0.0.1:8080/v1/models
3. In Xcode, use:
   Agents → Claude Agent
4. Ask a question that requires Xcode-native file access, for example to read or inspect a Swift file in the project.
5. Observe that Claude starts responding, sees tools, then fails when attempting XcodeRead, XcodeGrep, Glob, etc.
6. Check logs:
   tail -f ~/Library/Logs/xcode-copilot-server.out.log
   tail -f ~/Library/Logs/xcode-copilot-server.err.log
   Additional notes
   The local Chat provider route appears usable:
   Chat → Copilot → /v1/chat/completions
   The failure is specific to Claude Agent / /v1/messages?beta=true with the in-process MCP tool bridge.
   This does not appear to be a GitHub authentication issue, model availability issue, Xcode permission issue, or basic proxy routing issue. The proxy starts, authenticates, lists models, routes Claude Agent requests, exposes tools, and receives MCP calls. The failing point appears to be conversation/session lifecycle around isolated MCP conversations.

[theblixguy]

Fix is available in v5.0.2 - https://github.com/theblixguy/xcode-copilot-server/releases/tag/v5.0.2

Let me know if you have any further issues!

[LibertyDev18]

@theblixguy, thanks for the update/fix for this. Do you usually publish releases out to the npm registry right away or do you wait a bit? https://www.npmjs.com/package/xcode-copilot-server is still showing 5.0.1.

[theblixguy]

@LibertyDev18 It should be live now (I just published it)