Xcode MCP

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

• #10735

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Sorry I am exhausted it's now midnight and this has been an extremely trying experience. If I came across rude I don't mean to.

No that issue isn't a duplicate.

As a temporary workaround, running a MCP proxy (find one that does stdio to streaming HTTP) more or less works. The proxy holds the "single connection" that keeps Xcode happy and lets Codex constantly open new sessions on its side.

Which reveals the core issue here: Xcode wants a single persistent connection while Codex is _constantly_ creating new connections to MCP, with any excuse at all. So Xcode sees each new MCP connection as requiring a new approval, which isn't really wrong. Codex should maintain a single connection.

I see, thanks for the insight and workaround. Hopefully they can fix it properly soon. Do you have any recommendations?

Following on the comment by @tabletcorry, I was able to get the following approach working for me. Hope this helps:

npm install -g mcp-proxy
mcp-proxy --port 9876 -- xcrun mcpbridge &

codex mcp remove xcode 2>/dev/null
codex mcp add --url http://localhost:9876/mcp xcode-proxy

Update Xcode to 26.3 RC2 (17C528) to fix MCP error -32600 on 26.3 RC1. Refer: Known Limitation in Xcode 26.3 RC 1 (Fixed in RC 2)

The TCC dialog should only fire once after this and you should be able to see mcp-proxy in the list on Xcode under Agent Activity:

<img width="364" height="212" alt="Image" src="https://github.com/user-attachments/assets/218f0a87-c965-4a21-900f-a792d991e0a2" />

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A script to manage this for both codex and claude: xcode-mcp-proxy-manager.sh

I have this problem too with the Xcode 26.4 Beta. The right solution here would be that Codex maintains one single connection to the Xcode MCP. Urgent fix would be very appreciated.

Or, look at the Xcode.app and see they simply have poor documentation.

``` shell
find /Applications/Xcode.app -type f -iname 'mcp*'

-rwxr-xr-x 1 501 80 398336 Jan 29 02:36 /Applications/Xcode.app/Contents/Developer/usr/bin/mcpbridge

Then 

mcpbridge -h

yields

mcpbridge - STDIO Bridge for Xcode MCP Tools

USAGE:
xcrun mcpbridge

DESCRIPTION:
Acts as a STDIO bridge between MCP (Model Context Protocol) clients and Xcode's MCP tool service.
Reads JSON-RPC 2.0 messages from stdin and forwards responses to stdout.

ENVIRONMENT VARIABLES:
MCP_XCODE_PID Optional. The process ID of the Xcode instance to connect to.

If not set, auto-detection uses the following fallback logic:

1. If exactly one Xcode process is running, use that
2. If multiple Xcode processes are running, use xcode-select

to determine which Xcode is selected and connect to that

1. If no Xcode processes found, exit with error

MCP_XCODE_SESSION_ID Optional. A UUID identifying an Xcode tool session.

EXAMPLES:
# Run with auto-detected Xcode instance
xcrun mcpbridge

# Run with specific Xcode PID
MCP_XCODE_PID=12345 xcrun mcpbridge

OPTIONS:
-h, -help, --help Show this help message

and there's how we use it correctly.

Then ask the local AGENT to give correct instructions on configuration of this so that it doesn't incorrectly keep respawning.

Hey! I ran into a similar pattern in our bug knowledge base and thought this might help.

What's happening: Xcode's MCP bridge (xcrun mcpbridge) uses stdio transport, which only supports a single connection. Codex's multi-agent architecture causes each agent to independently spawn its own mcpbridge process. Each spawned process triggers a macOS security permission prompt, producing the dialog spam shown in the screenshot. On Xcode 26.3 RC1, the bridge also returns MCP error -32600 on certain requests, causing agents to retry and re-spawn connections in a loop — amplifying the spam.

What worked for us:

Do NOT kill Codex agents — they are working as designed. Instead, run a single mcpbridge instance behind mcp-proxy (HTTP/SSE transport) so all agents share one bridge process and one permission grant. Then register the proxy URL in Codex instead of the raw stdio bridge. Also update to Xcode 26.3 RC2 (build 17C528) which fixes the -32600 protocol error that causes retry storms.

# 1. Install mcp-proxy globally
npm install -g mcp-proxy

# 2. Start a single mcpbridge behind the proxy (background)
mcp-proxy --port 9876 -- xcrun mcpbridge &

# 3. Replace the stdio-based xcode MCP with the proxied HTTP endpoint
codex mcp remove xcode 2>/dev/null
codex mcp add --url http://localhost:9876/mcp xcode-proxy

# 4. Update Xcode to 26.3 RC2 (build 17C528) via Xcode > Settings > Components
#    or download from developer.apple.com — fixes MCP -32600 error

Hope this helps! Let me know if it doesn't match your case — happy to dig deeper. 🦞

_Disclosure: This analysis is from Confucius Debug, an AI-powered community KB for agent bugs. Please verify before applying._

---
<sub>🦞 Confucius Debug — community knowledge base for AI agent bugs. Free to search via MCP.</sub>

The root issue is that xcrun mcpbridge only supports one connection, so each agent spawn triggers a new TCC prompt. Routing all agents through a single persistent mcp-proxy instance eliminates the spam. Works for both Codex App and Claude Code. Setup guide: https://cacheoverflow.dev/blog/Ev0ExgjA

@ilaikim99 That mcp-proxy approach is the right call. Props to @tabletcorry for originally identifying the single-connection constraint and @llk23r for the step-by-step setup.

For anyone still on Xcode 26.3 RC1: upgrading to RC2 (17C528) fixes the MCP error -32600. Combined with the proxy, that eliminates both the TCC prompt spam and the error loop.

Quick setup recap:

npm install -g mcp-proxy
mcp-proxy --port 9876 -- xcrun mcpbridge &
codex mcp add --url http://localhost:9876/mcp xcode-proxy

This works for both Codex App and Claude Code since neither maintains a persistent MCP connection natively.

I built xcode-cli-skill, CLI + Skill wrapper official Xcode 26.3+ MCP tools, so the "Allow access to Xcode?" popup only appears once per computer boot, plus a Skill that saves ~5K tokens of context per conversation.

I can recommend this xcode mcp proxy https://github.com/lynnswap/XcodeMCPKit

This bug report hasn't received any upvotes or posts in a month. I presume that users are no longer seeing the problem. I'm going to close the issue. If you're still seeing a related issue, please open a new bug report and reference this one.