claudeai-mcp-bridge

Disclaimer: This project is not affiliated with, endorsed by, or officially supported by Anthropic. It is an independent, experimental project for educational and research purposes. It uses undocumented internal APIs that may change or break at any time. Using Claude subscription tokens outside official clients may violate Anthropic's Terms of Service. Use at your own risk -- no warranty is provided.

Use your claude.ai connectors (Slack, Atlassian, Gmail, Google Calendar) inside any MCP client -- zero credential setup.

This is a standard MCP server (stdio) that bridges connectors you've already authorized through claude.ai into any MCP-compatible tool. Works with OpenCode, Claude Desktop, Cursor, Cline, Windsurf, and more.

How it works

┌────────────┐  stdio (MCP)  ┌──────────────────┐   HTTPS    ┌──────────────────┐
│ Any MCP    │──────────────>│ This MCP Server  │──────────>│ mcp-proxy.       │
│ Client     │<──────────────│                  │<──────────│ anthropic.com    │
│            │  tools/list   │ Reads Keychain   │           │                  │
│ OpenCode   │  tools/call   │ Discovers servers│           │ Slack, Atlassian │
│ Claude     │               │ Proxies calls    │           │ Gmail, Calendar  │
│ Desktop    │               └──────────────────┘           └──────────────────┘
│ Cursor     │
│ ...        │
└────────────┘

1. Reads your OAuth token from macOS Keychain (written by Claude Code)
2. Discovers your connectors via api.anthropic.com/v1/mcp_servers
3. Connects to each via mcp-proxy.anthropic.com (Streamable HTTP)
4. Exposes all tools over stdio MCP protocol

Prerequisites

• Claude Code logged in (claude --version)
• Connectors authorized at https://claude.ai/settings/connectors
• Bun runtime (bun -v)

Quick start

1. Clone and install

git clone https://github.com/kitimark/claudeai-mcp-bridge.git
cd claudeai-mcp-bridge
bun install

2. Verify it works

bun run src/poc-discover.ts

You should see your connectors and their tools listed:

[claudeai-mcp] Found 5 connector(s):
[claudeai-mcp]   - Slack (id: mcpsrv_0...)
[claudeai-mcp]   - Atlassian (id: mcpsrv_0...)
[claudeai-mcp] --- Slack ---
[claudeai-mcp]   Tools (13):
[claudeai-mcp]     - slack_send_message: Sends a message to a Slack channel...

For TypeScript validation in this repo, use project-mode checks:

bun run typecheck

3. Add to your MCP client

OpenCode

// opencode.json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "claudeai": {
      "type": "local",
      "command": ["bun", "run", "/absolute/path/to/claudeai-mcp-bridge/src/server.ts"]
    }
  }
}

Claude Desktop

// ~/Library/Application Support/Claude/claude_desktop_config.json
{
  "mcpServers": {
    "claudeai": {
      "command": "bun",
      "args": ["run", "/absolute/path/to/claudeai-mcp-bridge/src/server.ts"]
    }
  }
}

Cursor

// .cursor/mcp.json
{
  "mcpServers": {
    "claudeai": {
      "command": "bun",
      "args": ["run", "/absolute/path/to/claudeai-mcp-bridge/src/server.ts"],
      "env": {
        "CLAUDEAI_MCP_EXCLUDE": "Gmail,Google Calendar"
      }
    }
  }
}

4. Use it

> search slack for messages about the deployment from yesterday

> what are my open jira issues?

> find the confluence page about onboarding

Available tools

Once connected, you get the same tools as Claude Code:

Connector	Tools	Examples
Slack	13	search messages, send messages, read channels, read threads, manage canvases
Atlassian	31	Jira issues (CRUD, transitions, search), Confluence pages (CRUD, search, comments)
Gmail	varies	read/send email (requires active auth)
Google Calendar	varies	manage events (requires active auth)

Tool names follow the pattern: {connector}_{tool_name}

Examples: slack_search_public, atlassian_getJiraIssue

(Your MCP client may add its own prefix, e.g. OpenCode: claudeai_slack_search_public)

Configuration

Environment variables

Variable	Default	Description
CLAUDEAI_MCP_DEBUG	0	Set to 1 for verbose logging
CLAUDEAI_MCP_TIMEOUT	30000	Connection timeout per connector (ms)
CLAUDEAI_MCP_FILTER	(all)	Comma-separated connector names to include
CLAUDEAI_MCP_EXCLUDE	(none)	Comma-separated connector names to exclude
CLAUDE_CODE_UA_VERSION	package version	Override User-Agent Claude Code version for protocol parity simulation

Managing tools (OpenCode)

Disable specific connectors:

{ "tools": { "claudeai_atlassian_*": false } }

Enable only for specific agents:

{
  "tools": { "claudeai_*": false },
  "agent": {
    "slack-agent": { "tools": { "claudeai_slack_*": true } }
  }
}

Troubleshooting

Problem	Solution
No OAuth token found	Run claude to log in
Token expired	Open Claude Code to auto-refresh
Connector shows "auth required"	Re-authorize at https://claude.ai/settings/connectors
Tools don't appear	Restart your MCP client after config change
Too many tools	Use CLAUDEAI_MCP_EXCLUDE env var
VS Code/Zed shows errors but bun run typecheck passes	Reopen the repository root (not a single loose file), run bun install, restart the TypeScript server in your editor, and ensure the editor uses workspace TypeScript from node_modules/typescript/lib

Compatibility

MCP Client	Supported	Config location
OpenCode	Yes	opencode.json
Claude Desktop	Yes	claude_desktop_config.json
Cursor	Yes	.cursor/mcp.json
Cline	Yes	.cline/mcp_settings.json
Windsurf	Yes	MCP settings
Continue.dev	Yes	config.json
Zed	Yes	settings.json
Any stdio MCP client	Yes	--

How it compares to Claude Code

	Claude Code	Any client + this bridge
Same Slack/Atlassian tools	Yes	Yes (identical, same upstream servers)
Credential setup	Zero	Zero (reads from Keychain)
Custom tools alongside	Limited	Whatever your client supports
Works with any editor/tool	No	Yes

Docs

• ideas/how-it-works.md -- Full protocol research, architecture diagrams, source code analysis
• ideas/setup-guide.md -- Detailed setup guide with troubleshooting

Caveats

• Uses undocumented Anthropic endpoints (/v1/mcp_servers, mcp-proxy.anthropic.com) that may change
• Using Claude subscription tokens outside official clients may violate Anthropic's ToS
• Token refresh depends on Claude Code -- keep it installed
• macOS Keychain primary; Linux/Windows falls back to ~/.claude/.credentials.json

License

MIT