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     │
│ ...        │
└────────────┘

Reads your OAuth token from macOS Keychain (written by Claude Code)
Discovers your connectors via api.anthropic.com/v1/mcp_servers
Connects to each via mcp-proxy.anthropic.com (Streamable HTTP)
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

MCP Servers