lunchmoney-mcp-server-oauth

Self-hostable remote MCP server for Lunch Money with a built-in OAuth 2.1 authorization server — so it works as a claude.ai custom connector on Claude mobile, web, and desktop, as well as Claude Code and any other Streamable-HTTP MCP client.

Wraps @akutishevsky/lunchmoney-mcp (40+ tools covering transactions, budgets, categories, recurring items, assets, crypto, tags) and serves it over HTTP.

Why this exists

If you want Claude on your phone to see your Lunch Money data, your options were all bad:

Option	Problem
stdio MCP servers (most community servers)	Local-only; Claude mobile can't use them
HTTP server + static bearer token	claude.ai custom connectors have no field for a static header — OAuth is the only supported auth (anthropics/claude-ai-mcp#112)
Hosted MCP platforms	You hand a third party your Lunch Money API token — full read/write access to your finances
No auth	Your finances, public

This server closes the gap: it implements the minimal OAuth 2.1 surface Claude needs (RFC 8414 + RFC 9728 discovery, RFC 7591 dynamic client registration, authorization-code grant with mandatory S256 PKCE, rotating refresh tokens), with a single shared secret as the consent "login". Your API token never leaves your box.

How it works

1. You add https://lm.example.com/mcp as a custom connector in Claude.
2. Claude discovers the OAuth metadata, registers itself as a client, and opens a browser to the consent page.
3. You paste your MCP_AUTH_TOKEN (a secret you generated) once.
4. Claude receives access + refresh tokens and keeps them fresh on its own, across all your Claude surfaces.

Stateless by design: every artifact the server issues — client IDs, authorization codes, access and refresh tokens — is an HMAC-signed blob keyed off MCP_AUTH_TOKEN via HKDF. There is no database and no session store, which means:

• container restarts don't log Claude out
• the container runs with a read-only filesystem
• rotating MCP_AUTH_TOKEN instantly revokes every client and token — that's your kill switch

Artifact	Lifetime
authorization code	2 min, single-use
access token	1 hour
refresh token	90 days, rotated on every refresh

Quick start

# 1. Secrets
cp docker-compose.example.yml docker-compose.yml
cat > .env <<EOF
LUNCHMONEY_API_TOKEN=<lunchmoney.app -> Settings -> Developers>
LUNCHMONEY_MCP_TOKEN=$(openssl rand -base64 48)
EOF

# 2. Set BASE_URL in docker-compose.yml to your public https URL, then:
docker compose up -d

# 3. Put a TLS reverse proxy in front (see below), then add the connector
#    in Claude: Settings -> Connectors -> Add custom connector ->
#    https://lm.example.com/mcp