open-banking.io MCP server

A thin, read-only Model Context Protocol server for the open-banking.io PSD2 API. It lets AI agents (Claude Desktop, Cursor, any MCP client) answer questions like “What's my balance?” and “Summarise last month's transactions” over your own bank accounts.

It wraps the official open-banking-io Python SDK and inherits its zero-knowledge property: the service only ever returns ciphertext, and every sensitive field (IBAN, owner name, amounts, counterparties) is decrypted in-process with your exported private key. No plaintext ever touches a third party — including the LLM only sees what your MCP client sends it.

Tools

All tools are read-only. There are intentionally no sync, payment-initiation or consent-management tools — see Limitations.

Related MCP server: saldo-mcp

Configuration

Export credentials in the app → Settings → Credentials to get the bundle file.

Claude Desktop

claude_desktop_config.json (Claude → Settings → Developer → Edit Config):

{
  "mcpServers": {
    "open-banking-io": {
      "command": "uvx",
      "args": [
        "--from", "git+https://github.com/open-banking-io/mcp-server.git",
        "obi-mcp"
      ],
      "env": {
        "OBI_CREDENTIALS": "/absolute/path/to/credentials.json"
      }
    }
  }
}

Cursor

.cursor/mcp.json:

{
  "mcpServers": {
    "open-banking-io": {
      "command": "uvx",
      "args": [
        "--from", "git+https://github.com/open-banking-io/mcp-server.git",
        "obi-mcp"
      ],
      "env": {
        "OBI_CREDENTIALS": "/absolute/path/to/credentials.json"
      }
    }
  }
}

Requires uv (curl -LsSf https://astral.sh/uv/install.sh | sh). Once published to PyPI the --from git+… argument can be dropped.

Run locally / from source

git clone https://github.com/open-banking-io/mcp-server.git
cd mcp-server
uv venv && uv pip install -e '.[dev]' --python .venv/bin/python
OBI_CREDENTIALS=/path/to/credentials.json .venv/bin/obi-mcp   # speaks MCP over stdio
.venv/bin/python tests/smoke.py                               # network-free smoke test
uv run --python .venv/bin/python pytest -q                    # full test suite

Example questions for your agent

• “Show the booked balance of every account.”

• “How much did I spend on groceries in July?” (get_transactions + grouping)

• “Which of my bank connections expire soon?” (list_connections)

Design notes

• Read-only by construction. Only the SDK's get_* methods are exposed. sync/sync_all exist in the SDK but are deliberately not offered; agents cannot move money or alter consents through this server.

• Exact money. Amounts are returned as exact decimal strings ("1234.56"), never floats.

• Clean errors. Missing credentials, bad dates, unknown account ids and upstream HTTP errors are surfaced as actionable tool errors (e.g. listing valid account ids on a miss).

• Context-friendly. get_transactions defaults to 50 items and clamps at 500 to protect agent context windows; use offset to paginate.

Limitations (honest list)

• No write tools: no sync, no payment initiation, no consent creation/renewal. Consent renewal always happens in the open-banking.io app (PSD2 SCA).

• No bank/institution directory tool: the upstream API (SDK v1.0.0) does not expose a public ASPSP-search endpoint — TODO if/when the API adds one.

• Not yet on PyPI — install via uvx --from git+… (above) or from source. Publishing to PyPI as open-banking-io-mcp is planned.

• Data minimisation is your responsibility: transactions include counterparties and remittance text; only point this server at MCP clients you trust, and prefer local MCP clients (Claude Desktop / Cursor) over hosted ones for privacy.

API surface wrapped

Auth: X-Api-Key header. Responses carry zero-knowledge envelopes (ECDH P-256 → HKDF-SHA256 → AES-256-GCM) decrypted locally by the SDK. Full wire format: clients repo · THREAT_MODEL.md.

License

MIT — same as the clients SDK repos.