Documentation

Banker MCP speaks MCP over Streamable HTTP at one endpoint. It is read-only and metered.

Endpoint and authentication

POST https://bankermcp.io/mcp
Authorization: Bearer bmcp_<your key>
Content-Type: application/json

Create keys in your dashboard. A key is shown once and stored only as a hash. Revoked keys stop working immediately.

Tools

Tool	Arguments	Returns
`list_banks`	none	Connected banks, each with a `simulated` flag.
`list_accounts`	`bank`	Accounts with masked numbers.
`get_balance`	`bank`, `account_id`	Current and available balance as decimal strings.
`list_transactions`	`bank`, `account_id`, optional `from`, `to`, `limit`	Newest first. Signed decimal amounts; negative is a debit.

All four tools carry readOnlyHint: true. There is no tool that creates, changes or deletes anything at a bank.

The simulated flag

Every result includes bank and simulated. When simulated is true the data is synthetic and the result carries a notice. Treat it as test data: do not show it to a person as their real finances.

Try it with curl

curl -s https://bankermcp.io/mcp \
  -H "Authorization: Bearer $BANKERMCP_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"list_banks","arguments":{}}}'

Metering and errors

Situation	What you see
Missing or revoked key	HTTP 401 with `WWW-Authenticate: Bearer`.
Allowance used up	A tool result with `isError: true` explaining the plan limit. Not billed.
Real bank on the Sandbox plan	A tool result with `isError: true`. Not billed.
Unknown bank or account	A tool result with `isError: true`. Billed as a call.
Unknown method or bad parameters	A JSON-RPC error (`-32601`, `-32602`).

Protocol version: 2025-06-18. Server-initiated streams are not offered in this version, so GET /mcp returns 405.