OpenAI Responses API

First-class MCP tool type.

Building your own GPT-powered app with the OpenAI API? Register BankBridge as an MCP tool — OpenAI proxies the tool calls server-side. No client-side MCP runtime needed.

Step 01

Add the tool to your request.

POST /v1/responses

{
  "model": "gpt-4.1",
  "input": "How much did I spend on restaurants last month?",
  "tools": [
    {
      "type": "mcp",
      "server_label": "bankbridge",
      "server_url": "https://bankbridge.money/api/mcp",
      "headers": {
        "Authorization": "Bearer bbk_your_api_key_here"
      },
      "require_approval": "never"
    }
  ]
}

Grab a key from your dashboard.

Step 02

Verify it works.

Send the request. OpenAI fetches the tool list from BankBridge, lets the model call tools as needed, and streams results back. Expected first tool call:

expected

list_transactions({ category: "FOOD_AND_DRINK", start_date: "2026-03-01", end_date: "2026-03-31" })

What about per-user keys?

If you’re shipping a consumer app where each user should link their own bank, pass their BankBridge API key in the Authorizationheader per-request. Your app holds one key per user (collect at signup or via an “Connect BankBridge” button that deep-links to our dashboard).

Troubleshooting

401 Unauthorized on every call.

The API key is missing, typo'd, or got revoked. Check the Authorization header starts with `Bearer ` (note the space) and ends in a key you still own.

Fix: Paste a fresh key from Settings.

403 Forbidden.

Your BankBridge subscription is inactive (canceled or past-due), or your account has no connected banks.

Fix: Visit Settings to confirm your subscription is active.

Tools return a NO_CONNECTIONS warning.

You haven't linked a bank yet.

Fix: Visit Connect a bank — the bank-connect flow opens automatically, ~30 seconds.

Problems? Email hello@bankbridge.money.