---
title: "Vertex AI: Bank Data for Gemini via MCP | BankBridge"
description: "Let your Gemini app answer real money questions through Vertex AI's native MCP support. One tool block, then ask for last month's biggest charges."
url: "https://bankbridge.money/docs/vertex-ai"
---
[← All integrations](https://bankbridge.money/docs)

Vertex AI

# Native MCP in the Gemini SDK.

Build a Gemini app on Vertex? The Gemini Python/JS SDK has a native MCP client. Pass the BankBridge URL in your `tools` list.

Step 01

## Register BankBridge as an MCP tool.

Python

```
from google import genai
from google.genai import types

client = genai.Client(vertexai=True, project="your-project", location="us-central1")

response = client.models.generate_content(
    model="gemini-2.0-flash",
    contents="How much did I spend on restaurants last month?",
    config=types.GenerateContentConfig(
        tools=[
            types.Tool(
                mcp=types.McpTool(
                    endpoint="https://bankbridge.money/api/mcp",
                    headers={"Authorization": "Bearer bbk_your_api_key_here"},
                )
            )
        ]
    ),
)
print(response.text)
```

The same shape works in the **Agent Development Kit (ADK)**. Any ADK agent can attach MCP tools this way. Grab a key from [your dashboard](https://bankbridge.money/dashboard).

Step 02

## Verify it works.

Run the script. You should see Gemini call `list_transactions` or `get_spending_summary` against BankBridge, then return a natural-language answer about March restaurants.

expected tool call

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

Troubleshooting

Vertex returns 'Unknown tool' errors.

BankBridge's tool list wasn't fetched. Usually an auth failure on the initial handshake.

**Fix:** Verify the Authorization header contains a real bbk\_ key and that your Vertex project has outbound HTTPS allowed.

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](https://bankbridge.money/dashboard/settings).

Tools return setup\_required.

Your BankBridge account has no active subscription yet, or it was canceled or is past due. The connection itself works; each tool answers with the link that finishes setup.

**Fix:** Visit [Settings](https://bankbridge.money/dashboard/settings) to start or restore your subscription, then connect a bank.

Tools return a NO\_CONNECTIONS warning.

You haven't linked a bank yet.

**Fix:** Visit [Connect a bank](https://bankbridge.money/dashboard/connect) . The bank-connect flow opens automatically, ~30 seconds.

Problems? Email [hello@bankbridge.money](mailto:hello@bankbridge.money).