mcp-brex

This MCP server, brex, exposes a read-only, projection-friendly interface to Brex financial data through the Model Context Protocol. It is optimized for safe responses with support for pagination, selective field expansion, and filtering to keep payloads small while allowing agents to fetch exactly what they need. Available tools let you read budgets, spend limits, budget programs, expenses, transactions, card and cash statements, accounts, and receipts-related actions. Most operations are read-only (except a few endpoints for receipts and updates described in the docs), and results can be further controlled with parameters like page_size, max_items, date ranges, status, and expand to include nested objects. Use the provided action names (e.g., get_expenses, get_all_expenses, get_card_transactions) with an arguments payload to retrieve data in a paginated, efficient manner. Always supply parameters under arguments rather than input to keep requests consistent with the server’s expectations.

Prerequisites:

• Node.js and npm installed on your system
• Internet access to install npm packages
• Access to Brex API and an API key

Installation steps:

1. Install the Brex MCP server globally npm install -g mcp-brex

2. (Optional) Add to Claude Code or your environment using npx claude mcp add brex --env BREX_API_KEY=your_brex_api_key -- npx mcp-brex

3. Set up a local development run (example using Claude Desktop config):

   • Create or update claude_desktop_config.json with: { "mcpServers": { "brex": { "command": "npx", "args": ["mcp-brex"], "env": { "BREX_API_KEY": "your_brex_api_key" } } } }

4. For a manual development setup from source (if you clone and build): git clone https://github.com/dennisonbertram/mcp-brex.git cd mcp-brex npm install npm run build claude mcp add brex --env BREX_API_KEY=your_key -- node build/index.js

Tips and common considerations:

• Use pagination parameters (page_size ≤ 50, max_items ≤ 200) to keep responses manageable.
• Filter by date ranges (start_date, end_date) and status to fetch only relevant records.
• Use expand to include nested objects like merchant or budget when more detail is required, but be aware this can substantially increase payload size.
• If a request returns a large dataset, batch it using window_days or multiple paginated calls.
• For write operations like match_receipt, upload_receipt, or update_expense, ensure proper authorization and validate payloads before sending.
• The Brex API key should be kept secure and not exposed in logs or client code.