Brex MCP server for your AI

One API token. In Brex, an account admin or card admin goes to Settings, then Developer, and clicks Create Token. The first time, your company accepts Brex's developer terms on that page. There is nothing to apply for, the token works straight away, and the connection is locked to the Brex account it belongs to.

Only if it goes unused. Brex stops a token after 90 days without a call, or when its owner stops being an active user. You can revoke it any time on the same Developer page. If that happens, a tool says so and you make a new token and reconnect.

Brex's own server needs an admin to turn on a beta first and offers a chosen set of tools. PopMCP connects to the Brex API instead, which reaches far more, including transfers, card transactions, statements and company structure. Once that beta is on, the same token also reaches Brex's own tools for bills, banking transactions and spend questions, through list_official_tools and read_official_tool.

No. PopMCP leaves out Brex's card number call and its call that emails card details, and never uses their permission, so only the last four digits are shown. Expiry dates are hidden too. A card number or security code sent to a tool is refused before it reaches Brex. Full bank account numbers come back as their last four.

It can move money if you let it. create_transfer pays vendors by ACH, wire or check, create_incoming_transfer pulls funds in from a linked bank, update_vendor changes where money goes, and create_card and update_spend_limit let people spend. Those tools say so in their descriptions, and prepare_transfer lays a payment out for someone to confirm without sending anything. To keep it to reading, pick Read only when you make the token, or choose read-only for the connection in PopMCP.

A token's scopes are fixed when it is made. The error names what the call accepts: make a new token with that one set to Read only or Write, and reconnect Brex in PopMCP with it. Custom fields are in beta, so an admin also turns them on in Settings, Beta features. Accounting records are in alpha and open by invitation from Brex.

Brex's API only returns settled transactions. It also has no end date, search or amount filter on its transaction calls, so find_transactions reads the pages and applies those for you.

108 operations across cards, expenses, transactions, statements, budgets, spend limits, vendors, transfers, people, company structure, travel, custom fields, accounting and webhooks, plus nine tools of PopMCP's own such as spend_summary and prepare_transfer. 41 load into your AI client by default and the rest stay searchable.

Webhook triggers cover transfers processed and failed, expense payment changes, people updated, and accounting records ready to export. Updated expenses, settled card transactions and trips are picked up by checking regularly, and so are new transfers, vendors, cards, people and card statements. Brex allows one webhook address per customer.

No. PopMCP hosts it and gives you a Streamable HTTP MCP URL. There is nothing to deploy, no callback URL to register, and no infrastructure to keep running or patch.

Any client that supports a remote Streamable HTTP MCP server: Claude Desktop, Claude Web, Claude Code, ChatGPT custom connectors, Codex and the Codex CLI, OpenCode and Z.ai's ZCode, as well as editors such as Cursor, Windsurf and Zed. Your client signs in to PopMCP with OAuth; the provider credential never leaves the server.

Connect Brex in PopMCP first, then run claude mcp add --transport http popmcp https://app.popmcp.com/mcp in a terminal. Inside Claude Code, run /mcp and sign in to PopMCP in the browser window it opens, ticking Brex on the consent screen. The Brex tools are then available in that session, and no Brex credential is stored on your machine.

Loading 115 tool definitions into every conversation burns context before the work starts. PopMCP loads a curated 41-tool set covering the everyday workflows and keeps the rest searchable, so your AI pulls a specialist tool only when a task needs it. Every tool stays searchable, and on Scale the owner can load the full catalog for a teammate's connection.

A tool is something your AI calls, and there are 115 here. A trigger is something PopMCP watches for you: 13 Brex events that can start work on the PopMCP side. Triggers never enter your AI client's context, and none of them ask you to paste a callback URL into Brex.