Independent review. IonBin has no partnership with Brex and was not paid for this page. Our evaluation is our own, based on public documentation and our research. Product names are trademarks of their owners and are used for identification only. How disclosure works.
Corporate cards, expense management, bill pay and business banking. Brex MCP (beta) lets AI assistants look up expenses, users, cards, banking transactions and bills under each user's Brex permissions; approvals and card management are not available via MCP yet.
IonBin provides general information and software comparisons, not tax, legal, accounting or financial advice. Tax and legal rules vary by situation and jurisdiction; consult a qualified professional (CPA, enrolled agent or attorney) before acting.
AI tools can make mistakes. Verify every figure against the original documents and official IRS or state guidance before filing or signing.
Redact Social Security numbers, account numbers and EINs before uploading documents to any AI assistant, and check its data-retention settings. Upload originals only to the filing or signing software.
Brex lists Essentials ($0 per user per month, including accounting integrations and Brex API access), Premium ($12 per user per month, adding customizable expense policies and ERP and HRIS integrations) and custom-priced Enterprise. Checked 2026-10-17. source ↗
An account or card admin accepts the Developer API agreement and enables the Brex in AI assistants beta. Then any user can connect over OAuth to https://api.brex.com/mcp with their own permissions. source ↗
How Brex connects to each AI platform: native connector or MCP, API through code the agent writes, browser control, or file upload.
| Platform | MCP / connector | API (agent-written code) | Browser | Upload / export |
|---|---|---|---|---|
| Claude (incl. Claude Code) | Not documented Brex has an official MCP server and Claude (incl. Claude Code) supports MCP, but Brex's docs don't name this pairing. Auth setup may differ. Brex MCP docs ↗Claude (incl. Claude Code) MCP docs ↗ | Confirmed Claude (incl. Claude Code) can run code; Brex publishes an API. Claude (incl. Claude Code) docs ↗ | Confirmed Claude Code with the Claude in Chrome extension (Chrome, Edge and other Chromium browsers) Claude (incl. Claude Code) browser docs ↗ | Confirmed Export from Brex, then works on the files in your project; chat accepts attachments Claude (incl. Claude Code) docs ↗ |
| OpenAI Codex | Not documented Brex has an official MCP server and OpenAI Codex supports MCP, but Brex's docs don't name this pairing. Auth setup may differ. Brex MCP docs ↗OpenAI Codex MCP docs ↗ | Confirmed OpenAI Codex can run code; Brex publishes an API. OpenAI Codex docs ↗ | Confirmed Only in the ChatGPT desktop app; not in the Codex CLI or IDE extension OpenAI Codex browser docs ↗ | Confirmed Export from Brex, then works on local repositories OpenAI Codex docs ↗ |
| Google Antigravity | Not documented Brex has an official MCP server and Google Antigravity supports MCP, but Brex's docs don't name this pairing. Auth setup may differ. Brex MCP docs ↗Google Antigravity MCP docs ↗ | Confirmed Google Antigravity can run code; Brex publishes an API. Google Antigravity docs ↗ | Confirmed Browser subagent via /browser, documented as an Antigravity App feature; the IDE has separate browser docs Google Antigravity browser docs ↗ | Confirmed Export from Brex, then works on local projects and worktrees Google Antigravity docs ↗ |
Confirmed means both the tool's and the platform's official docs describe that route (links in the cell); IonBin has not tested every pairing. Not documented means it may work, but no official docs describe that route end to end. Checked Oct 17, 2026.
| Level | Status | Detail / source |
|---|---|---|
| Native connector / MCP | Yes | Official docs ↗ |
| API / CLI | Yes | Brex API, included on Essentials (https://developer.brex.com/guides/quickstart) |
| Browser-only | No | Web app; also reachable programmatically |
| Bulk upload / import | Yes | Download the Expenses table as CSV (https://www.brex.com/support/updated-expense-table-downloads) |
Recorded Oct 17, 2026. Setup and plan limits vary; check the vendor's docs. How levels are assigned.
Via its official MCP server, from MCP-capable platforms such as ChatGPT, Claude, Gemini (Google), Google Antigravity, OpenAI Codex.
Via its API, through automation hubs: Gumloop, Make, n8n, Zapier.
No long-form review yet. Verdict is based on research, not hands-on testing.
Corporate cards, expenses and bill pay with spend controls. Ramp MCP (marked subject to change) lets AI assistants query spend and act on approvals, reimbursements and cards within each user's permissions; a developer API is also documented.
Business banking for startups. Mercury MCP (in beta) connects AI tools over OAuth to read accounts and transactions and to request payments or transfers, which still need approval in Mercury; an API is also documented.
