# Brex AI integration on Definable

> Brex provides corporate credit cards, spend management, and financial tools tailored for startups and tech businesses to optimize cash flow, accounting, and growth

## What this connects

Brex provides corporate credit cards, spend management, and financial tools tailored for startups and tech businesses to optimize cash flow, accounting, and growth

Vendor: https://www.brex.com/

## Tools available

**84** tools available. First 12:

- `BREX_ADD_WEBHOOK_GROUP_MEMBERS` — Add Webhook Group Members — Add webhook subscription members to a webhook group. This action associates one or more webhook subscriptions with an existing webhook group, allowing those subscriptions to receive events targeted at the group. Note: Webhook groups are only available for Brex partner accounts. Requires an existing webhook group ID and valid webhook subscription IDs. Use this when you need to organize webhook subscriptions into groups for easier management of webhook events across multiple subscriptions.
- `BREX_ARCHIVE_BUDGET` — Archive Budget — Archive a budget to mark it as inactive and prevent future expenses. Archives the specified budget, making it unusable for new transactions and removing it from active budget lists in the UI. This action is permanent and cannot be undone.
- `BREX_ARCHIVE_SPEND_LIMIT` — Archive Spend Limit — Archive a spend limit in Brex. Archives an existing spend limit to remove it from active use, making it unusable for future expenses and hiding it from the UI. Once archived, the spend limit cannot be used to authorize new transactions.
- `BREX_CREATE_BUDGET` — Create Budget — Create a new budget for departments or projects.
- `BREX_CREATE_BUDGET_V1` — Create Spend Limit (Budget V1) — Tool to create a new Spend Limit (Budget) in Brex. Use when you need to set up spending controls with specific limits, visibility settings, and period types.
- `BREX_CREATE_CARD` — Create Card — Create a new card and assign it to a user.
- `BREX_CREATE_DEPARTMENT` — Create Department — Create a new department.
- `BREX_CREATE_DOCUMENT` — Create Document Upload for Referral — Create a document upload URL for a referral and return a pre-signed S3 upload URL. Use this tool when you need to upload supporting documents for a business referral application. The tool returns a pre-signed S3 URL that can be used to upload document files (PDF, JPG, PNG, etc.) up to 50 MB. The pre-signed URL expires 30 minutes after creation and can only be used for a PUT operation. Supported document types: - ARTICLES_OF_INCORPORATION: Company incorporation documents - IRS_EIN_CONFIRMATION: IRS CP 575 or 147C form (EIN confirmation letter) - IRS_EIN_APPLICATION: IRS SS4 form (Application for Employer Identification Number) - CERTIFICATE_GOOD_STANDING: Certificate of good standing from the state
- `BREX_CREATE_EXPENSE` — Create Expense — Create a new expense.
- `BREX_CREATE_FIELD` — Create Custom Field — Create a new custom field in Brex. Use when you need to add custom metadata fields for accounting or ERP integrations. Fields can be associated with specific integrations and can be enabled or disabled as needed.
- `BREX_CREATE_FIELD_VALUES` — Create Field Values — Create custom field values for a specific Brex field. Use when you need to add new dropdown options or values to a custom field (up to 1000 values per request). This action allows you to bulk-create field values for custom fields in Brex. Custom fields are used throughout Brex for categorizing expenses, cards, budgets, and other entities. Each value can have a custom ID, be marked as disabled, and include an external system reference for integrations.
- `BREX_CREATE_LOCATION` — Create Location — Create a new location.

## Auth

Auth schemes: `OAUTH2`, `API_KEY`.

## How agents use Brex

Inside a Definable workflow, Brex is one of the tools the **Distributor specialist** can call. Example coordination patterns:

- **Researcher → Brex** — the Researcher (GPT-5.5) pulls context from Brex (records, threads, documents), synthesises findings, and briefs the rest of the team.
- **Writer → Distributor → Brex** — the Writer (Claude Opus 4.7) drafts copy in brand voice, the Verifier passes it, then the Distributor writes the result into Brex (create record, post message, draft email).
- **Designer / Engineer → Distributor → Brex** — the Designer ships an asset or the Engineer ships a code change, the Distributor delivers it via Brex (attach file, open PR comment, post status).

The Verifier checks every Brex call. On rate limit, schema drift, or auth refresh it self-heals and retries — the workflow completes without manual intervention.

## Categories

- accounting — https://definable.ai/apps/category/accounting/
- payment processing — https://definable.ai/apps/category/payment-processing/

## Related

- HTML page: https://definable.ai/apps/brex/
- Same category (accounting): https://definable.ai/apps/category/accounting/
- All integrations: https://definable.ai/apps/
- Workflow (multi-agent loop): https://definable.ai/workflow/
- Apps llms.txt index: https://definable.ai/llms-apps.txt