Brex Budgets (BYOK)

Brex Budgets (BYOK) — connector documentation

• MCP endpoint: https://byok-brex-budgets-fields.connectorbay.com/mcp
• REST API: POST https://byok-brex-budgets-fields.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://byok-brex-budgets-fields.connectorbay.com/openapi.json
• Transport: Streamable HTTP, stateless, MCP specification 2025-06-18 or later
• Authentication: your own Brex Budgets Brex user token with read scopes for budgets and fields, sent in the X-Upstream-Key header of every request (never stored, logged or cached)
• Health: https://byok-brex-budgets-fields.connectorbay.com/health · Tool schemas: https://byok-brex-budgets-fields.connectorbay.com/tools.json
• Publisher: Unify Dynamics LLC · connectorbay.com/byok-brex-budgets-fields · agent@connectorbay.com

What Brex Budgets (BYOK) is for

Brex Budgets (BYOK) lets an AI assistant read your own Brex Budgets data through the Brex Budgets API with a key you supply (Brex user token with read scopes for budgets and fields). Read-only: 9 tools (list_budget_programs, get_budget_program, list_budgets, get_budget, list_spend_limits, get_spend_limit, list_custom_fields, get_custom_field, list_custom_field_values). The BYOK key travels with each request, is used for that one call only and is never stored, logged or cached; it is only ever sent to api.brex.com. Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by Brex Budgets. Brex Budgets and its logos are trademarks of their owners and are used only to say which service the connector works with.

Ask your assistant things like:

• "Which Brex budget programs do we run?"
• "What does Brex budget program bp_1 define?"
• "What budgets do we have in Brex and how big are they?"
• "What is the amount of Brex budget bud_1?"
• "Which Brex spend limits are active and how much is left in each?"
• "How much of Brex spend limit sl_1 has been used this period?"

What it does

• list_budget_programs: List budget programs (templates that create budgets for groups of employees) with blueprints, existing budget ids and status. Owner and member user ids are not returned.
• get_budget_program: Get one Brex budget program by id with its blueprints, linked budget ids and status.
• list_budgets: List Brex budgets with name, parent budget, period, dates, amount and status. Owner and member user ids are not returned.
• get_budget: Get one Brex budget by id with period, dates, amount, status and limit type.
• list_spend_limits: List Brex spend limits with name, status, period, spend type, per-transaction limit, visibility, current period balance, department and legal entity. Owner and member user ids are not returned.
• get_spend_limit: Get one Brex spend limit by id with status, period, spend type, per-transaction limit and current period balance. Owner and member user ids are not returned.
• list_custom_fields: List custom accounting fields (such as cost center or project) defined in Brex with name, remote id, group and whether disabled.
• get_custom_field: Get one Brex custom field by id with name, remote id, group and disabled state.
• list_custom_field_values: List the allowed values of one Brex custom field, optionally filtered by value text.

BYOK key

You bring your own Brex Budgets Brex user token with read scopes for budgets and fields (https://dashboard.brex.com/settings/developer). Your assistant sends it in the X-Upstream-Key header with each request. ConnectorBay uses it for that one call only: it is never stored, logged or cached, never shown in an answer, and it is only sent to api.brex.com over https, with no redirects followed. Create a key with the fewest permissions the tools need (read-only if the provider offers it), and revoke it at the provider whenever you like.

Data sources

• https://developer.brex.com/openapi/budgets_api.md (the API this connector calls, with a BYOK key)

Live from the Brex Budgets API (api.brex.com) with a BYOK key; documentation: https://developer.brex.com/openapi/budgets_api.md. Endpoints checked against that documentation on 2026-10-16.

What it is not

Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by Brex Budgets. Brex Budgets and its logos are trademarks of their owners and are used only to say which service the connector works with. It is read-only: it never creates, changes, sends or deletes anything in your Brex Budgets account.

Built for: Worldwide. Languages: English.

Brex Budgets (BYOK) — Privacy Policy

Effective 24 October 2026. Unify Dynamics LLC ("we", "us"), Menlo Park, California.

What Brex Budgets (BYOK) is. Brex Budgets (BYOK) is a connector (an MCP server and REST API) that an AI assistant calls on your behalf to read your own Brex Budgets data: Read your Brex budgets, spend limits, budget programs and custom accounting fields with your own user token. You bring your own Brex Budgets Brex user token with read scopes for budgets and fields; the assistant sends it to us with each request.

BYOK key. The key you supply is used to make the one Brex Budgets call you asked for. Our application does not store it, write it to a log, put it in a cache, or share it. It is sent only to api.brex.com, over https, and is removed from any text we return to you or your assistant. We do not follow redirects with your key. If Brex Budgets rejects it, we say so without repeating it.

What we receive. The arguments of each tool call, the BYOK key (for that call only), the technical headers needed to serve the request (an IP address or a client identifier supplied by the assistant) and standard server logs. What Brex Budgets receives. The request we make on your behalf, including the key and the arguments, under Brex Budgets's own terms and privacy policy. Brex Budgets acts at your direction and is the only recipient of the data of your request besides our hosting provider.

What we return. The answer Brex Budgets gives for your request, trimmed to the fields the tool documents. We do not keep it: it is returned to your assistant and not stored, cached or used to train anything.

What we do not do. We do not build a profile, sell or share personal information, or keep your Brex Budgets data. Rate-limit counters (a client identifier and timestamps) are held in memory for at most 24 hours. Hosting access logs (IP addresses, request paths and status codes) are kept for up to 30 days for security and abuse prevention; our application adds no request headers or bodies to them.

Sub-processors. Brex Budgets (the API you call with a BYOK key, at your direction). Hosting: Vercel (United States regions).

Your rights. Because we store no personal data beyond short-lived logs, requests to access, correct or delete data are usually satisfied automatically; you can still contact agent@connectorbay.com and we will respond within 30 days. Revoke your key at Brex Budgets at any time to end all access.

Children. Brex Budgets (BYOK) is a general-audience service operated by the adult using the assistant, under Brex Budgets's own age rules.

Changes. We will post changes here with a new effective date.

Brex Budgets (BYOK) — Terms of Service

Effective 24 October 2026. These terms govern use of the Brex Budgets (BYOK) connector ("the Service") operated by Unify Dynamics LLC ("we", "us").

1. The Service. Brex Budgets (BYOK) provides: Read your Brex budgets, spend limits, budget programs and custom accounting fields with your own user token. It is accessed through an AI assistant or directly over MCP or HTTP, and is read-only.
2. Your own key, your own account. You must use your own Brex Budgets credentials and only access data you are allowed to access. Brex Budgets's terms apply to your use of Brex Budgets; you are responsible for complying with them, including any rate limits and permitted uses. Do not share a key you do not own.
3. Independent. Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by Brex Budgets. Brex Budgets and its logos are trademarks of their owners and are used only to say which service the connector works with.
4. No advice, no guarantees. Output is the data Brex Budgets returns, lightly trimmed; it may be incomplete, delayed or changed by Brex Budgets. Check important facts at the source.
5. Read-only. The Service does not create, change, send or delete anything in your Brex Budgets account.
6. Acceptable use. Automated use within the published rate limits is welcome. Do not use the Service to access data you are not entitled to, to circumvent Brex Budgets's controls, or to attack any system.
7. Availability. The Service is provided "as is" without warranty. We may change, limit or discontinue it at any time; Brex Budgets may change or end its API at any time.
8. Data. Our Privacy Policy describes what we process. In short: the BYOK key is used for the one call and not stored or logged.
9. Pro keys. Optional ConnectorBay Pro API keys are issued at our discretion and are separate from your Brex Budgets key.
10. Liability. To the fullest extent permitted by law, Unify Dynamics LLC is not liable for any loss arising from use of or reliance on the Service, including any action Brex Budgets takes on your account. Our total liability is limited to US $100.
11. Governing law. California law; venue in San Mateo County, California.
12. Contact. Unify Dynamics LLC · agent@connectorbay.com · https://connectorbay.com/byok-brex-budgets-fields

Brex Budgets (BYOK) support

Email agent@connectorbay.com. We answer within two business days.

• MCP endpoint: https://byok-brex-budgets-fields.connectorbay.com/mcp
• REST API: https://byok-brex-budgets-fields.connectorbay.com/openapi.json
• Live status: https://byok-brex-budgets-fields.connectorbay.com/health

When you report a problem, include the question you asked your agent, roughly when, and which agent you used (for example Claude, ChatGPT or Gemini). Never send us passwords, account numbers or ID numbers. Brex Budgets (BYOK) never asks for them.