Mercury (BYOK)

Mercury (BYOK) — connector documentation

• MCP endpoint: https://byok-mercury.connectorbay.com/mcp
• REST API: POST https://byok-mercury.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://byok-mercury.connectorbay.com/openapi.json
• Transport: Streamable HTTP, stateless, MCP specification 2025-06-18 or later
• Authentication: your own Mercury Mercury API token, read-only (paste the whole value, including the secret-token: prefix), sent in the X-Upstream-Key header of every request (never stored, logged or cached)
• Health: https://byok-mercury.connectorbay.com/health · Tool schemas: https://byok-mercury.connectorbay.com/tools.json
• Publisher: Unify Dynamics LLC · connectorbay.com/byok-mercury · agent@connectorbay.com

What Mercury (BYOK) is for

Mercury (BYOK) lets an AI assistant read your own Mercury data through the Mercury API with a key you supply (Mercury API token, read-only (paste the whole value, including the secret-token: prefix)). Read-only: 12 tools (list_accounts, list_account_transactions, list_transactions, get_transaction, list_account_statements, list_categories, list_credit_accounts, list_treasury_accounts, list_cards, list_invoices, list_invoice_customers, list_send_money_requests). 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.mercury.com. Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by Mercury. Mercury 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:

• "What are the balances of my Mercury accounts?"
• "Show the last 20 transactions on my Mercury operations account"
• "Which Mercury transactions mention 'AWS' this quarter?"
• "Show the Mercury transaction 11111111-1111-1111-1111-111111111111"
• "What was my Mercury account balance at the end of each month?"
• "What custom expense categories do I have in Mercury?"

What it does

• list_accounts: List the bank accounts with name, nickname, kind, type, status, current balance and available balance. Account and routing numbers are not returned.
• list_account_transactions: List the transactions of one account (default: last 30 days) with amount, status, counterparty, description, note and category.
• list_transactions: List transactions across all accounts, filtered by created or posted date, status, account, card, search text or category, with cursor paging.
• get_transaction: Get one transaction by its id with amount, status, kind, counterparty, description, note, category and dates.
• list_account_statements: List the monthly statements of one account with period start and end and ending balance (download links are not returned).
• list_categories: List the custom expense categories of the organization.
• list_credit_accounts: List the credit accounts with current balance, available balance and status.
• list_treasury_accounts: List the treasury accounts with current balance, available balance and status.
• list_cards: List debit and credit cards with nickname, last four digits, type, status, account and card holder id.
• list_invoices: List the invoices you issued through Mercury with number, customer id, amount, status, dates and currency.
• list_invoice_customers: List the customers you invoice through Mercury with id and name.
• list_send_money_requests: List pending or past send-money approval requests with amount, status, memo, payment method and scheduled date.

BYOK key

You bring your own Mercury Mercury API token, read-only (paste the whole value, including the secret-token: prefix) (https://app.mercury.com/settings/tokens). 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.mercury.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://docs.mercury.com/docs/welcome (the API this connector calls, with a BYOK key)

Live from the Mercury API (api.mercury.com) with a BYOK key; documentation: https://docs.mercury.com/docs/welcome. 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 Mercury. Mercury 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 Mercury account.

Built for: Worldwide. Languages: English.

Mercury (BYOK) — Privacy Policy

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

What Mercury (BYOK) is. Mercury (BYOK) is a connector (an MCP server and REST API) that an AI assistant calls on your behalf to read your own Mercury data: Read your Mercury business bank accounts, balances, transactions, statements, cards and invoices with BYOK. You bring your own Mercury Mercury API token, read-only (paste the whole value, including the secret-token: prefix); the assistant sends it to us with each request.

BYOK key. The key you supply is used to make the one Mercury 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.mercury.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 Mercury 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 Mercury receives. The request we make on your behalf, including the key and the arguments, under Mercury's own terms and privacy policy. Mercury acts at your direction and is the only recipient of the data of your request besides our hosting provider.

What we return. The answer Mercury 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 Mercury 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. Mercury (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 Mercury at any time to end all access.

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

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

Mercury (BYOK) — Terms of Service

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

1. The Service. Mercury (BYOK) provides: Read your Mercury business bank accounts, balances, transactions, statements, cards and invoices with BYOK. 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 Mercury credentials and only access data you are allowed to access. Mercury's terms apply to your use of Mercury; 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 Mercury. Mercury 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 Mercury returns, lightly trimmed; it may be incomplete, delayed or changed by Mercury. Check important facts at the source.
5. Read-only. The Service does not create, change, send or delete anything in your Mercury 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 Mercury'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; Mercury 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 Mercury 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 Mercury 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-mercury

Mercury (BYOK) support

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

• MCP endpoint: https://byok-mercury.connectorbay.com/mcp
• REST API: https://byok-mercury.connectorbay.com/openapi.json
• Live status: https://byok-mercury.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. Mercury (BYOK) never asks for them.