YNAB (BYOK)

YNAB (BYOK) — connector documentation

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

What YNAB (BYOK) is for

YNAB (BYOK) lets an AI assistant read your own YNAB data through the YNAB API with a key you supply (personal access token). Read-only: 10 tools (get_user, list_plans, list_accounts, list_categories, list_payees, list_months, get_month, list_transactions, list_account_transactions, list_scheduled_transactions). 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.ynab.com. Unofficial connector by Unify Dynamics LLC: not affiliated with, endorsed by or sponsored by YNAB. YNAB 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 YNAB user is my token connected to?"
• "Which YNAB plans do I have?"
• "What are my YNAB account balances?"
• "How much is left in each YNAB category this month?"
• "Which payees exist in my YNAB plan?"
• "How did my YNAB budget look month by month?"

What it does

• get_user: Show the ID of the YNAB user the token belongs to.
• list_plans: List your plans (budgets) with ID, name, last modified time, first and last month and currency format, optionally with their accounts.
• list_accounts: List a plan's accounts with type, on-budget and closed flags, balances and linked-import status. Amounts are in milliunits (1000 = one currency unit); the *_formatted fields are text.
• list_categories: List a plan's category groups with their categories, including budgeted, activity and available balance for the current plan month and goal info. Amounts are in milliunits (1000 = one currency unit); the *_formatted fields are text.
• list_payees: List a plan's payees with ID, name and transfer account (for transfer payees).
• list_months: List a plan's months with income, budgeted, activity, to-be-budgeted and age of money. Amounts are in milliunits (1000 = one currency unit); the *_formatted fields are text.
• get_month: Get one plan month with its totals and the budgeted, activity and balance of every category. Amounts are in milliunits (1000 = one currency unit); the *_formatted fields are text.
• list_transactions: List a plan's transactions (pending ones excluded), optionally from a date, until a date or only uncategorized or unapproved ones. Large plans can be big: use since_date. Amounts are in milliunits (1000 = one currency unit); the *_formatted fields are text.
• list_account_transactions: List the transactions of one account, optionally from a date or only uncategorized or unapproved ones. Amounts are in milliunits (1000 = one currency unit); the *_formatted fields are text.
• list_scheduled_transactions: List a plan's scheduled (recurring) transactions with first and next date, frequency, amount, payee and category. Amounts are in milliunits (1000 = one currency unit); the *_formatted fields are text.

BYOK key

You bring your own YNAB personal access token (https://app.ynab.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.ynab.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://api.ynab.com/v1 (the API this connector calls, with a BYOK key)

Live from the YNAB API (api.ynab.com) with a BYOK key; documentation: https://api.ynab.com/v1. 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 YNAB. YNAB 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 YNAB account.

Built for: Worldwide. Languages: English.

YNAB (BYOK) — Privacy Policy

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

What YNAB (BYOK) is. YNAB (BYOK) is a connector (an MCP server and REST API) that an AI assistant calls on your behalf to read your own YNAB data: Read your YNAB plans, accounts, categories, payees, months, transactions and scheduled transactions with your own personal access token. You bring your own YNAB personal access token; the assistant sends it to us with each request.

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

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

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

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

YNAB (BYOK) — Terms of Service

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

1. The Service. YNAB (BYOK) provides: Read your YNAB plans, accounts, categories, payees, months, transactions and scheduled transactions with your own personal access 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 YNAB credentials and only access data you are allowed to access. YNAB's terms apply to your use of YNAB; 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 YNAB. YNAB 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 YNAB returns, lightly trimmed; it may be incomplete, delayed or changed by YNAB. Check important facts at the source.
5. Read-only. The Service does not create, change, send or delete anything in your YNAB 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 YNAB'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; YNAB 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 YNAB 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 YNAB 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-ynab

YNAB (BYOK) support

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

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