There are two ways to pay for APIs on Zyla API Hub. Use the one that fits how you work; you can use both from the same account.
Two ways to pay
| Pay per call | Monthly plan | |
|---|---|---|
| Best for | AI agents and occasional use | Steady use of one API from your own software |
| How it works | Your agent calls any API through the Zyla MCP server. Each successful call is charged at that API's price per call | You subscribe to a plan on the API's page: a number of calls per month for a fixed price |
| Subscription | None. You pay only for calls that succeed | One per API. Renews automatically until you cancel |
| You need | A credit card on file | A plan for each API you use |
Pay per call. No monthly fee and no minimum. If the card is missing, your agent gets a payment link (402) to open and add it. Ask your agent for your account status to see what you have spent this cycle.
Monthly plans. Each API has its own plans, set by its provider: price, calls per month and a requests-per-minute limit. Some APIs offer a free trial with a few calls. You can upgrade, downgrade or cancel from the API page at any time; plans renew automatically at the end of each period until you cancel. Invoices and payment methods are in Billing, in the account menu. Refunds follow the refund policy.
Limits
- Requests per minute. Each plan allows 60, 120 or 240 requests per minute. Above that, calls are rejected until the next minute starts.
- Calls per month. When you use all the calls in your plan, calls are rejected until you upgrade or the next cycle starts.
- Unpaid invoices. If an invoice stays unpaid for 72 hours, the subscription is paused until it is paid in the Billing Portal.
Developers can track usage from the response headers; see Call an API over HTTP.
When something fails
Errors from the hub come with a message that says what happened:
| Status | What it means | What to do |
|---|---|---|
401 |
Missing or wrong key, no subscription to this API, wrong HTTP method, or an expired complimentary trial | Check the key and the subscription; agents subscribe on their own |
402 |
No credit card on file (agents, pay per call) | Open the payment link and add a card |
403 |
The account is blocked, or the key is limited to other APIs | Use a key allowed for this API |
404 |
The API or the endpoint does not exist or is not public | Check the API and endpoint |
410 |
The endpoint was retired | Use the alternative listed on the API page |
422 |
A parameter has the wrong type or format | Fix the parameter named in the message |
429 |
Too many requests per minute, plan or trial calls used up, or a paused subscription | Wait, upgrade the plan or pay the pending invoice |
Any other status (for example a 400 or 500 with the provider's own message) comes from the API itself. If it persists, write to our team with the API name and the time of the call.
