The model failed before payment.
No payment was taken. The same valid authorization can be reused for the same request.
How Synal works
A request.
A price. An answer.
Your wallet pays for one AI call at a time.
x402 puts the price inside the conversation between your agent and the API.
This walkthrough explains the sequence.
It does not send a request or payment.
Your agent → Synal
Ask as usual.
Send an OpenAI-compatible request with a model, messages and an output limit.
REQUEST
POST /x402/v1/chat/completionsNo account or API key.
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When the happy path changes
Clear status.
No guessing.
The settlement outcome is unknown.
Check the existing payment. Keep its request and authorization; don’t create another signature just because the connection failed.
Payment completed; the call failed later.
On some networks, and for async video jobs, the payment settles before the model runs; if the model then fails, a refund is owed. The refund is owed until its return is recorded. There is no promised arrival time.
One signature, one payment