Backend code for "this access token was already used".
Returned by POST /x402/settle when a v3 token is settled a second time.
Deliberately not forgery-gated on the backend: it says plainly that the
token was spent, so a client can tell a spent token apart from a
declined one (insufficient credits, wrong plan) and from a forged one
(BCK.X402.0005, an envelope edited to disagree with the signature).
Backend code for "this access token was already used".
Returned by
POST /x402/settlewhen a v3 token is settled a second time. Deliberately not forgery-gated on the backend: it says plainly that the token was spent, so a client can tell a spent token apart from a declined one (insufficient credits, wrong plan) and from a forged one (BCK.X402.0005, an envelope edited to disagree with the signature).