ExperimentalOptional ExperimentalagentOverrides the agent id the seller's challenge names — the minted token is
addressed to this agent id instead of whatever the challenge carries.
Unlike planId, this is not a guard: a mismatch is not checked or
refused, it simply replaces what the seller asked for. Leave unset to
honor the challenge as issued.
ExperimentaldelegationThe delegation that backs the payment — the same one x402 uses.
Optional ExperimentalmaxBudget for the WHOLE call, not for one challenge: the helper refuses to
mint whenever the credits named so far plus the credits this challenge
asks for would exceed it. A seller unilaterally names the price, and a
re-challenge names it again — a per-turn cap would therefore bound each
turn at maxCredits and the call at twice it, which is not what "cap"
reads as. creditsPresented on the result is the same running total, so
the two always speak about the same number.
Must be a non-negative integer (a decimal string, a safe integer, or a
bigint); anything else is refused with a PaymentsError at entry,
before the first request, rather than mid-flight on the first 402.
Optional ExperimentalplanFail before minting if the challenge names a different plan than this.
Options for mppFetch /
MppAPI.fetch.The MPP buyer surface may change in a minor release.
The request's
init.body, if any, must be replayable if the endpoint may challenge the request: aReadableStreambody throws a typed PaymentsError once a 402 challenge actually requires a retry, since the stream cannot be resent. A request that is never challenged sends a stream body exactly once, exactly like plainfetch.This helper mints
nvm:erc4337access tokens only in this release — a buyer holding annvm:card-delegationdelegation cannot use it yet.