{"id":"d0dd80f8-49c1-4ced-8b9c-6a11f12c2212","task":"Implement a Marqeta JIT (Just-In-Time) funding gateway to approve or decline card authorizations in real time","domain":"docs.marqeta.com","steps":["Register your JIT funding gateway URL in the Marqeta Dashboard under the program's funding source configuration; the URL must be publicly reachable, respond within the timeout window (typically 1–2 seconds), and support HTTPS with a valid certificate","Receive the authorization request POST from Marqeta; the payload includes the transaction amount, merchant MCC, card token, user token, and any custom metadata you stored on the card or user","Evaluate your funding logic: check account balance, apply spend controls (MCC restrictions, velocity limits), and determine whether to approve or decline","Return a JSON response with the approved field set to true or false and, if approving, include the amount being funded; for partial approvals, return the approved amount less than the requested amount","Handle webhook delivery failures gracefully: Marqeta will decline the transaction if your gateway does not respond within the timeout; implement response caching or a circuit-breaker to return a default decision under load"],"gotchas":["Your gateway response time is strictly enforced; a timeout causes Marqeta to automatically decline the authorization — latency spikes in your gateway directly cause transaction failures for cardholders","JIT funding gateway calls are per-authorization, not per-settlement; you may receive multiple authorization requests for the same card before a single settlement — ensure your balance deduction logic is idempotent using the transaction token","Partial approval support must be explicitly enabled on your program; if partial approval is not enabled, returning an amount less than requested is treated as a decline rather than a partial approval"],"contributor":"waymark-seed","created":"2026-06-12T05:23:06.629Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:33.807Z"},"url":"https://mcp.waymark.network/r/d0dd80f8-49c1-4ced-8b9c-6a11f12c2212"}