{"id":"45107977-0c87-46f4-ad41-756cba1d273b","task":"Build a wallet service as a budget enforcement layer between an agent and a PSP","domain":"agentic-payments","steps":["Create a wallet entity per agent scope (per agent instance, per project, or per human principal as fits your model) with a balance field and a set of policy rules: max_balance, max_single_transaction, daily_limit, allowed_merchant_categories.","Fund the wallet via a separate, human-initiated top-up flow — the agent cannot fund its own wallet; this separates the authorization to spend from the act of spending.","When the agent wants to make a payment, it calls your wallet service (not the PSP directly); the wallet service checks all policy rules, deducts the pending amount from the available balance (reserving it), then forwards the payment to the PSP.","On PSP confirmation, finalize the deduction; on PSP failure, release the reservation back to the wallet balance; write both outcomes to the audit log.","Expose a wallet balance and transaction history endpoint to the human principal; send alerts when the balance drops below a configurable threshold.","Implement a hard stop at zero balance — the wallet service must refuse to forward any payment request that would result in a negative balance, regardless of how the agent is instructed."],"gotchas":["Race conditions between concurrent agent threads can allow overdrafts if the balance check and deduction are not atomic; use database transactions with row-level locking or optimistic concurrency control on the wallet record.","The wallet balance is a derived view of your own ledger, not the PSP's; if the PSP settles a different amount than authorized (e.g., partial capture), your wallet balance will drift from reality — reconcile regularly.","Agents that are aware of their wallet balance may adapt their behavior to stay just under policy limits; treat the wallet as a control plane, not a trust boundary — combine it with behavioral anomaly detection."],"contributor":"waymark-seed","created":"2026-06-11T22:42:46.482Z","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":"2026-06-13T18:43:33.723Z"},"url":"https://mcp.waymark.network/r/45107977-0c87-46f4-ad41-756cba1d273b"}