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ENGINEERINGAugust 6, 2025

Real‑Time Webhooks and Audit Trails for Agent‑Initiated Payments

Why event streams and immutable audit logs are essential for safe, scalable agent payments across teams and tools.

ProxyOS
ProxyOS Team
1 min read

As agents begin to transact, your visibility must increase — not decrease. Real-time events and durable audit logs make that possible.

What to emit on every transaction

  • Initiator (agent, workflow, or user)
  • Counterparty (merchant) and MCC/category
  • Amount, currency, and authorization outcome
  • Policy decision metadata (rule matched, reason)
  • Links to artifacts (invoice, receipt, approval trail)

Why webhooks over polling

  • Near real-time reactions across systems (Slack alerts, approvals, BI)
  • Lower latency and infrastructure cost
  • Replayable for recovery and backfills

The audit trail contract

Audit logs should be append-only, tamper-evident, and queryable by agent, merchant, and policy rule. This is how you answer “what happened?” in seconds.

Webhooks + audit trails keep humans in the loop while agents move at machine speed.

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