# Replayer

> Replays recorded webhook payloads through the mapping layer and diffs the resulting billing events. Use when investigating a mis-billed tenant or verifying a mapping change.

- Skill: `ncoevoet/replayer` (Agent Skill)
- Install (CLI): `npx skillmds@latest add ncoevoet/replayer`
- Raw SKILL.md: https://api.skillmd.com/api/skills/ncoevoet/replayer/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: ncoevoet (https://skillmd.com/u/ncoevoet)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/ncoevoet/replayer

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# Replayer

A replay reads a recorded payload set, runs it through the current mapping, and
diffs the produced events against what was billed at the time.

## Using a replay

- Keys used for idempotency must exclude the delivery timestamp, or a retry looks new
- A diff with only ordering changes is expected: ordering is per-tenant, not global