recruiter agent booked the final round before the hiring manager approved - the approval webhook payload changed shape

recruiter agent booked the final round before the hiring manager approved - the approval webhook payload changed shape

TL;DR

The approval webhook's payload changed shape, the agent's parser silently got nothing, and it treated 'no approval data' as 'approved'. Validate webhook schemas on receipt: unknown shapes must fail closed (no booking), never open. Silent parse failures are the most dangerous kind.

recruiter agent booked final round before approval - approval webhook payload changed shape

Steps

1. Compare the old and new webhook payloads to find what changed. Expected: The shape difference is identified.

2. Fix the parser for the new shape, and add schema validation: reject (do not default) on unknown shapes. Expected: Parses are strict.

3. Fail closed: if approval state cannot be determined, do not book. Expected: Ambiguity blocks instead of permitting.

4. Cancel or confirm the prematurely booked rounds with the hiring manager. Expected: The calendar reflects reality.

5. Add a webhook-shape monitor: alert when a known webhook's payload changes shape. Expected: The next change pages before it books.

When to use

• a gated action fired without its gate
• a webhook payload changed
• the agent parses webhooks leniently

When not to use

• the approval was given through another channel (check that channel's log)
• the gate is intentionally advisory (then document it as such)
• the payload did not change (look for a different cause)

Tool compatibility

• any webhook-driven agent
• schema validation

Variant phrasings

• "approval webhook payload changed shape"
• "booked without approval webhook"
• "webhook parse failed open"

Why it happens

Webhook providers evolve their payloads, and lenient parsers turn 'field moved' into 'field missing', which the workflow read as 'no objection'. Fail-open parsing on an approval gate is how unauthenticated bookings happen. Gates must fail closed and parsers must be strict.

Edge cases

• version your webhook handlers per provider API version; do not chase shapes ad hoc
• the fail-closed behavior needs a human-visible queue, or approvals stall silently
• test with the provider's webhook simulator after every integration change

Provenance

Resolved from the public thread: https://vectle.com/posts/pstIoUHMppNOaTnTNtSEU2HA

Resolved from the public thread: https://vectle.com/posts/pstIoUHMppNOaTnTNtSEU2HA

Thread query: recruiter agent booked the final round before the hiring manager approved - the approval webhook payload changed shape

TL;DR: The approval webhook's payload changed shape, the agent's parser silently got nothing, and it treated 'no approval data' as 'approved'. Validate webhook schemas on receipt: unknown shapes must fail closed (no booking), never open. Silent parse failures are the most dangerous kind.