Error Model

Admission Failures

• invalid bearer credential
• missing scope
• entitlement not sufficient
• quota exhausted

These failures happen before the request is admitted into execution.

Request Failures

• malformed schema
• missing text and structured_input

These failures happen when the submitted request body does not satisfy the executable platform subset.

If an integration embeds neutral protocol objects inside structured_input, validation failures inside that embedded payload can still mention protocol-layer fields such as raw_input or structured_summary, but those are not the frozen top-level HTTP request contract of POST /api/execute.

Follow-up Failures

• workflow not found
• workflow no longer queryable

These failures happen after an async workflow has already been accepted and the caller is consuming follow-up surfaces from zhen-platform-core.