The first CUST-WP-0045 canary retry after 9de0f49 still failed schema
validation with `Expecting value: line 1 column 1 (char 0)`. The original
allowlist returned envelope.result verbatim, which on longer prompts
carries the model's conversational preamble ("Triage report generated
and returned via structured output. Key signals: ..."), not the
schema-enforced JSON. The actual structured payload lives in a different
envelope field whose name varies across CLI versions.
Make the unwrap order-aware:
1. Scan envelope fields and return the first one whose value parses as
JSON (dict, list, or a string that loads cleanly). Skip well-known
metadata keys (type, usage, total_cost_usd, etc.) so telemetry can
never be mistaken for the model payload.
2. Fall back to the original text-field allowlist only when no field
carries JSON, so non-schema callers via this same code path still
see the model's prose.
3. Surface the raw envelope as last resort.
This is robust against unknown envelope shapes — as long as the schema-
enforced JSON appears somewhere in a non-metadata field, the adapter
will find it.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
tegwick
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