[sjungwon03]

Closes #552. Refs #116; unresolved Jev #7 remains unchanged.

Actual pinned Output.object now exercises generateText/streamText on both bases through managed OpenAI/delegated OpenRouter, asserting exact schema/name/description/strict delivery. Forty-eight new cases cover valid/malformed/type-mismatched/extra-property output, admission/required persistence failures and native Anthropic/Gemini pre-secret schema rejection. No production code, pins, dependencies or storage change.

Measured client boundaries matter for accounting: malformed/wrong-type output raises a content-bearing NoObjectGeneratedError after successful provider completion/usage. Default Zod strips extra properties while gateway text stays exact. After a streaming audit/usage error the SDK may still resolve an object from delivered text, even though the server emits an error and withholds actual final usage/DONE. Parsed objects and client finish events must not be treated as server persistence acknowledgments or full returned-instance conformance.

Plan: 552-ai-sdk-structured-output. Contracts: AI SDK workflows, response formats. Reproduction: structured objects.

Validation:

• Tests preceded any runtime changes. Initial 40 cases: 36 passed, 4 failed on the provisional assumption that stream result.output must reject after a persistence error. The measured SDK can resolve it; assertions now explicitly require both this client behavior and the server error/final-frame withholding. No gateway defect or production red/green cycle is claimed.
• Final focused SDK/format selection on approved main c22b303 passed 258 cases, including the 8 added extra-property probes and merged image coverage.
• Full npm run check on approved main c22b303: 7,725 total, 7,724 passed, zero failures/cancellations, one optional external PostgreSQL skip (~232sec). Typecheck, lint, planning/link/fixture-secret validation and all six offline integrity checks passed.
• Existing 42 lint warnings/65 infos are unchanged. Planning/link/fixture-secret scan, whitespace and CLAUDE.md symlink checks passed. Production source, scripts, all six pins, dependencies and migrations are byte-unchanged relative to approved main.

The branch began independently from fcb40ea and updated onto approved c22b303 after PR #551 received approval/green CI and merged. Other Output modes/partial-object semantics, native mappings, server-side validation/repair, live provider guarantees, other SDK versions and full #116 remain uncertified.

[sjungwon03-ai]

Review summary

Verdict: Approved

• Reviewed: Structured-object schema forwarding, client parsing and extra-property behavior, admission and persistence gates, native-provider rejection, privacy assertions, and matching contract documentation across both API bases.
• Checks: All three GitHub checks passed; 258 focused AI SDK/response-format tests, TypeScript typecheck, focused Biome validation, and planning/link/fixture-secret validation passed locally.