vllm-omni/.claude/skills/review-pr/references/modules/input-output-modality.md

Input, Output, and Modality Contracts

Primary design: Input, Output, and Modality Contracts.

Use for requests, prompt and modality types, message schemas, serialization, output types, accumulation, completion, and compatibility shims crossing entrypoint, orchestration, stage, connector, or model boundaries.

Contract checks

• Give every boundary value an explicit modality and validated typed schema.
• Preserve request and stage identity across conversion, serialization, streaming updates, batching, cancellation, and errors.
• Distinguish partial, final, empty, and failed output states for every modality.
• Verify producer and consumer agreement on shape, layout, dtype, device, ownership, metadata, ordering, and optional or unknown fields.
• Keep internal objects out of public protocols; translate them at the owning entrypoint.
• Preserve wire compatibility deliberately and give deprecated shims a bounded migration path.

Require construction, round-trip, accumulation, completion, rejection, and compatibility tests at each changed producer-consumer boundary.