(MOT-3868) fix(harness): publish typed request schema for harness::react

[ytallo]

Summary

• Add a typed ReactEvent wire-schema wrapper for harness::react while preserving the lossless serde_json::Value runtime payload (same pattern as NotifyAgentEvent in harness::notify_agent).
• Register harness::react with that typed request shape so release interface collection no longer publishes AnyValue for its request schema.
• Add harness::react to the harness schema catalog and commit the new golden snapshot.

Root Cause

The harness release publish gate collected worker-interface.json successfully, then failed because harness::react.request_schema was the permissive AnyValue schema. The handler was registered with a raw serde_json::Value event payload even though the registry publish gate requires typed function request/response schemas.

Validation

• UPDATE_GOLDENS=1 cargo test --manifest-path harness/Cargo.toml --test schemas
• cargo test --manifest-path harness/Cargo.toml
• cargo clippy --manifest-path harness/Cargo.toml --all-targets -- -D warnings
• git diff --check

Fixes MOT-3868

Summary by CodeRabbit

• New Features

  • Added support for a new reactive event handler in the harness.
  • Event payloads now accept and preserve any valid JSON value, improving compatibility with a wider range of inputs.

• Bug Fixes

  • Registration now uses a concrete request schema, avoiding issues with unsupported untyped payload definitions.
  • Updated the published function catalog and schema expectations to include the new handler.

[vercel]

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Project	Deployment	Actions	Updated (UTC)
workers	Ready	Preview, Comment	Jul 3, 2026 10:56pm
workers-tech-spec	Ready	Preview, Comment	Jul 3, 2026 10:56pm

[github-actions]

skill-check — worker

0 verified, 32 skipped (no docs/).

Layer	Result
structure	✓
vale	✓
ai	✓
render	✓

Four for four. Nicely done.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: c2c97b55-0d92-4443-bf40-2147ea79cf87

📥 Commits

Reviewing files that changed from the base of the PR and between 9b1dd79 and 5f167a4.

📒 Files selected for processing (5)

• harness/src/functions/mod.rs
• harness/src/functions/react.rs
• harness/src/surface.rs
• harness/tests/golden/schemas/harness.react.json
• harness/tests/schemas.rs

---

📝 Walkthrough

Walkthrough

The harness::react function registration now uses a typed ReactEvent(pub Value) wrapper implementing JsonSchema instead of a generic Value, with corresponding catalog wiring, golden schema file, and registration-order test updates.

Changes

ReactEvent typed schema integration

Layer / File(s)	Summary
ReactEvent type and schema harness/src/functions/react.rs	Adds ReactEvent(pub Value) wrapper implementing schemars::JsonSchema covering all JSON value types.
Registration and catalog wiring harness/src/functions/mod.rs, harness/src/surface.rs	Updates register_all to use typed ReactEvent and pass ev.0 to react::handle; imports and registers ReactEvent/ReactResult in the catalog under REACT_ID.
Golden schema and tests harness/tests/golden/schemas/harness.react.json, harness/tests/schemas.rs	Adds golden request/response schema for harness::react and updates expected registration order to include the new function id.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• iii-hq/workers#333: Both PRs modify the same register_all function-registration wiring to add new handlers to the harness catalog.

Poem

A rabbit hops with schema in paw,
ReactEvent typed, no more raw!
Catalog updated, tests all align,
Golden JSON schemas, oh so fine,
Hop, hop, hooray for react::handle's new law! 🐇

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/harness-react-schema

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