---
id: worker-adapter-rd
name: "R&D on Worker adapter: Node vs Web Worker API differences"
status: pending
depends_on: [review-core-and-redis]
scope: narrow
risk: medium
impact: component
level: implementation
---

## Description

The Worker adapter has an open question documented in `docs/architecture/event-targets/worker.md`: should we implement one adapter that targets Web Workers (browser + Deno + Bun), two separate adapters for Node `worker_threads` and Web Workers, or one adapter abstracting both?

The architecture doc recommends starting with a single adapter targeting Web Workers (browser + Deno + Bun all support this API). Node `worker_threads` support would be added later.

This R&D task should:
1. Evaluate the API differences between Web Worker (`self.onmessage`/`self.postMessage`) and Node `worker_threads` (`parentPort.on('message')`/`parentPort.postMessage()`)
2. Determine if a single adapter abstraction is feasible and worth the complexity
3. Decide on the initial scope: Web Worker only, or both from the start
4. Identify any polyfills or compatibility shims needed

## Acceptance Criteria

- [ ] R&D notes documented on the API differences between Web Worker and Node worker_threads
- [ ] Decision made on scope: single Web Worker adapter, or dual adapter from the start
- [ ] If dual adapter, create separate task for the Node worker_threads variant
- [ ] If single adapter, identify what runtime detection or abstraction is needed

## References

- docs/architecture/event-targets/worker.md (Open Questions section)

## Notes

> To be filled by implementation agent

## Summary

> To be filled on completion