Effect 4 in the kernel only
- Status: accepted
- Date: 2026-10-02
Context and problem statement
Section titled “Context and problem statement”The kernel needs structured concurrency, typed errors, retries, resource safety, tracing, durable workflows and an OpenAPI-described API. Plugin and UI contributors should not need to learn a new programming model.
Decision
Section titled “Decision”packages/kernel, packages/api and packages/protocol use Effect 4 (LTS). Every boundary that plugins or UI code touch is plain TypeScript: Promise and AsyncIterable signatures, DTO payloads validated with Standard Schema. dependency-cruiser forbids effect imports outside the three core packages.
Consequences
Section titled “Consequences”Kernel contributors learn Effect (an onboarding guide is required); plugin authors never see it. Durable workflows are gated by a spike of effect/workflow on SQLite with a Restate sidecar as fallback.