CJS↔SDK hard seam — one source of truth per Shared Module
- Status: Proposed
- Date: 2026-05-14
- Tracking issue: #3524
- Related PRD:
docs/prd/3524-cjs-sdk-hard-seam.md - Extends: ADR-0005 (seam map) — adds the Shared-Module Source Policy to the seam family
- Defers to: ADR-0001 (Dispatch Policy Module), ADR-0003 (Model Catalog Module), ADR-0004 (Planning Workspace Module), ADR-0006 (Planning Path Projection Module), ADR-0009 (Shell Command Projection Module — post-Phase 3–4, also subsuming superseded ADR-0010)
We decided to harden the boundary between the CJS tooling layer (get-shit-done/bin/lib/*.cjs) and the SDK (sdk/src/**/*.ts) by making every Module that is conceptually shared between the two runtimes have exactly one hand-authored source of truth and at most one generated artifact per runtime. The trigger is the recurring drift bug class — #1535, #1542, #2047/#2052, #2638/#2655, #2653/#2670, #2687/#2706, #2798/#2816, #3055/#3116, #3523 — each of which was a fix landing on one side without the other.
The precedent shape is already in the repo. sdk/scripts/gen-command-aliases.ts emits sdk/src/query/command-aliases.generated.ts and get-shit-done/bin/lib/command-aliases.generated.cjs from one TypeScript source. sdk/scripts/check-command-aliases-fresh.mjs is the CI freshness gate. The two consuming sides are pure Adapters over the generated artifact. This ADR generalizes that pattern to the other Shared Modules and forbids the hand-synced-pair anti-pattern that produced #3523.
Decision
1. Shared-Module Source Policy
A Shared Module is any Module whose Interface is consumed identically by both the CJS toolset and the SDK. The CONTEXT.md domain glossary already calls these out — e.g. STATE.md Document Module is explicitly typed as "Shared CJS/SDK pure transform Module."
For every Shared Module: