tegwick
76912adef8
Completes FLUID-WP-0002. The record types in internal/contract are generated from schemas/ by a dependency-free generator; fixtures transcribed from the spec's worked examples validate against those schemas and round-trip through the generated types with DisallowUnknownFields, so a spec change that misses the schemas fails CI rather than drifting silently. Adds identifier prefix helpers, Makefile, GitHub Actions, and five ADRs recording the Go choice, out-of-process attachment, the wire contract as boundary, the evidence store, and revision identity. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014KmVxhJ35tCo7rE7UnLwWu Assistant: claude-code Assistant-Model: opus Assistant-Process: 1116572@bnt-lap001 Assistant-Session: 8ba9bb93-a72a-4883-b189-2499cce5c400
1.5 KiB
ADR-0004 — Append-only evidence store, SQLite then Postgres
Status: accepted · Date: 2026-09-04
Context
Blueprint §26 requires an evidence store favouring append-only history, with mutable summaries derived from immutable events. §45 suggests a relational starting model and explicitly argues it is simpler than a graph database for a first implementation.
Decision
One relational schema, two backends. SQLite for development, single-node
deployments and the CI conformance suite; PostgreSQL for anything shared. The
event table is append-only: no UPDATE, no DELETE, enforced by trigger rather
than by convention.
Summary tables are derived views, rebuildable from events at any time.
Rationale
The first real workload — publishing hall-of-helix entries to a Telegram channel — produces a handful of events per day. Requiring Postgres to run the framework at that scale would be an operational tax with no return.
Keeping one schema across both means the CI suite exercises the same statements production runs, which is where divergence usually hides.
Consequences
- Portable SQL only; no backend-specific features in the core path.
- Blueprint invariant 8 (every promotion is auditable) is a storage property, not an application convention: rewriting history has to be blocked at the database.
- Evidence-store failure must not stop the data plane (Blueprint §34.6). The gateway serves from cached published configuration and buffers telemetry.