Reasoning Layer

An ambient reasoning and review system that sits between a developer and an AI coding agent. It intercepts non-trivial tasks, surfaces architectural questions, routes high-risk decisions to reviewers via Slack (async — no blocking), enforces coherence between decisions and code, and stores every answer as searchable project memory — so your AI agent never re-litigates a settled decision.

→ Executive Summary · How to Use · Dev conventions

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How it works

Developer types a task in Claude Code
        │
        ▼
Step 0 — Catch-up: surface decisions that arrived from Slack + in-flight questions
Step 0b — Drift check: surface tracked files with unimplemented decisions
        │
        ▼
Pipeline intercepts → classifies risk → generates clarifying questions
        │
        ├── Low-risk → developer answers inline → WAL entry written
        └── High-risk → interim WAL entry written, question routed to Slack (fire-and-forget)
                │
                ▼  (async — developer does not wait)
        Reviewer answers in Slack thread (/settle, /wont-do, /table)
        Final WAL entry supersedes interim; surfaced at next session start
                │
                ▼
        Future prompts automatically enriched with relevant past decisions
        Pre-commit hook enforces coherence between decisions and tracked files

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Stack

Layer	Technology
Backend API	Fastify · Prisma · Postgres · pgvector
AI pipeline	Claude Haiku (classification) · Claude Sonnet (question generation)
Notifications	Slack Bolt — Socket Mode threads + modals
Frontend portal	Next.js 15 App Router
Developer integration	VS Code extension + Claude Code agent file (fully automatic)
Infrastructure	EC2 · nginx · pm2

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Monorepo structure

reasoning-layer/
├── packages/backend/          Fastify API, Prisma, LLM pipeline
│   ├── src/
│   │   ├── routes/            prompts.ts · questions.ts · decisions.ts
│   │   │                      sessions.ts · artifacts.ts · repos.ts · slack.ts
│   │   ├── llm/               analyzer.ts · embedder.ts · prompts.ts
│   │   ├── slack/             bolt-app.ts · message-builder.ts · routing.ts
│   │   └── db/                repos.ts
│   ├── prisma/
│   │   ├── schema.prisma
│   │   └── migrations/
│   └── scripts/
│       ├── pre-commit         coherence hook (bundled into VS Code extension)
│       └── install-coherence-hook.sh
├── packages/ui/               Next.js 15 decision portal
├── packages/vscode-extension/ VS Code extension (.vsix)
├── docs/
│   └── PHASES.md              full implementation plan — Phases 1–5 all shipped
├── EXECUTIVE_SUMMARY.md
├── HOW_TO_USE.md
└── CLAUDE.md

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Decision memory model

Every answer is stored as an append-only WAL entry — never edited, only superseded via rollback:

Type	Meaning
decision	Settled positive answer
wont_do	Explicit rejection ("not doing in v1")
table	Deferred to a later phase
branch	Needs decomposition into sub-decisions
rollback	Supersedes a prior decision (must reference original)
observation	Constraint note — no action needed

Each entry stores the answer, rationale, alternatives considered, reopen condition, reviewer, linked files, and reasoning arc — the full dialogue context that led to the decision, assembled from the refining session messages.

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API reference

Method	Path	Description
POST	/api/prompts	Submit a task for analysis
POST	/api/prompts/:id/analyze	Run LLM pipeline — classifies risk, generates questions
GET	/api/prompts/:id	Get prompt with questions and decisions
GET	/api/prompts/:id/enriched	Get prompt enriched with relevant past decisions + in-flight assumptions
POST	/api/questions/:id/answer	Answer a question inline
POST	/api/questions/:id/route	Route a question to Slack (async); writes interim WAL entry immediately
POST	/api/questions/route-batch	Route multiple questions under one session thread
GET	/api/sessions/catch-up	Settled decisions + in-flight open sessions since a timestamp
GET	/api/sessions/:id	Full session with messages and decisions
POST	/api/sessions/:id/settle	Write final WAL entry, supersede interim, close session
POST	/api/sessions/:id/table	Enrich interim entry with rationale, close as tabled
GET	/api/decisions	List decisions (?repo=&limit=)
POST	/api/decisions	Seed a standalone historical decision
GET	/api/decisions/export	Full ADR-style markdown export
GET	/api/decisions/export-since	Decisions since timestamp — used by Sync Decision Log
POST	/api/decisions/search	Semantic similarity search
GET	/api/decisions/:id/linked-artifacts	Tracked files linked to a specific decision
GET	/api/repos/:id/artifacts	List tracked artifacts for a repo
POST	/api/repos/:id/artifacts	Register a file as a tracked artifact
POST	/api/artifacts/drift	Check which tracked files have decisions newer than their last commit
POST	/api/decisions/:id/link-artifacts	Link a decision to tracked files
GET	/api/repos/:id/context-log	Full WAL as narrative or ADR markdown (?format=narrative|adr&since=&type=)

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Development

pnpm install
pnpm dev        # backend on :3002
pnpm ui:dev     # UI on :3001
pnpm db:migrate # run pending migrations
pnpm db:studio  # open Prisma Studio

See HOW_TO_USE.md for full local setup, VS Code extension install, and Slack configuration.

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Implementation phases

Phase	What it delivers
1 — WAL Upgrade	reasoningArc + sessionId on every decision; rollback validation
2 — Async Refining Session	Fire-and-forget Slack routing; interim WAL entry; catch-up cadence
3 — Artifact Coherence	Tracked files linked to decisions; drift detection; pre-commit hook
4 — Agent File Cadences	Pre-task drift check; post-decision propagation — both in the Claude Code agent file
5 — Context Log Export	Full WAL as narrative/ADR markdown on demand from Postgres
6 — Conversation-native Capture	Settling-cue detection; direct WAL capture without a question pipeline; captureDecision command
7 — Conflict Detection	Capture-time + commit-time conflict detection; append-only override flow

See docs/PHASES.md for the full implementation detail and EXECUTIVE_SUMMARY.md for the architecture overview.