---
date: '2026-01-31T14:00:00Z'
author: claude-opus-4-5-20251101
session: session_01YP2rP5pf1LPxxkWQehFGQ7
type: handoff
importance: 0.8
tags: [handoff, observability, ci, fastify-otel]
supersedes: 2026-01-30-05-session-handoff.md
signature: pending
---

# Handoff: Observability Library, @fastify/otel, CI Pipeline

## What Was Done This Session

1. **Created `docs/MANIFESTO.md`** — the MoltNet manifesto articulating the vision for agent autonomy, provided by Edouard.

2. **Built `@moltnet/observability` library** (`libs/observability/`) with TDD:
   - Pino structured logging with optional OTel transport bridge
   - OpenTelemetry tracing with OTLP proto export
   - Request metrics (duration histogram, total counter, active gauge)
   - SDK orchestrator composing all three pillars
   - Fastify plugin for automatic request instrumentation
   - 38 tests across 5 suites, all passing

3. **Integrated `@fastify/otel`** — replaced generic OTel Fastify instrumentation with the official Fastify plugin for lifecycle-hook-level tracing (onRequest, preHandler, handler, onSend, onResponse, onError).

4. **Created OTel Collector configs** — production (Axiom export) and development (stdout debug) configs with Docker Compose.

5. **Set up CI pipeline and local safeguards**:
   - ESLint + Prettier configs
   - Husky + lint-staged pre-commit hook
   - GitHub Actions CI with 4 parallel jobs (lint, typecheck, test, build)
   - Fixed monorepo tsconfig issues, added per-workspace configs
   - Added `npm run validate` script

6. **Fixed CI failure** — vitest exits code 1 on empty workspaces; added `--passWithNoTests` to three workspace test scripts.

## What's Not Done Yet

- No application code (WS5 MCP server, WS6 REST API) — the observability library is ready to consume but no apps exist yet
- No integration tests verifying `@fastify/otel` spans during actual Fastify request handling
- OTel Collector is configured but not deployed — needs `AXIOM_API_TOKEN` and `AXIOM_DATASET` env vars
- The diary service (WS3) is not started
- Auth webhook for JWT enrichment (WS2) is not built

## Current State

- Branch: `claude/moltnet-manifesto-VKLID` (merged to main)
- Tests: 38 passing, 0 failing
- Lint: 0 errors, 13 warnings (all `no-non-null-assertion`)
- Typecheck: clean
- Build: all 4 workspaces emit to `dist/`
- CI: passing

## Decisions Made

- Used `@fastify/otel` over `@opentelemetry/instrumentation-fastify` for Fastify-aware lifecycle tracing
- Separated tracing plugin (`fastifyOtelPlugin` from `@fastify/otel`) from metrics plugin (`observabilityPlugin` with counters/histograms) — different concerns
- Built custom `TestMetricReader` because the version in `@opentelemetry/sdk-metrics` doesn't export one
- Root tsconfig is a pure base config (no rootDir/outDir); each workspace overrides
- `vitest --passWithNoTests` for workspaces without test files

## Open Questions

- When will the first app (`apps/mcp-server` or `apps/rest-api`) be built to consume `@moltnet/observability`?
- Should the OTel Collector run as a sidecar or a shared service in production?
- What Axiom dataset naming convention — one per service or one shared `moltnet` dataset?

## Where to Start Next

1. Read this handoff entry
2. Read `docs/FREEDOM_PLAN.md` for workstream priorities
3. Likely next steps:
   - **WS3**: Build `libs/diary-service/` — CRUD + semantic search with pgvector
   - **WS5**: Build `apps/mcp-server/` using `@getlarge/fastify-mcp`, register observability plugins
   - **WS2**: Build token enrichment webhook for JWT custom claims
4. When building an app, integrate observability:
   ```typescript
   import {
     initObservability,
     observabilityPlugin,
   } from '@moltnet/observability';
   const obs = initObservability({
     serviceName: 'mcp-server',
     tracing: { enabled: true },
   });
   if (obs.fastifyOtelPlugin) app.register(obs.fastifyOtelPlugin);
   app.register(observabilityPlugin, {
     serviceName: 'mcp-server',
     shutdown: obs.shutdown,
   });
   ```
5. Write journal entries for decisions and discoveries along the way
