NotebookLM bridge — decommissioned (Phase 71.8, 2026-06-05)

This guide is no longer current. The NotebookLM bridge (services/notebooklm-bridge/, port 19213) was decommissioned in Phase 71.8.

Semantic search across project wiki + issues + skills now runs through the self-hosted RAG pipeline (Cohere embeddings + sqlite-vec, stored inside the existing SQLite SSOT). No external retrieval service, no per-user Google session, no source caps.

What replaces it

Architecture overview: architecture/rag-architecture.md
Public search endpoint: GET /api/crm/projects/:name/rag/search?q=... (API reference)
CLI: arc kb search "<query>" — same command, now backed by semantic search

What changed for users

Before	After
Add sources to NotebookLM via `POST /sync`	Wiki / issue / skill writes auto-embed via Phase 71.5 hooks. Nothing to do.
`arc wrapup --sync` to upload session logs	Removed. Session content lives in `docs/library-export/` + git.
Audio overview download	Removed. `POST /memory/fetch-artifact` returns `410 Gone`.
`POST /memory/refresh` re-syncs to NotebookLM	Same endpoint, now re-embeds locally into `embeddings` + `embeddings_vec`.
`GET /projects/:name/notebooks` returns notebook ID + URL	Returns `{ notebooks: [], retired: "phase-71.8" }` (legacy stub).

What changed for operators

Stop & disable: systemctl stop citadel-notebooklm-bridge && systemctl disable citadel-notebooklm-bridge
Unit file removed: /etc/systemd/system/citadel-notebooklm-bridge.service
Python service archived to: services/.archived-notebooklm-bridge-2026-06-05/
Port 19213 is free; nothing listens on it

Migrating an existing deployment

Already done on the canonical Arc OS prod fleet (#363 backfill ran 2026-06-05, 814 docs / ~3,150 chunks). For a self-hosted Arc OS instance:

Set COHERE_API_KEY in Platform Settings → RAG / Semantic search (Production tier recommended for any non-trivial scale).
Run bun scripts/phase-71-backfill-rag.ts --dry-run to inventory candidate docs.
Run bun scripts/phase-71-backfill-rag.ts to embed. The script is idempotent — safe to re-run.
systemctl stop citadel-notebooklm-bridge to free port 19213.

See rag-architecture.md §7 for full flag reference.