# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## What CTXD is

A single-process daemon that stores per-project "context dossiers" (multiple `.MD` files:
`CONTEXT.MD`, `DECISIONS.MD`, `RUNBOOKS.MD`, `PROMPTS.MD`, `GLOSSARY.MD`) and serves them to
LLM harnesses (Claude, ChatGPT, Hermes, Codex, Cursor) over **MCP via Streamable HTTP**, plus a
web UI and REST API. `CONTEXT.MD` can be synced to a repo as `AGENTS.md` with symlinks
(`CLAUDE.md`, `.cursorrules`, `CODEX.md`). The full user/operator guide is `README.md`; this file
is the orientation for editing the code.

All source lives in `app/src/ctxd/`. Run commands from `app/`.

## Architecture (the parts that need multiple files to grasp)

- **One ASGI app multiplexes three protocols.** `server.py` → `CombinedApp` (~line 1455) dispatches
  every request to: REST + Web UI, the OAuth 2.0 authorization server, and the MCP endpoints. There
  is no separate service per surface — "MCP is 502" and "web UI is 502" are the same process being
  down. `serve_sync(cfg)` boots it under uvicorn.
- **Two MCP transports.** Streamable HTTP is the public one (paths in `MCP_STREAMABLE_PATHS` =
  `/mcp`, `/readonly/mcp`, `/oauth/mcp`, all served by `CombinedApp`). `mcp_stdio.py` is a *separate*
  stdin/stdout JSON-RPC server Hermes spawns directly — keep tool definitions in sync between the two
  when adding tools.
- **MCP tools are built in two functions, gated by scope.** `make_mcp_server(cfg, readonly, oauth_scoped)`
  exposes read tools (+ everything when API-key/LAN); `make_write_mcp_server(cfg)` exposes the write
  set (`update_file`, `set_project_tags`, `sync_to_project`). OAuth `ctxd.read` vs `ctxd.write` scopes
  decide what a token sees. To add an MCP tool, edit the `list_tools`/`call_tool` handlers inside these
  builders.
- **`db.py` is plain functions over a `conn`, no ORM, dual-backend.** PostgreSQL is primary; SQLite
  (`$CTXD_HOME/ctxd.db`) is the fallback when `DATABASE_URL` is empty (`cfg.use_postgres`). The same
  query strings run on both via `_is_pg(conn)` and the placeholder helper `_ph(conn, n)`. **`schema.sql`
  (PG) and `schema_sqlite.sql` must be kept in lockstep** — a table added to one must be added to the other.
- **OAuth state and web sessions are file-based JSON, not in the DB.** `OAuthStore` (`oauth_state.json`)
  and `WebSessionStore` (`web_sessions.json`) live in `$CTXD_HOME` (`/data` in the container). They
  survive DB swaps but are *not* covered by `pg_dump` — back them up separately.
- **Metadata headers are computed, never stored.** `build_metadata_header()` prepends the header on
  read; `strip_metadata_header()` removes it before persisting. Don't store headers in the DB.
- **File paths are normalized** to uppercase with `.MD` (`normalize_file_path`). `CONTEXT.MD` is the
  minimum file and cannot be deleted; in the `ctxd-docs` project, `CONTEXT.MD` and `LLM-CLIENT.MD` are
  also locked against update/delete.
- **Writes are version-checked.** `file_update`/`context_update` take `base_version`; a mismatch is a
  `409 conflict`. Every mutating op also writes an append-only `audit_log` row and may take a rotating
  snapshot (`SNAPSHOT_MIN_KEEP`/`MAX_KEEP`).

### Latent / not wired up

`schema.sql` and `db.py` define a full collaborative-review flow — `user_workspaces` → `workspace_files`
→ `change_requests` → `reviews`, with `workspace_fork`, `workspace_submit`, `change_request_approve`,
etc. As of now this is **DB-layer only**: it is exposed through neither `server.py` (REST/MCP) nor
`cli.py`. Treat it as scaffolding, not a live feature.

## Entry points

`pyproject.toml` defines two console scripts (and `python -m ctxd` dispatches the same way via
`__main__.py`, choosing CLI vs daemon by the first arg):

- `dossier <command>` → CLI (`cli.py`, `cli_entry`). In production these run inside the container:
  `docker exec ctxd dossier <command>`.
- `ctxd` → starts the daemon (`daemon_entry` → `serve_sync`).

## Build / run / deploy

Everything runs from `app/`. There is **no test runner or linter configured** — `scripts/test_*.py`
are standalone MCP smoke scripts, not a suite.

```bash
# Local dev (SQLite, no Docker)
cd app
pip install -e ".[mcp]"
export CTXD_HOME=./dev-data
python -m ctxd init        # initialize DB
python -m ctxd             # serve → http://localhost:9091

# Production deploy (Docker + bundled PostgreSQL 16)
./scripts/deploy.sh        # builds ctxd, starts postgres, waits for healthy, recreates ctxd, smoke-tests /status

# MCP smoke tests against a running server
python scripts/test_unified_mcp.py
python scripts/test_write_mcp.py

# Health
curl http://localhost:9091/status   # → {"status":"ok", ...}
```

**Deploy gotcha (the #1 source of public 502s):** `ctxd` depends on the `postgres` container being up
first. Always use `./scripts/deploy.sh` (or `docker compose up -d`, which starts both). **Never**
`docker compose up -d --no-deps ctxd` and **never** `docker restart ctxd` after a code change — the
former crash-loops without the DB, the latter runs the old image. After editing code you must rebuild
(`docker compose build ctxd`) before recreating.

## Config

All config is env-driven through `config.py` (`CtxConfig`), precedence **env var > `data/ctxd.yaml` >
default**. Key switches: `DATABASE_URL` (empty ⇒ SQLite fallback), `CTXD_HOME` (`/data` in container),
`CTXD_AUTH_ENABLED` + `CTXD_API_KEY` (shared key for LAN/Hermes = full MCP tools), `OAUTH_ENABLED` +
`OAUTH_ISSUER` (must be set together or the app won't start cleanly). The full table is in `README.md`.

## Conventions when changing code

- Adding a context-data operation: write the `conn`-taking function in `db.py` (handle both backends
  via `_is_pg`/`_ph`), then expose it in the relevant surface(s) — `server.py` for REST/MCP, `cli.py`
  for CLI, and `mcp_stdio.py` if Hermes needs it.
- Adding a column/table: edit **both** `schema.sql` and `schema_sqlite.sql`; for live PG instances add
  a guarded migration (see `_migrate_pg` in `db.py` and the standalone `migrate_*.py` scripts).
- Don't persist metadata headers; don't bypass `base_version` checking on writes; keep every mutation
  audit-logged.