# AGENTS — LegacyHUB

Operating instructions for AI agents working inside this repository.

## What this project is

LegacyHUB ingests legacy PDF archives at scale (~70k docs), runs OCR
(OCRmyPDF/Tesseract), extracts structured content with Docling, indexes chunks
into PostgreSQL + OpenSearch (BM25) + Qdrant (BGE-M3 dense), and serves a
hybrid lexical + semantic search API (FastAPI) reranked by BGE.

It is one module of the TeamHUB Suite.

## Stack (canonical)

| Layer    | Tech                                          |
|----------|-----------------------------------------------|
| API      | FastAPI, Pydantic v2, SQLAlchemy 2, Alembic   |
| Workers  | Celery + Redis                                |
| OCR      | OCRmyPDF + Tesseract (rus+eng)                |
| Extract  | Docling                                       |
| Store    | PostgreSQL 16, MinIO, OpenSearch 2.x, Qdrant  |
| ML       | BAAI/bge-m3 (dense, 1024), bge-reranker-v2-m3 |
| Frontend | React 18, TS 5, Vite 5, Tailwind, shadcn, TanStack Query, Zustand, Framer Motion, Recharts |
| Tests    | pytest                                        |
| CI       | GitHub Actions                                |

## Entry points

- **Backend API** — `app/main.py` (`uvicorn app.main:app`)
- **Celery worker** — `celery -A app.workers.celery_app worker`
- **CLI scripts** — `scripts/init_db.py`, `scripts/init_opensearch.py`,
  `scripts/init_qdrant.py`, `scripts/ingest_folder.py`,
  `scripts/reindex_document.py`, `scripts/smoke_test.py`
- **Frontend dev** — `cd frontend && npm run dev` (port 5273)
- **Docker** — `docker compose up -d --build` (dev), `docker compose -f
  docker-compose.yml -f docker-compose.prod.yml ...` (prod)

## Inventory

```text
legacy-knowledge-indexer/
  app/
    api/             routers + Pydantic schemas
    db/              SQLAlchemy models + Alembic migrations
    indexing/        OpenSearch + Qdrant clients, embeddings, reranker, hybrid
    ingestion/       scanner, OCR, Docling, chunker, table/figure processors,
                     quality, pipeline
    storage/         MinIO client + key conventions + ensure_artifact helper
    utils/           hashing, text cleaning, language detection, pdf helpers
    workers/         Celery app + tasks
  scripts/           init / ingest / reindex / smoke CLIs
  tests/             pytest suite
  docker/Dockerfile  API + worker image (OCRmyPDF + tesseract-rus+eng)
  docker-compose.yml dev orchestration
  docker-compose.prod.yml  production overlay
  frontend/          React app — see frontend/README.md
  .github/workflows  CI gate (ruff + pytest + tsc + vite build + compose config)
```

## Code discovery order

Bounded discovery order for this repo. Use the first available that returns a
usable answer; mark the rest "not available" for the task.

1. **Grep / rg** — reliable fallback, always available. First choice for
   strings, configs, docs, scripts, route paths, hashes.
2. **Glob** — file shape lookups (`app/**/*.py`).
3. **Semantic search** (if Sourcegraph, Zoekt, or Serena MCP is configured at
   user level) — go-to-symbol, references. Document the smoke command before
   relying on results.
4. **Docling / extracted Markdown in MinIO** — for content questions about
   ingested documents, not source code.

Smoke command for layer 1:

```bash
rg --version && rg "@router" app/api -n
```

If any indexer times out or returns stale results, capture the error and fall
through. Do not retry the same failing indexer.

## Module contracts (high level)

- `app/ingestion/pipeline.py::process_document_id(document_id, run_id)` — single
  document end-to-end. Idempotent. Returns `{status, chunks, error?}`.
- `app/indexing/hybrid_search.py::run_search(SearchRequest) -> SearchResponse` —
  the only public search entry. Lexical + semantic + reranker.
- `app/storage/artifacts.py::ensure_artifact(...)` — single source of truth for
  `document_artifacts` upsert. Used by scanner, pipeline, table_processor,
  figure_processor.
- `app/storage/minio_client.py::MinioStorage` — bucket bootstrap + retryable
  put/get. Never bypass for object IO.
- `app/indexing/opensearch_client.py::ensure_index() / index_chunks()` — chunk
  index lifecycle.
- `app/indexing/qdrant_client.py::ensure_collection() / upsert_chunks()` —
  vector index lifecycle.

## Runtime vs legacy scope

Everything under `app/` is runtime. `scripts/` are operational tools. `tests/`
are non-runtime. There is no archived/legacy code yet.

## Baseline checks

```bash
# Backend
python -m pip check
python -m compileall -q app scripts tests
python -m pytest tests/ -q

# Frontend
cd frontend
npx tsc --noEmit
npm run lint
npm run build

# Docker
docker compose config --quiet
```

## Operating rules for agents

- Inspect before changing. `git status` first.
- Small reviewable commits. One ownership boundary per commit.
- Do not delete files, routes, migrations, or env vars without evidence (see
  `software-project-delivery-governance` skill).
- Do not invent secret values. Use `.env.example` placeholders.
- Use `ensure_artifact` instead of re-implementing artifact upsert.
- Use existing UI primitives in `frontend/src/components/ui/*` before adding new
  ones.
- Never commit `node_modules/`, `dist/`, `.env`, `data/input/*`, `data/work/*`.
- Failures must be logged via `processing_events` (backend) or `sonner` toast
  (frontend) — not silenced.

## Ownership

- Backend, ingestion, search — Vadim Malanov.
- Frontend, design system — Vadim Malanov.

## Where to update what

- New behavior — update `README.md`.
- New repeated agent rule — update this file.
- New deployment / recovery step — update `RUNBOOK.md`.
- Cleanup findings — `docs/cleanup-report.md` (create on demand).