Architecture overview¶

Components¶

┌─────────────────────────────────────────────────────────────┐
│  FastAPI UI (server.py)         port 8501                   │
│  - upload, queue, results                                   │
│  - reads/writes queue.db                                    │
│  - starts worker subprocess                                 │
└──────────────────────────┬──────────────────────────────────┘
                           │
                           ▼
┌─────────────────────────────────────────────────────────────┐
│  Worker (worker.py)           separate process              │
│  sbobina worker                                             │
│  - claim_next_job() loop                                    │
│  - run_pipeline()                                           │
└──────────────────────────┬──────────────────────────────────┘
                           │
          ┌────────────────┼────────────────┐
          ▼                ▼                ▼
    ┌──────────┐    ┌────────────┐   ┌───────────┐
    │ pipeline │    │ transcribe │   │ summarize │
    └──────────┘    │   + NeMo   │   │ LexRank / │
                    └────────────┘   │   LLM     │
                                     └───────────┘
                           │
                           ▼
                    ┌────────────┐
                    │ jobs.py    │
                    │ SQLite WAL │
                    └────────────┘

Main modules¶

Module	Responsibility
`config.py`	Paths, models, device, summary enums
`jobs.py`	SQLite queue, `JobRecord`, CRUD
`worker.py`	Worker process, PID file
`pipeline.py`	Single-job orchestration
`transcribe.py`	NeMo ASR, chunking
`extract.py`	ffmpeg/ffprobe
`export.py`	TXT, SRT
`summarize.py`	Extractive / abstractive summary
`cli.py`	Typer CLI
`ui/server.py`	FastAPI web UI
`ui/launch.py`	Start uvicorn subprocess

Why a separate worker¶

NeMo/PyTorch/Lightning are not stable in a thread inside the FastAPI server on Windows. The worker runs in a dedicated Python process with a clean NeMo import.

Version¶

0.3.0 — SQLite queue, worker subprocess, human-readable folder IDs.