A parallel session is building an agent-comm stdio MCP server with an append-only NAS mailbox (infra/agent_bridge/, uncommitted). Rather than proposing a second channel, spec 21 now maps the task/result/requirement envelopes onto its message kinds and adopts its sanitization rules as system rules. Also states the boundary the parallel work should not cross: a mailbox is a transport, not a scheduler. It carries tasks; leases and heartbeats must not become 'a file in a folder'.
UmbraAudio Specifications
Index of all specification documents for the UmbraAudio audiobook generation system.
Specifications
| File | Topic | Description |
|---|---|---|
| 00-project-overview.md | Architecture | Pipeline overview, tech stack, data layout |
| 01-parsing.md | Pass 1a | EPUB, PDF, TXT, MD manuscript parsing |
| 02-analysis.md | Pass 1b | BookNLP, character profiling, pronunciation |
| 03-voice-design.md | Pass 2 | Per-character voice reference generation |
| 04-mapping.md | Pass 3 | Text segmentation, speaker attribution, manifests |
| 05-generation.md | Pass 5 | Audio generation, caching, retry, CUDA management |
| 06-normalization-watermarking.md | Post-gen | Audio normalization, ACX compliance, Perth watermark |
| 07-assembly-export.md | Export | M4B, MP3, WAV export via FFmpeg |
| 08-database.md | Database | SQLite schema, entity relationships, CRUD API |
| 09-web-review-ui.md | Web UI | FastAPI + HTMX review interface |
| 10-cli-orchestrator.md | CLI | Click commands, full pipeline orchestration |
| 11-configuration-dependencies.md | Config | Pydantic settings, dependencies, build system |
| 12-quality.md | Quality | MOS, WER, consistency, ACX compliance |
Quick Reference
Pipeline Passes
1a: Parse → chapters table
1b: Analyze → characters, pronunciation_guide
2: Voices → voice_ref WAVs
3: Map → manifests/*.json
4: Test → sample audio (optional)
5: Generate → audio/*.wav, audio_normalized/*.wav
Export → export/*.m4b, *.mp3
Key Entry Points
| Component | File | Class/Function |
|---|---|---|
| CLI | cli.py |
main Click group |
| Pipeline | orchestrator.py |
run_pipeline() |
| TTS | voices/chatterbox.py |
ChatterboxEngine |
| Segmenter | mapping/segmenter.py |
Segmenter |
| Generator | generation/chapter.py |
ChapterGenerator |
| Normalizer | assembly/normalize.py |
AudioNormalizer |
| Web UI | web/__init__.py |
create_app() |
| Database | database.py |
Database |