# Dia / Dia2

Nari Labs' dialogue-focused TTS — generates ultra-realistic
multi-speaker conversation in a single pass — served via
[devnen/Dia-TTS-Server](https://github.com/devnen/Dia-TTS-Server), the
same actively-maintained OpenAI-compat wrapper author as our
[chatterbox](../chatterbox/) stack. The wrapper carries multi-model
support for the whole Dia family:

| Model | HF repo | Notes |
|---|---|---|
| Dia 1.6B | [nari-labs/Dia-1.6B](https://huggingface.co/nari-labs/Dia-1.6B) | original, dialogue in one pass (in-image default) |
| Dia2-1B | Nari Labs Dia2 family | streaming, lower latency |
| Dia2-2B | Nari Labs Dia2 family | highest quality |

Dia2 was released 2025-11-19 ([nari-labs/dia2](https://github.com/nari-labs/dia2)).

**Server:** irv-ml1 (Irvine, WireGuard-only)
**Port:** 8200 (container listens on 8003)
**GPUs:** pins to device 0 (RTX 3090) by default; ~7 GB VRAM at BF16
**Image:** `local/dia:v1` — built locally from a pinned git SHA of the
wrapper repo via docker buildx's git URL context
**Upstream wrapper:** [devnen/Dia-TTS-Server](https://github.com/devnen/Dia-TTS-Server) (MIT)
**Upstream model:** [nari-labs/dia](https://github.com/nari-labs/dia) / [nari-labs/dia2](https://github.com/nari-labs/dia2) (Apache-2.0 weights)

## Why this stack exists

Fills the **dialogue-scene** slot none of the other TTS own cleanly.
Dia generates multi-speaker turn-taking in one pass with inline `[S1]`/
`[S2]` speaker tags and nonverbal cues — `(laughs)`, `(coughs)`,
`(sighs)`, `(clears throat)` — directly in the prompt. That's a
different shape from the single-speaker engines:

- **Fish S2-Pro / IndexTTS-2 / Chatterbox** are excellent single-voice
  readers (rich emotion, cloning) but you'd have to stitch turns
  yourself.
- **VibeVoice** does long-form multi-speaker but is podcast/narration
  shaped, not fast turn-taking with nonverbals.
- **Dia** is the one built for *scene dialogue* — the
  multi-character-storytelling case skaldsong is aimed at.

OpenAI-compatible (`POST /v1/audio/speech`), so skaldsong can target it
by base-URL once we add a `dia` engine option to its router.

## Deploy

```bash
# from this workstation (irv-ml1 is WG-only — routes via ana-wg):
scripts/deploy-stack.sh irv-ml1 dia
# then on irv-ml1, first run builds the image from the pinned SHA:
#   docker compose up -d --build
```

First boot pulls the checkpoint (~6-10 GB) into `DIA_CACHE_DIR` and can
take several minutes; the healthcheck's 600 s `start_period` covers it.

## Notes

- **Pin `DIA_SHA`** to a full 40-char commit before relying on this —
  `.env.example` ships `main` for convenience, but `main` is not
  reproducible (chatterbox learned this when an upstream restructure
  broke its `main` build).
- **Model switching** is config.yaml-driven in the wrapper, or live from
  the Web UI at `http://10.100.79.3:8200/`. To pin a non-default model
  declaratively, mount a host `config.yaml` (see the commented volume in
  `compose.yaml`).
- Endpoints: `/v1/audio/speech` (OpenAI-compat), `/health` (liveness),
  `/api/model-status` (download/load progress), `/api/model-info`.