| # WRITER.md — Script Writer |
|
|
| The pipeline uses `midnight_static.writer.ScriptWriter` as the boundary between |
| script generation and audio rendering. |
|
|
| ## Implementations |
|
|
| - `fixture`: deterministic, schema-valid local writer used for tests and Day 1 |
| pipeline proof. |
| - `nemotron`: lazy-loaded Transformers writer targeting |
| `nvidia/NVIDIA-Nemotron-3-Nano-4B-BF16` by default. |
|
|
| The model ID was verified from Hugging Face Hub search results on June 12, 2026. |
| Related official repos include: |
|
|
| - `nvidia/NVIDIA-Nemotron-3-Nano-4B-BF16` |
| - `nvidia/NVIDIA-Nemotron-3-Nano-4B-FP8` |
| - `nvidia/NVIDIA-Nemotron-3-Nano-4B-GGUF` |
|
|
| ## Commands |
|
|
| Fast schema smoke: |
|
|
| ```bash |
| uv run python scripts/check_writer_premises.py --writer fixture |
| ``` |
|
|
| Real model smoke, downloads/loads the 4B model: |
|
|
| ```bash |
| uv sync --extra dev --extra tts --extra writer |
| uv run python scripts/check_writer_premises.py --writer nemotron |
| ``` |
|
|
| Local macOS fallback smoke using the Llama-architecture Nemotron Nano 4B repo: |
|
|
| ```bash |
| uv run python scripts/check_writer_premises.py \ |
| --writer nemotron \ |
| --model-id nvidia/Llama-3.1-Nemotron-Nano-4B-v1.1 \ |
| --limit 1 \ |
| --max-new-tokens 900 |
| ``` |
|
|
| Runtime knobs: |
|
|
| - `MIDNIGHT_NEMOTRON_MODEL` |
| - `MIDNIGHT_NEMOTRON_DEVICE_MAP` |
| - `MIDNIGHT_NEMOTRON_MAX_NEW_TOKENS` |
|
|
| The current implementation validates generated JSON with `script_from_json_dict`. |
| If model output fails parsing or cross-field validation, the next pipeline step |
| should add one retry with the validation error appended, then fixture fallback. |
|
|
| ## Current Runtime Notes |
|
|
| `nvidia/NVIDIA-Nemotron-3-Nano-4B-BF16` loads custom Nemotron-H code and failed |
| on local macOS arm64 because `mamba-ssm` was unavailable. That package is |
| CUDA/Linux-oriented, so the likely target for this exact model is Space/ZeroGPU |
| or Modal rather than local Mac execution. |
|
|
| `nvidia/Llama-3.1-Nemotron-Nano-4B-v1.1` avoided the `mamba-ssm` import path, |
| but local smoke was interrupted after 3m47s while fetching two checkpoint |
| shards. Treat local Mac execution as non-critical; the real model smoke should |
| run on the deployment GPU path. |
|
|
