Phase 0→1 setup for alknet-firewall — a behavioral signal detection library that screens untrusted LLM inputs using small model activations. Architecture docs (5 specs, 10 ADRs, 7 open questions): - overview: vision, scope, dependencies, package structure - firewall: core API, alarm protocol, score composition, error handling - codebook: SVD basis, spline distributions, calibration, tensor format - model: activation extraction, model-agnostic interface, lazy loading - configuration: thresholds, model selection, detection tuning Research reports: - modern-python-project-setup: uv, pyproject.toml, src layout, ruff, CI - python-ml-packaging: optional PyTorch, HF Hub download, safetensors - llm-input-safety-landscape: threat taxonomy, defenses, academic evidence Agent role adaptations for Python project (replaced Rust conventions).
53 lines
1.8 KiB
Markdown
53 lines
1.8 KiB
Markdown
# ADR-007: Runtime Model Download via HuggingFace Hub
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## Status
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Accepted
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## Context
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The detector model (SmolLM2-135M) is ~269MB. This is too large to bundle in a
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Python package — PyPI has a 60MB per-file limit and 1GB total project size
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limit. Even if it were allowed, a 269MB wheel download is terrible UX.
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Options:
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- **Bundle in package**: Not feasible due to size constraints
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- **Separate package for model**: Possible but awkward, requires users to
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install two packages
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- **Runtime download via HuggingFace Hub**: Standard approach used by
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transformers. Provides caching, authentication, offline mode, and
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checksum verification
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- **Custom download (S3, etc.)**: Works but reinvents the wheel
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## Decision
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Download the detector model at runtime via HuggingFace Hub (`snapshot_download`
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or `from_pretrained` with automatic caching). Support offline mode via
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`HF_HUB_OFFLINE=1` or `local_files_only=True`. Provide a CLI command for
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pre-downloading models in air-gapped environments.
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Pin model revisions to specific commit hashes for reproducibility.
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## Consequences
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**Positive**:
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- Package stays small (~30MB base install)
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- HuggingFace Hub provides automatic caching, deduplication, and checksum
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verification
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- Offline mode supported via environment variable
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- Authentication for gated models via `HF_TOKEN`
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- Standard approach — users familiar with transformers will recognize the
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pattern
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**Negative**:
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- First run requires network access and ~269MB download (with progress bar)
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- Model availability depends on HuggingFace Hub uptime
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- Users in restricted networks need to pre-download models
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- Different model versions may produce different detection results — must
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pin revisions
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## References
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- [python-ml-packaging.md](../research/python-ml-packaging.md) — Section 2:
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Model file distribution
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- [model.md](../model.md) |