# Model Format

TinyRustLM currently uses a custom local `.slm` model format. This is the format the runtime can validate and load in the browser today.

## Why `.slm` exists

The `.slm` path is a constrained proof lane. It avoids the complexity of broad external model formats while the runtime stabilizes:

- header validation;
- checksum validation;
- tokenizer metadata;
- tensor directory validation;
- f32, q8_0, and q4_0 storage;
- context/token limits;
- adapter compatibility;
- browser byte budgets;
- manifest sidecars.

The domain name is GGUF-facing, but the current source does not claim full GGUF import. GGUF support belongs on the roadmap until it has the same style of validation and proof.

## Core `.slm` concepts

| Concept | Meaning |
| --- | --- |
| Header | Versioned binary record that defines shape, quantization, tokenizer, tensor count, and checksums. |
| Tensor directory | Explicit map of tensor names, offsets, sizes, types, and layout. |
| Tokenizer section | Byte tokenizer or custom BPE fixture metadata. |
| Quantization metadata | f32, q8_0, or q4_0 route metadata. |
| Manifest sidecar | Human- and agent-readable route that records checksum, shape, source kind, admission status, and quality boundary. |
| Admission status | Whether the artifact is accepted for runtime smoke, pending evaluation, or rejected. |

## Current model artifacts

The source bundle references deterministic smoke models and TinyLM-16M f32/q8_0/q4_0 artifacts. Those artifacts exist to prove runtime execution, not to claim finished assistant quality.

## Quality boundary

A manifest can say `runtime-execution-smoke-only` or `trained_quality_claim=not-claimed`. The public site must preserve that distinction. A model that can load and generate one deterministic smoke output is not automatically a trained, useful assistant.

## Future route

Future trained or converted models should enter through validated source manifests, provenance sidecars, runtime-smoke evidence, eval sidecars, promotion gates, selector admission, and browser route proof.