---
license: other
license_name: sam-license
license_link: https://huggingface.co/facebook/sam3/blob/main/LICENSE
base_model: facebook/sam3
pipeline_tag: image-segmentation
tags:
- coreai
- apple
- aimodel
- apple-silicon
- segmentation
- sam3
---

# SAM 3 — official Apple Core AI export

A pre-converted **`.aimodel` segmenter bundle from Apple's official
[coreai-models](https://github.com/apple/coreai-models) export recipe — unmodified**, with
the exact environment, hashes, and measured performance published.

[SAM 3](https://huggingface.co/facebook/sam3) (Segment Anything Model 3, Meta) is a unified,
**promptable** segmentation model. This bundle is the **image + text-prompt** variant: give
it an image and a phrase (`cat`, `the red car`) and it returns instance masks, boxes, and
per-instance scores — open-vocabulary, no fixed class list. It runs on the **stock** Core AI
runtime via Apple's `CoreAIImageSegmenter` (no engine patch).

```bash
# from an apple/coreai-models checkout (gated model — accept the SAM license + hf auth login first)
uv run models/sam3/export.py --dtype float16
```

## Why a pre-converted bundle?

An `.aimodel` is a build artifact, not a pure function of the recipe — the toolchain and OS
lowering matter, and the source checkpoint is **gated**. This is the exact, hash-stamped
bundle behind the published numbers, so you can drop it in and reproduce them without a
conversion environment or accepting the upstream license just to get the converted graph.

## Bundle layout & integrity

A segmenter bundle directory (`metadata.json` schema 0.2 + the `.aimodel` + a CLIP `tokenizer/`):

```
sam3_float16.aimodel/   main.mlirb + main.hash + metadata.json
tokenizer/              tokenizer.json + tokenizer_config.json
metadata.json           kind: segmenter, assets.main → sam3_float16.aimodel
```

| File | Contents | SHA-256 |
|---|---|---|
| `sam3_float16.aimodel/main.mlirb` | float16 weights + graph (~1.5 GB) | `be9484b4c5fa75f9011668c481e27de253e1db55fcde39a1ba0cab8698706620` |
| `sam3_float16.aimodel/main.hash` | graph hash | `9f631da3be044ad5de56a1d29af88394e7e725e3cf52f50ac556dcce9cdd568c` |

## Measured

Apple's official `image-segmenter` CLI, **M4 Max**, the COCO two-cats image (640×480, resized
to 1008×1008 internally), text prompt `cat`:

| Metric | Value |
|---|---|
| Inference (warm, incl. pre/post-processing) | **0.55 s** |
| Output | 2 high-confidence instance masks for "cat" (scores **0.97** and **0.96**); spurious queries fall below the 0.5 threshold |

**float16 vs float32 fidelity** (same recipe, both exported and run through the engine): top-2
scores differ by **≤ 1e-4** (0.9746 vs 0.9747, 0.9646 vs 0.9645), bounding boxes within **1 px**,
and the top-3 masks have **identical** foreground pixel counts. float16 is shipped (half the
size, iOS-friendly); float32 reproduces with `--dtype float32`.

## Export environment

- macOS 27.0 beta · Xcode 27.0 beta
- `coreai-core 1.0.0b1` · `coreai-torch 0.4.0` · `transformers 5.x`
- apple/coreai-models recipe `models/sam3/export.py` (unmodified upstream)

## Run it

```bash
# CLI (from an apple/coreai-models checkout)
swift run -c release image-segmenter \
    --model <downloaded-bundle-dir> --prompt "cat" --image cats.jpg
```

Or in the [CoreAISegment sample app](https://github.com/john-rocky/coreai-model-zoo/tree/main/apps/CoreAISegment)
(macOS + iOS): pick an image, type a prompt, tap Segment.

```swift
import CoreAIImageSegmenter
let segmenter = try await ImageSegmenter(resourcesAt: "<bundle-dir>")
let result = try await segmenter.segment(image: cgImage, prompt: "cat")
// result.segments: [Segment] — each has .mask, .box, .score
```

iOS bundles should be AOT-compiled before device use:
`xcrun coreai-build compile <ir>.aimodel --platform iOS --architecture h18p`
(h18p = iPhone 17 Pro), then point `metadata.json` `assets.main` at the `.aimodelc`.

## License

SAM 3 is distributed under Meta's **SAM License** (see `LICENSE` and the
[upstream model card](https://huggingface.co/facebook/sam3)). This bundle is a format
conversion of those weights and inherits that license; review it before use.

---
Maintained alongside [coreai-model-zoo](https://github.com/john-rocky/coreai-model-zoo)
(see [`official/`](https://github.com/john-rocky/coreai-model-zoo/tree/main/official) for the
other unmodified official-recipe conversions).