Use it from Swift

Add the package

Package.swift:

.package(url: "https://github.com/john-rocky/CoreML-LLM", branch: "main"),

// In your target:
.product(name: "CoreMLLLM", package: "CoreML-LLM"),

Platforms: iOS 18+ / macOS 15+.

Download + call

import CoreMLLLM

let modelsDir = try FileManager.default.url(
    for: .applicationSupportDirectory, in: .userDomainMask,
    appropriateFor: nil, create: true)

// Pulls the bundle from this repo on first call, then loads.
let fg = try await FunctionGemma.downloadAndLoad(modelsDir: modelsDir)

// Plain chat-templated generation
let stream = try await fg.generate("How do I list files in Swift?")
for await chunk in stream { print(chunk, terminator: "") }

// Function-call generation (returns a single JSON object)
let json = try await fg.generateFunctionCall(
    tools: tools,                  // your [String: Any] schema
    userMessage: "Get me weather for Tokyo")
print(json)

See Gemma3FunctionGemma.swift for the full API.

FunctionGemma-270M for Apple CoreML (ANE-optimized)

CoreML conversion of google/functiongemma-270m-it produced with the CoreML-LLM pipeline. Targets iOS 26 / macOS 26.

What's in this repo

ANE residency

99.42% on Apple Neural Engine (1893/1904 dispatched ops, verified via MLComputePlan on macOS 26). The 11 CPU-only ops are unavoidable input-boundary ops (token gather, argmax, scalar squeeze).

Use it

Via the CoreML-LLM Swift package:

import CoreMLLLM
let bundleURL = try await Gemma3BundleDownloader.download(
    .functionGemma270m, into: appSupportDir)
let fg = try await FunctionGemma.load(bundleURL: bundleURL)
let text = try fg.generate(prompt: "Turn on the flashlight",
                           maxNewTokens: 64)

For raw Core ML usage, the model expects the same I/O contract as Gemma 4: input_ids (1,1) int32, position_ids (1,) int32, causal_mask (1,1,1,ctx) fp16, update_mask (1,1,ctx,1) fp16, with a stateful kv_cache_0 MLState (2*L, kv_heads, ctx, head_dim).

License

Inherits Google's Gemma terms of use.

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More models in this format: Core ML Model Zoo — 46 models, each with the recipe that produced it.

Want a different model on-device? Open a request — free, open weights only; the export and its measured numbers get published publicly.