seisei_apple 0.1.0-dev.1

Apple Foundation Models provider and Flutter bridge for Seisei.

seisei_apple

Apple Foundation Models provider boundary and Flutter bridge for Seisei.

This package contains:

• AppleFoundationModelsProvider, which implements Seisei's generic provider contract.
• FmCliBackend, a local /usr/bin/fm backend for development probes.
• MethodChannelAppleFoundationModelsBackend, a Flutter method-channel backend for iOS and macOS apps.

First Run

On macOS 27 machines that provide /usr/bin/fm, the fastest smoke path is:

fm available
fm respond --no-stream 'Reply with exactly: seisei-ok'

To verify Seisei itself can use local AFM, run the package smoke command:

dart run bin/local_afm_smoke.dart

That command uses FmCliBackend, AppleFoundationModelsProvider, and SeiseiClient to send the prompt through the local system model. A passing run prints providerId: apple_system and response: seisei-ok.

To verify PCC from the same Seisei path, run:

dart run bin/local_afm_smoke.dart --mode pcc

That command requires fm available to report PCC availability in the same terminal/process context. If it fails with PCC inference is not available in this context, the local system model can still work while PCC is unavailable to that shell.

For a minimal Flutter host, create an app and point seisei_apple at this workspace with a path dependency:

flutter create --platforms=macos /tmp/seisei_afm_host

dependencies:
  seisei_apple:
    path: /path/to/your/seisei/packages/seisei_apple

Then use the native bridge directly from lib/main.dart:

final backend = MethodChannelAppleFoundationModelsBackend();
final availability = await backend.availability();
final response = await backend.respond(
  const AppleFoundationModelsRequest(
    prompt: 'Reply with exactly: seisei-ok',
    mode: AppleFoundationModelsMode.system,
  ),
);

The native bridge is intentionally narrow. It checks system-model availability and sends plain system-model prompts through FoundationModels.LanguageModelSession. It can also send schema-backed system model requests when schemaPath points to a JSON-encoded FoundationModels.GenerationSchema file. PCC and streaming are not implemented in the native bridge yet.

If you want the typed Seisei client layer, add a direct seisei dependency in the host app and build AppleFoundationModelsProvider on top of the native backend. Keep the request in system mode and avoid streaming or PCC settings. For schema-backed requests, use AppleFoundationModelsProvider.schemaPathMetadataKey only with a provider-specific FoundationModels schema file; Seisei does not yet map seisei_schema descriptors into native FoundationModels schemas.

CI tests use fake and mocked method-channel backends; /usr/bin/fm and local Apple Foundation Models are optional validation only.