Quickstart: run a model on the device

This quickstart uses the core LlamaEngine API.

Minimal generation example#

Start with a model source instead of a machine-specific file path. On native Dart/Flutter targets, loadModelSource(...) downloads the file on first run, stores it in the package-managed model cache, and reuses the cached file on later runs.

import 'package:llamadart/llamadart.dart';

Future<void> main() async {
  final LlamaEngine engine = LlamaEngine(LlamaBackend());

  try {
    await engine.loadModelSource(
      ModelSource.parse(
        'hf://unsloth/SmolLM2-135M-Instruct-GGUF/'
        'SmolLM2-135M-Instruct-Q2_K.gguf',
      ),
      modelParams: const ModelParams(contextSize: 1024, gpuLayers: 0),
      onProgress: (progress) {
        final fraction = progress.fraction;
        if (fraction != null) {
          print('download ${(fraction * 100).toStringAsFixed(1)}%');
        }
      },
    );

    final output = StringBuffer();
    await for (final chunk in engine.create(
      const [
        LlamaChatMessage.fromText(
          role: LlamaChatRole.user,
          text: 'Rewrite professionally: i need this done asap',
        ),
      ],
      params: const GenerationParams(maxTokens: 64, temp: 0.2),
    )) {
      final text = chunk.choices.first.delta.content;
      if (text != null) {
        output.write(text);
      }
    }
    print(output.toString());
  } finally {
    await engine.dispose();
  }
}

engine.create(...) applies the chat template but keeps no history; see Choosing the right API.

The SmolLM2 135M Q2_K model is a smoke-test model: it downloads quickly but is not a measure of output quality. See Finding models for real starting points. Run it once before a demo; later runs load from the cache without a network.

LiteRT-LM .litertlm bundles load through the same engine; see Choosing llama.cpp or LiteRT-LM.

Next steps#

• Use First chat session for automatic history.
• Choose a runtime with Choosing llama.cpp or LiteRT-LM.
• Compute embeddings with Embeddings.
• Tune Runtime Parameters.
• Add tools with Tool Calling.