go-ai/mlx/model/model.go
Snider 92c6282d50 refactor(mlx): drop mlx build tag, auto-enable on darwin/arm64
Remove the manual -tags mlx requirement. MLX is now automatically
compiled on darwin/arm64 via build constraints. Stubs remain for
other platforms. No functional change.

Co-Authored-By: Virgil <virgil@lethean.io>
2026-02-17 16:57:41 +00:00

74 lines
1.9 KiB
Go

//go:build darwin && arm64
// Package model provides transformer model architectures for MLX inference.
package model
import (
"encoding/json"
"fmt"
"os"
"path/filepath"
"forge.lthn.ai/core/go-ai/mlx"
"forge.lthn.ai/core/go-ai/mlx/cache"
"forge.lthn.ai/core/go-ai/mlx/tokenizer"
)
// Model is the common interface for all transformer model architectures.
type Model interface {
// Forward runs the model forward pass on token IDs with KV caches.
Forward(tokens *mlx.Array, caches []cache.Cache) *mlx.Array
// NewCache creates per-layer KV caches for generation.
NewCache() []cache.Cache
// NumLayers returns the number of transformer layers.
NumLayers() int
// Tokenizer returns the model's tokenizer.
Tokenizer() *tokenizer.Tokenizer
// ModelType returns the architecture identifier (e.g. "gemma3", "qwen3").
ModelType() string
}
// QuantizationConfig holds quantization parameters from config.json.
type QuantizationConfig struct {
GroupSize int `json:"group_size"`
Bits int `json:"bits"`
}
// resolveWeight looks up a weight with optional "language_model." prefix.
func resolveWeight(weights map[string]*mlx.Array, name string) *mlx.Array {
if w, ok := weights[name]; ok {
return w
}
if w, ok := weights["language_model."+name]; ok {
return w
}
return nil
}
// LoadModel auto-detects the model architecture from config.json and loads it.
func LoadModel(modelPath string) (Model, error) {
data, err := os.ReadFile(filepath.Join(modelPath, "config.json"))
if err != nil {
return nil, fmt.Errorf("model: load config: %w", err)
}
var probe struct {
ModelType string `json:"model_type"`
}
if err := json.Unmarshal(data, &probe); err != nil {
return nil, fmt.Errorf("model: parse model_type: %w", err)
}
switch probe.ModelType {
case "qwen3":
return LoadQwen3(modelPath)
case "gemma3", "gemma2":
return LoadGemma3(modelPath)
default:
return nil, fmt.Errorf("model: unsupported architecture %q", probe.ModelType)
}
}