# pkg/llm

> Multi-provider abstraction for language models.

## Responsibility

Define a common interface (`LLMClient`) and adapters for the main providers.

## Public API

```go
type LLMClient interface {
    Generate(ctx context.Context, req CompletionRequest) (CompletionResponse, error)
    Stream(ctx context.Context, req CompletionRequest) iter.Seq2[StreamChunk, error]
    Name() string
    Capabilities() ProviderCapabilities
}

type CompletionRequest struct {
    Messages    []Message
    Tools       []tools.Tool
    ToolChoice  ToolChoice
    Model       string
    Temperature *float32
    MaxTokens   *int
}

type CompletionResponse struct {
    Content    string
    ToolCalls  []tools.Call
    Usage      TokenUsage
    StopReason string
}

type ProviderCapabilities struct {
    SupportsTools    bool
    SupportsVision   bool
    MaxContextWindow int
}
```

## Included providers

| Provider | Package | Tool support |
|---|---|---|
| OpenAI | `providers/openai` | ✅ |
| Anthropic | `providers/anthropic` | ✅ |
| Ollama | `providers/ollama` | ✅ (models that support it) |
| llama.cpp | `providers/llamacpp` | ✅ (with grammar) |

## Usage

```go
import "github.com/VictorVargas/rony-llm-agent/pkg/llm/providers/anthropic"

client, err := anthropic.New(anthropic.Config{
    APIKey: os.Getenv("ANTHROPIC_API_KEY"),
    Model:  "claude-sonnet-4.5",
})

resp, err := client.Generate(ctx, llm.CompletionRequest{
    Messages: []llm.Message{
        {Role: llm.RoleUser, Content: "Hello"},
    },
})
```

## Streaming

```go
for chunk, err := range client.Stream(ctx, req) {
    if err != nil { return err }
    fmt.Print(chunk.Delta)
}
```

## Mock for tests

```go
import "github.com/VictorVargas/rony-llm-agent/pkg/llm/mock"

mockClient := mock.New(mock.Responses{
    {Match: "hello", Response: "Hi! How are you?"},
    {Match: "*",    Response: "default"},
})
```

## See also

- [pkg/agent](../agent/README.md) — Uses `LLMClient`
- [pkg/tools](../tools/README.md) — The `Tool` definitions