# LLM

Lightweight Elixir client for LLM APIs.

It provides a normalized interface for text generation, streaming responses, tool calls, and provider-specific wire formats across:

- OpenAI Chat Completions
- OpenAI Responses
- Anthropic Messages
- Gemini
- OpenRouter (OpenAI-compatible)

## Installation

Add `llm` to your dependencies:

```elixir
def deps do
  [
    {:llm, "~> 0.1.0"}
  ]
end
```

## Configuration

Configure API keys in application config:

```elixir
config :llm, :providers,
  openai: [api_key: "sk-..."],
  anthropic: [api_key: "sk-ant-..."],
  gemini: [api_key: "AIza..."],
  openrouter: [api_key: "sk-or-..."]
```

Or set them at runtime:

```elixir
LLM.put_key(:openai, "sk-...")
LLM.put_key(:anthropic, "sk-ant-...")
```

## Quick start

### Generate text

```elixir
{:ok, response} =
  LLM.generate("What is Elixir?",
    provider: :openai,
    model: "gpt-4"
  )

response.message.content
```

### Stream responses

```elixir
{:ok, response} =
  LLM.stream("Tell me a story",
    provider: :anthropic,
    model: "claude-sonnet-4-5-20250514",
    on_chunk: &IO.write/1
  )
```

### Use provider modules

You can use provider modules directly for cleaner configuration:

```elixir
# Using provider module (reads API key from config)
{:ok, response} =
  LLM.generate("Hello",
    provider: LLM.Provider.OpenAI,
    model: "gpt-4"
  )

# With explicit API key via tuple
{:ok, response} =
  LLM.generate("Hello",
    provider: {LLM.Provider.OpenAI, api_key: "sk-..."},
    model: "gpt-4"
  )

# Anthropic
{:ok, response} =
  LLM.generate("Hello",
    provider: LLM.Provider.Anthropic,
    model: "claude-sonnet-4-5-20250514"
  )

# Gemini
{:ok, response} =
  LLM.generate("Hello",
    provider: LLM.Provider.Gemini,
    model: "gemini-2.5-flash"
  )

# OpenRouter
{:ok, response} =
  LLM.generate("Hello",
    provider: LLM.Provider.OpenRouter,
    model: "anthropic/claude-3-opus"
  )
```

### Use a custom provider

```elixir
{:ok, response} =
  LLM.generate("Hello",
    provider: %{
      adapter: LLM.Adapter.Anthropic,
      base_url: "https://my-proxy.com",
      api_key: "sk-ant-..."
    },
    model: "claude-sonnet-4-5-20250514"
  )
```

### Use tools

```elixir
{:ok, response} =
  LLM.generate("Read mix.exs",
    provider: :openai,
    model: "gpt-4",
    tools: [MyApp.ReadFileTool]
  )
```

## Providers

A provider can be:

- A preset atom: `:openai`, `:anthropic`, `:gemini`, `:openrouter`, `:openai_responses`
- A provider module: `LLM.Provider.OpenAI`, `LLM.Provider.Anthropic`, etc.
- A tuple `{module, opts}` for runtime API key: `{LLM.Provider.OpenAI, api_key: "sk-..."}`
- A map with `:adapter`, `:base_url`, and optionally `:api_key`

List the built-in presets with:

```elixir
LLM.providers()
```

## Development

- `mix compile`
- `mix test`
- `mix test test/llm_generate_test.exs`
- `mix test test/llm_generate_test.exs:11`
- `mix format --check-formatted`