Anthropic (Claude)

Use Anthropic's Claude models as the LLM provider in a CompositeVoice pipeline.

Use AnthropicLLM when you want Claude’s strong instruction-following and reasoning for your voice assistant.

Prerequisites

An Anthropic API key or a CompositeVoice proxy server
Install the peer dependency:

npm install @anthropic-ai/sdk

Basic setup

import { CompositeVoice, AnthropicLLM, NativeSTT, NativeTTS } from '@lukeocodes/composite-voice';

const agent = new CompositeVoice({
  stt: new NativeSTT({ language: 'en-US' }),
  llm: new AnthropicLLM({
    proxyUrl: '/api/proxy/anthropic',
    model: 'claude-haiku-4-5',
    maxTokens: 512,
    systemPrompt: 'You are a concise voice assistant. Keep answers under two sentences.',
  }),
  tts: new NativeTTS(),
});

await agent.start();

Configuration options

Option	Type	Default	Description
`model`	`string`	`'claude-haiku-4-5'`	Model identifier. See model variants below.
`maxTokens`	`number`	`1024`	Maximum tokens per response. Anthropic requires this field.
`systemPrompt`	`string`	—	System-level instructions for the assistant.
`temperature`	`number`	—	Randomness (0 = deterministic, 2 = creative).
`topP`	`number`	—	Nucleus sampling threshold (0—1).
`stream`	`boolean`	`true`	Stream tokens incrementally.
`proxyUrl`	`string`	—	CompositeVoice proxy endpoint. Recommended for browsers.
`apiKey`	`string`	—	Direct API key. Use only in server-side code.
`maxRetries`	`number`	`3`	Retry count for failed requests.

Model variants

Model	Speed	Capability
`claude-haiku-4-5`	Fastest	Best for low-latency voice
`claude-sonnet-4-6`	Balanced	Good reasoning + speed
`claude-opus-4-6`	Slowest	Most capable

Complete example

import {
  CompositeVoice,
  AnthropicLLM,
  DeepgramSTT,
  DeepgramTTS,
} from '@lukeocodes/composite-voice';

const agent = new CompositeVoice({
  stt: new DeepgramSTT({
    proxyUrl: '/api/proxy/deepgram',
    language: 'en',
    options: { model: 'nova-3', smartFormat: true },
  }),
  llm: new AnthropicLLM({
    proxyUrl: '/api/proxy/anthropic',
    model: 'claude-haiku-4-5',
    maxTokens: 256,
    temperature: 0.7,
    systemPrompt: 'You are a friendly voice assistant. Answer briefly.',
  }),
  tts: new DeepgramTTS({
    proxyUrl: '/api/proxy/deepgram',
    voice: 'aura-2-thalia-en',
  }),
  conversationHistory: { enabled: true, maxTurns: 10 },
});

await agent.start();

Tips

maxTokens is required. Anthropic’s API rejects requests without it. The provider defaults to 1024, but for voice applications, lower values (128—512) produce faster responses.
System prompts are handled automatically. AnthropicLLM extracts system messages and passes them as the top-level system parameter, which is what the Anthropic API expects.
Use a proxy in browsers. The proxy server injects your API key server-side so it never reaches the client.
Streaming is on by default. Set stream: false only if you need the complete response before TTS begins.

Providers reference — all LLM providers at a glance
API reference — full class documentation
Configuration guide — global CompositeVoice settings

Prerequisites

Basic setup

Configuration options

Model variants

Complete example

Tips

Related