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Claude Sonnet 4.5 20250929

Going away Nov 30, 2026
anthropic/claude-sonnet-4-5-20250929

Claude Sonnet 4.5 20250929 is a reasoning model by Anthropic with vision, function calling, web search, prompt caching, structured output — designed for complex, multi-step problem solving where accuracy matters more than speed. It supports a 200K token context window with up to 64K tokens of output. Priced at $3 per million input tokens and $15 per million output tokens. Access Claude Sonnet 4.5 20250929 through Inworld LLM Inference with OpenAI SDK compatibility, built-in failover, and intelligent routing across providers.

Input
$3.00
Output
$15.00
Cache read
$0.30
Context
200K
Max output
64K
TextImage→Text
Function CallingWeb SearchReasoningPrompt CachingStructured outputVision
Run on your server. Set INWORLD_API_KEY to your API key. Python requires pip install openai; JavaScript requires Node.js 18+; save it as example.mjs.
curl --fail-with-body https://api.inworld.ai/v1/chat/completions \
  -H "Authorization: Basic $INWORLD_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "anthropic/claude-sonnet-4-5-20250929",
    "messages": [{"role": "user", "content": "Hello"}],
    "stream": true
  }'
Model Claude Sonnet 4.5 20250929OpenAI SDK compatible

Pricing and providers

Access Claude Sonnet 4.5 20250929 through Inworld LLM Inference or speech to speech via Anthropic. By using the providers below you agree to their terms, listed under each provider's name in the Legal section.

Modalities
AnthropicThis pageanthropic/claude-sonnet-4-5-20250929
$3.00$15.00$0.30$3.75200K64K
TextImage→Text
Prices in USD per 1M tokens.

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