Claude Sonnet 4.5

Claude Sonnet 4.5 by Anthropic, available on Aether API through one OpenAI-compatible API key. Priced at $2.1/M input, $10.5/M output. 200K context window.

Pricing

Provider	Anthropic
Model ID	claude-sonnet-4-5
Endpoint	https://aetherapi.dev/v1/chat/completions
Context window	200K
Cached input	$0.21/1M tokens
Input	$2.1/1M tokens
Output	$10.5/1M tokens
Official provider price	$3/1M input · $15/1M output

Supported endpoints

• POST https://aetherapi.dev/v1/chat/completions
• POST https://aetherapi.dev/v1/responses
• POST https://aetherapi.dev/v1/messages

How to call it

Send a request to https://aetherapi.dev/v1/chat/completions with your Aether API key:

curl https://aetherapi.dev/v1/chat/completions \
  -H "Authorization: Bearer sk-aetherapi-..." \
  -H "Content-Type: application/json" \
  -d '{"model":"claude-sonnet-4-5","messages":[{"role":"user","content":"Hello"}]}'

Related

Compare this model against every other model on the models page, or see Aether API pricing and the chat completions reference.