Anthropic's latest Opus release, with strong reasoning, agentic coding, and dependable long-horizon work across a 1M-token context. It lists below Opus 5, making it a strong default for demanding work that does not need Fable.
Every rate is 50% of the provider's official list price. USD per million tokens.
| Token type | List price | Tokenless |
|---|---|---|
| Input | $4.00 | $2.00 |
| Output | $20.00 | $10.00 |
| Cache write | $5.00 | $2.50 |
| Cache read | $0.20 | $0.10 |
Tokenless speaks the OpenAI Chat Completions format. Point your client at the base URL, set model to opus-5.5, and you are done.
curl https://api.tokenless.store/api/v1/chat/completions \
-H "Authorization: Bearer $TOKENLESS_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "opus-5.5",
"messages": [{ "role": "user", "content": "Hello" }]
}'