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Anthropic

Claude Opus 5.5

Facts

Model id
anthropic/claude-opus-5.5
Context window
1M
Maximum output
128K
Data policy
No training · Zero retention

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Call it

Send the id as model. The quickstart has the key and the SDK setup; models, limits and data policy explains each field above.

bash
curl https://api.sylphx.ai/v1/responses \
  -H "Authorization: Bearer $SYLPHX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"anthropic/claude-opus-5.5","input":"Say hello in one sentence."}'