Claude Opus 4.8

Earlier Opus release from the 4.x line.

Knowledge cutoff Jan 2026. Legacy model: Opus 5.5 is the current Opus release. Default effort is high.

Make your first request

{
  "model": "claude-opus-4-8",
  "messages": [
    {
      "role": "user",
      "content": "Hello, world."
    }
  ]
}