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Claude Opus 4.1
Claude Opus 4.1 is an updated version of Anthropic’s flagship model, offering improved performance in coding, reasoning, and agentic tasks. It achieves 74.5% on SWE-bench Verified and shows notable gains in multi-file code refactoring, debugging precision, and detail-oriented reasoning. The model supports extended thinking up to 64K tokens and is optimized for tasks involving research, data analysis, and tool-assisted reasoning.
8/5/2025
200,000 tokens
Specifications
Modalities
Input
image
text
file
Output
text
Supported Parameters
include_reasoning
max_tokens
reasoning
response_format
stop
structured_outputs
temperature
tool_choice
tools
top_k
top_p
Max Output Tokens
32,000Data policy
- Prompt retention
- Unknown — we could not confirm
- Training
- Unknown — not declared
"Unknown" does not mean "safe". It means we could not confirm it.
Whether a provider trains on prompts is a declared value from our terms with them. Retention is determined from the upstream listing for every host this model can reach. Neither is guessed.
Frequently asked questions
- Is Claude Opus 4.1 available on FastMetal?
- Not at the moment. Claude Opus 5.5, from the same lab, is available on the FastMetal API today.
- What is the context window of Claude Opus 4.1?
- 200,000 tokens, shared between the prompt and the response.