Claude Opus 4.1 API

Anthropic’s Claude Opus 4.1 represents the latest iteration in its flagship Opus series, officially launched on August 5, 2025. This drop-in replacement for Opus 4 brings targeted enhancements in agentic tasks, real-world coding, and multi-step reasoning.

AnnaAI model and API research team

Updated Sep 3, 2026 5 min read

Use this pattern

Make the first API call.

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_COMETAPI_KEY",
    base_url="https://api.cometapi.com/v1",
)

response = client.chat.completions.create(
    model="gpt-5-mini",
    messages=[{"role": "user", "content": "Build this workflow."}],
)

print(response.choices[0].message.content)

Anthropic’s Claude Opus 4.1 API represents the latest iteration in its flagship Opus series, officially launched on August 5, 2025. This drop-in replacement for Opus 4 brings targeted enhancements in agentic tasks, real-world coding, and multi-step reasoning.

Basic Information & Features

The release of Claude Opus 4.1 marks a strategic incremental update to Anthropic’s flagship model family, focusing on agentic reasoning, real-world coding, and safety enhancements. Made available on August 5, 2025, this version deepens Claude’s capabilities for complex, multi-step workflows while preserving the 200,000-token context window introduced in Opus 4 .

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Published on Aug 5, 2025

Last updated Sep 3, 2026

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Reviewed for clarity, source attribution and current API terminology.


`claude-opus-4-1-20250805`	Standard Edition，Anthropic’s flagship Claude Opus 4.1 model, achieving major breakthroughs in programming, reasoning, and agentic tasks, with SWE-bench Verified reaching 74.5%.
`claude-opus-4-1-20250805-thinking`	Claude Opus 4.1 version with extended thinking capabilities, providing up to 64K tokens of deep reasoning capacity.Optimized for research, data analysis, and tool-assisted reasoning tasks, with powerful detail-oriented reasoning abilities.
`cometapi-opus-4-1-20250805`	CometAPI exclusive. Standard version specifically designed for cursor integration
`cometapi-opus-4-1-20250805-thinking`	CometAPI exclusive. Extended reasoning version specifically for cursor integration

Read More

Claude Opus 4.1 API

Make the first API call.

Basic Information & Features

Connect this article to the next decision.

Key Features:

Technical Details

Benchmark Performance

Model Version in CometAPI

Limitations

Step 2: Send Requests to Claude Opus 4.1

Step 3: Retrieve and Verify Results

Read More

Claude Opus 4.1 API

Make the first API call.

Basic Information & Features

Connect this article to the next decision.

Key Features:

Technical Details

Benchmark Performance

Model Version in CometAPI

Limitations

Step 1: Sign Up for API Key

Step 2: Send Requests to Claude Opus 4.1

Step 3: Retrieve and Verify Results