Anthropic Unveils Claude Opus 4: The New Reasoning King

The SWE-bench leaderboard results are particularly notable, where Opus 4 solved 45% of the hardest software engineering issues autonomously. This metric is crucial for enterprise adoption, as it demonstrates the ability to fix bugs without human guidance. Competitors like GPT-5.4 Pro lag behind in these specific reasoning metrics, making Opus 4 the preferred choice for backend automation.

• MMLU Score: 89.5%
• HumanEval: 94.2%
• SWE-bench: 45% autonomous
• Benchmark Date: May 2025

API Pricing

Anthropic has maintained a premium pricing structure for Opus 4, reflecting its high compute costs and specialized reasoning capabilities. The input price is set at $15.00 per million tokens, while the output price is significantly higher at $60.00 per million tokens due to the extended thinking time required. This pricing model is designed for high-value enterprise workloads rather than casual consumer chat.

There is no free tier available for Opus 4, as the model is strictly positioned for paid API access. However, Anthropic offers a generous trial credit for new enterprise accounts to facilitate integration testing. The cost-efficiency is justified by the reduction in human-in-the-loop verification costs for complex tasks.

• Input Cost: $15.00 / 1M tokens
• Output Cost: $60.00 / 1M tokens
• Free Tier: No
• Trial: Enterprise Credits

Comparison Table

To contextualize Opus 4's capabilities, we compare it against its primary competitors in the current market. While GPT-5.4 Pro offers speed, it lacks the deep reasoning depth of Opus 4. Claude Sonnet 4.5 remains a strong budget option but sacrifices some of the autonomous agent capabilities found in the Opus tier.

The table below summarizes the key differentiators. Developers should choose Opus 4 when accuracy and complex reasoning are the priority, whereas Sonnet 4.5 is better suited for high-volume, lower-complexity tasks where cost is a primary constraint.

• Opus 4 is best for complex reasoning.
• Sonnet 4.5 is best for cost efficiency.
• GPT-5.4 Pro is best for speed.

Use Cases

The primary use case for Claude Opus 4 is full-stack autonomous development. Engineers can deploy agents that read existing codebases, identify vulnerabilities, and write patches without human supervision. This capability reduces the time-to-market for internal tools significantly and minimizes the risk of security breaches caused by human error.

Additionally, Opus 4 excels in RAG (Retrieval-Augmented Generation) pipelines. Its 200K context window allows it to ingest entire knowledge bases and answer queries with high precision. It is also ideal for legal and medical documentation processing, where the extended thinking feature ensures compliance and accuracy in sensitive data handling.

• Autonomous Code Refactoring
• Legal Document Analysis
• Enterprise RAG Systems
• Medical Data Processing

Getting Started

Accessing Claude Opus 4 requires an API key from the Anthropic Console. The model is available via the standard Anthropic API endpoint at `https://api.anthropic.com/v1/messages`. Developers can utilize the official Python SDK to manage parallel tool use and extended thinking parameters easily.

Integration involves setting the `model` parameter to `claude-opus-4` in your message request. For optimal performance, configure the `max_tokens` to 32000 or higher to utilize the extended thinking buffer. Documentation and SDK examples are available on the official Anthropic developer portal.

• API Endpoint: api.anthropic.com/v1
• Model Param: claude-opus-4
• SDK: Python/Node.js
• Docs: Anthropic Developer Portal

Comparison

API Pricing — Input: $15.00 / Output: $60.00 / Context: 200K

Sources