“We're seeing state-of-the-art coding performance from Claude Sonnet 4.5, with significant improvements on longer horizon tasks.

September 29, 2025 - Pricing for Sonnet 4.5 starts at $3 per million input tokens and $15 per million output tokens, with up to 90% cost savings with prompt caching and 50% cost savings with batch processing. To learn more, check out our pricing page. To get started, simply use claude-sonnet-4-5 via the Claude API.

Talk with Claude, an AI assistant from Anthropic

15 hours ago - Anthropic Claude: Anthropic’s Claude (founded by ex-OpenAI researchers) offers Claude 3.x (“Haiku”, “Sonnet”, “Opus” versions) and even a Claude 4 series. It has a free tier and a $20/mo Pro plan for individuals ([8]), plus $100/$200 power-user plans ([7]). Critically, Anthropic publishes per-token API prices for each model.

September 29, 2025 - Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. Run Claude Sonnet 4.5 with API

15 hours ago - Claude’s API offers multiple model families, each with different performance and cost profiles. Anthropic categorizes its models as “Haiku” (fastest, smallest), “Sonnet” (balanced), and “Opus” (most capable, most expensive).

1 week ago - For developers and businesses, Claude Sonnet 4.5 is available via the Anthropic API.

Build with the Claude API

3 weeks ago - Where does the bug appear (feature/product)? Cursor IDE Describe the Bug Hello, We are constantly receiving this error message. The strange thing is that all the failed requests are still being counted against the 500-request quota. Steps to Reproduce add claude-3-opus model from add models ...

January 18, 2025 - This comprehensive API tutorial teaches you how to integrate Claude 3.5 Sonnet into your applications. It includes code examples, best…

3 weeks ago - Gemini 3 Pro's million-token context window enables processing entire codebases, books, or extensive document collections in a single prompt. Claude 4.5 Sonnet offers a 1M beta via API header (context-1m-2025-08-07), while GPT 5.1's "compaction" ...

“We're seeing state-of-the-art coding performance from Claude Sonnet 4.5, with significant improvements on longer horizon tasks.

October 17, 2025 - We’ve launched an OpenAI-compatible API endpoint, allowing you to test Claude models by changing just your API key, base URL, and model name in existing OpenAI integrations. This compatibility layer supports core chat completions functionality.

Sonnet 4 is optimized for practical everyday use, providing advanced reasoning capabilities while maintaining efficiency and responsiveness in diverse internal and external scenarios. ... Prompt tokens measure input size. Reasoning tokens show internal thinking before a response. Completion tokens reflect total output length. ... OpenRouter provides an OpenAI-compatible completion API to 400+ models & providers that you can call directly, or using the OpenAI SDK.

👉 Claude-3-Sonnet API balances speed with performance, excels in multilingual tasks, and integrates seamlessly with cloud platforms. Important: Claude 3 Sonnet will be retired on July 21st, 2025.

1 month ago - Claude app conversations get automatically summarized past a maximum length, thus early details will be forgotten but there is no longer any maximum length for chats. Opus-specific caps on usage have been removed. Opus is now $5/$25 per million input and output tokens, a 66% price cut. It is now only modestly more than Sonnet, and given it is also more token efficient there are few tasks where you would use any model other than Opus 4.5.

August 6, 2025 - Learn how to access and integrate Claude Opus 4 and Claude Sonnet 4 APIs with this comprehensive technical guide.

October 16, 2025 - Claude Sonnet 4 balances impressive performance for coding with the right speed and cost for high-volume use cases: Coding: Handle everyday development tasks with enhanced performance—power code reviews, bug fixes, API integrations, and feature ...

November 26, 2025 - Tasks that were nearly impossible for Sonnet 4.5 just a few weeks ago are now within reach. ... With Claude Opus 4.5, Anthropic is also introducing a new variable, the "effort parameter," for the programming interface (API).

November 26, 2025 - Sonnet 4.5 works well for standard chat, mid-level coding, or fast drafting. Haiku 4.5 is often ideal for extremely high-volume, low-latency use cases. Multimodal or video-heavy tasks will still require specialized models outside the Claude lineup.