claude-opus-4-5-think · Anthropic
Claude Opus 4.5 does not enable reasoning mode by default. To access its deep reasoning capabilities, users would typically need to call the native Claude API. To make this capability available through an OpenAI-compatible interface, we provide the claude-opus-4-5-think model, which has reasoning mode pre-enabled and a default 32k-token context window, allowing it to be called directly via the OpenAI unified API. Claude Opus 4.5 Think is a reasoning-focused variant of Claude Opus 4.5 designed for advanced tasks that require rigorous reasoning, complex decision-making, and long-chain analysis. Aside from its enhanced reasoning mechanism, all other capabilities remain consistent with the standard Claude Opus 4.5 model, making it well suited for complex engineering problem decomposition, multi-stage planning, and logic-intensive analysis.
Claude Opus 4.5 does not enable reasoning mode by default. To access its deep reasoning capabilities, users would typically need to call the native Claude API. To make this capability available through an OpenAI-compatible interface, we provide the claude-opus-4-5-think model, which has reasoning mode pre-enabled and a default 32k-token context window, allowing it to be called directly via the OpenAI unified API. Claude Opus 4.5 Think is a reasoning-focused variant of Claude Opus 4.5 designed for advanced tasks that require rigorous reasoning, complex decision-making, and long-chain analysis. Aside from its enhanced reasoning mechanism, all other capabilities remain consistent with the standard Claude Opus 4.5 model, making it well suited for complex engineering problem decomposition, multi-stage planning, and logic-intensive analysis.
Claude Opus 4.5 Thinking has a 200,000 token context window.
On AIHubMix, Claude Opus 4.5 Thinking costs $5 per million input tokens and $25 per million output tokens. Cached input reads are billed at $0.5 per million tokens.
Claude Opus 4.5 Thinking accepts text, image and PDF input.
Claude Opus 4.5 Thinking supports thinking, tool calling, function calling and structured outputs. Per-protocol parameter support is listed in the capability table on this page.
Claude Opus 4.5 Thinking is available through the AIHubMix unified API. The API is OpenAI-compatible: point your OpenAI SDK at https://aihubmix.com/v1, use your AIHubMix API key, and set the model name to claude-opus-4-5-think — no other code changes needed.
Claude Opus 4.5 Thinking is developed by Anthropic. AIHubMix aggregates it alongside models from other providers behind one API and one bill.
Claude Opus 4.5 Thinking was released on November 24, 2025 by Anthropic.
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Use Claude Opus 4.5 Thinking via the AIHubMix unified API — one interface for every major LLM.