Claude Opus 4.8 (Fast)

claude-opus Reasoning Tool Calling Attachments Structured Output

Fast-mode variant of [Opus 4.8](/anthropic/claude-opus-4.8) - identical capabilities with higher output speed at 2x pricing relative to regular Opus 4.8. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-mode

Providers 2

Released May 27, 2026

Input Modalities text, image, pdf

Output Modalities text

Tarsk Use coding

Available Providers (2)

Provider	Model ID	Input Cost	Output Cost	Context	Max Output	Docs
OpenRouter	`anthropic/claude-opus-4.8-fast`	$10/MTok	$50/MTok	1M	128K
Venice AI	`claude-opus-4-8-fast`	$12/MTok	$60/MTok	1M	128K

Capabilities

Reasoning

Tool Calling

Attachments

Open Weights

Structured Output