releases.shpreview
AnthropicAnthropic/Claude Platform

Opus 5: 1M context, thinking on by default, effort controls

July 24, 2026Claude PlatformView original ↗
1 featureThis release1 featureNew capabilitiesAI-tallied from the release notes
From the original release noteView original ↗

Claude Opus 5 (claude-opus-5) is now available with 1M token context window, 128k max output tokens, and thinking enabled by default. Pricing: $5 / $25 per MTok (same as Claude Opus 4.8). Available on Claude API, Amazon Bedrock, Google Cloud, and Microsoft Foundry.

Breaking changes:

  • Disabling thinking on Claude Opus 5 is only allowed at effort high or below. Requests with thinking: {"type": "disabled"} at effort xhigh or max return a 400 error.
  • Effort becomes the primary control for steering the model; full ladder supported (low, medium, high, xhigh, max).

See What's new in Claude Opus 5 for migration guidance and new features.

Fetched July 28, 2026

Opus 5: 1M context, thinking on by default, effort… — releases.sh