Why is Claude 4.5 context limited to 200K on Vercel AI Gateway?

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Hey everyone,

I’ve been using Claude 4.5 series models through Vercel AI Gateway and noticed the context window is limited to 200K tokens.

However, according to Anthropic’s official documentation, Claude 4.5 should support up to 1M (1,000,000) tokens context window.

A few questions:

  1. Is this a limitation imposed by Vercel AI Gateway?

  2. Is there a specific configuration needed to unlock the full 1M context?

  3. Has anyone successfully used the full 1M context with Claude on Vercel?

Any insights would be greatly appreciated. Thanks! :folded_hands:

Environment:

  • Platform: Vercel AI Gateway

  • Model: Claude 4.5 Sonnet

  • Expected context: 1M tokens

  • Actual context: 200K tokens