claude-sonnet-4-5 contextWindow should be 1M, not 200k

[darconada]

Summary

The model registry in pi-ai/dist/models.generated.js has claude-sonnet-4-5 with contextWindow: 200000 (200k tokens), but according to Anthropic's documentation, Sonnet 4.5 supports 1 million tokens of context.

Current value

"claude-sonnet-4-5": {
    contextWindow: 200000,  // Should be 1000000
    maxTokens: 64000,
}

Impact

This causes auto-compaction to trigger at ~184k tokens instead of near the actual 1M limit, losing valuable conversation context unnecessarily.

Expected

"claude-sonnet-4-5": {
    contextWindow: 1000000,  // 1M as per Anthropic specs
    maxTokens: 64000,
}

Reference

• Anthropic Model Specs - Sonnet 4.5 has 1M context window

Thanks for the great work on pi!

[badlogic]

It only has 1M context window if you enable it via a beta header. pi does not enable that header, as the 1M context window isn't really working as expected.

You can try it by adding a custom model for the anthropic provider in models.json:
https://github.com/badlogic/pi-mono/blob/main/packages/coding-agent/docs/models.md

Ask pi to do that for you.