A developer's proxy makes Claude Code usage-aware by intercepting hidden rate limit headers. Sonnet and Opus share one quota pool despite separate UI bars.

A developer known as Inertia-UK built a local HTTP proxy that makes Claude Code aware of its own usage limits. The proxy intercepts Anthropic's rate limit headers, revealing that Sonnet and Opus share a single quota pool despite separate UI bars.

Key facts

Proxy intercepts anthropic-ratelimit-unified-5h-utilization and 7d headers

No per-model headers; Sonnet and Opus share one pool

GitHub issue #57050 confirms Sonnet bucket never shipped

Proxy writes status to ~/.claude/usage-status.md

Zero npm dependencies, plain Node.js stdlib

Claude Code has no idea how much quota it's burned. You can see usage bars in the UI, but the model itself is completely blind to them.…