Routing Claude API traffic to control costs after Max subscription change

API billing migration and cost implications

As of noon PT, Anthropic's Max subscription no longer covers usage from third-party tools like OpenClaw. All OpenClaw users are now on API billing with these rates:

• Claude Opus 4.6: $5 per million input tokens, $25 per million output tokens
• Claude Sonnet 4.6: $3 per million input tokens, $15 per million output tokens
• Claude Haiku 4.5: $1 per million input tokens, $5 per million output tokens

A heavy OpenClaw session on Opus can cost $1-4, while the same session on Sonnet costs $0.20-0.80 with similar results for most tasks.

The routing solution

Most OpenClaw operations don't require Opus: heartbeat checks, file reads, summaries, routing decisions, and short tool calls can all be handled by Sonnet. Without a routing layer, every request hits your default model, potentially wasting Opus budget on simple tasks.

A local proxy routes Claude requests by complexity: simple tasks go to Sonnet automatically, complex ones escalate to Opus. This approach has significantly reduced costs without quality loss on important tasks.

The proxy is open source and installable via npm: npm install -g @relayplane/proxy

Detailed documentation and discussion is available on r/ClaudeCode, where the solution has received 52K views.