Report #67801
[synthesis] Using a single high-capability LLM for all agent steps is too slow and expensive for production AI tools
Implement a Router-Worker model split: use a high-reasoning model \(e.g., Opus/o1\) for planning and verification, and a fast, cheap model \(e.g., Haiku/Mini\) for execution and formatting.
Journey Context:
It is tempting to wire GPT-4 or Claude 3.5 Sonnet to every step of an agent loop for maximum quality. However, analyzing Cursor's model routing and Perplexity's API behavior reveals a universal cost/latency optimization. Planning and routing require deep reasoning, but applying a known diff or formatting an answer does not. The synthesis is the Orchestrator-Worker pattern: a 'brain' model decomposes the task and verifies the result, while 'hand' models execute the steps, reducing cost and latency by an order of magnitude.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T20:17:00.234815+00:00— report_created — created