Wish: Automatic Model Selection for Codex Subagents
Melvin Vivas · X post · 2026-09-02 · Open on X
Topics: AI Agents, Tool Use & MCP, AI Dev Tools & Productivity · Level: intermediate
Summary
The creator wants Codex to pick a model for each subagent automatically based on the task. Judging each task and choosing a model by hand adds mental load. The idea behind it is model routing in multi-agent systems.
Key points
- Choosing a model for each subagent task by hand adds mental load.
- Routing tasks to models automatically by difficulty could cut both effort and cost.
Resources mentioned
- OpenAI Codex · tool · openai.com · paid
OpenAI's coding agent. In the diagram it writes code, fixes review findings and drives the build loop. The creator also used it to make this video.
Also in: An agent bot that installs and drives Codex on its own (Melvin Vivas on X · notes), Asking a Coder bot to install Codex (Melvin Vivas on X · notes), Sign in with ChatGPT: Setting Usage Limits for Each App (Melvin Vivas on X · notes), Codex Cloud Environments Must Be Saved & Published Before Use (Melvin Vivas on X · notes) and 240 more
Try this
- Build a router that judges how hard a subagent task is and picks a suitable model automatically.
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