Splitting Codex work across models with Jev: Sol writes, Luna reads, Astra checks
The author shares an agent tree to paste into Codex, where forks that need no thinking go to Jev for sub-second decisions and large models only handle real disagreements.
Codex tip: once GPT-6.1 Sol runs your main session, stop paying Sol prices for the grunt work hand the reading to Luna and put Astra on call Sol keeps writing the code Luna agents read the repo and pull the docs, fast and cheap Astra only gets spawned at three moments: → before a plan: is this the right approach? → when the same error comes back: am I digging in the wrong place? → before "done": what did I miss? Sol ships. Luna reads. Astra checks jev engineering is the same move one layer down: the forks that need no thinker (which file, which tool, retry or stop) go to jev in under half a second, and the big models only see the ones that split - the full tree > GPT-6.1 Sol on high runs the main session > explorer reads the code on Luna > researcher pulls the docs on Luna > worker edits and runs tests on Sol > Astra on call as the architect > auto_review watches every approval paste the tree and this prompt into Codex ↓ "Rebuild my Codex setup around this tree: 1. Check ~/.codex/agents and .codex/agents for agents that already fit explorer, researcher and worker. > Draft new TOML files only for missing roles > explorer and researcher on gpt-6-luna, worker on gpt-6.1-sol, all with model_reasoning_effort medium > Add an architect agent on gpt-6-astra, model_reasoning_effort high, that only reviews plans, repeated errors and finished work > List any that pin a different model before changing them 2. In ~/.codex/config.toml set model to gpt-6.1-sol, model_reasoning_effort to high and approvals_reviewer to auto_review 3. Find anything that would override this (active profiles, flags in my shell aliases, agents.default_subagent_model). Report it, change nothing 4. Add one rule to AGENTS.md: spawn the architect before a large plan, when an error repeats, and before calling a long task done Show me every change as a diff first. No edits until I say go." ↳ https://developers.openai.com/codex/subagents
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