Codex setup
Point Codex at 9router when coding sessions need fallback
Codex-style terminal work can generate large tool outputs and long sessions. 9router gives Codex a stable OpenAI-compatible endpoint plus a route stack that can move from premium quota to lower-cost continuity.
For Codex users who want fewer interrupted sessions and clearer model-routing control.
Basic Codex shape
The typical setup is to run 9router locally, copy the generated API key from the dashboard, then point Codex to the 9router /v1 endpoint.
A practical model route starts with your preferred Codex or subscription-backed model, then falls back to a cheap provider, then a free continuity lane if the session can tolerate it.
- Set OPENAI_BASE_URL to http://localhost:20128/v1.
- Set OPENAI_API_KEY to the dashboard key, not an upstream provider key.
- Use a named combo for the route rather than editing every session manually.
- Keep RTK enabled when Codex uses shell-heavy workflows.
Why Codex benefits from RTK
Repository work often sends diffs, grep matches, logs, and directory listings back into the model. Those are exactly the inputs that can become expensive or push a context window toward the edge.
RTK-style filters help reduce that load while keeping the operational meaning of the tool result available.
Buying path
Codex users usually know whether the first route is useful within minutes. The pricing page keeps annual billing selected and defaults to Pro because a real team setup needs more than a one-off local test.
Common questions
Does Codex need a special 9router API?
No. Use the OpenAI-compatible /v1 endpoint and the API key generated by the 9router dashboard.
Can Codex use free fallback models?
Yes, if the route is configured and the task can tolerate the quality and availability tradeoff.
Why is annual billing selected?
Router adoption usually lasts longer than one month. Annual billing is selected by default and is 50% cheaper than the monthly run-rate.