Configure ZetaAPI in Cursor
Replace the official OpenAI / Anthropic endpoints in the Cursor editor with ZetaAPI — configure once, get 0.3x–0.4x of official pricing.
Updated 2026-04-17
When to use this
Cursor is the most popular AI coding editor right now, with built-in Chat / Composer / Agent modes that call models via Cursor’s own service or directly through OpenAI / Anthropic. Switch the model provider to ZetaAPI and all AI features keep working, but are billed at ZetaAPI’s multipliers, with balance and usage visible live in the console.
Prerequisites
- Cursor ≥ 0.42 (upgrading to the latest stable build is recommended)
- An API key from the ZetaAPI console
- We suggest enabling “low-balance alerts” in the dashboard first
Setup
1. Open Cursor Settings → Models
Press Cmd/Ctrl + , to open settings, then choose Models on the left.
2. Configure the OpenAI-compatible endpoint
In the OpenAI API Key section:
- Override OpenAI Base URL: check it and enter
https://api.staging.cosmos-router.com/v1 - API Key: paste your ZetaAPI key (starts with
sk-) - Click Verify to test connectivity
3. Configure the Anthropic endpoint (optional)
If you want to use Claude models:
- Anthropic API Key: the same ZetaAPI key (ZetaAPI supports both the OpenAI and Anthropic protocols)
- Override Anthropic Base URL:
https://api.staging.cosmos-router.com
4. Pick models
In Cursor’s top chat model selector, enable the models you want (Claude Sonnet 4.6 / GPT-4o / Gemini 2.5 Pro, etc.). ZetaAPI’s router forwards each request to the right channel automatically.
FAQ
Q: Can ZetaAPI power Cursor’s Tab autocomplete?
No. Tab completion uses Cursor’s own small model and does not go through your configured API. Only Chat / Composer / Agent conversations use the configured provider.
Q: Can I use ZetaAPI only for Claude and keep the rest on Cursor’s official service?
Yes. Just fill in the Anthropic config and leave the OpenAI Override unchecked.
Q: What if my balance runs out?
ZetaAPI returns 402 Payment Required and Cursor reports a failed call. Top up in the console and it recovers immediately — no need to restart Cursor.