Use Cursor with Halfbill

Point the Cursor editor at Halfbill with one address, one key, and a short list of model names.

Cursor is a code editor with an AI panel built in. It can send that panel's requests to Halfbill instead of to Cursor's own AI service. You change one address, paste one key, and add the model names you want.

What you'll need

Cursor installed from cursor.com, and a Halfbill account with credits or a Halfbill Code plan.

1. Create a key in the dashboard

  1. Open halfbill.uk/dashboard → API Keys → Create API Key.
  2. Name it Cursor, optionally set a spending limit, click Create API Key, and copy the key. It is shown once.
The API Keys page in the Halfbill dashboard

2. Open Cursor's model settings

  1. In Cursor, open Settings (the gear icon), then Cursor Settings.
  2. Click Models in the left list.

3. Enter the key and the address

  1. Find the OpenAI API Key field and paste your Halfbill key. Cursor calls it an OpenAI key; a Halfbill key works in the same place.
  2. Turn on Override OpenAI Base URL and enter:
https://api.halfbill.uk/v1

This is the address Cursor will send its requests to. Keep the /v1 at the end.

  1. Click Verify. Cursor sends a test request through Halfbill. If it fails, check the key and the address for typos.

4. Add the models

In the same Models screen, add the models you want by their ids and switch them on. Good first choices:

Model idUse it for
claude-sonnet-5Everyday coding and questions
claude-opus-5Hard, multi-file changes
claude-haiku-4-5Fast, cheap answers
gpt-5.5The OpenAI equivalent of Sonnet

Ids must match exactly. The current list is on halfbill.uk/models.

5. Try it

  1. Open any file and press Cmd/Ctrl + L to open the AI panel.
  2. Pick one of your Halfbill models from the panel's model menu and ask a question.
  3. Check Activity in your Halfbill dashboard: the request appears there with its cost.

What goes through Halfbill, and what does not

  • Through Halfbill: the AI panel (Cmd/Ctrl + L), in both chat and agent mode.
  • Not through Halfbill: Tab autocomplete and inline edit (Cmd/Ctrl + K). Cursor keeps these on its own service, whatever key you enter.

If you want every AI request to go through Halfbill, use a terminal tool such as Claude Code.

If something goes wrong

  • Verify fails. Re-copy the key, check the address is exactly https://api.halfbill.uk/v1, and confirm you have credits.
  • "Model not found". The id has a typo or is not on halfbill.uk/models.
  • Autocomplete ignores your key. Expected; see the section above.

More cases are in Troubleshooting.

Want the technical details?

The Cursor integration guide has screenshots of each Cursor screen and covers plan and agent modes.

Next step

Credits or subscription? →

How is this guide?

Use Claude Code with Halfbill

Set up Claude Code with a Halfbill key, step by step, for people who have never opened a terminal.

Credits or subscription?

Three short scenarios to help you choose between prepaid credits, a Chat plan, and a Halfbill Code plan, and what happens when an allowance runs out.

On this page

1. Create a key in the dashboard2. Open Cursor's model settings3. Enter the key and the address4. Add the models5. Try itWhat goes through Halfbill, and what does notIf something goes wrongWant the technical details?Next step