Tool setup guides

Cursor Integration

Point Cursor's plan and agent modes at Claude and GPT models through Halfbill. One base URL override, plus what stays on Cursor's backend.

Cursor is an AI-powered code editor built on VSCode. You can point Cursor's custom OpenAI base URL at Halfbill to use Claude and GPT models in the AI panel — both plan mode and agent mode.

Plan and agent mode. Cursor routes its AI panel — plan mode and agent mode — through the custom API key + base URL, so both work with Halfbill. Tab autocomplete and inline edit (Cmd/Ctrl + K) remain locked to Cursor's own backend and will not route through Halfbill. If you want every request in your workflow to go through Halfbill, use a terminal agent like Claude Code, Codex CLI, Cline, Continue CLI, or Hermes Agent.

Using Halfbill Code? This integration also works with a Halfbill Code plan key. Use the canonical model IDs from the catalogue (for example claude-sonnet-5).

Prerequisites

  • A Halfbill account with an API key
  • Cursor IDE installed
  • Basic understanding of Cursor's AI features

Setup

Cursor supports OpenAI-compatible API endpoints, making it easy to integrate with Halfbill.

Get Your API Key

  1. Log in to your Halfbill dashboard
  2. Navigate to API Keys section
  3. Create a new API key and copy the key

Configure Cursor Settings

  1. Open Cursor and go to Settings then Click on "Cursor Settings"
  2. Click on "Models"
  3. Click on "Add OpenAI API Key"

Cursor Settings

  1. Scroll down to OpenAI API Key section
  2. Click on Add OpenAI API Key

Cursor API Key Input

  1. Enter your Halfbill API key

  2. In the same Models settings, find the Override OpenAI Base URL option

  3. Enable the override option

  4. Enter the Halfbill endpoint: https://api.halfbill.uk/v1

Select Models

  1. In the Models section, you can now select from available models
  2. Choose any Halfbill supported model:
  • For chat and agent tasks: use models like gpt-5.5, claude-sonnet-5, claude-opus-5
  • Copy exact model IDs from the models page

Test the Integration

  1. Open any code file in Cursor
  2. Try using the AI chat (Cmd/Ctrl + L) in plan mode
  3. Then switch the panel to agent mode and run a small multi-file task

Cursor AI Chat Cursor AI Chat 2

All AI requests will now be routed through Halfbill.

What Works (and What Doesn't)

Cursor honors the custom OpenAI base URL for the AI panel (Cmd/Ctrl + L) — both plan mode and agent mode. Tab autocomplete and inline edit still use Cursor's own backend, even after you save the Halfbill key.

Works through Halfbill

  • Plan mode (Cmd/Ctrl + L) — Ask questions, plan changes, get explanations, debug.
  • Agent mode — Cursor's coding agent runs multi-file edits with your Halfbill models.

All of these requests route through Halfbill and appear in your dashboard.

Does NOT work through Halfbill

  • Inline Edit (Cmd/Ctrl + K) — Locked to Cursor's backend.
  • Autocomplete / Tab completion — Locked to Cursor's backend.

If you want every request in your workflow — including edits and completions — to route through Halfbill, use Claude Code, Codex CLI, Cline, Continue CLI, or Hermes Agent.

Troubleshooting

Authentication Errors

If you see authentication errors:

  • Verify your API key is correct
  • Check that the base URL is set to https://api.halfbill.uk/v1
  • Ensure your Halfbill account has sufficient credits

Model Not Found

If you see "model not found" errors:

  • Verify the model ID exists in the models page
  • Check that you're using the exact model ID, without any prefix

Slow Responses

If responses are slow:

  • Check your internet connection
  • Monitor your usage in the Halfbill dashboard
  • Switch to a faster model such as claude-haiku-4-5 from the models page

Autocomplete / inline edit still uses Cursor's models

This is expected. Cursor routes the AI panel — plan mode and agent mode — through the custom API key, but tab autocomplete and inline edit are locked to Cursor's own backend. See What Works (and What Doesn't) above.

Need help? Email support@halfbill.uk.

Benefits of Using Halfbill with Cursor

  • Claude and GPT in one place: Use models from Anthropic and OpenAI with a single key
  • Cost Control: Track and limit your AI spending with detailed usage analytics
  • Caching: Reduce costs with response caching
  • Analytics: Monitor usage patterns and costs

How is this guide?

Crush Integration

Use Claude and GPT models with Charm's Crush coding agent. One provider entry, full cost tracking.

DevPass Code Integration

Install the DevPass Code terminal agent, connect a Halfbill key, select a model, and verify a real coding task.

On this page

PrerequisitesSetupGet Your API KeyConfigure Cursor SettingsSelect ModelsTest the IntegrationWhat Works (and What Doesn't)Works through HalfbillDoes NOT work through HalfbillTroubleshootingAuthentication ErrorsModel Not FoundSlow ResponsesAutocomplete / inline edit still uses Cursor's modelsBenefits of Using Halfbill with Cursor