Cursor IDE OpenAI-Compatible Base URL Configuration Guide (2026)

Step 2 — Install Cursor and Open the Settings Panel

Download Cursor from the official website and install it like any other desktop application. When it launches for the first time, you can either import your existing VS Code settings or start clean.

Once the editor is open, press the keyboard shortcut to open the settings file directly:

• macOS: ⌘ + Shift + P
• Windows / Linux: Ctrl + Shift + P

Type Open User Settings (JSON) into the command palette that appears and press Enter. Cursor will open a file called settings.json at the top of the editor.

Step 3 — Add the HolySheep Base URL to settings.json

Cursor reads its model provider overrides from a few keys inside settings.json. The exact keys depend on your Cursor version, but the ones below are the ones that work on the 2026 stable build I tested. Paste the snippet inside the curly braces, then save the file (⌘ + S or Ctrl + S):

{
  "cursor.openaiBaseUrl": "https://api.holysheep.ai/v1",
  "cursor.openaiApiKey": "YOUR_HOLYSHEEP_API_KEY",
  "cursor.defaultModel": "gpt-4.1",
  "cursor.modelOverrides": {
    "gpt-4.1": {
      "baseUrl": "https://api.holysheep.ai/v1",
      "apiKey": "YOUR_HOLYSHEEP_API_KEY"
    },
    "claude-sonnet-4.5": {
      "baseUrl": "https://api.holysheep.ai/v1",
      "apiKey": "YOUR_HOLYSHEEP_API_KEY"
    },
    "gemini-2.5-flash": {
      "baseUrl": "https://api.holysheep.ai/v1",
      "apiKey": "YOUR_HOLYSHEEP_API_KEY"
    },
    "deepseek-v3.2": {
      "baseUrl": "https://api.holysheep.ai/v1",
      "apiKey": "YOUR_HOLYSHEEP_API_KEY"
    }
  }
}

Notice how every single model points to the same https://api.holysheep.ai/v1 endpoint. That is the magic of an OpenAI-compatible gateway: one URL, four different brains.

Step 4 — Set the Environment Variable (Optional but Safer)

If you would rather not store the key inside settings.json — for example because you sync your dotfiles to a public Git repo — you can move the secret into an environment variable. Cursor will read it automatically.

On macOS or Linux, add this line to your ~/.zshrc or ~/.bashrc:

export HOLYSHEEP_API_KEY="hs-sk-7Hf2...your-real-key...a9Z"
export CURSOR_OPENAI_API_KEY="$HOLYSHEEP_API_KEY"
export CURSOR_OPENAI_BASE_URL="https://api.holysheep.ai/v1"

On Windows 11, open Settings → System → About → Advanced system settings → Environment Variables and create two user variables named CURSOR_OPENAI_API_KEY and CURSOR_OPENAI_BASE_URL with the same values. Restart Cursor afterward so the new variables are picked up.

Step 5 — Verify the Connection

Open the Cursor chat panel with ⌘ + L (or Ctrl + L on Windows). In the model dropdown at the top, pick claude-sonnet-4.5 so we are exercising a non-OpenAI family. Type:

Write a Python function that returns the Fibonacci sequence up to n. Add type hints and a docstring.

Hit Enter. If everything is wired correctly, the assistant should respond in under two seconds with a working snippet, and you will see a small "HolySheep" badge in the response footer (depending on Cursor version). If you see the words "Network error" or "401 Unauthorized", jump straight to the troubleshooting section below.

Step 6 — Switching Models on the Fly

You can hot-swap models inside the same chat by clicking the model name in the dropdown. A typical workflow that I use daily looks like this:

• Use DeepSeek V3.2 ($0.42 / MTok) for first-draft boilerplate — cheap and surprisingly fluent at CRUD code.
• Switch to Gemini 2.5 Flash ($2.50 / MTok) for unit-test generation where speed matters.
• Promote to Claude Sonnet 4.5 ($15.00 / MTok) for tricky refactors and architecture questions.
• Reserve GPT-4.1 ($8.00 / MTok) for cases where you specifically need the OpenAI tool-calling schema.

Because all four share the same base URL, the switch is instant — no settings dialog, no restart, no extra keys.

Common Errors & Fixes

Error 1 — "401 Unauthorized" or "Incorrect API key"

This almost always means the key in settings.json does not match the one in your HolySheep dashboard, or the key has been revoked. Fix it with this checklist:

# 1. Re-copy the key from the HolySheep dashboard
2. Make sure there are no stray spaces or newline characters
echo -n "$YOUR_HOLYSHEEP_API_KEY" | wc -c   # should be the exact length shown in the dashboard

3. Test the key directly with curl before touching Cursor
curl https://api.holysheep.ai/v1/models \
  -H "Authorization: Bearer YOUR_HOLYSHEEP_API_KEY"
Expected: a JSON list including "gpt-4.1", "claude-sonnet-4.5", etc.

Error 2 — "404 model not found" or Chat silently refuses to answer

Cursor's dropdown sometimes caches an old model name from a previous session. The 2026 model identifiers are case-sensitive, and the gateway rejects anything that is not on its allow-list. Force a refresh:

// In settings.json, delete the modelOverrides block entirely,
// then re-add only the four supported names:
"cursor.modelOverrides": {
  "gpt-4.1":            { "baseUrl": "https://api.holysheep.ai/v1" },
  "claude-sonnet-4.5":  { "baseUrl": "https://api.holysheep.ai/v1" },
  "gemini-2.5-flash":   { "baseUrl": "https://api.holysheep.ai/v1" },
  "deepseek-v3.2":      { "baseUrl": "https://api.holysheep.ai/v1" }
}
// Then: Cmd/Ctrl + Shift + P → "Developer: Reload Window"

Error 3 — "Network error" or requests hang forever

If curl works but Cursor still hangs, the most common cause is a corporate proxy or a leftover HTTP_PROXY environment variable intercepting localhost traffic. Disable it just for the editor session:

# macOS / Linux — launch Cursor with a clean proxy slate
NO_PROXY="*" HTTP_PROXY="" HTTPS_PROXY="" \
  /Applications/Cursor.app/Contents/MacOS/Cursor

Windows PowerShell — set for the current shell only
$env:HTTP_PROXY=""
$env:HTTPS_PROXY=""
Start-Process "C:\Users\YOU\AppData\Local\Programs\cursor\Cursor.exe"

If the problem persists, run a quick traceroute to confirm that api.holysheep.ai resolves and that no firewall is blocking outbound TCP 443.

Final Thoughts

Swapping the base URL in Cursor is genuinely a five-minute change, and the upside is enormous: you keep the editor you already love, but you gain access to four frontier model families through one cheap, fast, Alipay-friendly endpoint. I have been running this exact configuration since the beginning of 2026 and my monthly bill dropped from the equivalent of a nice dinner out to roughly the price of a coffee. If you have not tried it yet, the free signup credits are more than enough to feel the difference on your first coding session.