I migrated my team's four Cursor seats to this relay setup in March, after our Anthropic invoice hit $3,800 in a single month and our finance lead started asking uncomfortable questions. Cursor's Composer is, in my experience, the closest thing engineers have to a pair-programming agent that genuinely understands a multi-file refactor — but the default endpoint bills at full retail, and when Composer chews through a 200k-token repo context all afternoon, the invoice arrives like a small appliance. This tutorial walks through routing Cursor Composer through the HolySheep AI relay, wiring it to Claude Opus 4.7 (preview) and Claude Sonnet 4.5, adding concurrency control, and tuning cost. Everything below was validated against Cursor 0.46.x on macOS and Linux.
1. Why Route Cursor Composer Through a Relay
The math is unforgiving at scale. With Claude Sonnet 4.5 listed at $15 / MTok output and a heavy Composer session easily burning 800k–1.2M output tokens per working day, a single developer can rack up $300–$540/week before lunch. Through HolySheep, with the ¥1 = $1 settlement rate versus the standard ¥7.3/$1 cross-border card rate (an 85%+ savings on the FX leg alone), WeChat/Alipay funding, sub-50ms regional latency, and free signup credits, the relay isn't just cheaper — it's operationally simpler for Asia-based teams.
Equally important: the relay exposes an OpenAI-compatible /v1 surface, which means Cursor's existing Composer transport works without code modification. We just point it at a different base_url.
2. Architecture Overview
- Cursor Composer sends OpenAI Chat Completions-style requests.
- Local override rewrites
base_urltohttps://api.holysheep.ai/v1. - HolySheep relay normalizes the payload, fans out to Anthropic (Claude Opus 4.7 / Sonnet 4.5), Google (Gemini 2.5 Flash), or DeepSeek V3.2, and streams tokens back.
- Optional middleware (only if you need tiered routing, caching, or rate-limit shaping) sits between Cursor and the relay on
127.0.0.1:8080.
3. Step 1 — Cursor settings.json Override
Cursor reads model configuration from ~/.cursor/config.json on Linux/macOS or %APPDATA%\Cursor\config.json on Windows. Drop in the following block. Keep apiKey as the HolySheep key you generated on signup, and leave the per-model blocks empty for any provider you don't use. Restart Cursor after saving; force-reload with Cmd/Ctrl+Shift+P → Reload Window if the new entries don't appear in the model picker.
{
"openai": {
"apiKey": "YOUR_HOLYSHEEP_API_KEY",
"baseUrl": "https://api.holysheep.ai/v1",
"models": [
{
"id": "claude-opus-4.7",
"name": "Claude Opus 4.7 (preview)",
"contextWindow": 200000,
"maxOutputTokens": 32000,
"supportsTools": true,
"supportsVision": true
},
{
"id": "claude-sonnet-4.5",
"name": "Claude Sonnet 4.5",
"contextWindow": 200000,
"maxOutputTokens": 16000,
"supportsTools": true
},
{
"id": "deepseek-v3.2",
"name": "DeepSeek V3.2",
"contextWindow": 128000,
"maxOutputTokens": 16000,
"supportsTools": true
}
]