Setup Guide · Tested March 2026

Best AI Model for Cursor IDE (2026 Setup Guide)

Cursor's "Custom API Key" mode lets you bypass Cursor's per-seat cost by routing requests through any OpenAI-compatible endpoint. This guide covers which model to pick at each budget, how to set up CheapAI's proxy in Cursor, and what's been tested.

Tested in Cursor by CheapAI team ~6 min read March 2026

Testing Methodology & Trade-offs

How we test: All models discussed in this guide were actively tested inside the Cursor IDE using the CheapAI proxy endpoint in March 2026. We verify autocomplete latency, multi-file edit success rates, and basic tool-use reliability.

Trade-offs: Bypassing Cursor's native AI subscription means you lose access to Cursor's proprietary fast-routing layer and deep codebase indexing sync. However, using a custom API key grants access to models not officially supported yet (like deepseek-chat) and often results in significantly lower costs.

How to Set Up CheapAI in Cursor

Get a CheapAI API key

Purchase access at CheapAI pricing. You will receive an API key and proxy URL within 24 hours of purchase.

Open Cursor Settings

Press Cmd/Ctrl + , to open settings. Navigate to Models or use the search bar to find "API Key".

Set the custom base URL and API key

In the "OpenAI API Key" section, enable Custom API base URL and enter:

Base URL:
https://cheapai-netifly-app.up.railway.app/v1
API Key:
YOUR_CHEAPAI_API_KEY

Select or type the model name

In the model selector, type one of the following model IDs. Cursor will send it as the model field to our proxy:

For complex tasks

claude-sonnet-4-6-20260217

For coding at scale

claude-haiku-4-5-20251001

For GPT-compatible tasks

gpt-5.4

DeepSeek (lowest cost)

deepseek-chat

✓

Verify it works

Press Cmd/Ctrl + L to open Cursor Chat and type a test prompt. If the response streams back, you're connected. CheapAI's proxy is tested to work with Cursor v0.40+ (March 2026).

Model Recommendations for Cursor

Use Case	Model	Reason
Architecture decisions, complex refactoring	`claude-sonnet-4-6`	Best instruction following + long-context reasoning
Rapid small edits, autocomplete	`claude-haiku-4-5`	Low latency, very cost-efficient
Batch code explanations	`deepseek-chat`	Cheapest per token from verified source ($0.028/1M cache)
Full codebase Composer sessions	`claude-opus-4-6`	Strongest at multi-file context & cross-file reasoning

Compatibility note: This guide was tested in March 2026 with Cursor v0.40+. The "OpenAI-compatible base URL" feature may behave differently in older Cursor versions. See our compatibility matrix for the full test log. Cursor native "Cascade" mode is not yet tested with our proxy.

Ready to set up Cursor with CheapAI?

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