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Jenny Met
Jenny Met

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AI Coding Tools Complete Guide: Use Cursor, Cline & Aider with One API Key

#ai #vscode #productivity #tutorial

The Problem

In 2026, AI coding tools are essential. Cursor, Cline, Aider, Continue... but each requires separate API keys and different configurations.

This guide shows you how to use one API key across all AI coding tools, accessing 624+ models and switching freely.

Why an API Gateway?

Problem Example
Key management chaos Separate keys for OpenAI, Anthropic, Google, DeepSeek
Scattered billing Different dashboards per provider
Per-tool config Set up keys separately in Cursor and Cline
Model switching friction Changing providers means changing SDKs

We'll use Crazyrouter — fully OpenAI-compatible, 624+ models, one key.

Common Setup 

# Add to ~/.bashrc or ~/.zshrc
export OPENAI_API_KEY="sk-your-crazyrouter-key"
export OPENAI_API_BASE="https://crazyrouter.com/v1"
export OPENAI_BASE_URL="https://crazyrouter.com/v1"
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1. Cursor

  1. Open Cursor → Settings → Models
  2. Enter API key in OpenAI API Key
  3. Set Override OpenAI Base URL to https://crazyrouter.com/v1
  4. Add models, save

Recommended:

Use Case Model Why
Tab completion gpt-4o-mini Fast & cheap
Chat claude-sonnet-4-20250514 Best code understanding
Composer deepseek-chat Best value

Pro tip: No need for Cursor Pro ($20/mo). Your own API key enables AI features on the free tier.

2. Cline (VS Code)

  1. Install "Cline" from marketplace
  2. Settings → API Provider → OpenAI Compatible
  3. Enter: 
Base URL: https://crazyrouter.com/v1
API Key:  sk-yourkey
Model ID: claude-sonnet-4-20250514
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Task-based model selection:

Complex refactoring  → claude-sonnet-4-20250514
Daily coding         → deepseek-chat ($0.14/1M tokens)
Bug fixes            → gpt-4o-mini (fast)
Algorithm problems   → deepseek-reasoner
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3. Continue (VS Code / JetBrains)

Edit ~/.continue/config.json:

{
  "models": [
    {
      "title": "Claude Sonnet",
      "provider": "openai",
      "model": "claude-sonnet-4-20250514",
      "apiBase": "https://crazyrouter.com/v1",
      "apiKey": "sk-yourkey"
    },
    {
      "title": "DeepSeek V3",
      "provider": "openai",
      "model": "deepseek-chat",
      "apiBase": "https://crazyrouter.com/v1",
      "apiKey": "sk-yourkey"
    }
  ],
  "tabAutocompleteModel": {
    "title": "Tab Autocomplete",
    "provider": "openai",
    "model": "gpt-4o-mini",
    "apiBase": "https://crazyrouter.com/v1",
    "apiKey": "sk-yourkey"
  }
}
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4. Aider (Terminal) 

pip install aider-chat

# Uses env vars from common setup
aider --model deepseek-chat              # Best value
aider --model claude-sonnet-4-20250514   # Best quality
aider --model gpt-4o                     # Balanced
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Cost Optimization

Complexity Model Cost (in/out per 1M tokens)
High claude-sonnet-4 $3 / $15
High gpt-4o $2.5 / $10
Medium deepseek-chat $0.14 / $0.28 ← recommended
Low gpt-4o-mini $0.15 / $0.60

100 AI assists/day, monthly cost:

Model Monthly
deepseek-chat ~$0.13
gpt-4o-mini ~$0.59
gpt-4o ~$9.75
claude-sonnet-4 ~$13.50

Recommended setup (under $5/month):

Tab completion:   gpt-4o-mini
Daily coding:     deepseek-chat
Important review: claude-sonnet-4
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Python Script Usage 

from openai import OpenAI

client = OpenAI(
    base_url="https://crazyrouter.com/v1",
    api_key="sk-yourkey"
)

response = client.chat.completions.create(
    model="deepseek-chat",
    messages=[
        {"role": "system", "content": "You are a senior engineer. Review code and suggest improvements."},
        {"role": "user", "content": "Review this:\n\n```

python\ndef fibonacci(n):\n    if n <= 1: return n\n    return fibonacci(n-1) + fibonacci(n-2)\n

```"}
    ]
)
print(response.choices[0].message.content)
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Summary

Tool Config Difficulty
Cursor Settings → Models ⭐ Easy
Cline Sidebar → Settings ⭐ Easy
Continue ~/.continue/config.json ⭐⭐ Medium
Aider Env vars ⭐ Easy
Python pip install openai ⭐ Easy

Key takeaways:

  • Same API key and base URL everywhere
  • Environment variables = auto-detection
  • DeepSeek V3 is the best value at $0.14/1M tokens

Top comments (1)

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bhongnews profile image
bhongnews@gmail.com •

One thing I would add for coding-agent costs: don't use one unlimited API key for every long run.

What I usually do is create a fresh token for a task, put a quota on it, then point Cursor/Cline/Aider at that token through an OpenAI-compatible base URL. It does not fix bad context growth, but it makes a runaway loop much less painful.

The checklist I use is:

base_url: explicit /v1 endpoint
api_key: task-scoped token with a quota
model: exact model id
logs: check prompt/completion tokens after a few turns
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I wrote the setup pattern down here: github.com/alicekellings/cursor-cl...

Disclosure: I maintain Wappkit (api.wappkit.com), an OpenAI-compatible gateway. The same idea works with any compatible endpoint that gives you per-token quota and request logs.