Cursor API Key Management

Configure Bring Your Own Key (BYOK) for AI model providers in Cursor. BYOK lets you use your own API keys to bypass Cursor's monthly quota, pay per token directly, and access models not included in Cursor's subscription.

Supported Providers

Provider	Key Format	Models Available
OpenAI	sk-proj-... or sk-...	GPT-4o, GPT-4o-mini, o1, o3, GPT-5
Anthropic	sk-ant-api03-...	Claude Sonnet, Claude Opus, Claude Haiku
Google	AIzaSy...	Gemini 2.5 Pro, Gemini Flash
Azure OpenAI	Azure portal key	Any deployed Azure OpenAI model
AWS Bedrock	IAM credentials	Claude, Titan, Llama models
OpenAI-compatible	Varies	Ollama, LM Studio, Together AI, etc.

Configuration Steps

OpenAI

1. Go to platform.openai.com/api-keys
2. Create a new API key (project-scoped recommended)
3. In Cursor: Cursor Settings > Models > check Use own API key
4. Paste key in the OpenAI API Key field
5. Select model from dropdown (e.g., gpt-4o)

Anthropic

1. Go to console.anthropic.com/settings/keys
2. Create a new API key
3. In Cursor: Cursor Settings > Models > check Use own API key
4. Paste key in the Anthropic API Key field
5. Select Claude model from dropdown

Google (Gemini)

1. Go to aistudio.google.com/apikey
2. Create API key
3. In Cursor: Cursor Settings > Models > check Use own API key
4. Paste key in the Google API Key field

Azure OpenAI

Azure requires additional configuration beyond a simple API key:

1. In Azure Portal: create an Azure OpenAI resource
2. Deploy your desired model (e.g., gpt-4o)
3. Note the Endpoint URL and API Key from the resource
4. In Cursor: Cursor Settings > Models:

Azure Configuration:
  API Key:        xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
  Endpoint:       https://your-instance.openai.azure.com
  Deployment:     your-gpt4o-deployment-name
  API Version:    2024-10-21

Custom OpenAI-Compatible Endpoints

For self-hosted models (Ollama, vLLM) or third-party providers:

1. Cursor Settings > Models > Add Model
2. Model name: e.g., llama-3.1-70b
3. Check Override OpenAI Base URL
4. Enter base URL:

Ollama:        http://localhost:11434/v1
LM Studio:    http://localhost:1234/v1
Together AI:  https://api.together.xyz/v1

5. Enter API key if required by the provider
6. The model appears in the Chat/Composer model dropdown

What BYOK Covers (and What It Does Not)

BYOK key used:                    Cursor model (always):
┌──────────────────────┐         ┌──────────────────────┐
│  Chat (Cmd+L)        │         │  Tab Completion      │
│  Composer (Cmd+I)    │         │  Apply from Chat     │
│  Agent Mode          │         │  (diff application)  │
│  Inline Edit (Cmd+K) │         │                      │
└──────────────────────┘         └──────────────────────┘

Tab Completion and Apply always use Cursor's proprietary models. You cannot route these through your own API key.

Cost Management

Monitoring Usage

With BYOK, you pay the provider directly. Monitor costs at:

• OpenAI: platform.openai.com/usage
• Anthropic: console.anthropic.com/settings/billing
• Azure: Azure Cost Management portal

Setting Spending Limits

Set monthly spending limits at the provider level:

• OpenAI: Settings > Limits > Set monthly budget
• Anthropic: Settings > Limits > Set spending limit
• Azure: Create budget alerts in Azure Cost Management

Cost-Saving Strategies

1. Use Auto mode: Cursor selects cheaper models for simple tasks
2. Default to Sonnet/GPT-4o: Reserve Opus/o1 for hard problems
3. Shorter context: Use @Files not @Codebase when you know the location
4. Fewer round-trips: Write detailed prompts to reduce back-and-forth

Approximate Token Costs (as of early 2026)

Model	Input (per 1M tokens)	Output (per 1M tokens)
GPT-4o	$2.50	$10.00
GPT-4o-mini	$0.15	$0.60
Claude Sonnet	$3.00	$15.00
Claude Opus	$15.00	$75.00
o1	$15.00	$60.00

A typical Composer session generating multi-file code uses 5K-20K tokens.

Security Best Practices

Key Storage

Cursor stores API keys locally in its settings database:

• macOS: ~/Library/Application Support/Cursor/
• Linux: ~/.config/Cursor/
• Windows: %APPDATA%\Cursor\

Keys are stored in the local Cursor configuration, not in project files. They do not sync between machines.

Rotation

1. Generate a new key at the provider
2. Update the key in Cursor Settings > Models
3. Revoke the old key at the provider
4. Verify Chat/Composer work with the new key

Team Key Management

For teams using BYOK:

• Individual keys: Each developer uses their own key. Simplest setup, hardest to audit.
• Shared project key: Create a project-scoped key at the provider. Share via secure channel. Track usage per project.
• Azure gateway: Route all requests through a central Azure OpenAI deployment. Full audit logging, spending controls, model governance.

Troubleshooting

Error	Cause	Fix
401 Unauthorized	Invalid or expired API key	Regenerate key at provider
429 Rate Limited	Too many requests	Wait, or upgrade provider plan
403 Forbidden	Key lacks model access	Enable model access at provider
Model not appearing	Key not saved or wrong provider	Re-enter key in Cursor Settings
Azure connection refused	Wrong endpoint or API version	Verify endpoint URL and version
Slow responses with BYOK	Provider rate limits apply	Check provider dashboard

Enterprise Considerations

• Compliance: BYOK routes requests directly to the provider, bypassing Cursor's infrastructure. Verify this meets your data governance requirements.
• Azure private endpoints: Enterprise Azure deployments can use private endpoints for network-level isolation
• Key rotation policy: Implement quarterly key rotation as standard practice
• SSO + BYOK: Team admins can configure shared BYOK keys via the admin dashboard (Enterprise plan)

Resources

• Cursor API Keys Documentation
• Cursor Data Use Policy
• OpenAI API Reference
• Anthropic API Reference