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Using OpenAI With Roo Code

Roo Code supports accessing models directly through the official OpenAI API, including the latest GPT-5 family with advanced features like reasoning effort control and verbosity settings.

Website: https://openai.com/

Getting an API Key​

  1. Sign Up/Sign In: Go to the OpenAI Platform. Create an account or sign in.
  2. Navigate to API Keys: Go to the API keys page.
  3. Create a Key: Click "Create new secret key". Give your key a descriptive name (e.g., "Roo Code").
  4. Copy the Key: Important: Copy the API key immediately. You will not be able to see it again. Store it securely.

Supported Models​

GPT-5 Family (Latest)​

The GPT-5 models are OpenAI's most advanced, offering superior coding capabilities and agentic task performance:

  • gpt-5-2025-08-07 (default) - Best model for coding and agentic tasks
  • gpt-5-mini-2025-08-07 - Faster, cost-efficient for well-defined tasks
  • gpt-5-nano-2025-08-07 - Fastest, most cost-efficient option

GPT-4.1 Family​

Advanced multimodal models with balanced capabilities:

  • gpt-4.1 - Advanced multimodal model
  • gpt-4.1-mini - Balanced performance
  • gpt-4.1-nano - Lightweight option

o3 Reasoning Models​

Models with configurable reasoning effort for complex problem-solving:

  • o3, o3-high, o3-low - Different reasoning effort presets
  • o3-mini (medium reasoning effort)
  • o3-mini-high (high reasoning effort)
  • o3-mini-low (low reasoning effort)

o4 Models​

Latest mini reasoning models:

  • o4-mini, o4-mini-high, o4-mini-low

o1 Family​

Original reasoning models:

  • o1 - Original reasoning model
  • o1-preview - Preview version
  • o1-mini - Smaller variant

GPT-4o Family​

Optimized GPT-4 models:

  • gpt-4.5-preview
  • gpt-4o - Optimized GPT-4
  • gpt-4o-mini - Smaller optimized variant

Refer to the OpenAI Models documentation for the most up-to-date list of models and capabilities.

Configuration in Roo Code​

Setup​

  1. Open Roo Code Settings: Click the gear icon () in the Roo Code panel.
  2. Select Provider: Choose "OpenAI" from the "API Provider" dropdown.
  3. Enter API Key: Paste your OpenAI API key into the "OpenAI API Key" field.
  4. Select Model: Choose your desired model from the "Model" dropdown (defaults to gpt-5-2025-08-07).
  5. (Optional) Base URL: If you need to use a custom base URL, enter the URL. Most people won't need to adjust this.

Advanced Features​

Reasoning Effort Control​

For models that support reasoning (GPT-5, o1, o3, o4 families), you can control how deeply the model thinks:

GPT-5 Models:

  • minimal - Fastest responses with basic reasoning
  • low - Quick responses with light reasoning
  • medium (default) - Balanced reasoning and response time
  • high - Deep reasoning for complex problems

o1/o3/o4 Models:

  • low - Minimal thinking time
  • medium - Balanced approach
  • high - Maximum thinking for complex problems

Some models have preset reasoning levels (e.g., o3-high always uses high reasoning).

Verbosity Control​

Available for GPT-5 models and select others, verbosity controls the detail level of responses:

  • low - Concise, direct responses
  • medium (default) - Balanced detail
  • high - Comprehensive, detailed responses

Temperature Settings​

Temperature controls output randomness (0.0 to 2.0):

  • GPT-5 models: Default 1.0 for balanced creativity
  • Other models: Default 0.0 for deterministic output
  • Note: Not available for o1/o3 reasoning models

Conversation Continuity (GPT-5)​

GPT-5 models maintain conversation context efficiently through response IDs, reducing token usage while preserving context. This happens automatically - no configuration needed.

Tips and Notes​

  • Pricing: Refer to the OpenAI Pricing page for details on model costs.
  • Azure OpenAI Service: If you'd like to use the Azure OpenAI service, please see our section on OpenAI-compatible providers.