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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.

Want to use a ChatGPT Plus/Pro subscription instead?

Use the OpenAI – ChatGPT Plus/Pro provider to sign in via OAuth (no API key): OpenAI – ChatGPT Plus/Pro.

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.

Available Models​

Roo Code supports all models available through OpenAI's API.

For the complete, up-to-date model list and capabilities, see OpenAI's models documentation.

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.
  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 that cannot be changed.

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 current model costs and discounts, including prompt caching.
  • Azure OpenAI Service: If you'd like to use the Azure OpenAI service, please see our section on OpenAI-compatible providers.
  • Context Optimization: For GPT-5-Codex, leverage prompt caching by maintaining consistent context across requests to reduce costs significantly.