All Parameters

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Available Parameters

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Core Settings

• tools: Registry of tools the agent can call. Example
• skills (or skill_ids): List of skill IDs to load (e.g., ['skill-uuid'] or ['*'] for all). Requires BROWSER_USE_API_KEY. Docs
• browser: Browser object where you can specify the browser settings.
• output_model_schema: Pydantic model class for structured output validation. Example

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Vision & Processing

• use_vision (default: "auto"): Vision mode - "auto" includes screenshot tool but only uses vision when requested, True always includes screenshots, False never includes screenshots and excludes screenshot tool
• vision_detail_level (default: 'auto'): Screenshot detail level - 'low', 'high', or 'auto'
• page_extraction_llm: Separate LLM model for page content extraction. You can choose a small & fast model because it only needs to extract text from the page (default: same as llm)

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Fallback & Resilience

• fallback_llm: Backup LLM to use when the primary LLM fails. The primary LLM will first exhaust its own retry logic (typically 5 attempts with exponential backoff), and only then switch to the fallback. Triggers on rate limits (429), authentication errors (401), payment/credit errors (402), or server errors (500, 502, 503, 504). Once switched, the fallback is used for the rest of the run. Example

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Actions & Behavior

• initial_actions: List of actions to run before the main task without LLM. Example
• max_actions_per_step (default: 4): Maximum actions per step, e.g. for form filling the agent can output 4 fields at once. We execute the actions until the page changes.
• max_failures (default: 3): Maximum retries for steps with errors
• final_response_after_failure (default: True): If True, attempt to force one final model call with intermediate output after max_failures is reached
• use_thinking (default: True): Controls whether the agent uses its internal “thinking” field for explicit reasoning steps.
• flash_mode (default: False): Fast mode that skips evaluation, next goal and thinking and only uses memory. If flash_mode is enabled, it overrides use_thinking and disables the thinking process entirely. Example

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System Messages

• override_system_message: Completely replace the default system prompt.
• extend_system_message: Add additional instructions to the default system prompt. Example

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File & Data Management

• save_conversation_path: Path to save complete conversation history
• save_conversation_path_encoding (default: 'utf-8'): Encoding for saved conversations
• available_file_paths: List of file paths the agent can access
• sensitive_data: Dictionary of sensitive data to handle carefully. Example

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Visual Output

• generate_gif (default: False): Generate GIF of agent actions. Set to True or string path
• include_attributes: List of HTML attributes to include in page analysis

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Performance & Limits

• max_history_items: Maximum number of last steps to keep in the LLM memory. If None, we keep all steps.
• llm_timeout (default: 90): Timeout in seconds for LLM calls
• step_timeout (default: 120): Timeout in seconds for each step
• directly_open_url (default: True): If we detect a url in the task, we directly open it.

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Advanced Options

• calculate_cost (default: False): Calculate and track API costs
• display_files_in_done_text (default: True): Show file information in completion messages

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Backwards Compatibility

• controller: Alias for tools for backwards compatibility.
• browser_session: Alias for browser for backwards compatibility.

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Environment Variables

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Agent Timeouts

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Browser Action Timeouts

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Browser Lifecycle Timeouts

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Tab Management Timeouts

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Navigation Event Timeouts

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Storage & Download Timeouts

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Example Usage

# Increase timeouts for slow network or complex pages
export TIMEOUT_NavigateToUrlEvent=30.0
export TIMEOUT_TypeTextEvent=120.0
export TIMEOUT_BrowserStateRequestEvent=60.0

# Increase agent shutdown timeout
export TIMEOUT_AgentEventBusStop=10.0