> ## Documentation Index
> Fetch the complete documentation index at: https://browseruse-0aece648-mintlify-cli-docs-1773354647.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# All Parameters

> Complete reference for all agent configuration options — LLM settings, prompts, tools, output format, and callbacks.

## Available Parameters

### Core Settings

* `tools`: Registry of <a href="../tools/available">tools</a> the agent can call. <a href="../tools/basics">Example</a>
* `skills` (or `skill_ids`): List of skill IDs to load (e.g., `['skill-uuid']` or `['*']` for all). Requires `BROWSER_USE_API_KEY`. <a href="../skills/basics">Docs</a>
* `browser`: Browser object where you can specify the browser settings.
* `output_model_schema`: Pydantic model class for structured output validation. [Example](https://github.com/browser-use/browser-use/blob/main/examples/features/custom_output.py)

### 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`)

### 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](https://github.com/browser-use/browser-use/blob/main/examples/features/fallback_model.py)

### Actions & Behavior

* `initial_actions`: List of actions to run before the main task without LLM. [Example](https://github.com/browser-use/browser-use/blob/main/examples/features/initial_actions.py)
* `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](https://github.com/browser-use/browser-use/blob/main/examples/getting_started/05_fast_agent.py)

### System Messages

* `override_system_message`: Completely replace the default system prompt.
* `extend_system_message`: Add additional instructions to the default system prompt. [Example](https://github.com/browser-use/browser-use/blob/main/examples/features/custom_system_prompt.py)

### 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](https://github.com/browser-use/browser-use/blob/main/examples/features/sensitive_data.py)

### 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

### 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.

### Advanced Options

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

### Backwards Compatibility

* `controller`: Alias for `tools` for backwards compatibility.
* `browser_session`: Alias for `browser` for backwards compatibility.

***

## Environment Variables

These environment variables can be used to tune agent and browser behavior without code changes. They are particularly useful for debugging, slow networks, or deployment-level tuning.

### Agent Timeouts

| Variable                    | Default | Description                                                                                       |
| --------------------------- | ------- | ------------------------------------------------------------------------------------------------- |
| `TIMEOUT_AgentEventBusStop` | `3.0`   | Timeout in seconds for the agent's event bus to finish processing pending events during shutdown. |

### Browser Action Timeouts

| Variable                            | Default | Description                                       |
| ----------------------------------- | ------- | ------------------------------------------------- |
| `TIMEOUT_NavigateToUrlEvent`        | `15.0`  | Timeout for page navigation                       |
| `TIMEOUT_ClickElementEvent`         | `15.0`  | Timeout for clicking elements                     |
| `TIMEOUT_ClickCoordinateEvent`      | `15.0`  | Timeout for clicking at coordinates               |
| `TIMEOUT_TypeTextEvent`             | `60.0`  | Timeout for typing text (longer for large inputs) |
| `TIMEOUT_ScrollEvent`               | `8.0`   | Timeout for scrolling                             |
| `TIMEOUT_ScrollToTextEvent`         | `15.0`  | Timeout for scrolling to find text                |
| `TIMEOUT_SendKeysEvent`             | `60.0`  | Timeout for sending keyboard shortcuts            |
| `TIMEOUT_UploadFileEvent`           | `30.0`  | Timeout for file uploads                          |
| `TIMEOUT_GetDropdownOptionsEvent`   | `15.0`  | Timeout for fetching dropdown options             |
| `TIMEOUT_SelectDropdownOptionEvent` | `8.0`   | Timeout for selecting dropdown option             |
| `TIMEOUT_GoBackEvent`               | `15.0`  | Timeout for browser back navigation               |
| `TIMEOUT_GoForwardEvent`            | `15.0`  | Timeout for browser forward navigation            |
| `TIMEOUT_RefreshEvent`              | `15.0`  | Timeout for page refresh                          |
| `TIMEOUT_WaitEvent`                 | `60.0`  | Timeout for explicit wait actions                 |
| `TIMEOUT_ScreenshotEvent`           | `15.0`  | Timeout for taking screenshots                    |
| `TIMEOUT_BrowserStateRequestEvent`  | `30.0`  | Timeout for fetching browser state/DOM            |

### Browser Lifecycle Timeouts

| Variable                        | Default | Description                              |
| ------------------------------- | ------- | ---------------------------------------- |
| `TIMEOUT_BrowserStartEvent`     | `30.0`  | Timeout for starting browser session     |
| `TIMEOUT_BrowserStopEvent`      | `45.0`  | Timeout for stopping browser session     |
| `TIMEOUT_BrowserLaunchEvent`    | `30.0`  | Timeout for launching browser process    |
| `TIMEOUT_BrowserKillEvent`      | `30.0`  | Timeout for killing browser process      |
| `TIMEOUT_BrowserConnectedEvent` | `30.0`  | Timeout for CDP connection               |
| `TIMEOUT_BrowserStoppedEvent`   | `30.0`  | Timeout for browser stopped confirmation |
| `TIMEOUT_BrowserErrorEvent`     | `30.0`  | Timeout for browser error events         |

### Tab Management Timeouts

| Variable                         | Default | Description                     |
| -------------------------------- | ------- | ------------------------------- |
| `TIMEOUT_SwitchTabEvent`         | `10.0`  | Timeout for switching tabs      |
| `TIMEOUT_CloseTabEvent`          | `10.0`  | Timeout for closing tabs        |
| `TIMEOUT_TabCreatedEvent`        | `30.0`  | Timeout for tab creation events |
| `TIMEOUT_TabClosedEvent`         | `10.0`  | Timeout for tab closed events   |
| `TIMEOUT_AgentFocusChangedEvent` | `10.0`  | Timeout for focus change events |
| `TIMEOUT_TargetCrashedEvent`     | `10.0`  | Timeout for crash events        |

### Navigation Event Timeouts

| Variable                          | Default | Description                            |
| --------------------------------- | ------- | -------------------------------------- |
| `TIMEOUT_NavigationStartedEvent`  | `30.0`  | Timeout for navigation started events  |
| `TIMEOUT_NavigationCompleteEvent` | `30.0`  | Timeout for navigation complete events |

### Storage & Download Timeouts

| Variable                          | Default | Description                             |
| --------------------------------- | ------- | --------------------------------------- |
| `TIMEOUT_SaveStorageStateEvent`   | `45.0`  | Timeout for saving cookies/localStorage |
| `TIMEOUT_StorageStateSavedEvent`  | `30.0`  | Timeout for storage save confirmation   |
| `TIMEOUT_LoadStorageStateEvent`   | `45.0`  | Timeout for loading storage state       |
| `TIMEOUT_StorageStateLoadedEvent` | `30.0`  | Timeout for storage load confirmation   |
| `TIMEOUT_FileDownloadedEvent`     | `30.0`  | Timeout for file download events        |

### Example Usage

```bash theme={null}
# 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
```