_prepare_context passes last_model_output/last_result to the message
manager for the "previous action result" prompt section. Clearing
them before context preparation drops this context.
Move the clear to after _prepare_context but before _get_next_action,
so prompt assembly still sees the previous step's output while
preventing stale data on timeout during the LLM call or action phase.
Two related bugs when step() is cancelled by timeout:
1. step() does not clear last_model_output/last_result at the start,
so if timeout occurs before _get_next_action, _finalize() sees
stale values from the previous step and records a duplicate history
entry with wrong step numbers.
2. _finalize() early-returns when last_result is falsy, skipping the
n_steps increment. On timeout, this means the while loop retries
the same step number repeatedly.
Fix: clear last_model_output and last_result at step() entry, and
ensure _execute_step increments n_steps after a timeout if _finalize
did not already do so.
Add disabled parameter to SignalHandler class to allow opting out of
signal handling. This enables browser-use to be embedded in applications
like uvicorn/FastAPI that need to manage their own signal lifecycle.
Add enable_signal_handler parameter to Agent class (default True for
backward compatibility). When set to False, the Agent will not register
signal handlers, allowing the host application to control graceful
shutdown and signal handling.
Fixes#4385
The system_prompt.md incorrectly documented the browser state format as:
[index]<type>text</type>
Example: [33]<div>User form</div>
But the actual serializer output format is:
[index]<tagname attribute=value />
With text content as child nodes on separate lines
This update:
- Corrects the format description to match actual DOMTreeSerializer output
- Updates examples to show realistic tree structure
- Documents |SCROLL| prefix for scrollable containers
- Documents |SHADOW(open/closed)| prefix for shadow DOM elements
Fixes#3782
The circuit breaker and agent error handler were using a hardcoded 20s
timeout, but the worst-case auto-reconnect window is ~48s (3 attempts *
15s + 7s delays). Handlers would raise ConnectionError while reconnection
was still in progress. Now both use BrowserSession.RECONNECT_WAIT_TIMEOUT
(54s) derived from the actual reconnect parameters.
Move action_name extraction before the try block so it's always
defined when the except block references it. Previously, if
_check_stop_or_pause() raised InterruptedError before action_name
was assigned, the exception handler would fail with:
UnboundLocalError: cannot access local variable 'action_name'
where it is not associated with a value
Also reuse the action_data dict for the 'done' action check since
it's now available earlier in the loop.
Co-authored-by: Magnus Müller <MagMueller@users.noreply.github.com>
The done_output field has max_length=100000, but agent.history.final_result()
can return arbitrarily long strings (e.g., large data extractions). This caused
Pydantic validation errors when constructing UpdateAgentTaskEvent at the end of
agent.run(), crashing the entire run even though the task itself succeeded.
Truncate done_output to MAX_STRING_LENGTH before passing to the constructor.
Co-authored-by: Magnus Müller <MagMueller@users.noreply.github.com>
- Add max_clickable_elements_length parameter to Agent.__init__ with default 40000
- Add max_clickable_elements_length to AgentSettings
- Pass parameter through MessageManager to AgentMessagePrompt
- Bump version to 0.11.10a2
Co-authored-by: Magnus Müller <MagMueller@users.noreply.github.com>
laithrw