Connect to a Pernosco trace by URL or trace ID. Opens the tab in Firefox if not already open.

List available Pernosco traces (open Firefox tabs with pernos.co loaded)

Get current focus position (event number, source file, line) for the connected session

Disconnect from the current Pernosco session

Find all calls to a function across the trace. Optionally evaluate C++ expressions at each call site using print_exprs (semicolon-delimited).

Get the call stack at the current focus position

Evaluate a C++ expression at the current focus position

Navigate to a specific execution point by result index (from a previous query) or raw focus object

Get the complete process/thread hierarchy for the trace

Search for symbols, functions, or types by name

Get complete write history for a memory address across the trace (reads all writes before and after current focus)

Get stdout/stderr output around the current focus position. Output is scoped to the current process — use goto to navigate to a content process first if needed. Results include event IDs for navigation.

Get active processes and threads at the current focus moment

Read Pernosco notebook annotations saved in this session

Find all hits of a specific source line. Use when you have a file:line from a stack trace or crash report.

Show which lines of the current source file executed at the current focus, with execution counts for loops. Essential for understanding which code paths and branches ran.

Read source code lines from the current trace. Use after stack or session_status to see code around the current position.

Navigate forward to the next execution of the current source line (or a specified line). Useful for stepping through loop iterations or repeated calls.

Get the complete write history of a C++ variable. Evaluates the expression to find its memory address, then traces all writes. Simpler than manually using evaluate + watchpoint_history.

Navigate backward to the previous execution of the current source line (or a specified line). Useful for reverse debugging.