TUI Interactive Launch

fastsim_tui is a lazygit-inspired two-panel terminal interface built with Textual. It provides the same functionality as the fastsim CLI with a visual command browser and real-time output.

bash

fastsim_tui

Layout

Left panel: Command list grouped by category (Simulation / Config Tools / Recording / Registry). Navigate with arrow keys, press Enter to run.
Right panel: Terminal output area + bottom status bar showing real-time command output and simulation state.

Command Groups

Group	Commands	Description
Simulation	`launch_simulation`	Start simulation (subprocess mode)
Config Tools	`validate_configuration`, `show_config`, `diff_config`, `inspect_scene`, `inspect_task`, `inspect_extension`	Config validation and inspection
Recording	`inspect_recording`, `plot_trajectory`	Recording data analysis
Registry	`show_registery`, `show_stereotype_params`, `show_static_api`	Registry and API inspection

Execution Flow

Select command: Navigate with Up / Down in the left panel
Press Enter: An input modal pops up for command arguments
Fill arguments: Text inputs for paths, toggle switches for boolean options
Confirm: Press Enter or click Run to execute; Esc to cancel
View output: Real-time output streams to the right panel

Commands requiring confirmation (like launch_simulation) show a confirmation dialog first.

Execution Modes

Function call: Runs in-process, output redirected to the right panel. Used for lightweight operations (validate, show config, inspect).
Subprocess: Runs as a separate process with stdout streaming. Used by launch_simulation to avoid blocking the TUI.

Only one subprocess can run at a time.

When launch_simulation runs with --monitor yes (the default), the TUI parses real-time state from the simulation process, displaying simulation step count, dt, and running status in the bottom status bar.

Command Filtering

Press / to enter search mode and filter commands by keyword. Press Esc to clear the filter.

Keyboard Shortcuts

Key	Action
`Up` / `Down`	Navigate command list
`Enter`	Run selected command
`Tab`	Switch focus between panels
`/`	Filter commands (search mode)
`Esc`	Clear filter / cancel modal
`Ctrl+X`	Kill running subprocess
`Ctrl+L`	Clear output panel
`Ctrl+S`	Save output to file
`?`	Show help modal
`Ctrl+C`	Exit TUI

Typical Usage

Run fastsim_tui
Select validate_configuration, enter config path, verify results
Select inspect_scene to check entity details
Select launch_simulation, confirm and start
Monitor real-time output and status in the right panel
Press Ctrl+X to stop if needed
After simulation, select inspect_recording to analyze data