furb, the command line

furb is the command line of furb. With no command, it opens the TUI. With a command, it runs one life and prints what it gave. With --mode rpc, it serves one life to another program.

pip install furb                     # Gives the command furb. It needs Python 3.14 or later.

From a clone, uv run furb runs the furb of the clone, and cargo run -p furb-cli -- builds it and runs it.

The commands

These words go with each command that opens a life. extensions and checkpoint take only --record and --cwd:

• --record FILE keeps the life in a record, and goes on from it when it holds a life already. A name that ends in .sqlite, .sqlite3 or .db makes a database of SQLite. With no record, the life keeps nothing.
• --cwd DIR is the directory where the chains start, the current directory when unsaid.
• --model ACTOR and --roster MODEL choose the models, as the page of models says.

furb --help, and furb <command> --help, give every word.

Examples

furb run "close(1 + 1)"                                       # Prints 2, and asks no model.
furb prompt "How many files?" --shape int --to operator      # Asks you, and prints the number you type.
furb prompt "How many lines does README.md hold?" --shape int # Asks the default model.
furb prompt "Fix the failing test." --record fix.jsonl        # Keeps the life, so a second run goes on from it.
furb turns --record fix.jsonl                                 # Shows what the model read.

Where furb finds the TUI

The TUI is a program of its own. furb runs the one that FURB_TUI names, else furb-tui on PATH, else the TUI of the clone that furb was built from. A furb that finds none says so. The TUI runs from a clone, as the TUI says. The words after -- go to the TUI, as furb -- --view loom.