YYLO documentation

Install and initialize

npm install -g @yylo/cli@0.1.0-rc.1
yylo init --task "Describe one verifiable outcome" --subagent claude

The yy and yylo launchers are behaviorally equivalent. Use one installation; collisions or mixed legacy installs fail clearly.

Make the first run bounded

yy start -b shell -s claude -i 1 -v
# the long launcher is equivalent
yylo -b shell -s pi -i 1 -p "Fix the selected ready task and run its tests"

Use first-class product delegates

yy ledger --help
yy benchmark --help
# yylo ledger and yylo benchmark are equivalent

Repeat commands with yy loop

yy loop repeats arbitrary shell commands sequentially. Its -n/--iterations flag bounds the outer command workflow; the existing global and agent -i/--max-iterations flag keeps its meaning of bounding iterations inside one agent invocation. The loop never parses or rewrites yy pi, yy cc, clone, switch, or other provider commands.

yy loop -n 5 \
  --step 'yy pi "Implement the next increment"' \
  --step 'yy cc "Inspect and improve your work"' \
  --step 'npm test'

Save the same contract as YAML for a reusable workflow. CLI values override YAML top-level defaults, for example yy loop --workflow flow.yaml -n 2 --continuity run --on-error stop. The workflow accepts only iterations, continuity, on_error, and a nonempty ordered steps list; every step requires nonempty run text and may set its own on_error: continue|stop.

iterations: 5
continuity: iteration
on_error: continue
steps:
  - run: yy pi "Implement the next increment"
  - run: yy cc "Inspect and improve your work"
  - run: npm test

yy loop --workflow flow.yaml

Continuity controls which existing YYLO continue scope child commands share:

• iteration (default): every iteration gets a new scope. yy pi, yy cc, yy clone, and yy switch steps in that iteration share it; the next iteration is isolated.
• run: all iterations share one scope, enabling explicit continuation or cloning across iteration boundaries.
• shell: the loop injects no scope and preserves the caller’s inherited YYLO_CONTINUE_SCOPE behavior.

The default failure policy is continue: a failed step is recorded, the remaining steps in that iteration are skipped, and the next iteration starts. With --on-error stop (or a YAML step override of on_error: stop), nothing further is launched. Any failed command makes the final loop exit nonzero even if later iterations run. SIGINT/SIGTERM stop the active child and prevent later launches, and the terminal summary reports the loop ID with completed, failed, and skipped work.

Every step receives one-based loop metadata through YYLO_LOOP_ID, YYLO_ITERATION, YYLO_ITERATION_COUNT, YYLO_STEP, and YYLO_STEP_COUNT.

Mental model

Source

Review YYLO on GitHub.