Zero-config Flask TODO demo

Preview. This command does not yet complete a first run: all three seeded tasks fail, and the task server can die and restart mid-run. What it no longer does is claim otherwise — the summary reports Tasks completed 0 / 3 against the seeded count and the command exits non-zero, so a wrapper or CI job can tell the run apart from a good one (#3902). Plain bernstein demo has a separate first-run failure — a cold run can exceed the task-server readiness budget and exit 1 (the error says 10.0s; the actual budget is 30s, see #3905) — and aborts with a UnicodeEncodeError on a Windows console using a legacy code page. Both are tracked from #3825. Use bernstein init to set up a real project in the meantime.

bernstein demo --flask-todo runs a self-contained demo: it creates a temporary Flask TODO API project with intentional gaps, seeds three tasks against it, runs agents to complete them, and prints a summary — with no bernstein.yaml and no prior project setup required. It exists to let a new user see multi-agent orchestration work end to end before committing to a real project.

For a guided walkthrough that sets up your own project instead of a throwaway demo, see the interactive tutorial.

Usage

bernstein demo --flask-todo                # run and clean up the temp dir
bernstein demo --flask-todo --keep         # keep the temp dir for inspection
bernstein demo --flask-todo --timeout 120  # cap orchestration wait time
bernstein demo --flask-todo --real --adapter codex

Flag	Default	Meaning
--keep	off	Preserve the temp project directory after completion instead of deleting it.
--timeout SECONDS	300	Maximum seconds to wait for all seeded tasks to finish.
--adapter NAME	mock	CLI adapter to drive the agents. Like the rest of bernstein demo, real agents run only behind --real; without it the scenario runs on mock agents and costs nothing.

bernstein quickstart remains registered as a deprecated alias for the whole 3.x line and is unregistered in 4.0.0.

What it does

1. Creates a temp directory (bernstein-quickstart-*) containing a minimal Flask TODO API (app.py) that is missing input validation, 404 error handling, and a test suite — bundled from examples/quickstart/ when present, or written inline as a fallback.
2. Seeds three backlog tasks into .sdd/backlog/open/:
   • input validation on create_todo (role: backend)
   • 404 handling on update_todo/delete_todo (role: backend)
   • a pytest suite covering the API (role: qa)
3. Starts a task server on port 8056 and bootstraps orchestration (bootstrap_from_goal) against those tasks.
4. Polls /status every 2 seconds, printing each task's completion or failure as it happens, until every task reaches done/failed or the timeout elapses.
5. Stops the server, spawner, and watchdog processes it started.
6. Prints a summary table (tasks completed, elapsed time, Python files produced, API cost) and, unless --keep is passed, deletes the temp directory.

Exit code

0 only when all three seeded tasks reached done. Anything else — a failed task, an interrupted run, a bootstrap that raised — exits 1.

The denominator in Tasks completed is the seeded count, not the length of the task list the server happens to hold, so a retry that spawns a fresh task id cannot inflate it and a torn-down server cannot deflate it to 0 / 0. The snapshot behind the table is taken while the server is still running; if it could not be read, the table says Task server unreachable instead of quietly reporting zeros.

Cost

Before starting, the command prints a cost estimate. The two spellings do not reach it the same way.

bernstein demo --flask-todo follows demo's rule. Without --real it runs on mock agents and prints $0.00 (mock) whatever agent CLIs are installed on the machine. With --real it prints roughly $0.20 for the 3 tasks, and if no adapter can be resolved it stops rather than running on mock.

The deprecated bernstein quickstart spelling has no --real option and keeps the behaviour it always had: it picks up an installed agent CLI by itself and prints ~\$0.20, falling back to $0.00 (mock) only when it finds none. On a machine with an agent CLI on PATH it therefore spends money with no flag asked for. Pass --adapter mock to pin it, or move to bernstein demo --flask-todo.

Source

src/bernstein/cli/commands/quickstart_cmd.py.