# Hydrogen computer app

Exported by REA's `export-desktop-application` from a capture of the `hydrogen` package
(capture Evidence `ev_a1833b86c146e19d831723570e4627d5ce982983af7091cf3790ef22ae27d682`). It was checked against agentenv-framework
0.9.1431.

- `envs/hydrogen/` is a computer app on the `ubuntu-24.04` base with the `reference` driver, for
  `amd64` and `arm64`. It installs `hydrogen` from the distribution archive, launches `sh -c cd "$HOME" 2>/dev/null; exec 'hydrogen' "$HOME"/'Documents/backbeat.h2song'` at boot and is ready
  when a window of class `Hydrogen` appears.
- Installed beside the app because the export was asked for them with `--extra-package`, as a build computer asks
  for the packages its request named: `pulseaudio`.
- At launch the app opens `~/Documents/backbeat.h2song`, the seed's one document.
- Owned paths: `~/.hydrogen`, `~/Documents`.
  `data/get` returns their files and a typed JSON view of each; `data/reset` restores the seed.
- Seed: 3 file(s) made for the task, as saved at checkpoint `seed`.
  Text files and dconf keys spell the capture host's name as `localhost`, `user@host` as `user@localhost`
  and the home as `/home/user`, which the computer respells to its own at boot.
- Neither owned nor seeded, so the app starts without what it saved there: these files or folders, which changed
  during the capture, `~/.config/QtProject.conf`.
  To own them, capture again naming them with `state_paths` on `start_build_capture`, or `--state-path` on `capture-desktop-application`.
- `tasks/smoke.json` deploys the app.

Run the task with `agent-env run <this folder>`, or only the deploy with `--task smoke`.

The seed was made for this task, not taken from a user's own data; read `envs/hydrogen/seed/` before publishing the bundle.

## Task `change-tempo`

`tasks/change-tempo.json` deploys the app, has the agent work through the computer from the prompt below, and grades
the outcome with `artifacts/change-tempo-check/verify.py`, which reads the app's `data/get` views and needs
no model. It grades once the app's files have held for 3 s, so a save the app makes on its own within that
time of the agent stopping counts; each result's `settled` is false when they were still changing 15 s after the
first read. `evals/hydrogen.toml` names it, so a run of the bundle runs it.

> In Hydrogen, change the tempo of the Backbeat Sketch song in Documents/backbeat.h2song to 112 BPM and save it.

Checks, each of which must pass:

- `tempo`: `{"kind":"text_equals","file":"Documents/backbeat.h2song","pointer":"/root/children/[name=bpm]","value":"112"}`
- `song-name-kept`: `{"kind":"text_equals","file":"Documents/backbeat.h2song","pointer":"/root/children/[name=name]","value":"Backbeat Sketch"}`
- `groove-notes-kept`: `{"kind":"member_count","file":"Documents/backbeat.h2song","pointer":"/root/children/[name=patternList]/children/[name=pattern][>name=Verse Groove]/children/[name=noteList]/children","matching":"[name=note]","equals":8}`

REA kept the task because its checks fail on the seed (`tempo`) and all
pass on the captured end state.

To measure a solve rate, run the task k times (3 by default) with the agent and model to measure, and count the runs
whose summary line says `passed`; a run that says `failed` did not finish and is run again rather than counted:

    agent-env run <this folder> --task change-tempo --agent claude-code --model MODEL