Run QA with Mo

Mo runs browser QA in a hosted sandbox. Its files and processes are remote.

Work while Mo runs

Keep the tested revision stable through the initial QA pass and its reproductions. Do not change anything the target serves or hot-reloads, restart the app, deploy to its URL, or mutate shared test data while Mo uses it. Other work, such as code review, is fine. For isolated bug fixes during a longer run, follow Repair loop.

Findings arrive through qa status "$session_id" --full. A kind: "bug" entry has been independently reproduced. A kind: "flag" entry is a static, single-frame mistake such as a typo, recorded without reproduction. Test-case verdicts are verified, issues_found, or blocked. When you report a finding to the user, include its name, evidence, status, and web_url.

If Mo is blocked, answer from the brief, repository, or authorized environment data when you can. Otherwise ask the user for the missing access, permission, or decision, then send the answer to root Mo. Root Mo relays context to its internal sub-agents. Never invent or reveal a secret.

Prepare the brief

Run qa version. If Mo is missing or outdated, read Installation. Read Authentication after an authentication error.

Use the target from the request. For a local or private target, read Tunneling.

The brief is Mo's specification. Include:

1. The exact target URL, including the affected path and query.
2. Expected behavior and pass criteria.
3. The login method, test account label, and allowed test data.
4. Prohibited actions and data that Mo must not change.
5. The product areas and user flows in scope, plus explicit exclusions.
6. Any non-default browser setup. Read Browser settings when needed.

Fill gaps from the request and repository. Ask only when missing scope, access, or permission would change the run.

Set scope and detail

The brief sets scope. --granularity sets detail within that scope:

• low for an early smoke pass: main happy paths and important failure states.
• medium when changed flows work: every meaningful interaction and important failure state.
• high for release-ready coverage: every in-scope path, alternate, failure state, and operable control.

Pass the setting explicitly because the default is high. For a happy-path-only smoke test, tell Mo to skip failure states. Mo has no session-wide time or test count option. For a hard time or spend cap, narrow the brief, monitor wall time or qa cost <session-id>, run qa stop <session-id> --subagents at the cap, and report unfinished coverage.

Start the session

Pass the brief as one argument:

brief=$(cat <<'EOF'
Target: https://preview.example.com/checkout?variant=express
Goal: Keep the selected shipping method after returning from payment.
Sign in: Use the staging QA buyer account.
Test data: Create test carts and orders only.
Do not: Submit payment, send email, delete data, or change the shared catalog.
Coverage: Smoke the express-checkout happy path and standard checkout. Skip other flows and failure states.
Pass criteria:
- The shipping method stays selected.
- The total does not change.
- Standard checkout still works.
EOF
)
session_json=$(qa start --granularity low "$brief")
session_id=$(jq -r .sessionId <<<"$session_json")
web_url=$(jq -r .webUrl <<<"$session_json")
created_at=$(jq -r '.createdAt // empty' <<<"$session_json")

Starting returns before Mo finishes. Preserve these values: every later command needs session_id, the user can watch or join through web_url, and created_at records when the session began. createdAt can be absent when the server runs an earlier API version.

A Momentic environment groups a BASE_URL with reusable non-secret variables under a name such as staging. --environment NAME selects one created under Environments in the Momentic dashboard, not one from the shell or momentic.config.yaml. Mo copies its variables into the session at start.

Use repeatable --env-file or --env-var NAME options for local values and secrets; they override matching environment variables. --env-var forwards a variable that is already present in the qa start process environment; it does not accept NAME=value. Never put the secret value in the command or brief. Use --tunnel for private access. Set --max-concurrency only when the target or test account limits parallel users. It is fixed at session start. If the target overloads, run qa stop --subagents and start a new session with a lower value.

Follow the session

Run this watcher in the background. It prints one line per new finding or state change and exits when Mo needs input or the session ends:

seen=""
while :; do
  snapshot=$(qa status "$session_id" --full) ||
    { echo "status request failed"; sleep 30; continue; }
  events=$(jq -r '"displayState \(.displayState // .state)",
    (.findings.bugs[] | "\(.kind) \(.name)"),
    (.findings.verdicts[] | "verdict \(.status) \(.testCaseName // "-")")' \
    <<<"$snapshot" | sort)
  comm -13 <(printf '%s\n' "$seen") <(printf '%s\n' "$events")
  seen=$events
  case $(jq -r '.displayState // .state' <<<"$snapshot") in
    needs_you | ready | sleeping | cancelled | failed_start) break ;;
  esac
  sleep 30
done

Run the watcher in one of two ways:

• Background command. Run it yourself with a host tool that notifies you on each output line, such as Claude Code's Monitor, and re-arm it when it expires. Without one, start it as a background session and check its output between other tasks.
• Runner sub-agent. Give a sub-agent the session_id, the watcher, and this skill. It messages you on each event and keeps watching. Use this only when a running sub-agent can message you, such as Codex with multi_agent_v2 enabled (send_message to /root, then wait_agent in the parent). Claude Code and default Codex sub-agents report only when they finish.

In Codex without a runner sub-agent, keep the watcher in the foreground of a long-running exec_command, retain its returned session ID, and drain it with write_stdin. Do not append &, detach it, or finish the turn while it runs. Shell variables do not persist across separate commands, so interpolate the literal Mo session ID or start the watcher in the same shell that set it.

Either way, you answer blockers and send Mo the user's decisions.

status.displayState describes the whole session for display and polling. status.state is its legacy alias:

status.sessionState is the lifecycle state shared by read, status, and report: starting, working, waitingOnUser, waitingOnAgents, idle, or stopped. createdAt is the session creation time, and lastActivityAt is the last persisted update. latestTurn contains the most recent persisted assistant timing metadata: startedAt, completedAt, and durationMs. A partial timing uses null. Servers running an earlier API can omit these new fields.

Use this bounded read for Mo's questions and replies, not findings:

qa read "$session_id" --from start --timeout 45s --json

It omits messages Mo sends during a running turn until that turn ends. --from latest also misses a turn that finishes before the read begins. In a read response, prefer sessionState; use its legacy alias state when the server omits it. timedOut: true means Mo is still working.

With --json, read writes one JSON response to stdout and no progress text. Without --json, a read that waits longer than two seconds prints liveness to stderr. Returned messages stay on stdout, while timeout or stopped status text stays on stderr.

qa wait "$session_id" --json returns when root Mo's turn finishes, stops, or needs input. Exit code 2 means Mo needs input; 4 means it was stopped. Internal sub-agents can still be running, so confirm status.displayState is ready or sleeping before treating the session as done.

Never send a message to ask for progress. Use status, read, or wait. Send only to answer a blocker or deliberately steer or recheck work. Prefer to send while Mo is idle or waiting:

qa send --session-id "$session_id" --wait 45s "Use the staging account."

Sending while active stops root Mo's current turn and in-flight tool call. Do that only when the new direction should take priority. Without --wait, confirm the reply with read.

Finish or repair

Before presenting final results, read Reports. Confirm that the brief still describes the product's expected behavior.

If the user asked for fixes, read Repair loop. Otherwise, do not change app code.

Choose how to stop:

• qa stop <session-id> interrupts root Mo only. Sub-agents keep testing, filing findings, and billing. Root Mo stays stopped until your next qa send. Use it to redirect Mo without losing in-flight tests.
• qa stop <session-id> --subagents also stops every running sub-agent. Use it to end spending. qa send can still resume the session.
• qa archive <session-id> cancels all work, hides the session, and rejects further qa send. Unarchive is web-only.

qa upload returns a sandbox path. Send that path to Mo because local paths do not exist in its sandbox. Create the destination directory before qa download when --output names a directory. Run qa <command> --help for syntax.