stack/docs/plans/2026-09-12_control-board-mvp.md

Control board MVP — plan

Tracking: Gitea issue #1503 (#1503)

Why

Jason is building blind. He has many agent sessions running across projects and no single place to see what they are doing or who is waiting on him. This plan replaces the registry line as the next thing to build. Registry increment 3 stays parked; it does not resume by inertia. Decision record: MOSAIC-STACK-D-001 (Jason, 2026-09-12).

What "done" looks like for the MVP

One web page lists my running agent sessions across projects, shows each one's current status, and flags which ones are waiting on me.

Acceptance:

• Jason opens one page and sees every live pi agent, grouped by project.
• Each agent shows a state in plain words (working, waiting, error, offline, idle, unknown).
• A "waiting on you" section sits at the top of the page.
• The page refreshes itself. Jason does not have to reload it by hand.
• Every state on the page comes from a status file written by the scanner, not from a guess made in the page itself.

Three steps

Step 1 (today): plan, ticket, scanner

• Write this plan and open the Gitea ticket.
• Build the status scanner script with tests. Running it writes one status file per agent under <dataRoot>/board/.
• This step does not touch any page or launcher. It only produces files.

Step 2: the web page

• Build a page that reads the status files the scanner writes and shows them grouped by project, with the waiting-on-you section on top.
• The page refreshes itself on a short timer. The small local server behind it may re-run the scanner on each refresh so the files stay fresh. No separate daemon is needed for this step.

Step 3: daily use and fixes

• Jason uses the page every day for real work.
• He says what is wrong or missing.
• Fix that one thing, then repeat. No new scope beyond what he actually hits.

Step 3 log

2026-09-12 — liveness follows the tmux pane, not just the session. Jason found agents marked "waiting" that were actually dead: their tmux session still existed but no longer ran pi (it had exited to a shell or something else). The scanner now checks which program each tmux pane is running (tmux list-panes -s -t '=<session>' -F '#{pane_current_command}') and only counts an agent alive if a pane is running pi. A tmux session with no pi pane is now "offline" instead of "waiting".

2026-09-12 — a "Seen" mark for rows that don't need a reply. Jason noticed most "waiting" rows were completion reports, not real asks, and they kept cluttering "Waiting on you". The page now has a "Seen" button on waiting/error rows; clicking it stores the row's lastActivity in <dataRoot>/board/seen.json (via POST /api/seen) and drops the row out of "Waiting on you" while keeping its state visible. The mark clears itself the moment the agent writes anything new, and "Unsee" puts a row back by hand. seen.json is only ever written by that click, never by a scan.

How the scanner decides state

The scanner reads the newest pi session log for each agent, plus whether the agent's tmux session is still alive. It does not guess; it only reports what the log and tmux say.

State	Plain-words meaning
working	The agent is in the middle of a turn: thinking or running a tool.
waiting	The agent finished its turn. It is your move now.
error	The agent's last turn ended in an error, was aborted, or was cut off. Go look at it.
offline	There is no live tmux session for this agent right now.
idle	The agent is live but has not had a conversation yet.
unknown	The scanner could not ask tmux (missing or not answering). It does not assume the agent is alive.

Two kinds of agents are scanned today:

• Repo agents: session logs live under .pi/state/<agent>/sessions in a project checkout, on the default tmux socket.
• Fleet agents: session logs live under ~/.mosaic/fleet/agents/<agent>/.pi/agent/sessions, on the tmux socket named mosaic-fleet.

Where files go

• One file per agent: <dataRoot>/board/sessions/<project>/<agent>.json
• One summary file for the whole board: <dataRoot>/board/index.json
• dataRoot comes from ~/.config/mosaic-dev/config.json. If that config is missing or broken, the scanner refuses to run. It does not guess a fallback location.

Board files are derived. They can be deleted and rebuilt at any time by running the scanner again. They are NOT run records and they are not evidence under the repository's write-once rules.

Commands

Scan once and print the table:

node packages/control-board/src/cli.mjs scan --print

Start the page (step 2), then open http://127.0.0.1:7331/ in a browser:

node packages/control-board/src/cli.mjs serve

Tests:

node --test packages/control-board/tests/

Boundaries

• No changes to any launcher script.
• No new files at the repository root.
• No secrets read, stored, or printed.
• No daemon yet. In step 1 the scanner is run by hand. In step 2 the page may trigger it on refresh; nothing runs it on a schedule.
• No changes to packages/mosaic.
• This plan does not authorize push or merge beyond whatever the existing refactor-branch plan already allows.

2026-09-12 — a place to find what you marked Seen. After using the button, Jason noted the board had no way to show seen rows again. The page now has a collapsed "Seen (N)" section between "Waiting on you" and "By project" that lists every marked row with an Unsee button. It stays open or closed across refreshes.

2026-09-12 — "Hide seen" per project. Jason suggested a checkbox like "Hide offline" so seen rows stop cluttering the fleet table now that the Seen section exists. Each project header has both boxes, on by default, and the note under the table reads "N offline hidden · N seen hidden".

2026-09-12 — Header count "N of N". Jason pointed out that "fleet (38)" sat above a table showing 13 rows. The header now reads "fleet (13 of 38)" while a checkbox hides something and falls back to "fleet (38)" when nothing is hidden. The note under the table stays: the header says how many, the note says why. One static test.