[FEATURE]: Live session status panel in sidebar + background session completion notifications

[ptandler]

Problem

OpenCode supports running multiple sessions simultaneously, but there is no way to
monitor them at a glance. The only option is the /sessions command (ctrl+x l),
which opens a modal list — it does not show live status and requires leaving the
current session to check.

When a background session finishes or errors, there is no notification. The user
only finds out by manually switching to that session.

Proposed Solution

1. Persistent session status panel in the TUI sidebar

Show a compact, always-visible list of sessions in the sidebar — filtered to those
that are currently relevant:

• Active sessions (busy or retry status per the existing SessionStatus model)
• Recently finished sessions (transitioned from busy/retry back to idle
  within the current TUI session)

Sessions that were never active in this TUI session should not clutter the panel.

For each entry, show:

• Session name / title
• Current status: busy / retry (with attempt count) / finished
• Model and agent in use, if space permits
• Last activity timestamp

Unvisited finished sessions must be visually highlighted — e.g. a distinct
color, badge, or marker — until the user switches to that session at least once.
This is the primary signal that work is ready for review. The highlight clears
as soon as the session is opened.

The panel should update live via the existing session.status SSE bus events —
no polling needed, the infrastructure is already there.

2. Completion / error notifications

When a background session transitions to idle (finished) or enters a retry
state (error with backoff), show an in-TUI notification — e.g. a toast or status
bar flash — so the user gets an immediate signal without having to watch the
sidebar.

The existing /tui/show-toast API already supports this; it would just need to
be wired to session.status events for non-foreground sessions.

Optional: a config flag to enable/disable notifications globally or per-session.

Why This Matters

Power users running parallel sessions (e.g. one session per feature, or a
background research session + a foreground build session) currently have no
visibility into what other sessions are doing. The most critical gap is not
knowing when a background session has finished — and whether it succeeded or
hit an error — without manually switching to it.

The server-side data (GET /session/status, session.status SSE events) already
exists. This is primarily a TUI rendering feature request.

Related

• Stale background subagents persist in UI after session restart/compaction #27373 — Stale background subagents persist in UI after session restart
• [Bug]: Renderer crashes with TypeError: Failed to fetch in fetchMessages when background subagent completes #27292 — Renderer crashes when background subagent completes
• Title: Desktop sidebar hides sessions where session.version = 'local' #27539 — Desktop sidebar hides sessions where session.version = 'local'
• GET /session/status API — already returns { [sessionID]: { type: "idle" | "busy" | "retry" } }
• session.status SSE bus event — already fired on every status transition

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• [FEATURE]: Agent Activity Panel -- sidebar view for monitoring running background agents #27995: Requests an "Agent Activity Panel" in the sidebar for monitoring background agents with live status — very similar concept to the session status panel proposed here.

If these are addressing the same need, consider consolidating or referencing each other.

[kommander]

We are working on better session navigation and overview already, should land shortly.

[ptandler]

#27995 is really related: it's about the agents, while this is about sessions

[ptandler]

We are working on better session navigation and overview already, should land shortly.

that's great to hear! One thing that is really important to me that I get clear notifications when a background session has stopped to get user input

[nexxeln]

im working on this. what are some things you'd like to see apart from notifications? would love to hear from other people as well

[ptandler]

im working on this. what are some things you'd like to see apart from notifications? would love to hear from other people as well

great!! 🫶

The most important part for me is that the session panel in the sidebar shows the recently active sessions and their status (working, finished, waiting for answers, ...), so I can monitor what's going on in the background.

[TheLoroXD]

I opened a couple of smaller draft PRs that should help support this kind of live session/status UI without bundling a large UI change up front:

• feat(opencode): add session status endpoint #29540 adds GET /session/:sessionID/status, so clients can query one session status directly.
• fix(opencode): emit SSE event ids #29541 emits standard SSE id: fields for /event and /global/event, which is a prerequisite for reliable reconnect/backfill.
• fix(opencode): keep SSE streams alive after serialization errors #29542 keeps SSE streams alive if an unserializable event payload would otherwise break the stream.

For the sidebar/status-panel UI itself, I am leaving that design here rather than opening a competing UI PR, since the contribution guide asks product/UI features to go through design review first and maintainers noted work is already in progress.