The first draft assumed the renderer calls a fixed /v1/email REST URL and
that an Electron-main sidecar manager would host it. Code review found the
UI surfaces email through the chat agent loop + SSE cards (the frontend has
no email REST client), and the agent already runs in-process in the Python
backend reading ~/.gaia/connectors/grants.json.

Reframe: the seam is the chat agent's email-tool layer and the host is the
Python UI backend (no Node backend needed). Both modes proxy over the same
HTTP path to a sidecar on :8131 — frozen binary for users, uvicorn --reload
from source for devs — keeping process isolation identical across modes and
preserving the existing SSE card pipeline.

Fold in the two product requirements and resolve every open item from the
architecture review:

- Dogfooding: user mode runs the exact Hub-published frozen binary (pinned via
  binaries.lock.json), so the Agent UI validates the shipped product. This is the
  rationale the sidecar earns over an editable in-process install.
- Lightweight UI: the sidecar is lazy-fetched on first email use, one platform
  binary only; core ships no email deps.
- Resolve open questions: use a proxy AGENT reusing agent_type=email machinery;
  remove the redundant in-process /v1/email mount (#1768) so the UI has one backend.
- Review fixes: own the dev-mode enabler (module-level app = build_app()), reuse the
  npm fetch SHA/lock integrity check instead of porting it to Python, ephemeral
  per-instance port (no fixed-8131 multi-instance clash), single-writer grant model
  (OAuth stays on backend; sidecar reads only), exact current-contract table.
- Sequence behind the in-flight REST build-out (pre-scan + #1779/#1780/#1781) and
  flag the #1767 in-process decision must be superseded with @itomek sign-off.

…tion)

itomek closed #1767/#1785 because mixing an npm package requiring Node.js into the
Python-backed Agent UI is too dirty. Remove that entirely: the Python backend fetches
the binary itself (verified SHA-256 download, no npx), spawns it, and proxies over
HTTP. No Node runtime, no npm package in the UI's path. The npm package remains the
external Node-integrator channel only.

)

The unanswered email you already sent is the inbox's biggest silent
failure mode — until now the agent had no way to surface it. A new
read-only check_followups tool scans the Sent folder of every connected
mailbox and flags threads whose latest message is still the user's own
outbound mail past a configurable window (default 3 days,
EmailAgentConfig.followup_window_days), returning message id, recipient,
subject, and age — most overdue first. Detection only: it never drafts
or sends a nudge; sends stay confirmation-gated (#1264) and autonomous
follow-ups remain #555's scope.

The Outlook backend gains a SENT branch in list_messages (Graph
sentitems folder) — an unknown label previously fell through to the
inbox folder, which would have made a Sent-folder scan silently read
the wrong mail — and the detector accepts both epoch-millis and
ISO-8601 internalDate values so Gmail and Outlook threads age
identically.