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CODER-007 — (Stretch) Real-time status push instead of polling (Durable Object / relay) #83
Description
Type: Backend
Description
Replace status polling with server-pushed updates so Working/Idle/Error and build-state transitions appear instantly and cheaply, using the existing WebSocket relay infrastructure.
Acceptance Criteria
- The runner's existing status transitions are pushed to the console over the existing relay/WebSocket path (no new public inbound server).
- Frontend subscribes and updates the header badge (CODER-005) and Builds panel (CODER-004) from pushed events, falling back to polling if the socket drops.
- No regression to the relay-token security model (relay token only, never the account JWT).
Technical Notes
- Builds on the existing
RelayDO/ relay-token handshake (see platform docs). This is a meaningful architecture change — only justified once polling proves insufficient. - Would supersede CODER-006's polling optimization for status (build history still reads from GitHub / CODER-002).
Dependencies
CODER-006 (shape of the status event), CODER-005 (consumer UI).
Activity
serge-ivo commentedon Aug 1, 2026
Architectural clarification (CODER-007)
Elevated to PRIMARY real-time mechanism (no longer a stretch goal). Working/Idle/Error and build-state transitions push over the existing
RelayDOWebSocket; polling (CODER-006) becomes the fallback only — used when the socket is unavailable or drops.KV vs DO (repo-wide decision). The Durable Object (
RelayDO) is used only for the real-time relay — not for build history or status storage. Persistent build history stays in KV (CODER-002); durable app state stays in KV/D1. This keeps the DO hibernatable/near-zero-cost when idle.Auth. The WS handshake uses the short-lived, instance-scoped relay token (minted via
POST /v1/relay/:instanceId/tokenwith the account bearer) — never the 30-day account JWT on the socket, and no GitHub token crosses the wire./connectaccepts the relay token only, so a leaked relay URL can't become account/machine takeover.serge-ivo commentedon Aug 1, 2026
Decision recorded: CODER-007 elevated to PRIMARY — build first
Decision: Build WebSockets (CODER-007) as the primary mechanism; polling (CODER-006) is fallback-only.
RelayDO) is the primary mechanism for all status updates.RelayDO) handles relay only; KV handles build-history persistence.Suggested build order: CODER-001 → CODER-002 → CODER-007 → CODER-003 → CODER-004 → CODER-005, with CODER-006 as an optional fallback at the end.
serge-ivo commentedon Aug 2, 2026
Status: correctly blocked on its own dependencies — deferring (kept open)
Investigated the existing relay infra (
workers/api/src/relay-do.ts) before implementing.RelayDOtoday is a request/response relay: one"runner"WebSocket class, cloudPOST /command→ runner replies. There is no console-side subscriber socket and no producer of status events — the console learns status by polling/capture.Implementing CODER-007 as specified is genuinely premature right now, for three concrete reasons:
Dependencies: CODER-006, CODER-005). Shipping the broadcast layer now = unwired dead code, which this repo explicitly avoids (see the PR feat(agents): formal declarative agent-definition schema (#51) #62 "removed as unwired dead code; rebuild it with the route when wired end-to-end").@proagentstore/browser-runner, bundled in the CLI) to emit transitions over the socket — a CLI release — and the event shape is CODER-006, unbuilt./deploymentsendpoint (shipped in CODER-001/002) + the aggregate (CODER-003) — not the WS push. So 004 does not need 007; it needs 003.Decision: defer CODER-007 until its consumer (004/005) and event shape (006) exist, then it's a clean, fully-wired change (RelayDO subscriber class + broadcast + runner emit + frontend subscribe-with-poll-fallback). Proceeding down the buildable order instead: CODER-003 (#79) → CODER-004 (#80) → CODER-005 (#81). Leaving this open.
feat(cli): pags up attaches newly configured agents without a restart (…
perf(coder): the polls slow down when nothing is happening (#83)
serge-ivo commentedon Aug 6, 2026
Delivered as a cadence policy, not a transport — push channel declined (commit a50b5ce)
The blockers from the last comment are gone: CODER-001…006 all closed, so the consumers (Builds panel #80, header badge #81) and the aggregate (#79) exist. Re-verified the polling before designing, and the conclusion changed.
The valuable part of this ticket is its cadence policy, not its transport. The decision recorded above defines three tiers — Active (something running), Passive (visible, idle), Halted (hidden, idle). Those describe when an update is worth fetching, not how it arrives, so they apply to a poll exactly as well as to a push. Shipped on the poll they cost no console WebSocket client (there is none today — the console has never had one;
/v1/agents/:id/wsexists server-side and is unused), no new token type on the socket, and no CLI release to emit runner events.What the polls actually cost. Nothing is near a rate limit: the default bucket is 240/min (
lib/rate-limit.ts),/captureand takeover ride a separate 3000/min bucket, and a Coding tab with a session open spends ~36/min of the 240. So the case is cost and reach, not breakage./runtime/status— console header/runtime/status— Coding tab/captureacross sessions/captureopen terminal/timelineCo-pilot/deployments+/builds/runtime/statusis the standout and the reason the header dot was the first thing wired: each poll does two relay/commandround-trips to the user's laptop (health + capabilities) plus arelayConnectedprobe — about three Durable Object hits — 21×/min across the two call sites, to re-read a boolean that changes about twice a day. Nothing in the console except one poll checkeddocument.hidden, so a backgrounded tab kept doing that indefinitely. The Builds polls additionally spend the installation's GitHub Actions rate limit thatrunDeployWatchis already spending every minute.Why not the push channel. Three reasons, in order of weight:
RelayDOas it stands.RelayDOis keyed per (instance, node) and accepts exactly one WebSocket tag,"runner"; the bare-instanceIdDO never holds a socket because every modern runner connects with?node=<hostname>. A console subscriber does not know which node to attach to, so pushing connectivity needs a second hop (per-node DO → per-instance fan-out) plus a new subscriber tag, a new token type or a security review of putting the account JWT on a socket, and reconnect/backoff on the client. That is real architecture for ≤4s of latency on a boolean — and only in the Active tier, where the poll is already fast. In the Passive tier latency is irrelevant by definition: nothing is running and nobody is waiting.pags up, so [bug] Coding tab's offline state is unrecoverable — it hides the only control that could clear it #241 does not regress.Multi-machine correctness untouched. Zero server-side lines changed:
RelayDO, the relay-token handshake,getBoundRunnerConn→getLiveRunnerConnlive-socket routing, theconfig.runnerNodepin, and the 4409 same-node rejection are all as they were.A real bug fixed on the way. The tiering needs a correct "is the engine working" signal, and the existing one was wrong. The runner reports
idle | thinking | responding(browser-runner/src/coding/runtime.ts), but five call sites had each independently writtenstate === "thinking" || state === "working"—"working"is not a state the runner can emit, and"responding"(the engine streaming its answer) fell through as not busy. So a mid-answer session read "Idle" in the repo list, and — worse —watchForFinishand the coding Loop both treat not-busy as finished, so they could fire the completion summary or the next instruction into an engine that was still talking. Now one tested predicate (engine-busy.ts), one vocabulary,"working"kept as a legacy alias.Shipped:
packages/sdk/src/poll-cadence.ts(pureresolvePollTier/resolvePollMs/shouldRefreshOnResume) +useTieredPollinginsdk/hooks.ts;agents/coder/web/src/engine-busy.ts;buildState/isBuildInFlight/anyBuildInFlightmoved intobuilds-view.ts. 31 new unit tests.Follow-up, not done here (same primitive, outside this ticket's surface): the console still has ungated always-on polls elsewhere — Board 2.5s, Activity 4s, Tmux 4s (MCP tool calls), Terminals 5s, notifications 30s, Usage 30s, and takeover frames at 500ms. They are all
useTieredPollingone-liners now that it exists. Worth a separate issue.Recommend closing this as delivered-by-different-means. If a push channel is ever revisited, the honest trigger is a product need for sub-second cross-tab state (multiple people watching one agent), not the cost of these polls.
serge-ivo commentedon Aug 6, 2026
Closing as delivered by different means —
a50b5ce.The blocker noted earlier is genuinely gone (CODER-001…006 all closed, so #79/#80/#81 exist). But re-measuring the polling changed the conclusion about what to build, and the push channel was declined for three reasons:
RelayDOas built. It is keyed per (instance, node) with one"runner"tag, and the bare-instanceIdDO never holds a socket because runners connect with?node=. A console subscriber does not know the node, so this needs a second hop, a new tag, a new token type (or a security review of putting the account JWT on a socket) and client reconnect logic — real architecture for ≤4s of latency on a boolean.Shipped instead: this issue's own three-tier policy, applied to the poll. Active/Passive/Halted describe when an update is worth fetching, not how it arrives.
/runtime/statuswas the worst offender — each poll is two relay round-trips to the user's laptop plus arelayConnectedprobe (~3 DO hits), 21×/min, re-reading a boolean that changes twice a day, and it ran forever in backgrounded tabs. Now 4s busy · 20s idle · off when hidden, with an immediate catch-up fetch on any tier speed-up so the suppression is unobservable.Two guards: busy beats hidden (the Coder Loop and
watchForFinishadvance off these polls — halting a busy background tab would stall real work), and believing the runner is offline counts as busy, so #241 cannot regress.A real bug surfaced on the way, worth more than the perf work: the runner emits
idle | thinking | responding, but five call sites each wrotestate === "thinking" || state === "working"."working"is never emitted, and"responding"— the engine streaming its answer — fell through as NOT busy. SincewatchForFinishand the coding Loop both treat not-busy as finished, they could fire the completion summary or the next instruction into an engine that was still talking. Now one tested predicate (engine-busy.ts), with"working"kept as a legacy alias.Zero server-side lines changed:
RelayDO, the relay-token handshake, live-socket routing, theconfig.runnerNodepin and the 4409 same-node rejection are untouched. 31 new unit tests; suite 237 files / 3408 tests green.The honest trigger for revisiting a push channel is a product need for sub-second cross-tab state (several people watching one agent), not the cost of these polls.
perf(console): the rest of the console stops polling a tab nobody is …