fix(remote): keepalive WS Ping so the /acp tunnel doesn't idle-flap - #54
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Cloudflare's tunnel idle-closes a WebSocket with no traffic (~100s) and tokio-tungstenite never pings on its own, so an idle /acp connection was flapping ~every 2 min: 8 reconnects in 45 min with 0 prompts, each a fresh session/new channel (diagnosed from the oab-prod-orca logs). Harmless while idle, but once chatting a >~100s quiet stretch would idle-close mid-turn and — until session/resume lands — reconnect into a new channel, losing agent context. Add a 45s tokio interval branch to run_once's select! loop that sends a WS Ping directly on the write half (the send() helper only frames JSON Text). 45s is well inside the ~100s idle window; the ping counts as traffic and keeps the tunnel open. The read arm already ignores inbound Ping/Pong, so this composes with the existing loop without touching the inbound path. Skip missed-tick behaviour avoids a burst of pings after any busy stretch. Diagnosed with Jellyfish (ECS log analysis). session/resume (so a real drop also preserves context) is a separate Part B item. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Emit an `app-log` info line on every keepalive tick so the operator can see in the Activity tab that the tunnel is being kept warm between prompts (not just infer it from the absence of reconnects). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Problem
Jellyfish's read of the
oab-prod-orcalogs: the/acpconnection flaps ~every 2 min — 8 reconnects in 45 min, 0 prompts, each ~100–125 s long, and each reconnect opens a freshsession/newchannel (notsession/resume).Root cause: Cloudflare's tunnel idle-closes a WebSocket with no traffic (~100 s), and tokio-tungstenite never pings on its own. openab doesn't idle-evict; Studio doesn't self-disconnect → the close comes from the CF edge idle-timing an idle WS.
Impact: harmless while idle (reconnect, no data lost), but once chatting a >~100 s quiet stretch idle-closes mid-turn and — until
session/resumelands — reconnects into a new channel, losing agent context.Fix
Add a 45 s
tokio::time::intervalbranch torun_once'sselect!loop that sends a WS Ping directly on the write half (thesend()helper only frames JSON Text). 45 s is well inside the ~100 s idle window; the ping is traffic and keeps the tunnel open between prompts.Ping/Pong/Frame(=> continue), so this composes with the loop without touching the inbound path.MissedTickBehavior::Skipavoids a burst of pings after any busy stretch.Scope
Keepalive only (止血).
session/resume— so even a genuine drop preserves agent memory — is a separate Part B item, not in this PR.Verification
Local Rust build OOMs this workspace (per project constraint); relies on CI (
build-test+bundle-macos). Change is transport-level and self-contained.Diagnosed with Jellyfish (ECS log analysis); implemented by Orca.