Addresses two issues identified by cubic on PR #3952.
1. Watchdog cancellation was too narrow — only `text`/`reasoning` parts
counted as progress, so a subagent that immediately ran tools
(Read/Bash/Edit) emitted `tool`/`tool_use`/`tool_result`/`tool-call`/
`step-start` parts that the watchdog ignored, risking a false fire
on actively-working subagents. Broaden to: any assistant part of any
known type counts as progress (the model has started responding,
whether or not visible text has arrived yet). `info.error` and
`info.finish` continue to cancel.
2. Test timing margins were tight (15ms pre-cancel against a 40ms
timer), risking CI flakiness on loaded runners. Bumped to a 100ms
threshold with a 40ms pre-cancel window and a 250ms post-fire wait,
giving a 60ms margin before the timer fires and ~2.5x the threshold
after — robust against scheduler delay.
Refactor for testability: extracted the OpenCode-event→watchdog-signal
translation out of `hook.ts` into an exported `observeEventForWatchdog`
helper on the watchdog module. This let me add direct unit tests for
every part-type case (text, reasoning, tool, tool_use, tool_result,
tool-call, step-start, file) plus the error/finish/empty-parts branches
without spinning up the full hook. Net diff: hook.ts shrinks, watchdog
module gains a small pure function with parametrised coverage.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
When a subagent is dispatched to a provider and the underlying SDK
enters a silent internal retry loop on a 429/quota error, no error
event is ever emitted back to OpenCode. The runtime-fallback hook —
which is fully reactive (listens to message.updated/session.error/
session.status) — has nothing to react to and never dispatches the
configured fallback. The subagent sits in `retry` status until the
parent's 30-minute poll timeout (DEFAULT_POLL_TIMEOUT_MS) gives up,
during which the parent's pending task tool call shows "waiting for
subagent" with no indication of failure.
This change adds a first-prompt watchdog that synthesises the missing
error-event trigger:
- Armed when a user message lands in a subagent session
(membership check via `subagentSessions`).
- Cancelled on the first sign of progress: any assistant message
with text/reasoning content, finish field, or an error field (any
of which is something the existing handlers will deal with).
- Cancelled on session terminal events (idle/stop/deleted/error).
- On fire (90s default): aborts the in-flight request and routes
into the existing dispatchFallbackRetry path — the same code that
runs when a session.error arrives. No new fallback mechanism.
Design choices:
- Dispatch fallback, do not abort the subagent outright. Network
loss looks identical to a stuck retry from the hook's vantage
point; with fallback-dispatch behaviour, network loss degrades
to today's baseline (both attempts fail, 30-min outer timeout
still ends things) rather than destructively aborting work.
- Scope strictly to subagents. Parent/user sessions can legitimately
take 90s+ to produce the first token; subagent dispatches in
practice produce first content much faster, so a 90s ceiling is
safe.
- Threshold is tunable via the third arg to createFirstPromptWatchdog;
DEFAULT_FIRST_PROMPT_WATCHDOG_MS = 90_000 in constants.ts.
Also adds a diagnostic log in session-status-handler when a
`session.status: retry` event arrives whose message does not match
RETRYABLE_ERROR_PATTERNS. This is the hook's other silent-return
spot for retry events; logging the raw retry message will let us
extend the patterns next time we hit a provider whose phrasing
we don't yet match.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>