opencode/big-pickle: intermittent socket disconnects cause silent drop (no UI error) + repeated Aborted in logs (v1.18.18, Linux/WSL2)

Summary

While using the built-in opencode provider with model big-pickle (Zen free), the connection can drop mid-stream with:

AI_APICallError: Cannot connect to API: The socket connection was closed unexpectedly ...

When this happens, the user reports that the UI effectively “loses the connection” without clearly surfacing the error (silent drop / no visible error state).

This appears to be the same class of problem as:

• #32366 (UI stuck on thinking after stream error)
• #38644 (silent failure after provider 500s)

…but this report is specifically the socket-closed failure mode on providerID=opencode modelID=big-pickle.

Environment

• OpenCode: 1.18.18 (from ~/.local/share/opencode/log/opencode.log)
• OS: Linux (Ubuntu 24.04) / WSL2 environment
• Provider/model: providerID=opencode modelID=big-pickle
• Agents impacted: plan, build, compaction (all small=false)

Evidence (last 5 minutes)

Log aggregation from ~/.local/share/opencode/log/opencode.log for the last 5 minutes (UTC):

• stream_error_big_p_k_socket_closed: 2
• aborted: 6
• failed_fetch_models.dev: 1

Verbatim lines (UTC):

timestamp=2026-08-16T23:51:13.948Z level=ERROR run=042c53b4 message="stream error" providerID=opencode modelID=big-pickle session.id=ses_ff3194081ffebphxmz8WESfcYH small=false agent=build mode=primary error.error="AI_APICallError: Cannot connect to API: The socket connection was closed unexpectedly. For more information, pass `verbose: true` in the second argument to fetch() (cause: Error: The socket connection was closed unexpectedly. For more information, pass `verbose: true` in the second argument to fetch())"

timestamp=2026-08-16T23:53:54.387Z level=ERROR run=042c53b4 message="stream error" providerID=opencode modelID=big-pickle session.id=ses_ff3194081ffebphxmz8WESfcYH small=false agent=compaction mode=primary error.error="AI_APICallError: Cannot connect to API: The socket connection was closed unexpectedly. For more information, pass `verbose: true` in the second argument to fetch() (cause: Error: The socket connection was closed unexpectedly. For more information, pass `verbose: true` in the second argument to fetch())"

# After the above, multiple Aborted entries follow (examples):
# timestamp=2026-08-16T23:53:26.380Z level=ERROR ... error=Aborted
# timestamp=2026-08-16T23:54:32.494Z level=ERROR ... error=Aborted

Session creation line confirms version/model:

timestamp=2026-08-16T23:27:24.030Z level=INFO run=042c53b4 message=created id=ses_ff3194081ffebphxmz8WESfcYH ... version=1.18.18 ... agent=plan model.id=big-pickle model.providerID=opencode

Additional observation

In the same hour, the models catalog fetch briefly failed:

timestamp=2026-08-16T23:25:20.625Z level=ERROR run=84bab50d message="Failed to fetch models.dev" cause="... Transport error (GET https://models.opencode.ai/api.json) ..."

But immediately after, manual curl -I https://models.opencode.ai/api.json succeeded with HTTP/2 200 (so this may be transient connectivity/DNS, but it’s correlated in time).

Expected

1. Stream transport errors (socket closed, 5xx, etc.) are always surfaced to the user.
2. The UI must never remain in an ambiguous “thinking”/silent state.
3. Provide clear recovery actions (Retry/Cancel) and a deterministic terminal state.

Actual

• opencode/big-pickle intermittently throws socket-closed stream errors.
• User-visible behavior: connection appears lost with no clear error surfaced on screen.

Related historical evidence

• In #38644 (open), there is quantitative evidence of hundreds of Internal server error events for providerID=opencode modelID=big-pickle across multiple days (see comment by aentrepreneur).

Ask

Can we:

1. Ensure all stream error paths transition the UI/session state to an explicit error (never silent).
2. Make retry/backoff behavior and timeouts consistent for small=false primary agents.
3. Consider logging a clear “giving up after N retries” and surfacing it to the UI.