Also still having this issue. @steipete @francisbrero

Version: 2026.2.19-2
Slack mode: Socket Mode

Config:
channels.slack.streaming=false
model streaming disabled
messages.inbound.byChannel.slack=750

Evidence that OpenClaw logs only one delivery but Slack shows two messages:

Two Slack permalinks:
https://openclaw-rgz7919.slack.com/archives/C0AEZKDUV1U/p1771643408280799
https://openclaw-rgz7919.slack.com/archives/C0AEZKDUV1U/p1771643408357489

Note: those two Slack messages are ~77ms apart

Log lines showing only one send:
lane enqueue … 2026-02-21T03:10:05.897Z
delivered reply … 2026-02-21T03:10:08.360Z (only once)

Hypothesis: Slack SDK @slack/web-api internal retries can cause double chat.postMessage when the original request succeeds but the response is lost/slow.

Request: Add a config knob, e.g. channels.slack.webClient.retryConfig (or similar), so users can set retries: 0 to fully eliminate duplicates.

Originally posted by @agentandyai in #1481