Slack ACP block replies stop duplicate fallback delivery
Slack messages sent via ACP blocks will no longer trigger duplicate fallback text—OpenClaw now correctly recognizes block replies as visible output and stops re-sending the final fallback message.
Slack ACP block replies weren't being recognized as visible output, causing OpenClaw to re-send the final fallback text after Slack had already rendered the block reply. The result was duplicate messages reaching users—first the nicely formatted block content, then an unwanted text fallback.
A new visibility check now marks Slack block messages as delivered output when they contain actual text content. Empty blocks are correctly excluded from this logic. With this fix in place, OpenClaw understands that block replies satisfy the delivery contract and stops firing redundant fallback messages.
The change lives in the Slack channel extension and affects how ACP-delivered messages flow through the system. Users should see cleaner Slack interactions without unexpected follow-up messages.
View Original GitHub Description
Summary
- mark Slack ACP block text as visible delivered output
- prevent ACP fallback text from being re-sent after Slack already showed the block reply
- cover the Slack outbound visibility contract with a regression test
Testing
- pnpm test extensions/slack/src/channel.test.ts src/auto-reply/reply/dispatch-acp-delivery.test.ts