openclaw - 💡(How to fix) Fix Slack: streaming preview completely silent when toolProgress: false — verbose mode broken since v2026.4.21 [4 comments, 3 participants]

Bug: Slack verbose mode produces no in-flight preview with streaming.preview.toolProgress: false (v2026.4.26)

Relates to: #71320 (partial fix), #69611 (introduced regression)

Environment

• OpenClaw 2026.4.26
• Channel: Slack socket mode
• Verbose level: on and full
• Config: channels.slack.accounts.<id>.streaming: { preview: { toolProgress: false } }

Steps to reproduce

1. Configure Slack account with streaming: { preview: { toolProgress: false } } (workaround recommended in #71320)
2. Set /verbose full in a Slack DM session
3. Send any message that triggers multiple tool calls (file reads, bash, third-party API calls)

Expected Streaming draft preview should show partial reply text in the Slack message while tool calls execute — matching v2026.4.15 behavior.

Actual Nothing appears during tool execution. The final message only appears after all tool calls complete. Behavior is identical to streaming: "off" — zero in-flight feedback.

Root cause hypothesis

Looking at pipeline.runtime-C4g9nxhG.js in v2026.4.26:

const previewToolProgressEnabled = Boolean(draftStream) && resolveChannelStreamingPreviewToolProgress(account.config);
// ...
const pushPreviewToolProgress = (line) => {
  if (!draftStream || !previewToolProgressEnabled || previewToolProgressSuppressed) return;
  // ...
};
const updateDraftFromPartial = (text) => {
  const trimmed = text?.trimEnd();
  if (!trimmed) return;
  previewToolProgressSuppressed = true; // <-- sets this to true
  // ...
  draftStream?.update(trimmed);
};

When toolProgress: false, previewToolProgressEnabled = false. The onToolStart / onItemEvent callbacks call pushPreviewToolProgress() which returns early — correct. But then updateDraftFromPartial() sets previewToolProgressSuppressed = true expecting to suppress tool-progress lines that already appeared — but since none appeared, the net effect is just that draftStream never gets a meaningful update during the tool phase.

More critically: with suppressDefaultToolProgressMessages: previewToolProgressEnabled ? true : void 0, when previewToolProgressEnabled = false this becomes undefined, which may change upstream behavior around when onPartialReply fires.

Before v2026.4.21, the draft preview was driven purely by text streaming, independently of toolProgress. The coupling introduced in #69611 broke this separation.

Suggested fix previewToolProgressEnabled should gate only the tool-progress bullet lines (pushPreviewToolProgress). The updateDraftFromPartial / text streaming path should fire regardless. Specifically:

• suppressDefaultToolProgressMessages should not depend on previewToolProgressEnabled
• previewToolProgressSuppressed logic should not interfere with the base text-streaming path when toolProgress: false

Workaround None. Both streaming: "off" and streaming: { preview: { toolProgress: false } } produce identical silent behavior.