Description

Block streaming replies can arrive out of order in Telegram (and likely other providers). The first paragraph of a response may appear after subsequent paragraphs.

Steps to Reproduce

1. Enable block streaming (default is on)
2. Send a message that triggers a multi-paragraph response
3. Observe that paragraphs may arrive in wrong order

Example

Agent generates:

Clawdbot. It's a tool built into the gateway.

Linux has similar concepts (background jobs with `&`, `nohup`, `screen`, `tmux`) but the `process` tool is Clawdbot's own abstraction that:

1. Wraps bash commands in managed sessions
2. Tracks them by sessionId
...

Telegram receives:

1. "Linux has similar concepts..." (paragraph 2+)
2. "Clawdbot. It's a tool built into the gateway." (paragraph 1)

The first paragraph arrived last.

Root Cause Analysis

In src/auto-reply/reply/agent-runner.ts around line 309, each block reply is wrapped in an async task:

const task = (async () => {
  if (!isHeartbeat) {
    await typing.startTypingOnText(cleaned);  // Variable delay based on text length
  }
  await opts.onBlockReply?.(blockPayload);
})()

These tasks are added to pendingBlockTasks with void (fire-and-forget), meaning they run in parallel:

pendingBlockTasks.add(task);
void task.finally(() => pendingBlockTasks.delete(task));

If Task 1 (first paragraph) has a longer typing delay than Task 2 (second paragraph), Task 2 may call sendBlockReply first, adding itself to the dispatcher chain before Task 1.

While the dispatcher uses a promise chain for serialization, the order tasks enter the chain depends on when they finish their typing delay — not when they were created.

Proposed Fix

Serialize block reply tasks instead of running in parallel:

// Instead of parallel fire-and-forget:
pendingBlockTasks.add(task);
void task.finally(...);

// Use sequential chaining:
blockReplyChain = blockReplyChain.then(() => task);

Or remove the typing delay from the critical path for block replies.

Environment

• Clawdbot version: latest main
• Provider: Telegram (likely affects all providers with block streaming)
• Block streaming: enabled (default)

Workaround

Disable block streaming in config:

{
  "agent": {
    "blockStreamingDefault": "off"
  }
}