[FEATURE]: inject queued messages into the next LLM call instead of interrupting the current task

[shdomi8599]

Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

Problem

Queued messages currently interrupt the running task. This causes several related issues:

• Messages lost after session interrupt ([FEATURE]: Graceful handling of queued messages after session interrupt #5333)
• Queued messages break todolist execution (Queued message interrupts todolist execution #5135)
• Users want delayed/non-interrupting queue ([FEATURE]: Delayed queue feature #5408)

The root cause: when a session is busy, SessionPrompt.assertNotBusy() throws BusyError. Queued messages either interrupt the task or wait until the session is fully idle. There's no mechanism to inject them as mid-task guidance.

Proposed solution

Drain queued messages at the start of each loop() iteration in prompt.ts and inject them as context before the next LLM.stream() call:

Current flow:
  loop() → LLM.stream() → streaming → tool execution
  → user queues message → ❌ BusyError or task interrupts

Proposed flow:
  loop() → [★ drain queue here] → LLM.stream() → streaming → tool execution
  → user queues message → next iteration picks it up → ✅ agent adjusts

Injection point — packages/opencode/src/session/prompt.ts, inside the loop() function's while(true), before LLM.stream() is called via SessionProcessor:

while (true) {
  // ... existing message history loading ...

  // ★ Inject queued messages here
  if (queue.hasMessages()) {
    const queued = queue.drainAll()
    const injection = `\n[USER_MID_TASK_MESSAGE]\n${queued.map(m => m.text).join("\n")}\n[/USER_MID_TASK_MESSAGE]`
    // append as user message content before LLM call
  }

  // ... existing SessionProcessor.create() + process() ...
}

This approach:

• Zero overhead when no messages are queued
• Doesn't interrupt the running task
• Preserves existing Esc interrupt behavior
• Addresses [FEATURE]: Graceful handling of queued messages after session interrupt #5333, Queued message interrupts todolist execution #5135, [FEATURE]: Delayed queue feature #5408

Prior art

I've implemented this same pattern in Roo Code PR #11813 — 25 lines in their equivalent Task.ts, all tests passing. I can open a PR if there's interest.

Additional context

• Related issues: [FEATURE]: Graceful handling of queued messages after session interrupt #5333, Queued message interrupts todolist execution #5135, [FEATURE]: Delayed queue feature #5408
• Key files reviewed: prompt.ts (loop), processor.ts (stream), session/index.ts (BusyError)

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Feature: Mid-stream context injection at natural breaks (like Claude Code) #5122: Very similar request for mid-stream/mid-task context injection at natural breakpoints rather than interrupting the current task

The core idea in both issues is to inject queued user messages into the agent loop at a safe point (after a tool call / at the start of the next loop iteration) rather than interrupting or waiting for full completion. The proposed implementation differs in specifics, but the underlying feature request is essentially the same.

If you believe your issue covers something meaningfully different, please clarify in a comment so the maintainers can assess.

[shdomi8599]

Thanks for flagging! #5122 describes the same goal. My issue adds concrete implementation details — the exact injection point in prompt.ts, a code sketch, and a working reference implementation in Roo Code PR.

Happy to contribute this as a PR linked to either issue.