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Version: 2026.1

Interactive Input

Two mechanisms let the agent pause mid-turn and get human input instead of guessing: ask_user for clarifying questions, and pauseAfter as a backstop that stops runaway agents and asks the user whether to continue.

ask_user — mid-turn questions​

ask_user is a Copilot SDK tool the agent can call to ask a question with optional choice buttons. The agent's execution pauses until the user responds or the wait times out.

How it feels to the user​

A question widget appears inline in chat — the question text plus buttons for each choice, optionally a freeform text box. The user clicks or types and the agent continues. After answering, the widget switches to a read-only "Answered: value" state.

How to enable it​

ask_user is not enabled by default. Opt in per agent:

includeSdkTools:
  - ask_user

Timeout​

If the user doesn't respond within AGENT_SERVER_ASK_USER_TIMEOUT_MS (default 5 minutes), the bridge auto-resolves with "No response from user (timed out)" and the agent continues with that as the answer. Adjust the env var if your agents ask questions that reasonably take longer to think about.

pauseAfter — "should I continue?" checkpoints​

Without a stop signal, an LLM can spiral on a long task — dozens of tool calls, minutes of processing. pauseAfter is an agent-level policy that automatically pauses execution and asks the user "Continue or stop?" when a threshold is hit.

Two thresholds, whichever trips first:

ThresholdMeaning
pauseAfter.toolCallsMax tool calls before pausing.
pauseAfter.timeoutMinutesMax active processing time. Excludes time spent waiting for ask_user responses.

Default (when not configured): 50 tool calls, 5 minutes.

What happens when a threshold trips​

  1. The SDK turn is aborted cleanly.
  2. A pause prompt is emitted via the ask_user channel: Continue or Stop.
  3. If the user chooses Continue → tool counters reset, a continuation prompt is sent, the agent resumes in a new SDK turn with history preserved.
  4. If the user chooses Stop (or the pause prompt times out) → the task ends gracefully, partial results are persisted.

Configuration​

pauseAfter:
  toolCalls: 100
  timeoutMinutes: 10

For long-running batch agents (bulk imports, mass tagging), raise both values. For interactive assistants, the defaults are usually right.

Edge cases worth knowing​

  • SSE reconnect — the ask_user widget is replayed from the TaskRunner buffer. If the user clicks after the request already resolved or timed out, the 404 is handled silently.
  • Cancel while waiting — POST /chat/:sessionId/cancel cancels the pending ask_user request and aborts the SDK turn cleanly.
  • Agent switch while waiting — pending requests are cancelled for the old agent before the switch completes.
  • Inactivity timeout — if no SDK events arrive for AGENT_SERVER_INACTIVITY_TIMEOUT_MS (default 5 minutes) and no ask_user is pending, the task ends with a "no activity" message. This is a separate fallback from pauseAfter.