queue_add MCP tool

Sends a follow-up message to a running agent (empty slug = yourself). The message is queued and delivered when the agent is ready to process it — or, with delay_seconds/deliver_at, deferred: it parks in the agent’s durable workflow (surviving VM sleep, unlike an in-session timer) and delivers as a normal follow-up at the deadline, waking a sleeping VM. This is the reliable “resume me at T” primitive for autonomous agents; cancel an undelivered message with clear_queue using the returned follow-up ID. Returns an error if the agent is not running. Equivalent to murmur queue add in the CLI. Follow-ups are delivered according to the agent’s dequeue strategy — all (drain everything), one (one per turn), or five (up to five per turn).

Parameters

Name	Type	Required	Description
`slug`	string	no	Agent task slug. Empty means self (on VMs) — with `delay_seconds`, that schedules your own resumption. Use an absolute path like `/w/{workspace}/{owner_provider}/{account}/{slug}` (e.g. `/w/backend/github_oauth/alice/fix-auth`) to target an agent outside your own path.
`description`	string	yes	Follow-up message to send to the running agent.
`tasks`	string[]	no	Checklist items to add to the agent’s task list.
`agent`	string	no	Agent persona override (e.g. `programmer`, `architect`).
`model`	string	no	Model override for this and subsequent turns (e.g. `claude-opus-4-8`). Sticky, like `agent` — empty leaves the agent’s current model unchanged. An explicit model overrides the persona’s model, exactly as at `spawn`. Must stay on the agent’s backend (claude vs codex); a cross-backend model is rejected.
`preempt`	boolean	no	Interrupt the agent’s in-flight turn and discard pending queued follow-ups, then enqueue this one — atomically, so it becomes the only work the agent runs next. Mutually exclusive with deferral.
`delay_seconds`	integer	no	Defer delivery this many seconds from now (max 30 days). At most one of `delay_seconds` or `deliver_at`.
`deliver_at`	string	no	Defer delivery to this absolute RFC3339 time (e.g. `2026-07-22T18:30:00Z`). At most one of `delay_seconds` or `deliver_at`. Requires the agent to be on a build ≥182 — older agents are rejected with `FAILED_PRECONDITION` (upgrade with `murmur can`).
`workspace`	string	no	Workspace name. Overrides the session default. Required only when nothing else supplies one: off a VM, with no session default, and with a slug that is not a `/w/{workspace}/...` path.

Response

Returns a confirmation string carrying the message’s effective follow-up ID (client-supplied or server-minted): follow-up <id> sent to <slug>, or for a deferral follow-up <id> deferred to <time> for <slug> (cancel with clear_queue + this ID).

Examples

Schedule your own resumption (from an agent VM)

{
  "delay_seconds": 2400,
  "description": "Deferred: check whether PR #123's CI finished"
}

The message parks in your workflow — your VM can sleep in the meantime — and delivers as a normal follow-up in 40 minutes, waking the VM. A pending deferred message also holds a terminate-on-idle service agent alive until it delivers.

Send a follow-up message

{
  "slug": "fix-auth",
  "description": "Also fix the session expiry logic while you're in that file."
}

Response:

follow-up sent to fix-auth

Send a follow-up with new tasks

{
  "slug": "fix-auth",
  "description": "Here are additional items to handle.",
  "tasks": ["Add rate limiting to the login endpoint", "Update the API docs"]
}

Interrupt then redirect

Use interrupt to stop the current turn, then send new instructions:

{
  "slug": "fix-auth",
  "description": "Stop what you're doing. Focus on the login handler instead."
}

Errors

Code	Meaning	What to do
`NOT_FOUND`	No agent with that slug exists.	Check the slug. Use `ls` to see running agents.
`FAILED_PRECONDITION`	Agent is not running.	Use `spawn` with `resurrect: true` to resume a dead agent.
`UNAUTHENTICATED`	Identity token is missing or expired.	Check credentials.

murmur queue add — equivalent CLI command
interrupt — stop the current turn before sending a follow-up
clear_queue — discard queued and deferred follow-ups (all, or one by follow-up ID)
status — check agent state
spawn — create an agent

Getting Started

Core Concepts

Guides

queue_add MCP tool

Parameters

Response

Examples

Schedule your own resumption (from an agent VM)

Send a follow-up message

Send a follow-up with new tasks

Interrupt then redirect

Errors

​Parameters

​Response

​Examples

​Schedule your own resumption (from an agent VM)

​Send a follow-up message

​Send a follow-up with new tasks

​Interrupt then redirect

​Errors

​Related

Parameters

Response

Examples

Schedule your own resumption (from an agent VM)

Send a follow-up message

Send a follow-up with new tasks

Interrupt then redirect

Errors

Related