---
title: Broker
order: 5
description: "The per-user background process that holds this host's capacity: the machine budget every run claims slots from, and the shared services runs keep warm. A run starts it on demand; broker: off in magus.yaml runs without one."
tags: [glossary, execution-and-caching]
---

# Broker

The per-user background process that holds this host's capacity: the machine
budget every run claims slots from, and the shared services runs keep warm. A
run starts it on demand; `broker: off` in `magus.yaml` runs without one.

## Elsewhere

A message broker (RabbitMQ, Kafka) routes messages between producers and consumers. The magus
broker passes no messages: it holds this host's build budget and the services runs share.

## Example

```sh
magus broker status
```

## Used in

<!-- BEGIN GLOSSARY USAGE (generated by glossary-usage-generate from the knowledge graph; edit the generator, not this list) -->

In the docs:

- [Relationship to the broker and the daemon](../concepts/concurrency.md#relationship-to-the-broker-and-the-daemon)
- [Slots stop being derived from memory under the broker](../decisions/0012-memory-claims-follow-a-measured-curve.md#slots-stop-being-derived-from-memory-under-the-broker)
- [The broker holds one budget per machine](../guides/integrations/agents/orchestration.md#the-broker-holds-one-budget-per-machine)
- [Supervising the broker](../guides/integrations/server.md#supervising-the-broker)
- [Broker](../reference/api/status/v1alpha1/status.md#broker)
- [MGS3022: no broker answered](../reference/codes/sandbox/MGS3022.md#mgs3022-no-broker-answered)

<!-- END GLOSSARY USAGE -->

## See also

- [Daemon](daemon.md)
- [Slot](slot.md)
- [The broker and the daemon](../guides/integrations/server.md)