Events

Event bus for agent-to-agent communication. Publish custom events that other agents subscribe to and react to.

Property	Value
Server ID	long-tail-events
Category	Communication
AI required	No
Credential providers	None
Tools	4

Compile hints

publish_event: topic follows app.{namespace}.{entity}.{action} convention. The app. prefix is auto-added if omitted. Events are delivered to all matching subscribers.

Tools

publish_event

Publish a custom event to the event bus. Other agents and workflows can subscribe to these events and react.

Read-safe: No · Gate: builder

Parameter	Type	Required	Description
topic	string	Yes	Event topic using dot-delimited segments (for example app.acme.orders.created). The “app.” prefix is auto-added if omitted.
data	object	No	Event payload: any structured data relevant to the event.
source	string	No	Source identifier (agent name, workflow type, or free-form label).

list_subscriptions

List all active agent event subscriptions, optionally filtered by topic pattern.

Read-safe: Yes · Gate: caller

Parameter	Type	Required	Description
topic	string	No	Optional topic pattern to filter subscriptions.

list_topics

Browse the topic catalog to discover available event topics, their descriptions, payload schemas, and subscriber counts.

Read-safe: Yes · Gate: caller

At /mcp this tool is listed as events_list_topics, because the admin server registers list_topics first.

Parameter	Type	Required	Description
category	string	No	Filter by category (task, workflow, escalation, activity, knowledge, agent, app, milestone).
search	string	No	Search topics by name or description.
limit	number	No	Max results (default 50).

register_topic

Declare a topic in the catalog with its description and payload schema. Use this to pre-register topics before first publish so other agents can discover them.

Read-safe: No · Gate: builder

Parameter	Type	Required	Description
topic	string	Yes	Topic name (e.g., app.vendor.orders.created).
description	string	No	Human-readable description of the event.
category	string	No	Category (defaults to first segment or “app”).
payload_schema	object	No	JSON Schema describing the event.data shape.
tags	string[]	No	Tags for filtering.