@radzor/event-bus

In-process typed publish/subscribe event bus. Decouples components without external infrastructure. Supports wildcard patterns, async handlers, error isolation, and event history replay.

Automationv0.1.0typescriptUniversalevent-buspubsubeventsasyncdecouplingobservermessagingby Radzor

Install

View source on GitHub →

$npx radzor@latest add event-bus

⚠ Constraints: In-process only — events do not cross process or service boundaries. For distributed systems, use a message queue (@radzor/queue-worker or @radzor/background-job). Handler errors are isolated — one failing handler does not prevent others from running.

Inputs

Name	Type	Default	Description
maxListeners	number	100	Maximum listeners per event before emitting a warning.
historySize	number	0	Number of past events to retain for late subscribers (0 = no history).
asyncHandlers	boolean	true	Await async handlers sequentially. Set to false for fire-and-forget.

maxListenersnumber

Maximum listeners per event before emitting a warning.

default: 100

historySizenumber

Number of past events to retain for late subscribers (0 = no history).

default: 0

asyncHandlers

{ "llm": { "constraints": "In-process only — events do not cross process or service boundaries. For distributed systems, use a message queue (@radzor/queue-worker or @radzor/background-job). Handler errors are isolated — one failing handler does not prevent others from running.", "usageExamples": "llm/examples.md", "integrationPrompt": "llm/integration.md" }, "name": "@radzor/event-bus", "tags": [ "event-bus", "pubsub", "events", "async", "decoupling", "observer", "messaging" ], "events": [ { "name": "onPublish", "payload": { "event": "string", "handlersInvoked": "number" }, "description": "Fired after an event is published and all handlers complete." }, { "name": "onHandlerError", "payload": { "error": "string", "event": "string" }, "description": "Fired when a handler throws. Other handlers continue to run." } ], "inputs": [ { "name": "maxListeners", "type": "number", "default": 100, "required": false, "description": "Maximum listeners per event before emitting a warning." }, { "name": "historySize", "type": "number", "default": 0, "required": false, "description": "Number of past events to retain for late subscribers (0 = no history)." }, { "name": "asyncHandlers", "type": "boolean", "default": true, "required": false, "description": "Await async handlers sequentially. Set to false for fire-and-forget." } ], "radzor": "1.0.0", "actions": [ { "name": "subscribe", "params": [ { "name": "event", "type": "string", "description": "Event name or glob pattern (e.g. 'user.*')." }, { "name": "handler", "type": "(payload: unknown) => void | Promise<void>", "description": "Handler function invoked on publish." } ], "returns": "() => void", "description": "Subscribe to an event. Returns an unsubscribe function." }, { "name": "once", "params": [ { "name": "event", "type": "string", "description": "Event name to listen for once." }, { "name": "handler", "type": "(payload: unknown) => void | Promise<void>", "description": "Handler function." } ], "returns": "() => void", "description": "Subscribe to an event for a single invocation, then auto-unsubscribe." }, { "name": "publish", "params": [ { "name": "event", "type": "string", "description": "Event name to publish." }, { "name": "payload", "type": "unknown", "required": false, "description": "Event payload passed to all handlers." } ], "returns": "Promise<{ handlersInvoked: number }>", "description": "Publish an event and invoke all matching handlers." }, { "name": "unsubscribeAll", "params": [ { "name": "event", "type": "string", "required": false, "description": "Event name to clear all handlers for." } ], "returns": "void", "description": "Remove all handlers for an event, or all handlers globally if no event given." } ], "outputs": [ { "name": "publishResult", "type": "{ event: string; handlersInvoked: number }", "description": "Publish result with the event name and number of handlers invoked." } ], "runtime": "universal", "version": "0.1.0", "category": "automation", "languages": [ "typescript" ], "description": "In-process typed publish/subscribe event bus. Decouples components without external infrastructure. Supports wildcard patterns, async handlers, error isolation, and event history replay.", "dependencies": { "packages": {} }, "composability": { "connectsTo": [ { "output": "publishResult", "description": "Fan-out internal events to notification channels.", "compatibleWith": [ "@radzor/slack-bot.action.sendMessage.text", "@radzor/email-send.action.send.message", "@radzor/push-notification.action.sendToDevice.notification", "@radzor/sms-send.action.send.body", "@radzor/discord-bot.action.sendMessage.content", "@radzor/telegram-bot.action.sendMessage.text" ] }, { "output": "publishResult", "description": "Queue events for async processing.", "compatibleWith": [ "@radzor/background-job.action.enqueue.payload" ] } ] } }

@radzor/event-bus

Install

Inputs

Outputs

Actions

Events

Composability

radzor.manifest.json

Version History