EventBridge

Overview

CloudMock emulates Amazon EventBridge, supporting event bus management, rule creation with event patterns, target association with fan-out to SQS, and custom event publishing.

Supported Operations

Operation	Status	Notes
CreateEventBus	Supported	Creates a custom event bus
DeleteEventBus	Supported	Deletes a custom event bus
DescribeEventBus	Supported	Returns event bus details
ListEventBuses	Supported	Returns all event buses including the default
PutRule	Supported	Creates or updates a rule on an event bus
DeleteRule	Supported	Deletes a rule
DescribeRule	Supported	Returns rule details
ListRules	Supported	Returns rules on an event bus
PutTargets	Supported	Associates targets (SQS, Lambda, etc.) with a rule
RemoveTargets	Supported	Removes targets from a rule
ListTargetsByRule	Supported	Returns all targets for a rule
PutEvents	Supported	Publishes custom events to event buses
EnableRule	Supported	Enables a disabled rule
DisableRule	Supported	Disables a rule without deleting it
TagResource	Supported	Adds tags to a rule or event bus
UntagResource	Supported	Removes tags
ListTagsForResource	Supported	Returns tags for a resource

Quick Start

curl

# Create an event bus
curl -X POST http://localhost:4566 \
  -H "X-Amz-Target: AWSEvents.CreateEventBus" \
  -H "Content-Type: application/x-amz-json-1.1" \
  -d '{"Name": "my-app-bus"}'

# Put events
curl -X POST http://localhost:4566 \
  -H "X-Amz-Target: AWSEvents.PutEvents" \
  -H "Content-Type: application/x-amz-json-1.1" \
  -d '{"Entries": [{"EventBusName": "my-app-bus", "Source": "com.myapp.orders", "DetailType": "OrderCreated", "Detail": "{\"orderId\": \"o-123\"}"}]}'

Node.js

import { EventBridgeClient, CreateEventBusCommand, PutRuleCommand, PutEventsCommand } from '@aws-sdk/client-eventbridge';

const eb = new EventBridgeClient({
  endpoint: 'http://localhost:4566',
  region: 'us-east-1',
  credentials: { accessKeyId: 'test', secretAccessKey: 'test' },
});

await eb.send(new CreateEventBusCommand({ Name: 'app-bus' }));
await eb.send(new PutRuleCommand({
  Name: 'OrderCreated', EventBusName: 'app-bus',
  EventPattern: JSON.stringify({ source: ['com.myapp.orders'] }),
  State: 'ENABLED',
}));
await eb.send(new PutEventsCommand({
  Entries: [{
    EventBusName: 'app-bus', Source: 'com.myapp.orders',
    DetailType: 'OrderCreated', Detail: JSON.stringify({ orderId: 'o-123' }),
  }],
}));

Python

import boto3, json

events = boto3.client('events', endpoint_url='http://localhost:4566',
                      aws_access_key_id='test', aws_secret_access_key='test',
                      region_name='us-east-1')

events.create_event_bus(Name='app-bus')
events.put_rule(
    Name='UserSignedUp', EventBusName='app-bus',
    EventPattern=json.dumps({'source': ['com.myapp.auth']}),
    State='ENABLED',
)
events.put_events(Entries=[{
    'EventBusName': 'app-bus', 'Source': 'com.myapp.auth',
    'DetailType': 'UserSignedUp',
    'Detail': json.dumps({'userId': 'u-456'}),
}])

Configuration

cloudmock.yml

services:
  eventbridge:
    enabled: true

No additional service-specific configuration is required.

Known Differences from AWS

• PutEvents stores events in memory and fans out to SQS targets within CloudMock.
• Scheduled rules (cron/rate expressions) are stored but do not trigger on a schedule.
• Lambda, SNS, and other target types are stored but delivery is not implemented beyond SQS.
• The default event bus (default) is always available.
• Schema discovery and event replay are not implemented.

Error Codes

Code	HTTP Status	Description
ResourceNotFoundException	400	The specified event bus or rule does not exist
ResourceAlreadyExistsException	400	An event bus with this name already exists
InvalidEventPatternException	400	The event pattern is not valid JSON
ConcurrentModificationException	400	The rule was modified by another request