---
title: Amazon EventBridge
---
# Amazon EventBridge

Events can be sent to Amazon EventBridge using the `eventBridge` sink type.

Like all Sinks, EventBridge sinks can be created in the Stream Portal...

![eventbridge-create](/img/stream/eventbridge-create.png)

... or [in the API](https://api.svix.com/docs#tag/Sink/operation/v1.streaming.sink.create).

```shell
curl -X 'POST' 'https://api.svix.com/api/v1/stream/strm_30XKA2tCdjHue2qLkTgc0/sink' \
  -H 'Authorization: Bearer AUTH_TOKEN' \
  -H 'Content-Type: application/json' \
  -d '{
  "type": "eventBridge",
  "config": {
    "eventBusName": "my-event-bus",
    "detailType": "application/json",
    "region": "us-east-1",
    "accessKeyId": "AKIA3LIKMTLDNWBX2PPD",
    "secretAccessKey": "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"
  },
  "uid": "unique-identifier",
  "status": "enabled",
  "batchSize": 1000,
  "maxWaitSecs": 300,
  "eventTypes": [],
  "metadata": {}
}'
```

Every event in the batch is sent to EventBridge as a separate entry.

- `eventBusName` — the name or ARN of the event bus that receives the events.
- `detailType` — a free-form string (max 128 characters) used as the `detail-type` of each event. Defaults to `application/json`.
- `region`, `accessKeyId`, `secretAccessKey` — the AWS region and credentials used to authenticate.

Each event is published with its `source` set to `svix-webhooks-<stream_id>`, its `detail-type` set to the configured `detailType`, and its `detail` set to the message produced by the transformation. You can match on the `source` and `detail-type` when writing EventBridge rules.

# Transformations

By default, all `eventBridge` Sinks come bundled with the following transformation code.

```JavaScript
/**
 * @param input - The input object
 * @param input.events - The array of events in the batch. The number of events in the batch is capped by the Sink's batch size.
 * @param input.events[].payload - The message payload (string or JSON)
 * @param input.events[].eventType - The message event type (string)
 *
 * @returns Object containing the request body
 * @returns returns.payloads - The array of messages (strings) to send to the Sink. Each payload is a distinct message sent to the Sink.
 */
function handler(input) {

  const payloads = input.events.map((event) => JSON.stringify(event))

  return {
    payloads
  }
}
```

`input.events` matches the events sent in [`create_events`](https://api.svix.com/docs#tag/Event/operation/v1.streaming.events.create).

Each entry in the returned `payloads` array becomes the `detail` of a separate EventBridge event. By default, each event is serialized to a JSON string containing its `payload` and `eventType`.

For example, if the following events are written to the stream:

```shell
curl -X 'POST' \
  'https://api.svix.com/api/v1/stream/{stream_id}/events' \
  -H 'Authorization: Bearer AUTH_TOKEN' \
  -H 'Accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
        "events": [
            {
                "eventType": "user.created",
                "payload": "{\"email\": \"joe@enterprise.io\"}"
            },
            {
                "eventType": "user.login",
                "payload": "{\"id\": 12, \"timestamp\": \"2025-07-21T14:23:17.861Z\"}"
            }
        ]
    }'
```

The default transformation code would send two events to your event bus, with the following `detail` bodies.

{/* SCREENSHOT: the resulting events received from the EventBridge bus */}

```json
{"payload":{"email":"joe@enterprise.io"},"eventType":"user.created"}
```

```json
{"payload":{"id":12,"timestamp":"2025-07-21T14:23:17.861Z"},"eventType":"user.login"}
```

To control the `detail` of each event, return your own array of strings in `payloads`. Each string becomes the `detail` of one EventBridge event.

EventBridge accepts at most 10 entries per request, so larger batches are automatically split across multiple `PutEvents` calls.