## Body Parameters

- `event` (string, required) — The name of the event to trigger. Must match the event name configured in an automation trigger step.

Either `contact_id` or `email` must be provided, but not both.

The contact ID (UUID) to associate with this event. Exactly one of
`contact_id` or `email` must be provided.

- `email` (string) — The email address to associate with this event. Exactly one of `contact_id` or `email` must be provided. If no contact with this email exists in your Audience, one will be created automatically when the automation runs.

- `payload` (object) — An optional object containing custom data to pass to the automation. This data can be used in template variables and conditions. If the event has a schema defined, the payload values will be validated and coerced to match the schema types.

:::code-group
```ts Node.js
import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.events.send({
  event: 'user.created',
  contactId: '7f2e4a3b-dfbc-4e9a-8b2c-5f3a1d6e7c8b',
  // or: email: 'steve.wozniak@gmail.com',
  payload: {
    plan: 'pro',
  },
});
```

```php PHP
$resend = Resend::client('re_xxxxxxxxx');

// Trigger with a contact ID
$resend->events->send([
  'event' => 'user.created',
  'contact_id' => '7f2e4a3b-dfbc-4e9a-8b2c-5f3a1d6e7c8b',
  'payload' => ['plan' => 'pro'],
]);

// Trigger with an email address
$resend->events->send([
  'event' => 'user.created',
  'email' => 'steve.wozniak@gmail.com',
  'payload' => ['plan' => 'pro'],
]);
```

```python Python
import resend

resend.api_key = "re_xxxxxxxxx"

# Trigger with a contact ID
params: resend.Events.SendParams = {
  "event": "user.created",
  "contact_id": "7f2e4a3b-dfbc-4e9a-8b2c-5f3a1d6e7c8b",
  "payload": {
    "plan": "pro",
  },
}

resend.Events.send(params)

# Trigger with an email address
params: resend.Events.SendParams = {
  "event": "user.created",
  "email": "steve.wozniak@gmail.com",
  "payload": {
    "plan": "pro",
  },
}

resend.Events.send(params)
```

```ruby Ruby
require "resend"

Resend.api_key = "re_xxxxxxxxx"

# Trigger with a contact ID
params = {
  event: "user.created",
  contact_id: "7f2e4a3b-dfbc-4e9a-8b2c-5f3a1d6e7c8b",
  payload: {
    plan: "pro",
  },
}

Resend::Events.send(params)

# Trigger with an email address
params = {
  event: "user.created",
  email: "steve.wozniak@gmail.com",
  payload: {
    plan: "pro",
  },
}

Resend::Events.send(params)
```

```go Go
package main

import "github.com/resend/resend-go/v4"

func main() {
	client := resend.NewClient("re_xxxxxxxxx")

	// Trigger with a contact ID
	params := &resend.SendEventRequest{
		Event:     "user.created",
		ContactId: "7f2e4a3b-dfbc-4e9a-8b2c-5f3a1d6e7c8b",
		Payload: map[string]any{
			"plan": "pro",
		},
	}

	client.Events.Send(params)

	// Trigger with an email address
	params = &resend.SendEventRequest{
		Event: "user.created",
		Email: "steve.wozniak@gmail.com",
		Payload: map[string]any{
			"plan": "pro",
		},
	}

	client.Events.Send(params)
}
```

```rust Rust
use resend_rs::{
  json,
  types::{ContactIdOrEmail, SendEventOptions},
  Resend, Result,
};

#[tokio::main]
async fn main() -> Result<()> {
  let resend = Resend::new("re_xxxxxxxxx");

  let opts = SendEventOptions {
    event: "user.created".to_owned(),
    contact_id_or_email: ContactIdOrEmail::ContactId(
      "7f2e4a3b-dfbc-4e9a-8b2c-5f3a1d6e7c8b".to_owned(),
    ),
    // or: ContactIdOrEmail::Email("steve.wozniak@gmail.com".to_owned())
    payload: json!({
      "plan": "pro"
    }),
  };

  let _event = resend.events.send(opts).await?;

  Ok(())
}
```

```java Java
import com.resend.Resend;
import com.resend.core.exception.ResendException;
import com.resend.services.events.model.SendEventOptions;
import com.resend.services.events.model.SendEventResponseSuccess;

public class Main {
    public static void main(String[] args) throws ResendException {
        Resend resend = new Resend("re_xxxxxxxxx");

        SendEventOptions params = SendEventOptions.builder()
                .event("user.created")
                .contactId("7f2e4a3b-dfbc-4e9a-8b2c-5f3a1d6e7c8b") // or: .email("steve.wozniak@gmail.com")
                .addPayload("plan", "pro")
                .build();

        SendEventResponseSuccess data = resend.events().send(params);
    }
}
```

```csharp .NET
using Resend;
using System.Text.Json;

IResend resend = ResendClient.Create( "re_xxxxxxxxx" );

var payload = JsonSerializer.SerializeToElement( new { plan = "pro" } );

// Trigger with a contact ID
var resp = await resend.EventSendAsync( new EventSendData()
{
    Event = "user.created",
    ContactId = new Guid( "7f2e4a3b-dfbc-4e9a-8b2c-5f3a1d6e7c8b" ),
    Payload = payload,
} );
Console.WriteLine( "Event={0}", resp.Content.Event );

// Trigger with an email address
await resend.EventSendAsync( new EventSendData()
{
    Event = "user.created",
    Email = "steve.wozniak@gmail.com",
    Payload = payload,
} );
```

```bash cURL
# Trigger with a contact ID
curl -X POST 'https://api.resend.com/events/send' \
     -H 'Authorization: Bearer re_xxxxxxxxx' \
     -H 'Content-Type: application/json' \
     -d '{
  "event": "user.created",
  "contact_id": "7f2e4a3b-dfbc-4e9a-8b2c-5f3a1d6e7c8b",
  "payload": {
    "plan": "pro"
  }
}'

# Trigger with an email address
curl -X POST 'https://api.resend.com/events/send' \
     -H 'Authorization: Bearer re_xxxxxxxxx' \
     -H 'Content-Type: application/json' \
     -d '{
  "event": "user.created",
  "email": "steve.wozniak@gmail.com",
  "payload": {
    "plan": "pro"
  }
}'
```

```bash CLI
# Trigger with a contact ID
resend events send \
  --event user.created \
  --contact-id 7f2e4a3b-dfbc-4e9a-8b2c-5f3a1d6e7c8b \
  --payload '{"plan":"pro"}'

# Trigger with an email address
resend events send \
  --event user.created \
  --email steve.wozniak@gmail.com \
  --payload '{"plan":"pro"}'
```
:::

:::callout{intent="note"}
Successful requests return **202 Accepted** with the JSON body below.
:::

:::code-group
```json Response
{
  "object": "event",
  "event": "user.created"
}
```
:::

## Related pages

- [Account Management](./account-management-index.md)
- [API Keys](./api-keys-2-index.md)
- [API Keys](./api-keys-index.md)
- [API Reference](./api-reference-index.md)
- [AudiencesDEPRECATED](./audiencesdeprecated-index.md)
- [Authorized Apps](./authorized-apps-index.md)
- [Automations](./automations-index.md)
- [Broadcasts](./broadcasts-index.md)
- [Build with AI](./build-with-ai-index.md)
- [Changelog](../changelog.md)

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