Condition - Resend

A branch step evaluates a condition against event or contact data and routes the Automation down one of two paths: condition met or condition not met. Common use cases:

Plan-based emails: Send different content to free vs. paid users.
Engagement splits: Take different actions based on user activity.
Personalization: Tailor follow-ups based on event payload values.

How it works

Using the dashboard
Using the API

Add a Condition step and configure the condition using the editor.

The condition step accepts a type and the corresponding rule fields.

import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.automations.create({
  name: 'Plan-based Welcome',
  steps: [
    {
      key: 'start',
      type: 'trigger',
      config: { eventName: 'user.created' },
    },
    {
      key: 'check_plan',
      type: 'condition',
      config: {
        type: 'rule',
        field: 'event.plan',
        operator: 'eq',
        value: 'pro',
      },
    },
    {
      key: 'send_pro_email',
      type: 'send_email',
      config: { template: { id: 'pro-welcome-template-id' } },
    },
    {
      key: 'send_free_email',
      type: 'send_email',
      config: { template: { id: 'free-welcome-template-id' } },
    },
  ],
  connections: [
    { from: 'start', to: 'check_plan', type: 'default' },
    { from: 'check_plan', to: 'send_pro_email', type: 'condition_met' },
    {
      from: 'check_plan',
      to: 'send_free_email',
      type: 'condition_not_met',
    },
  ],
});

$resend = Resend::client('re_xxxxxxxxx');

$resend->automations->create([
  'name' => 'Plan-based Welcome',
  'steps' => [
    [
      'key' => 'start',
      'type' => 'trigger',
      'config' => ['event_name' => 'user.created'],
    ],
    [
      'key' => 'check_plan',
      'type' => 'condition',
      'config' => [
        'type' => 'rule',
        'field' => 'event.plan',
        'operator' => 'eq',
        'value' => 'pro',
      ],
    ],
    [
      'key' => 'send_pro_email',
      'type' => 'send_email',
      'config' => ['template' => ['id' => 'pro-welcome-template-id']],
    ],
    [
      'key' => 'send_free_email',
      'type' => 'send_email',
      'config' => ['template' => ['id' => 'free-welcome-template-id']],
    ],
  ],
  'connections' => [
    ['from' => 'start', 'to' => 'check_plan', 'type' => 'default'],
    ['from' => 'check_plan', 'to' => 'send_pro_email', 'type' => 'condition_met'],
    ['from' => 'check_plan', 'to' => 'send_free_email', 'type' => 'condition_not_met'],
  ],
]);

import resend

resend.api_key = "re_xxxxxxxxx"

params: resend.Automations.CreateParams = {
  "name": "Plan-based Welcome",
  "steps": [
    {
      "key": "start",
      "type": "trigger",
      "config": {"event_name": "user.created"},
    },
    {
      "key": "check_plan",
      "type": "condition",
      "config": {
        "type": "rule",
        "field": "event.plan",
        "operator": "eq",
        "value": "pro",
      },
    },
    {
      "key": "send_pro_email",
      "type": "send_email",
      "config": {"template": {"id": "pro-welcome-template-id"}},
    },
    {
      "key": "send_free_email",
      "type": "send_email",
      "config": {"template": {"id": "free-welcome-template-id"}},
    },
  ],
  "connections": [
    {"from": "start", "to": "check_plan", "type": "default"},
    {"from": "check_plan", "to": "send_pro_email", "type": "condition_met"},
    {"from": "check_plan", "to": "send_free_email", "type": "condition_not_met"},
  ],
}

resend.Automations.create(params)

require "resend"

Resend.api_key = "re_xxxxxxxxx"

params = {
  name: "Plan-based Welcome",
  steps: [
    {
      key: "start",
      type: "trigger",
      config: { event_name: "user.created" },
    },
    {
      key: "check_plan",
      type: "condition",
      config: {
        type: "rule",
        field: "event.plan",
        operator: "eq",
        value: "pro",
      },
    },
    {
      key: "send_pro_email",
      type: "send_email",
      config: { template: { id: "pro-welcome-template-id" } },
    },
    {
      key: "send_free_email",
      type: "send_email",
      config: { template: { id: "free-welcome-template-id" } },
    },
  ],
  connections: [
    { from: "start", to: "check_plan", type: "default" },
    { from: "check_plan", to: "send_pro_email", type: "condition_met" },
    { from: "check_plan", to: "send_free_email", type: "condition_not_met" },
  ],
}

Resend::Automations.create(params)

package main

import "github.com/resend/resend-go/v3"

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

	params := &resend.CreateAutomationRequest{
		Name: "Plan-based Welcome",
		Steps: []resend.AutomationStep{
			{
				Key:  "start",
				Type: resend.AutomationStepTypeTrigger,
				Config: map[string]any{
					"event_name": "user.created",
				},
			},
			{
				Key:  "check_plan",
				Type: resend.AutomationStepTypeCondition,
				Config: map[string]any{
					"type":     "rule",
					"field":    "event.plan",
					"operator": "eq",
					"value":    "pro",
				},
			},
			{
				Key:  "send_pro_email",
				Type: resend.AutomationStepTypeSendEmail,
				Config: map[string]any{
					"template": map[string]any{"id": "pro-welcome-template-id"},
				},
			},
			{
				Key:  "send_free_email",
				Type: resend.AutomationStepTypeSendEmail,
				Config: map[string]any{
					"template": map[string]any{"id": "free-welcome-template-id"},
				},
			},
		},
		Connections: []resend.AutomationConnection{
			{From: "start", To: "check_plan", Type: resend.AutomationConnectionTypeDefault},
			{From: "check_plan", To: "send_pro_email", Type: resend.AutomationConnectionTypeConditionMet},
			{From: "check_plan", To: "send_free_email", Type: resend.AutomationConnectionTypeConditionNotMet},
		},
	}

	client.Automations.Create(params)
}

use resend_rs::{
  json,
  types::{
    AutomationStatus, AutomationTemplate, Connection, ConnectionType, CreateAutomationOptions,
    SendEmailStepConfig, Step, TriggerStepConfig,
  },
  Resend, Result,
};

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

  let opts = CreateAutomationOptions {
    name: "Plan-based Welcome".to_owned(),
    steps: vec![
      Step::Trigger {
        key: "start".to_owned(),
        config: TriggerStepConfig {
          event_name: "user.created".to_owned(),
        },
      },
      Step::Condition {
        key: "check_plan".to_owned(),
        config: json!({
          "type": "rule",
          "field": "event.plan",
          "operator": "eq",
          "value": "pro",
        }),
      },
      Step::SendEmail {
        key: "send_pro_email".to_owned(),
        config: SendEmailStepConfig::new(AutomationTemplate::new("pro-welcome-template-id")),
      },
      Step::SendEmail {
        key: "send_free_email".to_owned(),
        config: SendEmailStepConfig::new(AutomationTemplate::new("free-welcome-template-id")),
      },
    ],
    connections: vec![
      Connection::new("start", "check_plan").with_type(ConnectionType::Default),
      Connection::new("check_plan", "send_pro_email").with_type(ConnectionType::ConditionMet),
      Connection::new("check_plan", "send_free_email").with_type(ConnectionType::ConditionNotMet),
    ],
    status: AutomationStatus::Disabled,
  };
  let _automation = resend.automations.create(opts).await?;

  Ok(())
}

import com.resend.*;

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

        CreateAutomationOptions options = CreateAutomationOptions.builder()
                .name("Plan-based Welcome")
                .steps(
                    AutomationStep.trigger("start")
                        .eventName("user.created")
                        .build(),
                    AutomationStep.condition("check_plan")
                        .rule(ConditionRule.builder()
                                .field("event.plan")
                                .operator(ConditionOperator.EQ)
                                .value("pro")
                                .build())
                        .build(),
                    AutomationStep.sendEmail("send_pro_email")
                        .template("pro-welcome-template-id")
                        .build(),
                    AutomationStep.sendEmail("send_free_email")
                        .template("free-welcome-template-id")
                        .build()
                )
                .connections(
                    AutomationConnection.builder()
                        .from("start")
                        .to("check_plan")
                        .type(ConnectionType.DEFAULT)
                        .build(),
                    AutomationConnection.builder()
                        .from("check_plan")
                        .to("send_pro_email")
                        .type(ConnectionType.CONDITION_MET)
                        .build(),
                    AutomationConnection.builder()
                        .from("check_plan")
                        .to("send_free_email")
                        .type(ConnectionType.CONDITION_NOT_MET)
                        .build()
                )
                .build();

        CreateAutomationResponseSuccess data = resend.automations().create(options);
    }
}

using Resend;
using System.Text.Json;

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

var startConfig = JsonSerializer.SerializeToElement( new { event_name = "user.created" } );
var conditionConfig = JsonSerializer.SerializeToElement( new
{
    type = "rule",
    field = "event.plan",
    @operator = "eq",
    value = "pro",
} );
var proEmailConfig = JsonSerializer.SerializeToElement( new { template = new { id = "pro-welcome-template-id" } } );
var freeEmailConfig = JsonSerializer.SerializeToElement( new { template = new { id = "free-welcome-template-id" } } );

var resp = await resend.AutomationCreateAsync( new AutomationCreateData()
{
    Name = "Plan-based Welcome",
    Steps = new List<AutomationStepData>
    {
        new AutomationStepData { Ref = "start", Type = "trigger", Config = startConfig },
        new AutomationStepData { Ref = "check_plan", Type = "condition", Config = conditionConfig },
        new AutomationStepData { Ref = "send_pro_email", Type = "send_email", Config = proEmailConfig },
        new AutomationStepData { Ref = "send_free_email", Type = "send_email", Config = freeEmailConfig },
    },
    Connections = new List<AutomationEdge>
    {
        new AutomationEdge { From = "start", To = "check_plan", EdgeType = "default" },
        new AutomationEdge { From = "check_plan", To = "send_pro_email", EdgeType = "condition_met" },
        new AutomationEdge { From = "check_plan", To = "send_free_email", EdgeType = "condition_not_met" },
    },
} );

curl -X POST 'https://api.resend.com/automations' \
     -H 'Authorization: Bearer re_xxxxxxxxx' \
     -H 'Content-Type: application/json' \
     -d '{
  "name": "Plan-based Welcome",
  "steps": [{
    "key": "start",
    "type": "trigger",
    "config": { "event_name": "user.created" }
  }, {
    "key": "check_plan",
    "type": "condition",
    "config": {
      "type": "rule",
      "field": "event.plan",
      "operator": "eq",
      "value": "pro"
    }
  }, {
    "key": "send_pro_email",
    "type": "send_email",
    "config": { "template": { "id": "pro-welcome-template-id" } }
  }, {
    "key": "send_free_email",
    "type": "send_email",
    "config": { "template": { "id": "free-welcome-template-id" } }
  }],
  "connections": [
    { "from": "start", "to": "check_plan", "type": "default" },
    { "from": "check_plan", "to": "send_pro_email", "type": "condition_met" },
    { "from": "check_plan", "to": "send_free_email", "type": "condition_not_met" }
  ]
}'

resend automations create --name "Plan-based Welcome" --file ./automation.json

Connection types

A condition step always produces two outgoing connections.

Connection type	Description
`condition_met`	Taken when the condition evaluates to true
`condition_not_met`	Taken when the condition evaluates to false

{
  "from": "check_plan",
  "to": "send_pro_email",
  "type": "condition_met"
},
{
  "from": "check_plan",
  "to": "send_free_email",
  "type": "condition_not_met"
}

Configuration

config.type

string

required

The type of condition node. Possible values:

rule
and
or

For rule type:

config.field

string

required

The field to evaluate. Must use the event. or contact. namespace prefix (e.g., event.amount, contact.email).

config.operator

string

required

The comparison operator. Possible values:

eq: equals
neq: not equals
gt: greater than
gte: greater than or equal to
lt: less than
lte: less than or equal to
contains: contains a given value
starts_with: starts with a given value
ends_with: ends with a given value
exists: field exists
is_empty: field is empty

config.value

string | number | boolean | null

The value to compare against. Not required for exists and is_empty operators.

For and / or types:

config.rules

object[]

required

An array of nested condition config objects. Must contain at least one item.

Single rule example:

{
  "key": "check_plan",
  "type": "condition",
  "config": {
    "type": "rule",
    "field": "event.plan",
    "operator": "eq",
    "value": "pro"
  }
}

Use and or or to combine multiple rules into a single branch:

{
  "key": "check_plan_and_amount",
  "type": "condition",
  "config": {
    "type": "and",
    "rules": [
      {
        "type": "rule",
        "field": "event.plan",
        "operator": "eq",
        "value": "pro"
      },
      {
        "type": "rule",
        "field": "event.amount",
        "operator": "gte",
        "value": 100
      }
    ]
  }
}

​How it works

​Connection types

​Configuration

How it works

Connection types

Configuration