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Condition

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

Section titled “How it works”

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

Automation Branch

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

Node.js
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',    },  ],});
PHP
$resend = Resend::client('re_xxxxxxxxx');$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'],  ],]);
Python
import resendresend.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)
Ruby
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)
Go
package mainimport "github.com/resend/resend-go/v4"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)}
Rust
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(())}
Java
import com.resend.*;import com.resend.core.exception.ResendException;import com.resend.services.automations.model.AutomationConnection;import com.resend.services.automations.model.AutomationStep;import com.resend.services.automations.model.ConditionOperator;import com.resend.services.automations.model.ConditionRule;import com.resend.services.automations.model.ConnectionType;import com.resend.services.automations.model.CreateAutomationOptions;import com.resend.services.automations.model.CreateAutomationResponseSuccess;public class Main {    public static void main(String[] args) throws ResendException {        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);    }}
.NET
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
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" }  ]}'
CLI
resend automations create --name "Plan-based Welcome" --file ./automation.json

Connection types

Section titled “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
JSON
{  "from": "check_plan",  "to": "send_pro_email",  "type": "condition_met"},{  "from": "check_plan",  "to": "send_free_email",  "type": "condition_not_met"}

Configuration

Section titled “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:

JSON
{
  "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:

JSON
{  "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      }    ]  }}
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