Courier Java SDK

The Courier Java SDK gives typed access to the from Java 8+. It uses builder-pattern request construction, OkHttp for transport, and returns strongly typed response objects. Available on GitHub and Maven Central.

Installation

implementation("com.courier:courier-java:LATEST_VERSION")

<dependency>
  <groupId>com.courier</groupId>
  <artifactId>courier-java</artifactId>
  <version>LATEST_VERSION</version>
</dependency>

Replace LATEST_VERSION with the current version from Maven Central. Requires Java 8+.

Quick start

import com.courier.client.CourierClient;
import com.courier.client.okhttp.CourierOkHttpClient;
import com.courier.core.JsonValue;
import com.courier.models.UserRecipient;
import com.courier.models.send.SendMessageParams;

CourierClient client = CourierOkHttpClient.fromEnv();

SendMessageParams params = SendMessageParams.builder()
    .message(SendMessageParams.Message.builder()
        .to(UserRecipient.builder().userId("your_user_id").build())
        .template("your_template_id")
        .data(SendMessageParams.Message.Data.builder()
            .putAdditionalProperty("foo", JsonValue.from("bar"))
            .build())
        .build())
    .build();

var response = client.send().message(params);
System.out.println(response.requestId());

CourierOkHttpClient.fromEnv() reads COURIER_API_KEY from your environment, or the courier.apiKey system property. The builder also takes it: .apiKey("YOUR_COURIER_API_KEY").

Authentication

Get your API key from in the Courier dashboard. Set it as an environment variable:

export COURIER_API_KEY="YOUR_COURIER_API_KEY"

Or pass it via the builder:

CourierClient client = CourierOkHttpClient.builder()
    .apiKey("YOUR_COURIER_API_KEY")
    .build();

Setter	System property	Environment variable	Default
`apiKey`	`courier.apiKey`	`COURIER_API_KEY`	—
`baseUrl`	`courier.baseUrl`	`COURIER_BASE_URL`	`https://api.courier.com`

Sending notifications

Design your notification in , then reference it by ID:

var params = SendMessageParams.builder()
    .message(SendMessageParams.Message.builder()
        .to(UserRecipient.builder().userId("user_123").build())
        .template("nt_01kx4h2jdafq8bk9aftxak4b40")
        .data(SendMessageParams.Message.Data.builder()
            .putAdditionalProperty("order_id", JsonValue.from("10042"))
            .build())
        .build())
    .build();

var response = client.send().message(params);

Available resources

The SDK covers the full Courier API. Every method returns strongly typed response objects.

Resource	Namespace	Description
Send	`client.send()`	Send messages to one or more recipients
Messages	`client.messages()`	Retrieve status, history, and content of sent messages
Profiles	`client.profiles()`	Create, update, and retrieve user profiles
Users	`client.users()`	Manage preferences, tenants, and push tokens per user
Auth	`client.auth()`	Issue JWT tokens for client-side SDK authentication
Lists	`client.lists()`	Manage subscription lists and their subscribers
Audiences	`client.audiences()`	Define and query audience segments
Tenants	`client.tenants()`	Manage tenants for multi-tenant setups
Journeys	`client.journeys()`	Invoke and cancel runs. Create, list, publish, and archive
Brands	`client.brands()`	Manage brand settings (logos, colors, templates)
Notifications	`client.notifications()`	List and inspect notification templates
Translations	`client.translations()`	Workspace `.po` strings for the `{{t}}` helper

Common operations

Checking message status

var message = client.messages().retrieve("your-message-id");
System.out.println(message.status());
System.out.println(message.delivered());

Managing user profiles

client.profiles().create("user_123", ProfileCreateParams.builder()
    .profile(ProfileCreateParams.Profile.builder()
        .putAdditionalProperty("email", JsonValue.from("sarah@acme-corp.com"))
        .putAdditionalProperty("name", JsonValue.from("Sarah Bennett"))
        .build())
    .build());

var profile = client.profiles().retrieve("user_123");

Issuing JWT tokens

Courier’s (React, JavaScript, mobile) authenticate users with a JWT your backend issues. covers the token flow, the scope strings, and token refresh. Use client.auth().issueToken:

var result = client.auth().issueToken(AuthIssueTokenParams.builder()
    .scope("user_id:user_123 inbox:read:messages inbox:write:events")
    .expiresIn("2 days")
    .build());

System.out.println(result.token());

Scope	Permission
`user_id:<id>`	Which user the token is for (required)
`inbox:read:messages`	Read inbox messages
`inbox:write:events`	Mark messages as read/archived
`read:preferences`	Read notification preferences
`write:preferences`	Update notification preferences
`write:user-tokens`	Register push notification tokens

Configuration

Error handling

When the API returns a non-success status code, the SDK throws a CourierServiceException:

try {
    client.send().message(params);
} catch (CourierServiceException e) {
    System.out.println(e.statusCode());
    System.out.println(e.getMessage());
}

Retries

The SDK retries failed requests up to 2 times with exponential backoff. Configure globally:

CourierClient client = CourierOkHttpClient.builder()
    .maxRetries(0)
    .build();

Timeouts

Requests time out after 60 seconds by default. Configure globally:

CourierClient client = CourierOkHttpClient.builder()
    .timeout(Duration.ofSeconds(20))
    .build();

Or override per-request using withOptions:

client.withOptions(options -> options.timeout(Duration.ofSeconds(5)))
    .send().message(params);

Journeys

are multi-step workflows: send, delay, branch, throttle, digest, and more. Invoke one by ID or alias to start a run. Cancel runs by ID, or by a shared cancelation token.

// Start a run (by journey ID or alias); the response includes a runId
JourneysInvokeResponse response = client.journeys().invoke(
    "your-journey-id",
    JourneyInvokeParams.builder()
        .journeysInvokeRequest(JourneysInvokeRequest.builder()
            .userId("user_123")
            .build())
        .build());
System.out.println(response.runId());

Cancel a run with client.journeys().cancel(...), passing exactly one of run_id or cancelation_token (spelled with one “l”). Build and manage journeys from code with create, list, publish, and archive. See .

More operations

A few more resources from the full :

Resource	Method	Use case
User preferences	`client.users().preferences().retrieve(userId)`	Fetch a user’s notification preferences for your
Cancel a message	`client.messages().cancel(messageId)`	Cancel a delayed or queued message before delivery
Push tokens	`client.users().tokens().addSingle(token, params)`	Register a device push token for , , , or

API Reference

Full REST API docs with request/response examples.

Send API

Learn about the Send endpoint, routing, and message options.

Quickstart

Send your first notification in under two minutes.

GitHub

Source code, issues, and changelog.

Idempotent sends

Pass an idempotency key and Courier replays the first response for that key instead of sending again. The SDK sets the Idempotency-Key header for you. covers the scoping rule and the replay window.

SendMessageParams params = SendMessageParams.builder()
    .message(SendMessageParams.Message.builder()
        .to(UserRecipient.builder().userId("user_123").build())
        .template("nt_01kx4h2jdafq8bk9aftxak4b40")
        .build())
    .idempotencyKey("6f3b8c2a-9d4e-4b7a-a1c5-2e8f0d5b7a91")
    .build();
SendMessageResponse response = client.send().message(params);

Get started

Server

Client

Courier Java SDK

Installation

Quick start

Authentication

Sending notifications

Available resources

Common operations

Checking message status

Managing user profiles

Issuing JWT tokens

Configuration

Error handling

Retries

Timeouts

Journeys

More operations

API Reference

Send API

Quickstart

GitHub

Idempotent sends

​Installation

​Quick start

​Authentication

​Sending notifications

​Available resources

​Common operations

​Checking message status

​Managing user profiles

​Issuing JWT tokens

​Configuration

​Error handling

​Retries

​Timeouts

​Journeys

​More operations

API Reference

Send API

Quickstart

GitHub

​Idempotent sends

Installation

Quick start

Authentication

Sending notifications

Available resources

Common operations

Checking message status

Managing user profiles

Issuing JWT tokens

Configuration

Error handling

Retries

Timeouts

Journeys

More operations

Idempotent sends