Migrate from OneSignal

This guide helps you plan and execute a migration from OneSignal to Courier. It covers how the two platforms compare, where Courier gives you more flexibility, and a concrete step-by-step plan for moving everything over.

Mapping OneSignal Concepts to Courier

OneSignal	Courier
Apps	Workspaces
Segments	Audiences
Templates	Templates
Journeys	Journeys
Subscriptions	Channel tokens on User Profiles
Users / Aliases	Users / Profiles
Tags	Custom properties on profiles + Preferences
Outcomes	Analytics + Message Logs
In-App Messages	Inbox

Apps and Workspaces

OneSignal apps map to Courier workspaces. Each workspace has its own integrations, templates, and user profiles. Courier gives you separate Test and Production environments within a workspace, so you can develop safely without affecting live traffic.

Segments and Audiences

OneSignal segments use filters on user attributes, activity, and tags to create dynamic groups. Courier Audiences work similarly: define filter rules on profile attributes and Courier keeps membership current as profiles change. For static subscriber groups (mailing lists, beta testers, etc.), Courier also supports Lists.

Templates

OneSignal templates are reusable message blueprints for push, email, and SMS. Courier templates take a unified approach: a single resource holds content for every channel (email, SMS, push, chat, inbox), so you design all channel variants in one place. Design Studio uses drag-and-drop content blocks, and there’s a code-first path through Elemental JSON if you prefer to define content programmatically. Both support {{variable}} Handlebars-style personalization, channel-specific overrides, and localization. OneSignal uses Liquid syntax for templating; Courier uses Handlebars. The concepts are similar (conditionals, loops, variable interpolation), just with different syntax.

Journeys

OneSignal Journeys are automated multi-step message flows. Courier Journeys serve the same purpose with delays, branching, batching, digests, and cancellation.

Journey Step	Courier Equivalent
Send message	Send node (references a template)
Wait	Delay node
Yes/No branch	Branch node
Multi-split branch	Branch node with multiple paths

A journey starts from a trigger: an API invoke, an inbound webhook, a Segment event, or a user joining an audience. Build journeys visually in the UI or define them through the Journeys API.

Users, Subscriptions, and Profiles

OneSignal separates users (identified by aliases) from subscriptions (individual devices, email addresses, phone numbers). Courier consolidates these into a single profile per user that stores all contact information: email, phone, push tokens, and custom properties. Profiles accept nested JSON natively, so structured data like account tiers, team roles, or feature flags fits naturally. You can create profiles ahead of time through the API, or identify users inline at send time.

Tags and Preferences

OneSignal tags are key-value pairs on users used for both targeting and preference management. In Courier, these split into two features:

Custom profile properties: Store arbitrary attributes on user profiles for targeting and personalization
Preferences: A dedicated system for notification opt-in/opt-out by channel, category, or specific topic, enforced automatically at send time

Courier also ships a hosted preference page you can deploy in minutes and embeddable React components for building a preference center directly into your app.

In-App Messages and Inbox

OneSignal’s in-app messages are modal overlays triggered by user activity. Courier Inbox is a persistent in-app notification center with drop-in components for React, iOS, Android, and vanilla JS. Inbox runs on the same delivery pipeline as email, push, and SMS; there’s no separate provider to configure. Out of the box you get read/unread state, archiving, per-user history, toast notifications, and tab-based organization.

Outcomes and Analytics

OneSignal Outcomes track conversion events tied to notifications. Courier provides delivery observability through Message Logs (per-message timeline from API request to provider delivery) and Analytics (aggregate delivery and engagement metrics). For piping events to your own analytics, configure Outbound Webhooks.

Why Courier

Truly multi-channel. Courier treats email, SMS, push, chat, webhooks, and in-app as equal channels with unified orchestration. You’re not bolting non-push channels onto a push-first platform.
Content and logic stay separate. Templates and journeys are independent resources. Your product team updates copy in Design Studio while engineers tune journey timing; neither blocks the other.
Design Studio. Build email, SMS, push, and chat content with drag-and-drop blocks. Preview across channels, personalize with variables, and publish without deploying code.
Automatic failover. Configure multiple providers per channel and Courier fails over automatically. If your primary email provider goes down, traffic shifts to the backup without code changes.
Built-in in-app channel. Courier Inbox works without a third-party provider. Drop in a React, iOS, or Android component and deliver in-app notifications on the same pipeline as email and push.
Hosted preferences out of the box. Ship a user-facing preference center with a single config, or embed React components directly in your app. No custom UI required.
50+ integrations. Email, SMS, push, chat, webhooks, CDPs, and observability tools. Switch providers without changing your send code.
Full delivery observability. Message Logs track every message from API request to provider delivery with a detailed timeline, error details, and rendered content inspection.

Migration Steps

Create your Courier workspace

Sign up and create a workspace. Courier gives you separate Test and Production environments with independent API keys, so you can migrate safely without affecting live traffic.

Configure integrations

Go to Integrations in your Courier dashboard and connect delivery providers for each channel you use in OneSignal. If you send push via FCM and APNs, configure both. For email and SMS, connect your providers (SendGrid, Twilio, etc.). You can configure multiple providers per channel for failover.For in-app notifications, enable Courier Inbox; no external provider needed.

Recreate templates

OneSignal templates are per-channel. In Courier, a single template holds content for all channels:

Create a new template for each notification type
Add content blocks for each channel (email body, SMS text, push title/body, etc.)
Convert Liquid variables to Handlebars syntax ({{variable}}); the data comes from the send request’s data field
Publish the template to make it available for sending

Migrate user data

Create user profiles in Courier that consolidate your OneSignal user and subscription data. You can create profiles via the Profiles API or inline at send time.

{
  "user_id": "user_123",
  "profile": {
    "email": "user@example.com",
    "phone_number": "+15551234567",
    "firebaseToken": "fcm_device_token_here",
    "custom": {
      "name": "Jane Doe",
      "plan": "enterprise"
    }
  }
}

For bulk migration, use the Bulk API to upsert users in batches. Map OneSignal external_id to Courier user_id for a seamless transition.

Set up preferences

If you use OneSignal tags for opt-in/opt-out management, recreate that structure using Courier Preferences:

Define subscription topics for each notification category
Configure default channel routing per topic
Migrate user preference selections via the Preferences API

Courier also provides a hosted preference page you can deploy immediately, or React components for embedding preferences in your app.

Update your send calls

Replace OneSignal’s Create Notification API calls with Courier’s Send API:

curl -X POST https://api.courier.com/send \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "message": {
      "to": { "user_id": "user_123" },
      "template": "order-confirmation",
      "data": {
        "order_id": "ORD-456",
        "total": "$79.99"
      }
    }
  }'

import Courier from "@trycourier/courier";

const client = new Courier({ apiKey: "YOUR_API_KEY" });

await client.send.message({
  message: {
    to: { user_id: "user_123" },
    template: "order-confirmation",
    data: {
      order_id: "ORD-456",
      total: "$79.99",
    },
  },
});

from courier import Courier

client = Courier(api_key="YOUR_API_KEY")

client.send.message(
  message={
    "to": {"user_id": "user_123"},
    "template": "order-confirmation",
    "data": {
      "order_id": "ORD-456",
      "total": "$79.99",
    },
  }
)

Courier handles routing, preferences, and failover automatically based on your template and workspace configuration. For multi-channel sends, set the routing field:

{
  "message": {
    "to": { "user_id": "user_123" },
    "template": "order-confirmation",
    "routing": {
      "method": "single",
      "channels": ["push", "email", "sms"]
    }
  }
}

This tries push first, then email, then SMS; the first successful delivery wins.

Recreate journeys

If you use OneSignal Journeys, recreate them in Courier Journeys. Build them visually in the UI or define them via the Journeys API.For simple notification types that don’t need orchestration, you can skip journeys entirely and send directly via the Send API.

Test and cut over

Send test messages in your Test environment and verify delivery in Message Logs
Validate that preferences, routing, and template rendering match your OneSignal setup
Switch your production code to use Courier’s Production API key
Monitor Message Logs and Analytics for delivery confirmation

Migrating with an AI Agent

Most of this migration is mechanical: read a template definition, create the equivalent Courier template, rewrite the call site. That suits a coding agent well. Three things to set up first:

Courier Skills teaches the agent Courier’s real APIs and patterns so it stops guessing at endpoints:
npx skills add trycourier/courier-skills
In Claude Code you can install it as a plugin instead, which self-updates and ships the Courier docs MCP server.
Courier’s MCP server gives the agent direct access to your workspace, so it can create templates, build journeys, upsert users, and read send logs as it works. See Build with AI for setup in Claude Code, Cursor, Codex, and VS Code.
Docs for agents. Point it at llms-full.txt when it needs API detail beyond this page.

Then start it with a prompt like this one. Fill in the bracketed parts.

Help me migrate our notifications from OneSignal to Courier.

Read first:
- https://www.courier.com/docs/tutorials/migrate/from-onesignal
  (concept mapping and the migration steps you should follow)
- https://www.courier.com/docs/llms-full.txt
  (full Courier docs, for API detail as you need it)

Our setup:
- Codebase: [path]
- OneSignal API credentials: [env var]
- Courier: connected through the Courier MCP server

Work in this order. Stop after step 3 and wait for my review
before you create anything in Courier.

0. Setup. Install Courier Skills so you build against Courier's real
   APIs and patterns rather than guessing:
   npx skills add trycourier/courier-skills
   Then confirm the Courier MCP server is connected. If either one is
   missing, stop and tell me before going further.

1. Inventory. Use the OneSignal API to list every template, journey,
   and segment in each app. For each template record its channels; for
   each journey record its trigger, steps, and target segment.

2. Classify each as:
   - transactional (an action in our product must produce it)
   - marketing (campaign or lifecycle)
   - in-app messages (these are a separate surface, see the guide)

3. Find the send sites. Grep the codebase for OneSignal
   POST /notifications calls. Note which ones send inline content and
   which reference a template_id, and which target segments or filters
   rather than an external_id.

   Report the inventory, the classification, and the send-site list.
   Then wait.

4. Transactional first. For each one: create the Courier template with
   the channels it needs, then rewrite the call site to a Courier /send
   that names the template and passes data. Recipients addressed by
   external_id become a Courier user_id. Leave the OneSignal call in
   place behind a flag so we can run both and compare.

5. Journeys. Recreate each OneSignal journey through the Courier
   journeys API. Waits become delay nodes, branches become branch
   nodes, message steps become send nodes.

6. Segments and tags. Convert segments to Courier audiences built on
   profile attributes, and map the tags you use for opt-out into
   Courier subscription topics rather than leaving them as attributes.

Rules:
- Never send to a real user. Use a test profile in the Test
  environment for every verification send.
- Never pause, disable, or delete anything in OneSignal. That is my call.
- If something in OneSignal has no Courier equivalent, say so in your
  report rather than approximating it.

Step 6 deserves a careful pass. OneSignal commonly uses data tags for both segmentation and opt-out, and only the second kind should become a subscription topic. Anything that gates whether a user may be contacted belongs in preferences, where Courier enforces it at send time.

API Mapping

Operation	OneSignal	Courier
Send a notification	`POST /notifications`	`POST /send`
Create/update a user	`POST /apps/:id/users`	`PUT /profiles/:id`
Get a user	`GET /apps/:id/users/by/external_id/:id`	`GET /profiles/:id`
Add a subscription	`POST /apps/:id/users/by/external_id/:id/subscriptions`	Push tokens on `PUT /profiles/:id`
Manage segments	`POST /apps/:id/segments`	`PUT /audiences/:id`
Get message status	`GET /notifications/:id`	`GET /messages/:id`
Bulk operations	`POST /notifications` (with `include_aliases`)	`POST /bulk`
Create a template	`POST /templates`	Design Studio or Elemental API

Send Messages

Design Messages

User Journeys

Inbox & Preferences

Deploying and Debugging

Migrate to Courier

Migrate from OneSignal

Mapping OneSignal Concepts to Courier

Apps and Workspaces

Segments and Audiences

Templates

Journeys

Users, Subscriptions, and Profiles

Tags and Preferences

In-App Messages and Inbox

Outcomes and Analytics

Why Courier

Migration Steps

Migrating with an AI Agent

API Mapping

​Mapping OneSignal Concepts to Courier

​Apps and Workspaces

​Segments and Audiences

​Templates

​Journeys

​Users, Subscriptions, and Profiles

​Tags and Preferences

​In-App Messages and Inbox

​Outcomes and Analytics

​Why Courier

​Migration Steps

​Migrating with an AI Agent

​API Mapping

Mapping OneSignal Concepts to Courier

Apps and Workspaces

Segments and Audiences

Templates

Journeys

Users, Subscriptions, and Profiles

Tags and Preferences

In-App Messages and Inbox

Outcomes and Analytics

Why Courier

Migration Steps

Migrating with an AI Agent

API Mapping