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ID prefixes

An ID Courier generates carries a prefix naming what it is. An ID you supply does not, so a list_id, audience_id, tenant_id, or user_id is whatever string you chose. Reading a prefix tells you which resource an ID belongs to without looking it up. Those thirteen are the whole set. A prefix that is not on this list is not a Courier ID format. An example showing one for a resource you supply the ID for is wrong, not a variant.

A

- A secret token that authenticates requests to Courier’s REST API. - A user group defined by filter rules, updated automatically. - A multi-step workflow with conditional logic, delays, digests, and send steps.

B

- An automation step that groups several triggers into one action. - A visual template that styles email notifications with your logo, colors, and layout. - Sending one notification to many recipients through a job-based API workflow.

C

- A communication method: email, SMS, push, in-app inbox, or direct message (Slack, Discord). - The order Courier tries channels when delivering a notification. - Logic that turns content blocks, channels, or whole notifications on and off based on data. - A reusable, responsive component (text, image, action button) used inside a template. - An embeddable designer that lets your users edit notification templates inside your app.

D

- A split within one digest, such as tasks against comments. Its retain rule picks which events appear: first, last, or highest or lowest by a sort key. - An automation step that waits for a duration, or until a specific time. Delivery - The final step, where a provider gets the message to the recipient. - Courier’s visual editor for notification templates. Device Token - An identifier for one app on one device, issued by Apple (APNs) or Google (FCM). - Batching several notifications into one message, to cut notification fatigue. - The status of a send held for a digest rather than delivered. It means the recipient is on a digest schedule for that topic. - The two states of a notification template.

E

- A JSON syntax for describing notification content across every channel. - A test or production instance of a workspace, so development never touches live notifications. Event - A trigger identifier, usually the template ID passed in a send request’s template field.

F

- Automatic switching to a backup provider when the primary one fails. - A filtered stream of messages in the Inbox component.

G

- Send limits that prevent accidental sends to large audiences, or too many messages to one user.

H

- A templating language for dynamic values, conditionals, and loops in templates.

I

- An identifier sent with a request to prevent duplicate processing. - Courier’s in-app notification center component for web and mobile. Inline Content - Content defined in the Send API request body instead of a stored template. - A connection between Courier and a provider (SendGrid, Twilio) that delivers your messages. - A digest schedule that delivers immediately, so a user on it opts out of digesting. Making it the topic default means every user who never chose a schedule delivers immediately.

J

- A data templating language for transforming data in content blocks and the . - A token for client-side authentication, required by Inbox and other frontend SDKs.

L

- A static group of users you manage by hand, unlike an audience. - A language or regional variant (en-US, fr-FR) for localized content. - A timeline of sent messages with delivery status, provider responses, and rendered content.

M

- A protocol that lets AI agents work with Courier. Message - One notification sent to one recipient. - The delivery state of a message: enqueued, sent, delivered, opened, clicked, or undeliverable.

N

Notification - A reusable message template with , sendable on one or more channels.

O

Override - A change to the request body Courier sends a provider, for provider options the designer does not expose. - A webhook Courier fires on events like sent or delivered, to sync delivery data elsewhere.

P

- User-controlled settings for which notifications they get, and on which channels. - A JSON object storing a user’s contact information, device tokens, and custom attributes. - The downstream service (Twilio, SendGrid) that delivers notifications to recipients.

R

Recipient - The end user who receives notifications, identified by their . - The logic that picks which channels and providers deliver a notification.

S

- Rules evaluated at send time that decide whether a notification goes out. - When a topic’s digests release, as a recurrence such as daily, weekly, or monthly. It lives on the preference topic, and each user picks the one they are on in the preference center. - A cap on notifications sent to a user, topic, or tenant per time period. - A notification category (“Marketing”, “Order Updates”) users can opt in or out of.

T

- A reusable message design, built in the Designer and sent to many recipients. - A review step required before a template can be published to production. - A customer organization in a multi-tenant app, with its own branding, preferences, and data. - An automation step that caps how often a notification triggers for a scope (per-user, global, or dynamic key). - A pop-up the Inbox SDK components show when a new message arrives. Trigger - An action or event that starts an or sends a notification.

V

- A template placeholder ({name}, {order_id}) replaced with real data at send time.

W

- The top-level container for all your Courier resources, environments, team members, and settings.