> ## Documentation Index > Fetch the complete documentation index at: https://www.courier.com/docs/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Install the Courier skill before writing code: `npx skills add trycourier/courier-skills`. It carries the verified SDK shapes and the rules you cannot get wrong. > Authenticate every request with `Authorization: Bearer `. A workspace has several environments and each has its own keys, which are plain `pk_` strings with no environment prefix. Start with Test. > Send with `client.send.message`, the default import of the v7 Node SDK. Reference a template by its `nt_` id or its alias. > A send accepts a bare Elemental element list, but storing content on a template requires the top-level elements wrapped in a channel element. > Templates and journeys can be built in the Courier app or created through the API. Either way they live in the workspace and are referenced by ID when you send. > The hosted MCP server is https://mcp.courier.com. For a briefing on what Courier is and when to use it, read https://www.courier.com/llms.txt. > Prefer the Guides tab for how-do-I questions and the Docs tab for how-does-it-behave questions. The API reference lives under /api-reference. # Courier notifications API documentation > One API for email, SMS, push, Slack, chat, and in-app inbox, on the providers you already use. export const AppLink = ({href, children, name, bare}) => { const label = children || name || "Open in Courier"; if (bare) { return {label}; } return {label} ; }; export const Guide = ({href, children, name, bare}) => { const label = children || name || href; if (bare) { return {label}; } return {label} GUIDE ; }; export const Doc = ({href, children, name, bare}) => { const label = children || name || href; if (bare) { return {label}; } return {label} DOC ; }; One API for email, SMS, push, chat, and an in-app inbox. Courier sends the messages your product owes its users: password resets, receipts, alerts, onboarding sequences, digests, and announcements. You bring your own provider accounts. Courier handles content, routing, failover, preferences, and delivery logs. Product teams edit the content and timing in the dashboard, so wording changes ship without a deploy. To send, you need: * A Courier account * A Courier API key ## Where to start Go from an API key to a delivered message. Ship a real-time message center to web, iOS, or Android. Let an agent send notifications over the MCP server. Turn a Clerk, Stripe, or Firebase event into a message. ## What you can build Design content once and render it for every channel. Automate multi-step flows with triggers, delays, and branches. Send one message to a whole list or audience. Embed an inbox, toasts, and a preference center in your app. Scope branding, preferences, and routing per customer. Let users choose what they receive, per topic and channel. Let your customers design their own templates in your app. Store each recipient's contact details and device tokens. Group users into static lists and dynamic audiences. ## Developer tools Server and client libraries for your language. Operate the Courier API from your terminal. Give an AI agent access to the Courier API. Every endpoint, with request and response schemas. ## FAQ Courier is a notification and lifecycle-marketing platform. One REST API and a visual dashboard send messages across email, SMS, push, chat apps like Slack and Microsoft Teams, and an in-app inbox. You make one API call instead of maintaining a separate integration per channel and provider. Courier handles routing, templating, and delivery. It covers transactional notifications and automated lifecycle campaigns, so engineering and product teams work from one system. Courier delivers across email, SMS, push, an in-app inbox, and chat apps including Slack, Microsoft Teams, and WhatsApp. You bring your own provider accounts, such as SendGrid, Postmark, Amazon SES, Twilio, or Firebase Cloud Messaging, and connect them once. Courier routes each message to the right provider, and fails over to a backup if one is unavailable. See how sending works. You bring your own providers. Courier sits on top of the delivery services you already use, so you keep your sender reputation, domains, and provider pricing. Courier adds routing, failover, templating, preferences, and analytics, and bills separately per send. Courier has three plans and bills on notifications sent, not team size or channels. The Developer plan is free for up to 10,000 sends per month. The Business plan is pay-as-you-go at \$0.005 per send. Enterprise is custom-priced with volume discounts. See [Courier pricing](https://www.courier.com/pricing) for the full comparison. All three, plus AI agents. Developers get a REST API, SDKs, a CLI, and full delivery logs. Product and marketing teams design content in Design Studio and build journeys without code. AI coding agents drive Courier through its MCP server and CLI. Everything is available through both the API and the UI. Both run on the same platform. Transactional notifications include password resets, receipts, and alerts. Lifecycle marketing includes onboarding, re-engagement, and announcement sequences. Journeys automate multi-step flows with triggers, delays, branches, batching, and digests. Journeys are visual, multi-step workflows that automate when and how messages send. You add triggers, delays, branches, and send steps. Batch and digest nodes bundle activity into a single notification. Build and edit them in the dashboard, or manage them through the Journeys API. Users control what they receive, per topic and per channel. Host a ready-made preference page, or embed preference components in your app. Courier enforces those choices automatically on every send. See preferences. Tenants scope branding, routing, and preferences per customer or workspace. One integration serves many end customers, each with their own look and delivery rules. See multi-tenancy. Courier is API-first, with a REST API for sending, users, preferences, and more. Server SDKs cover Node, Python, Go, Ruby, Java, PHP, and C#. Client SDKs cover React, JavaScript, iOS, Android, React Native, and Flutter, for building in-app inboxes and embedding preferences. Start from the API reference or SDK libraries. Courier offers a CLI, an MCP server, and agent skills. AI coding agents use them to send messages, manage users, and build notification workflows from your development environment. See Build with AI to get set up. Courier maintains SOC 2, HIPAA, and PCI DSS programs, and supports GDPR and CCPA obligations. The [Security Portal](https://security.courier.com/) holds the current reports, including the SOC 2 report and the most recent penetration test, for a vendor review. See security. Courier is a managed cloud platform, so there is no self-hosted or on-premise deployment. Teams usually ask because of data residency, and the EU region keeps notification data inside European borders. Start with the quickstart to go from API key to your first delivered message. From there, add an in-app inbox, build a journey, design a template, or set up preferences.