> For the complete documentation index, see [llms.txt](https://docs.ebbot.ai/ebbot-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ebbot.ai/ebbot-docs/developer-resources/ebbot-automations/integrations-sdk/sdk-core-concepts.md).

# SDK Core Concepts

## Core concepts of Integrations SDK

A workflow server consists of the following concepts:

### The server

The server exposes a REST API that the ebbot platform can interpret. This SDK uses [FastAPI](https://fastapi.tiangolo.com/) to spin up that server.

### Connections

Integrating with external systems requires settings and credentials to access that system, and the credentials are different for each client. A connection represents a set of credentials that can be used to connect to the system you integrate with.

A server usually has many connections, one for each client that's using it.

### Subscriptions

A trigger can be subscribed to by a service, for example the Ebbot Automations platform. The SDK takes care of notifying all subscribers when a trigger is invoked.

### Actions

An action is something that can be performed by the workflow server. For example, it could be creating a ticket, updating an existing ticket or adding a reply.

### The Manifest

The manifest describes all available connections, triggers and actions. The manifest is automatically generated by the SDK, and it's used by the Ebbot platform to discover what capabilities a workflow server can have.