SDK (Software Development Kit)

An SDK (Software Development Kit) is a ready-made package of code libraries, tools and documentation that wraps an API in functions for one programming language. Instead of writing raw HTTP requests, developers call pre-built functions.

What is an SDK?

An SDK (Software Development Kit) is a ready-made package of code libraries, tools and documentation for one programming language. It wraps an API in functions that developers call directly. Instead of building HTTP requests by hand, parsing JSON responses and catching errors themselves, one line like client.messages.send() is enough. The SDK takes care of the rest.

SDKs come in two flavours. A thin SDK mirrors the API endpoints one to one and mainly adds types. A rich SDK adds convenience on top, such as automatic retries, pagination or checking webhook signatures. Every SDK is tied to one language: a provider that wants to serve Python, JavaScript and PHP developers has to build and maintain three separate packages.

SDK or direct REST API?

An SDK is always a layer on top of an API, usually a REST API. Both routes lead to the same result. What differs is the effort:

  • With an SDK: faster first steps, typed functions and fewer errors in the code. In exchange, you depend on the provider keeping the package up to date for your language and version.
  • Directly via REST: works in any language that can send HTTP requests, with no extra package. You see exactly what goes over the wire, but you write authentication, error handling and retries yourself.

For most messaging integrations, a few direct REST calls are enough: authenticate, send a message, receive status updates. That is why many teams skip SDKs entirely or generate their own client from the API description.

Your own client from an OpenAPI specification

Many APIs publish an OpenAPI specification: a machine-readable file that describes every endpoint, parameter and response. From this file you get much of what an SDK offers, without waiting for an official package:

  • Generate client code: tools such as OpenAPI Generator create a typed client for your language from the specification.
  • Test in API tools: Postman, Insomnia or Bruno import the specification, so you can try every endpoint before writing code.
  • Use AI coding tools: assistants such as Claude Code, Cursor or GitHub Copilot read the specification and the documentation and write the integration code for your stack.

SDKs at SendSeven

SendSeven offers no language SDKs for its REST API. The one SDK is the Push SDK: a small code snippet that adds browser push notifications to your own website. For everything else, you connect directly to the REST API, with these aids:

  • OpenAPI specification: generate client code or import it into Insomnia or Bruno.
  • Postman collection: ready-made requests to try the endpoints.
  • Docs for AI coding tools: every page of docs.sendseven.com is also available as Markdown, plus a ready-made prompt for Claude Code, Cursor and GitHub Copilot.
  • MCP server: AI agents such as Claude work with SendSeven directly.
  • No code: Zapier, Make and n8n connect SendSeven to other tools without programming.

Authentication uses an API key, sent as a Bearer token. Step-by-step instructions are in the API authentication guide, and all endpoints are in the developer documentation.