Introducing Mint, a new HTTP client for Elixir

Yesterday, the team at Elixir introduced Mint as their new low-level HTTP client that provides a small and functional core. It is connection based where each connection is a single structure with an associated socket belonging to the process that started the connection.

Features of Mint

Connections

The HTTP connections of Mint are managed directly in the process that starts the connection. There is no connection pool which is used when a connection is opened. This helps users to build their own process structure that fits their application.

Each connection has a single immutable data structure that the users can manage. Mint uses “active mode” sockets so the data and events from the socket are sent as messages to the process that started the connection. The user then passes the messages to the stream/2 function that further returns the updated connection and a list of “responses”. These responses get streamed back and the response is returned in partial response chunks.

Process-less

To many users, Mint may seem to be more cumbersome to use than other HTTP libraries. But by providing a low-level API without a predetermined process architecture, Mint gives flexibility to the user of the library.

If a user writes GenStage pipelines, a pool of producers can fetch data from external sources via HTTP. With Mint, it is possible to have GenStage producer for managing its own connection while reducing overhead and simplifying the code.

HTTP/1 and HTTP/2

The Mint.HTTP module has a single interface for both HTTP/1 and HTTP/2 connections which also performs version negotiation on HTTPS connections. Users can now specify HTTP version for choosing Mint.HTTP1 or Mint.HTTP2modules directly.