Typera helps you build backends in a type-safe manner by leveraging io-ts and some TypeScript type inference magic. It works with both Express and Koa.

Upgrading to version 2? See the upgrading instructions.

Features of typera in a nutshell:

• A purer approach to building your apps: Each route handler is an async function that takes a request and returns a response. Mutable req or res objects? Never again!

• Automatically parses request inputs like route params, query params, headers and request body into typed values.

• Infer the types of responses (status code, body, headers), allow type checking them according to your expectations.

• Middleware are fully typed. This means that you no longer have to guess what's available in req, or whether a middleware short-circuits and returns a response. Instead, everything is type checked!

• It's straightforward to start adding fully typed routes to an existing Express or Koa app. Old routes can be migrated gradually.

• Built-in support for automatically generating an OpenAPI definition from your app with typera-openapi.

Typera is a really thin layer on top of Express or Koa. Most of its code is TypeScript typings, and the actual runtime stuff is minimal.

See the documentation for tutorial, examples, API reference and more!

Run yarn to install dependencies.

Run yarn test.

You need Python 3 to build the docs.

python3 -m venv venv
./venv/bin/pip install mkdocs-material

Run a live reloading server for the documentation:

./venv/bin/mkdocs serve

Open http://localhost:8000/ in the browser.

$ yarn lerna version <major|minor|patch>
$ yarn lerna publish from-git

Open https://github.com/akheron/typera/releases, edit the draft release, select the newest version tag, adjust the description as needed.