A web framework for the BEAM
Build fault-tolerant, distributed web applications in Erlang, Elixir, or LFE.
Why Nova?
Nova is the web framework for the BEAM. Whether you write Erlang, Elixir, or LFE, Nova gives you the productivity of a modern web framework on the runtime you already trust:
- Routing, controllers, and views — familiar MVC patterns that map naturally to Erlang modules
- Plugin pipeline — composable middleware for auth, CORS, logging, and custom concerns
- WebSockets and Pub/Sub — real-time features backed by OTP's
pgmodule, distributed out of the box - Session management — ETS-backed by default, pluggable for custom backends
- Template rendering — ErlyDTL (Django Template Language) with hot reload
- OTP-native — your web app is a proper OTP application with supervision trees, hot code upgrades, and releases
Nova runs on Cowboy and supports Erlang, Elixir, and LFE.
Quick start
Install the rebar3 plugin:
# One-line install
sh -c "$(curl -fsSL https://raw.githubusercontent.com/novaframework/rebar3_nova/master/install.sh)"
# Or add to ~/.config/rebar3/rebar.config
{project_plugins, [rebar3_nova]}.
Create and run your app:
rebar3 new nova my_app
cd my_app
rebar3 nova serve
Open localhost:8080 — you're running Nova.
What a controller looks like
-module(my_app_main_controller).
-export([index/1, create/1]).
index(#{method := <<"GET">>} = _Req) ->
{json, #{message => <<"Hello from Nova!">>}}.
create(#{method := <<"POST">>, json := Body} = _Req) ->
%% Validate, persist, respond
{json, #{status => <<"created">>, data => Body}}.
Route it:
routes(_Environment) ->
[#{prefix => "/api",
security => false,
routes => [
{"/", {my_app_main_controller, index}},
{"/items", {my_app_main_controller, create}}
]}].
Features
| Feature | Details |
|---|---|
| Routing | Path parameters, prefixes, per-route security, environment-based routing |
| Controllers | Return {json, Map}, {ok, Variables}, {status, Code}, {redirect, Path}, {sendfile, ...} |
| Plugins | Pre/post request hooks — built-in CORS, CSRF, correlation ID, or write your own |
| WebSockets | Full WebSocket support via nova_websocket behaviour |
| Pub/Sub | Distributed messaging via nova_pubsub — channels, topics, broadcast |
| Sessions | ETS-backed sessions with pluggable backends |
| Templates | ErlyDTL (Django-style) with hot reload via rebar3 nova serve |
| Security | Per-route security functions for authentication and authorization |
| Static files | Built-in file controller with range request support |
| Observability | OpenTelemetry integration for tracing and metrics |
| Database | Kura — an Ecto-inspired database layer for Erlang |
Request pipeline
Request → Cowboy → Nova Router → Plugins (pre) → Security → Controller → Plugins (post) → Response
Ecosystem
| Package | Description |
|---|---|
| nova | Core framework |
| rebar3_nova | Project scaffolding and generators |
| nova_test | Testing utilities and request builder |
| kura | Database layer — schemas, migrations, changesets, queries |
| rebar3_kura | Migration generator for Kura |
| opentelemetry_nova | Automatic OpenTelemetry instrumentation |
Documentation
- The Nova Book — step-by-step tutorial building a complete blog platform
- API Reference — module documentation on HexDocs
- Quick Start Guide — get up and running in 5 minutes
Requirements
- Erlang/OTP 23+
- Rebar3
Community
- Erlang Slack —
#erlangerchannel - Nova Forum — questions and discussion
- Issue Tracker — bugs and feature requests
Contributing
Contributions are welcome! Check CODE_OF_CONDUCT.md and look for issues labeled good first issue.