Biff: full-stack Clojure web framework

Biff speeds up web development by providing as much functionality as possible out-of-the-box while making it easy to swap out, modify, or remove parts as your project grows. It's built with solo developers in mind and is quite opinionated in its approach to serving that use case. Biff has also been influenced by my experience working in enterprise SaaS and is perfectly capable of keeping large codebases maintainable.

In short: Biff is built on the idea that web development can be both simple and easy.

Resources

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Get started

Requirements:

Java 21 or higher
Clojure

Create a new project:

git clone https://github.com/jacobobryant/biff-starter my-project
cd my-project
clj -M:run dev

The first time you run the dev command you'll be prompted to choose a namespace for the new project. After the app starts, go to localhost:8080 and sign in. The sign-in code will be printed to the console. Changes are evaluated whenever you save a file.

Use clj -M:run -h to see the available commands.

Guide

Biff is a composition of libraries. Some of these are wrapper libraries that make other tools seamless to integrate in a Biff project; some of these are entirely new creations. Each library is documented individually and is meant to be usable on its own. Read the library documentation in this order to get a complete understanding of Biff:

biff.core: interfaces and code that connect all the other Biff libs. This is the "framework" part of Biff.
biff.config: a light wrapper around Aero.
biff.fx: an approach to keeping your application logic pure, with effects separated out. The starter app uses biff.fx to define its Ring handlers.
biff.graph: structure your data model as a queryable graph. Inspired by Pathom.
biff.sqlite: integrates SQLite with other parts of Biff and adds support for rich data types.
biff.ring: integrates Ring/Reitit/Jetty with other parts of Biff. Includes a default middleware stack.
biff.datastar: lightweight server-side rendering with Datastar.
biff.background: in-memory job queues and scheduled tasks.
biff.authenticate: signin-via-email functionality, including a default signin form.
biff.admin: admin dashboard with usage/performance metrics, user directory, and email alerting.
biff.run: lightweight clj-based task runner.
biff.tasks: collection of default biff.run tasks (what you see when you run clj -M:run -h).

Additional libraries:

biff.defaults: a wrapper/alias library that includes the above libraries, except for biff.run and biff.tasks since those are dev-only.
biff.xtdb: an alternative to biff.sqlite.

Reading Biff documentation

Each library's README links to a "schema" reference. This document describes the keywords owned by that library, which are all namespaced with the library name. For example, the biff.core schema reference specifies keys such as :biff.core/id, :biff.core/init, :biff.core/start, etc. So whenever you see a keyword, you can tell immediately what library owns it and which schema reference document you can read to get more info.

Other documentation assumes you are familiar with the schema reference and thus does not always describe what the keys are.

Content library

Most of the documentation is available within the individual libraries listed above. Additional documentation/content:

Understanding Datastar
Deploy an app with biff.tasks. Video tutorial for deploying a Biff app.
Biff 2.0 sneak peak: background info on the design of Biff.
How to write a Biff database adapter. Read this if you want to use a database other than SQLite or XTDB.
Migrating from Biff 1.0: guidance on the eponymous task.

LLMs

I don't have any hard rules for how I use or don't use LLMs, but typically:

I use LLMs to generate a rough draft of pretty much all the code I write, reading and often editing it thoroughly.
Tests are an exception: I usually glance over them but rarely edit them.
I write first drafts of documentation by hand. I often use LLMs to help keep docs up to date, with moderate editing.

In general, I'm moderately enthusiastic about using LLMs for code and pretty skeptical about using them for documentation. See 2x, not 10x: coding with LLMs in 2026.

Biff is intended to be a good framework for both manual and LLM-assisted development.