minijinja

[!IMPORTANT] The main branch contains development for MiniJinja 3. MiniJinja 2 maintenance and releases continue on the minijinja-2 branch. Pull requests for changes that apply to MiniJinja 2 should target that branch. Changes are merged forward from minijinja-2 into main, never in the other direction.

MiniJinja is a powerful but minimal dependency template engine which is based on the syntax and behavior of the Jinja2 template engine for Python.

It's implemented in Rust and Go and is also available via WASM for JavaScript, as a Python extension module, and as a command line utility.

It supports a range of features from Jinja2 including inheritance, filters and more. The goal is that it should be possible to use some templates in Rust programs without the fear of pulling in complex dependencies for a small problem. Additionally it tries not to re-invent something but stay in line with prior art to leverage an already existing ecosystem of editor integrations. The default build of MiniJinja is entirely free of dependencies, though some users might want to enable the serde dependency to enable the optional serde support.

$ cargo tree
minimal v0.1.0 (examples/minimal)
└── minijinja v3.0.0-alpha.1 (minijinja)

Additionally minijinja is also available as an (optionally pre-compiled) command line executable called minijinja-cli:

$ curl -sSfL https://github.com/mitsuhiko/minijinja/releases/latest/download/minijinja-cli-installer.sh | sh
$ echo "Hello {{ name }}" | minijinja-cli - -Dname=World
Hello World

You can play with MiniJinja online in the browser playground powered by a WASM build of MiniJinja.

Goals:

• Well documented, compact API
• Minimal dependencies, reasonable compile times and decent runtime performance
• Stay as close as possible to Jinja2
• Support for expression evaluation which allows the use as a DSL
• Support for all serde compatible types
• Well tested
• Support for dynamic runtime objects with methods and dynamic attributes
• Descriptive errors
• Bindings for JavaScript, Python, and C
• Also available for Go
• Comes with a handy CLI
• Compiles to WebAssembly

Example

Example Template:

{% extends "layout.html" %}
{% block body %}
  <p>Hello {{ name }}!</p>
{% endblock %}

Invoking from Rust:

use minijinja::{Environment, context};

fn main() {
    let mut env = Environment::new();
    env.add_template("hello.txt", "Hello {{ name }}!").unwrap();
    let template = env.get_template("hello.txt").unwrap();
    println!("{}", template.render(context! { name => "World" }).unwrap());
}

Getting Help

If you are stuck with MiniJinja, have suggestions or need help, you can use the GitHub Discussions.

Related Crates

• minijinja-autoreload: provides auto reloading functionality of environments
• minijinja-embed: provides utilities for embedding templates in a binary
• minijinja-contrib: provides additional utilities too specific for the core
• minijinja-py: makes MiniJinja available to Python
• minijinja-js: makes MiniJinja available to JavaScript via WASM (for Node and Browser)
• minijinja-go: a native Go implementation of MiniJinja
• minijinja-cli: a command line utility.
• minijinja-cabi: a C binding to MiniJinja.

Use Cases and Users

Here are some interesting Open Source users and use cases of MiniJinja. The examples link directly to where the engine is used so you can see how it's utilized:

• AI Chat Templating:

  • HuggingFace uses it to render LLM chat templates
  • mistral.rs uses it to render LLM chat templates
  • BoundaryML's BAML uses it to render LLM chat templates
  • LSP-AI uses it to render LLM chat templates
  • LoRAX uses it to render LLM chat templates
  • tensorzero uses it to render LLM and system templates

• Data and Processing:

  • Cube uses it for data modelling
  • PRQL uses it to handle DBT style pipelines
  • qsv uses it to render templates from CSV files, to construct payloads to post to web services and to infer Data Dictionaries, Descriptions & Tags or Chat with your data.

• HTML Generation:

  • Zine uses it to generate static HTML
  • Oranda uses it to generate HTML landing pages

• Code Generation:

  • OpenTelemetry's Weaver uses it to generate documentation, code and other outputs from the OTel specification.
  • Maturin uses it to generate project structures
  • cargo-dist uses it to generate CI and project configuration

• SQL Generation:

  • Spawn uses it to render database migration scripts and tests and for safe escaping of values.

Similar Projects

These are related template engines for Rust:

• Askama: Jinja inspired, type-safe, requires template precompilation. Has significant divergence from Jinja syntax in parts.
• Tera: Jinja inspired, dynamic, has divergences from Jinja.
• Liquid: an implementation of Liquid templates for Rust. Liquid was inspired by Django from which Jinja took its inspiration.
• TinyTemplate: minimal footprint template engine with syntax that takes lose inspiration from Jinja and handlebars.

Sponsor

If you like the project and find it useful you can become a sponsor.

AI Use Disclaimer

This codebase mostly predates LLM based code generation but some recent features have been built with support of AI. For the AI contribution rules see AI Disclosure Rules.

License and Links

• Documentation
• Discussions
• Examples
• Issue Tracker
• MiniJinja Playground
• Updating Guide
• License: Apache-2.0