Overview

Updated Nov 1, 2026

Textlane is a Rust-native replacement for unified: a pipeline that parses text into a syntax tree, runs plugins over it and serializes the result. The pipeline and its most expensive plugins run in Rust; existing JavaScript plugins can still take part, called only at the stage where they run.

Installation

pip install textlane

It needs Python 3.9 or later; the wheel carries a prebuilt extension for your platform, so no Rust toolchain is needed.

The Python package

pip install textlane installs a wheel with a prebuilt PyO3 extension for your platform, so no Rust toolchain is needed. The extension is the textlane Rust crate itself: the Python package only maps its types, so Python gets the same pipeline as Rust and Node.js, at the same version.

Conformance

Compatibility is defined by a language-neutral conformance suite: JSON cases, each naming a pipeline, an input and the expected output, ported from the upstream unified, remark, rehype, retext and MDX test suites. Every implementation, Python included, runs the same cases.

Status

Textlane is pre-release. textlane() builds a processor over the native pipeline, and textlane.md, textlane.html, textlane.mdx and textlane.nl hold one function per plugin, its options typed as a TypedDict generated from the crate's option structs.

from textlane import html, md, textlane

file = textlane().use(md.parse()).use(md.to_html()).use(html.stringify()).process("# hi")
file["value"]  # "<h1>hi</h1>"

Python plugins

A callable passed to use is an attacher: called with the processor and its options when the processor freezes, it returns a transformer taking the tree, as a dict, and the file. A run pauses before each run of consecutive Python plugins and hands them the tree, mdast or hast as the stage before left it; they change it in place or return a new one, and aprocess awaits one returning an awaitable, which process refuses with async-in-sync; one returning an exception fails the run. The file is vfile's shape: message, info and fail make HostMessages that land in the result's messages, file.data becomes its data, and process({"value": …, "path": …}) gives plugins path, dirname, stem and extname and puts path on the result.

def strong(processor, options=None):
    def transformer(tree, file):
        tree["children"][0]["children"][0]["type"] = "strong"

    return transformer

textlane().use(md.parse()).use(strong).use(md.to_html()).use(html.stringify()).process("*a*")

A Python plugin only transforms: syntax, parsers and compilers need native plugins.

Next steps

• Getting started — a first pipeline, syntax extensions and the result
• Processor — every method of the pipeline
• Recipes — pipelines for common jobs
• Markdown plugins, HTML plugins, MDX plugins and natural language plugins — each plugin and its options