Bionic Reader

Read text with emphasis on the beginnings of words.

Bionic Reader works with text streams, Markdown documents, and interactive shell sessions. It runs locally and keeps your words intact. Try different emphasis settings to find what feels comfortable; no reading-speed improvement is promised.

Bionic Reader emphasizes word beginnings.

Installation

Install with your package manager using the commands below. Homebrew installs prebuilt binaries; Cargo installs from crates.io. See installation details for channel availability, direct-download alternatives, and platform requirements.

Homebrew

brew tap arturoaviles/tap
brew trust arturoaviles/tap
brew install bionic-reader

Homebrew selects the matching prebuilt binary. See the Homebrew guide for updates, removal, and platform requirements.

Linux

# Debian / Ubuntu
curl -fL "https://github.com/arturoaviles/bionic-reader/releases/latest/download/bionic-reader-linux-$(dpkg --print-architecture).deb" -o bionic-reader.deb
sudo apt install ./bionic-reader.deb

# Fedora
curl -fL "https://github.com/arturoaviles/bionic-reader/releases/latest/download/bionic-reader-linux-$(rpm --eval '%{_arch}').rpm" -o bionic-reader.rpm
sudo dnf install --nogpgcheck ./bionic-reader.rpm

# Arch Linux
curl -fL "https://github.com/arturoaviles/bionic-reader/releases/latest/download/bionic-reader-linux-$(uname -m).pkg.tar.zst" -o bionic-reader.pkg.tar.zst
sudo pacman -U ./bionic-reader.pkg.tar.zst

Python and Node.js

# pip (in a virtual environment) or uv
pip install bionic-reader
uv tool install bionic-reader

# npm, Yarn, or pnpm
npm install --global @arturoaviles/bionic-reader
yarn add @arturoaviles/bionic-reader
pnpm add --global @arturoaviles/bionic-reader

Cargo

cargo install bionic-reader --locked

Yarn installs into the current project; run it with yarn bionic-reader. Package managers select the CPU architecture automatically. Linux release filenames use the native architecture query shown above. You can also download native binaries from GitHub Releases.

Application libraries

Install packages from PyPI, npm, or crates.io, or the Go module proxy. The library APIs below share the CLI's local transformation engine. See the library guide for complete options, errors, and platform requirements.

Earlier CLI-only releases do not include the callable APIs shown below. The registry installation commands select the latest available release.

Python

The library API requires Python 3.11+. Install into your application's virtual environment:

python -m pip install bionic-reader

See the Python examples for formats, profiles, Markdown, custom rendering, configuration, and file conversion.

from bionic_reader import Reader

reader = Reader()
print(reader.render("Hello world", format="html", profile="balanced"))
print(reader.segments("Hello world"))

JavaScript

The library API requires Node 22+. Install into your application:

npm install @arturoaviles/bionic-reader

See the JavaScript examples for Node.js, browser, TypeScript, and React usage.

Initialize the bundled WebAssembly engine once:

import { createReader } from '@arturoaviles/bionic-reader';

const reader = await createReader();
console.log(reader.render('Hello world', { format: 'html', profile: 'balanced' }));
console.log(reader.segments('Hello world'));

CommonJS uses const { createReader } = require('@arturoaviles/bionic-reader') and awaits initialization in an async function. Browser bundlers select the browser loader. React applications can use BionicReaderProvider and BionicText from @arturoaviles/bionic-reader/react; see the React example for initialization and hydration.

Rust

Requires Rust 1.85.1+. Add the crate to your application:

cargo add bionic-reader

See the Rust examples for document transformation, text segments, configuration, streaming, and custom segmentation.

use bionic_reader::reading::{Options, Reader};
use bionic_reader::settings::OutputFormat;

fn main() -> Result<(), bionic_reader::Error> {
    let reader = Reader::new();
    let options = Options::default();
    println!("{}", reader.render("Hello world", OutputFormat::Html, &options)?);
    println!("{:?}", reader.segments("Hello world", &options)?);
    Ok(())
}

Formatted output requires an explicit ansi, plain, markdown, or html format. Text segments contain literal text and an emphasized flag for custom presentation. Calls use explicit settings and deterministic defaults; they do not implicitly read CLI configuration or terminal state.

Go

Requires Go 1.25+. Install into your application:

go get github.com/arturoaviles/bionic-reader

See the Go examples for formats, profiles, Markdown, concurrent use, configuration, and file conversion.

package main

import (
    "context"
    "fmt"
    bionicreader "github.com/arturoaviles/bionic-reader"
)

func main() {
    ctx := context.Background()
    reader, err := bionicreader.NewReader(ctx)
    if err != nil { panic(err) }
    defer reader.Close()
    html, err := reader.Render(ctx, "Hello world", bionicreader.HTML, bionicreader.Options{})
    if err != nil { panic(err) }
    fmt.Println(html)
}

The Rust engine is embedded as WebAssembly and runs locally through wazero. Consumers need no CGO, Rust installation, separate CLI, or runtime downloads. Reuse and close the reader; calls are safe concurrently and accept contexts for cancellation. Go support starts with the 0.3.0 release.

The reader

bionic-reader read article.txt
cat article.txt | bionic-reader read

Scroll with the arrow keys or j/k, search with /, and press q to leave. Use ? for all shortcuts. Adjust emphasis while you read with +/-, or try settings interactively with bionic-reader preview.

The CLI

bionic-reader -t 'Make long passages easier to follow.'
cat article.txt | bionic-reader
bionic-reader --input-format markdown --style always < article.md

# Change the reading style.
bionic-reader --profile subtle -t 'A lighter touch.'
bionic-reader --fraction 0.6 --every 2 -t 'Choose your own emphasis.'

# Export HTML or Markdown.
bionic-reader --format html < article.txt > article.html
bionic-reader --format markdown < article.txt > emphasized.md

See bionic-reader --help and the usage guide for formats, profiles, safe terminal controls, and reader shortcuts.

Shell integration

Start a reading session with bionic-reader session. Known editors, pagers, and full-screen applications use passthrough. Inside a session, use bionic-reader off, on, or toggle to control emphasis, and exit to leave.

For automatic sessions, add one initializer to your shell configuration:

# ~/.bashrc
eval "$(bionic-reader init bash)"
# ~/.zshrc
eval "$(bionic-reader init zsh)"

Bash, Zsh, fish, shell completions, and seven framework adapters are covered in the shell guide.

Configuration

Save preferences in ~/.config/bionic-reader/config.toml, or beneath an absolute XDG_CONFIG_HOME:

profile = "balanced"
fraction = 0.5
emphasis = "bold"

Command-line settings override the file. See the configuration guide for all options and precedence.

Contributing

See CONTRIBUTING.md for development checks, BUILD.md for source builds, and RELEASE.md for release and package publication.

License

MIT.