IRIS (Interactive Renderer for Information Sources)

Terminal-native viewing for documents, data, and everything in between

IRIS is a general-purpose terminal viewer for rendering and exploring different kinds of files and structured data from one interface.

Instead of switching between separate tools for Markdown, JSON, CSV files, logs, images, PDFs, databases, and other formats, IRIS aims to provide a single terminal-native way to inspect them.

Think of it as a more visual and extensible less for modern files and data.

What can IRIS view?

IRIS is designed to support formats such as:

• Markdown
• JSON
• YAML
• TOML
• CSV
• Images
• PDFs
• SQLite databases
• Logs and plain text
• Standard input

The current release focuses on plain text and Markdown. Markdown rendering includes headings, lists and task lists, tables, blockquotes and GitHub-style alerts, syntax-highlighted code blocks, links, embedded HTML, and Markdown images. Additional format-specific renderers will be added incrementally.

Installation

Cargo

Install the latest published release from crates.io:

cargo install iris-reader --locked

The crate is named iris-reader, but the installed command is simply:

iris

Cargo installs binaries into ~/.cargo/bin by default, so make sure that directory is on your PATH.

Prebuilt GitHub release

Download the archive for your platform from the GitHub Releases page, extract it, and place the iris binary somewhere on your PATH.

On Linux and macOS, a local installation can use:

install -Dm755 iris ~/.local/bin/iris

Windows releases contain iris.exe; place it in a directory that is included in your PATH.

From source

IRIS requires Rust 1.94 or newer when building from source.

git clone https://github.com/KyanJeuring/iris.git
cd iris
make install

make install builds an optimized release binary and installs it to ~/.local/bin/iris by default.

Updating

How IRIS should be updated depends on how it was installed.

Cargo

cargo install iris-reader --locked --force

Prebuilt GitHub release

Download the newer release for your platform and replace the existing iris / iris.exe binary.

Source installation

From the cloned repository:

make update

This performs a fast-forward-only git pull, rebuilds IRIS in release mode, and reinstalls the binary.

Uninstalling

Cargo

cargo uninstall iris-reader

Prebuilt or local installation

If the binary was installed to ~/.local/bin:

rm -f ~/.local/bin/iris

For a source installation, the same can be done through the Makefile:

make uninstall

Support for additional package managers such as APT, Pacman/AUR, Homebrew, and WinGet is planned.

Usage

Open a file directly:

iris README.md
iris notes.txt

Or read standard input:

journalctl | iris
cat README.md | iris --format markdown

IRIS detects Markdown from file extensions. For piped input, use --format markdown when Markdown rendering is desired.

Useful options include:

iris --help
iris --version
iris --theme ember README.md
iris --icons unicode README.md
iris --list-themes

Ember is the built-in default theme and uses Nerd Font icons by default. If the terminal does not use a Nerd Font, switch to the portable Unicode icon set with --icons unicode or set icons = "unicode" in ~/.config/iris/config.toml.

Navigation

Inside the viewer:

j / k, arrows       Scroll vertically
h / l, arrows       Scroll horizontally
PgUp / PgDn         Scroll by page
g / G               Top / bottom
[h / ]h             Previous / next Markdown heading
/                    Search
n / N                Next / previous search result
Esc                  Clear search / close an overlay
w                    Toggle wrapping
?                    Help
q                    Quit

Mouse-wheel and trackpad scrolling are supported. Shift + wheel scrolls horizontally. Markdown links can be opened by clicking them.

Markdown images and HTML

Markdown images are rendered as terminal image blocks, including images placed inside normal paragraph flow. Standalone HTML <img> tags are rendered the same way. More complex inline HTML/image combinations fall back to a styled clickable placeholder so the surrounding text stays readable. IRIS detects terminal graphics capabilities and can use Kitty, Sixel, or iTerm2 image protocols, with a terminal-cell fallback when needed.

Local image paths are resolved relative to the Markdown document. Remote HTTP(S) images are also supported. Common raster formats include PNG, JPEG, GIF, WebP, BMP, and ICO, and SVG images are rasterized automatically before being sent to the terminal graphics protocol.

IRIS also renders a useful Markdown-oriented subset of embedded HTML, including common formatting, headings, links, lists, blockquotes, code, <pre>, <mark>, <kbd>, <br>, <hr>, and image tags. It does not execute JavaScript or behave as a web browser.

Unicode

IRIS uses UTF-8 throughout and display-width-aware wrapping. CJK text, accented characters, Cyrillic, Greek, language symbols, combining characters, and emoji can be rendered as long as the active terminal/font provides the required glyphs.

Full bidirectional layout for right-to-left scripts depends on terminal support and is not currently treated as a dedicated layout mode.