IPLD-CAR & CLI

A Rust implementation of the CAR v1 formats (well only Dag-pb at the moment), designed for reading and writing content-addressable archives without external IPFS infrastructure.

This workspace contains two crates:

• ipld-car — library for reading and writing CAR files, with an optional filesystem interface backed by the vfs trait.
• carcli — command-line tool for inspecting and extracting CAR files.

Library — ipld-car

Filesystem interface

CarFs<T> wraps a ContentAddressableArchive and implements vfs::FileSystem, giving you a familiar, path-based API over the archive contents.

use ipld_car::{CarFs, ContentAddressableArchive};
use vfs::FileSystem;
use std::fs::File;

let fs = CarFs::from(ContentAddressableArchive::load(File::open("archive.car")?)?);

// Read a directory
for entry in fs.read_dir("/subdir")? {
    println!("{entry}");
}

// Stream a file to stdout
let mut reader = fs.open_file("/subdir/hello.txt")?;
std::io::copy(&mut reader, &mut std::io::stdout())?;

You can also build an archive:

use ipld_car::{CarFs, Config, ContentAddressableArchive};
use vfs::FileSystem;
use std::{fs::File, io::{BufWriter, Write}};

let fs = CarFs::from(ContentAddressableArchive::new(Config::default())?);

fs.create_dir("/docs")?;
let mut file = fs.create_file("/docs/readme.txt")?;
write!(file, "hello")?;

// NOTE: the block is committed to the CAR on `drop`.
drop(file);

// Extract the CAR from the FS wrapper and write to disk.
let mut car = fs.into_inner().unwrap();
car.write(&mut BufWriter::new(File::create("out.car")?))?;

Features

CLI — carcli

Installation

cargo install --path carcli

Commands

info — archive summary

carcli info archive.car

File:            archive.car
Blocks:          4
  Roots:         1
  Non-roots:     3
Total DAG-PB:    208B
Total Data:      43B
  [0] bafybeietjm63oynimmv5yyqay33nui4y4wx6u3peezwetxgiwvfmelutzu

ls — list directory contents

carcli ls archive.car               # flat list of /
carcli ls archive.car /subdir       # list a specific path
carcli ls -T -B archive.car         # recursive tree with byte sizes

The -T flag renders the full directory tree; -B shows exact byte counts instead of SI prefixes:

Permissions  Size  User   Group  Date Modified         Name
drwxr-xr-x   -     alice  staff  2026-03-12T18:45:02Z  └──  subdir/
.r--r--r--   31B   alice  staff  2026-03-12T18:45:02Z      ├──  ascii.txt
.r--r--r--   12B   alice  staff  2026-03-12T18:45:02Z      └──  hello.txt

cat — print a file

carcli cat archive.car /subdir/hello.txt

hello world

Streams directly to stdout, so it composes naturally with other Unix tools:

carcli cat archive.car /data/records.json | jq '.items[]'
carcli cat archive.car /report.pdf > report.pdf

create — pack a directory or file into a CAR file

Recursively adds a local directory or file, preserving the directory structure:

carcli create out.car ./my-directory
carcli create out.car ./single-file.txt

write — pack individual files into a CAR file

Adds specific files at explicit destination paths using DEST=SRC mappings:

carcli write -o out.car --add /docs/readme.txt=./README.md --add /data/a.json=./a.json

License

MIT