Install c2patool with Homebrew, Nix

Project links

• Homepage
• Repository
• Upstream docs
• Package manager page

Commands and aliases

• c2patool

Project history

C2PA was founded in February 2021 by Adobe, Arm, the BBC, Intel, Microsoft, and Truepic to develop technical standards for certifying the source and history of media content. The c2pa-rs repository began with an initial public release on 23 May 2022 and became the Rust SDK and CLI implementation used by the Content Authenticity Initiative open-source tooling.

The c2patool README describes a CLI that works with C2PA manifests and audio, image, or video assets. It can read summary JSON, read detailed manifest data, add manifests to assets, use sidecar or remote manifests, inspect certificate chains, configure trust, and work with signing commands.

Adoption history

The tool is distributed through Homebrew for macOS, prebuilt GitHub release archives for macOS, Windows, and Linux, and source builds from the c2pa-rs repository. source_facts also records Nix packaging.

The broader adoption story is standards-driven: c2pa-rs implements part of the C2PA technical specification and CAWG identity assertion work, so the CLI serves developers, publishers, and tool builders testing Content Credentials workflows before or alongside application integration.

How it is used

Common c2patool usage includes printing manifest JSON from an asset, saving manifest reports to an output directory, adding a manifest definition to a file, generating `.c2pa` sidecars, embedding remote manifest references, extracting signing certificates, and producing ingredient records for asset history.

The CLI supports a settings file, defaulting to `~/.config/c2pa/c2pa.toml` unless C2PATOOL_SETTINGS or `--settings` overrides it. Signing can be delegated to subprocess signers so private key material does not need to pass directly through the CLI in production.

Why package nerds care

c2patool is package-nerd interesting because it turns a large media-authenticity standard into a composable Unix-style inspection and signing tool. That makes C2PA manifests testable in CI, build pipelines, image-processing scripts, and release workflows.

It also shows a modern package pattern: a Rust SDK repository shipping libraries, C FFI, documentation, examples, release archives, and a CLI, all around a fast-moving standard rather than a single old protocol.

Timeline

• 2021-02: C2PA is founded by Adobe, Arm, BBC, Intel, Microsoft, and Truepic.
• 2022-05-23: c2pa-rs upstream Git history begins with an initial public release.
• 2026-04-29: c2patool changelog records init trust, trust sidecars, and atomic sidecar writes.
• 2026-05-27: c2patool 0.26.60 adds intent support and create/update signing behavior.
• 2026-06-09: c2patool 0.26.65 fixes a DLL hijacking vulnerability.
• 2026-06-19: c2patool 0.26.68 is published in the upstream changelog.

Related projects

• c2pa-rs: the Rust SDK repository that contains c2patool.
• Content Authenticity Initiative: the open-source SDK and community context for C2PA tooling.
• C2PA technical specification: the standard implemented by the Rust SDK and CLI.
• c2patool-service-example: official example repository for using c2patool from a Node.js server application.

Sources

• https://c2pa.org/about/
• https://github.com/contentauth/c2pa-rs/blob/main/README.md
• https://github.com/contentauth/c2pa-rs/blob/main/cli/CHANGELOG.md
• https://github.com/contentauth/c2pa-rs/blob/main/cli/README.md
• https://github.com/contentauth/c2pa-rs/blob/main/cli/docs/usage.md
• source_facts.package-manager