Local C2PA Validation Arrives in Google's Credentio C++ Library

On August 13, 2026, Google released Credentio, an open-source C++ library for local-first validation of Coalition for Content Provenance and Authenticity (C2PA) credentials. The release allows developers to verify digital provenance metadata directly on device. By processing multi-gigabyte media files locally, the library eliminates the bandwidth overhead of sending assets to external validation servers.

Google already uses the underlying Credentio code in nearly 40 C2PA-conformant products. The engine has processed tens of billions of assets across the company’s ecosystem prior to this Apache-2.0 release.

Technical Specifications

Credentio currently supports C2PA specification versions 2.2 and 2.4. The initial release focuses on deep manifest parsing and trust list integration. Google plans to add full credential generation and embedding capabilities in future updates.

The library prioritizes a low memory footprint to handle large video and high-resolution image files on local hardware. This architecture provides instant validation verdicts and ensures user data never leaves the device, removing a major hurdle when developers audit local privacy requirements for media applications.

Credentio is built with the Bazel build system. Its core dependencies include Abseil, BoringSSL, Protocol Buffers, Google Tink, and Riegeli.

Supported Media Formats

The engine parses C2PA metadata across a wide range of standard media extensions:

Media Category	Supported File Formats
Images	.avif, .dng, .gif, .heic, .heif, .jpeg, .jpg, .png, .tif, .tiff, .webp
Audio/Video	.avi, .m4a, .mov, .mp3, .mp4, .wav, .flac
Documents	.pdf, .docx, .pptx, .xlsx

Gemini Ecosystem Context

The library release arrives alongside changes to Google’s consumer AI watermarking policies. On August 15, Google announced it will allow users to toggle off the visible “sparkle” watermark on Gemini AI generations.

Despite making the visible marker optional, the underlying C2PA metadata and invisible SynthID watermarks remain permanently embedded in all generated media. Credentio provides the required infrastructure for third-party developers to maintain visibility into these markers as they flow through external AI inference pipelines and social platforms.

If you build content moderation or media ingestion systems, you can pull the Credentio source code from Google’s internal Git service at mediaprovenance.googlesource.com/credentio/ to integrate verifiable provenance checks directly into your application binaries.