C2pa Metadata

---
name: c2pa-metadata
description: "Embed C2PA provenance in AI-generated images, video or PDF by script. \"add content credentials to this asset\""
---

# /digital-marketing-pro:c2pa-metadata — Embed Content Authenticity Provenance

## Purpose

Wraps `scripts/embed-c2pa.py` to add a **C2PA (Coalition for Content Provenance and Authenticity) manifest** to any AI-generated marketing asset. The manifest carries a machine-readable provenance trail (who generated it, what generator was used, what prompt produced it, when it was reviewed) plus a visible AI-generation claim in the IPTC digital-source-type vocabulary.

This is the technical mechanism brands use to comply with:

- **EU AI Act Article 50** (has applied since 2 August 2026; generative systems that existed before then have until 2 December 2026 to mark their output under Article 50(2)) — generative-AI marketing content must be marked in a machine-readable format using open, interoperable standards. C2PA is the emerging backbone. Penalty for non-compliance: up to **€15 million or 3% global annual turnover**.
- **NY synthetic-performer disclosure law** (S.8420-A, signed 2025-12-11, in force 2026-06-09: an ad that uses an AI-generated synthetic performer must disclose it conspicuously; $1,000 for a first violation and $5,000 for each later one; applies to ads reaching New York audiences ([Governor's release](https://www.governor.ny.gov/news/governor-hochul-signs-legislation-protect-consumers-and-boost-ai-transparency-film-industry), 2025-12-11; the effective date and penalties as reported by law-firm summaries)).
- **FTC rules on endorsements and reviews**: the Endorsement Guides (16 CFR Part 255, revised 2023) and the Consumer Reviews and Testimonials Rule (16 CFR Part 465, in force 2024-10-21), which bans fake reviews and testimonials, AI-generated ones included; the FTC's Q&A says an AI avatar can still be a testimonial and can deceive ([FTC Q&A](https://www.ftc.gov/business-guidance/resources/consumer-reviews-testimonials-rule-questions-answers)).
- **Australia Online Safety Act / UK Online Safety Act** — emerging deepfake disclosure requirements.

The resulting asset can be inspected by any C2PA-aware viewer (Adobe Photoshop, Lightroom, Truepic, [contentcredentials.org/verify](https://contentcredentials.org/verify)).

### C2PA spec versions to be aware of (June 2026)

- **C2PA 2.3** (December 2025 in the spec's version history; announced 9 February 2026 — [launch post](https://c2pa.org/the-c2pa-launches-content-credentials-2-3-and-celebrates-5-years-of-impact-across-the-digital-ecosystem/)) added format support for: **live video** (broadcast/streaming), **plain text documents**, **OGG Vorbis audio**, **large AVI video files**, and **EXIF Original Preservation Images**. If a brand is signing live-stream video or text-based assets for the first time, 2.3 is the floor version to target.
- **C2PA 2.5 is the current specification** (October 2026, spec.c2pa.org, read 2026-10-27). Whether the pinned c2pa-python reads 2.5 manifests is unverified; check `embed-c2pa.py --verify` on a 2.5 file before relying on it.
- **C2PA Spec 2.4** (April 2026 — [spec.c2pa.org/specifications/specifications/2.4](https://spec.c2pa.org/specifications/specifications/2.4/specs/C2PA_Specification.html)) introduces the **AI Disclosure Assertion (`c2pa.ai-disclosure`)** for machine-readable AI transparency info — this is the assertion the EU AI Act Article 50 deployer pathway will rely on. The final Code of Practice on Transparency of AI-Generated Content (published 10 June 2026) references C2PA-style assertions as the canonical machine-readable marking mechanism for both providers and deployers. See `skills/context-engine/eu-code-of-practice.md` for the full Article 50 context.
- The **C2PA Trust List** is now handled via the public C2PA Conformance Program (any CA meeting the Certificate Policy can join). Production signing certificates should come from a Conformance-Program-listed CA, not an ad-hoc cert.

**For DMP outputs**: `embed-c2pa.py` now supports `--ai-disclosure`. Pass it to embed the C2PA 2.4 `c2pa.ai-disclosure` assertion alongside the existing IPTC digital-source-type claim. The combination gives you both human-readable (IPTC) and machine-readable (`c2pa.ai-disclosure`) EU AI Act **Article 50** signaling — this is the deployer-side machine-readable pathway the final Code of Practice (10 June 2026) points to as the canonical marking mechanism. See `skills/context-engine/eu-code-of-practice.md` for the full Article 50 context.

## When to invoke

- Right after any AI image / video / audio generation step in the engagement workflow (Part 11 — AI Creative Instructions output)
- Before handing a generated asset to the design team for review
- As a pre-publish gate in `/digital-marketing-pro:check` for EU-targeted assets
- Bulk-applying to a backlog of AI-generated assets for EU publication (Article 50 applies since 2 Aug 2026; content made before that date needs no retroactive label)

## Quick examples

```bash
# Single asset — image generated by Vertex AI / Nano Banana Pro
/digital-marketing-pro:c2pa-metadata \
    --input assets/q3-launch-hero.png \
    --output assets/signed/q3-launch-hero.png \
    --brand "Acme Corp" \
    --generator "Vertex AI / Nano Banana Pro" \
    --ai-claim ai-generated-content \
    --prompt "minimalist product hero shot, soft natural lighting"

# Video with human review tracked
/digital-marketing-pro:c2pa-metadata \
    --input campaigns/launch-video-v3.mp4 \
    --output campaigns/signed/launch-video-v3.mp4 \
    --brand "Acme Corp" \
    --generator "Runway Gen-4" \
    --ai-claim ai-generated-content \
    --reviewer "Jane Smith"

# EU-targeted asset — add the machine-readable Article 50 AI-disclosure assertion (C2PA 2.4)
/digital-marketing-pro:c2pa-metadata \
    --input assets/q3-launch-hero.png \
    --output assets/signed/q3-launch-hero.png \
    --brand "Acme Corp" \
    --generator "Vertex AI / Nano Banana Pro" \
    --ai-claim ai-generated-content \
    --ai-disclosure \
    --prompt "minimalist product hero shot, soft natural lighting"

# Human-created image with AI-assisted edits
/digital-marketing-pro:c2pa-metadata \
    --input assets/founder-headshot-edited.jpg \
    --output assets/signed/founder-headshot-edited.jpg \
    --brand "Acme Corp" \
    --generator "Adobe Generative Fill" \
    --ai-claim ai-assisted-edits

# Production sign with a real C2PA signing certificate
/digital-marketing-pro:c2pa-metadata \
    --input assets/q3-launch-hero.png \
    --output assets/signed/q3-launch-hero.png \
    --brand "Acme Corp" \
    --generator "Vertex AI / Nano Banana Pro" \
    --ai-claim ai-generated-content \
    --signing-cert /secure/c2pa-prod-cert.pem \
    --signing-key /secure/c2pa-prod-key.pem
```

## AI claim values (IPTC digital source type)

| Value | When to use | Maps to IPTC URI |
|---|---|---|
| `ai-generated-content` | Asset fully generated by AI | `algorithmicMedia` |
| `ai-assisted-edits` | Human-created + AI-edited (e.g. Generative Fill) | `compositeWithTrainedAlgorithmicMedia` |
| `ai-no-substantive-changes` | AI used (e.g. upscaling) but no semantic change | `minorHumanEdits` |

The IPTC vocabulary is what EU AI Act regulators reference — using these values rather than ad-hoc strings makes the asset interoperable with the Article 50 enforcement tooling.

## Supported asset formats

`.png` · `.jpg/.jpeg` · `.webp` · `.gif` · `.tiff` · `.mp4` · `.mov` · `.webm` · `.mp3` · `.wav` · `.pdf`

## Signing certificate

Production C2PA signatures require a certificate from a CAI-recognized signing authority. The script will use one if you pass `--signing-cert` and `--signing-key`. If you omit them, the script generates a **self-signed 90-day dev certificate** for development testing only — a self-signed asset will verify as "signature present but signer not in trust list" at [contentcredentials.org/verify](https://contentcredentials.org/verify).

For production deployment:

1. Obtain a C2PA-compatible signing certificate from a CAI-recognized authority (Adobe, Truepic, Numbers Protocol, Microsoft Azure Confidential Ledger).
2. Store the cert + key securely (do NOT commit to git; use an environment-variable path or secret store).
3. Pass `--signing-cert` and `--signing-key` on every production invocation.

Reference: [opensource.contentauthenticity.org/docs/manifest/signing-manifests/](https://opensource.contentauthenticity.org/docs/manifest/signing-manifests/)

## Python dependencies

- `c2pa-python==0.38.0`: required for signing and for `--verify`
- `cryptography==46.0.3`: only needed for the dev self-signed cert path

The script never installs anything. If either package is missing it prints the exact `python -m pip install "…"` command and exits with code 2; show that command to the user and let them decide whether to run it. Do not run pip on their behalf.

Each signature requests a timestamp from `http://timestamp.digicert.com` (a hash of the claim, not the asset). The dev key, when used, is deleted as soon as the script exits.

## Output

The script prints a JSON status report to stdout:

```json
{
  "status": "success",
  "input": "assets/q3-launch-hero.png",
  "output": "assets/signed/q3-launch-hero.png",
  "size_bytes": 482371,
  "brand": "Acme Corp",
  "generator": "Vertex AI / Nano Banana Pro",
  "ai_claim": "ai-generated-content",
  "created": "2026-05-16T10:30:00+00:00",
  "manifest_assertions": ["c2pa.actions", "stds.schema-org.CreativeWork"],
  "using_dev_cert": false,
  "verify_url": "https://contentcredentials.org/verify"
}
```

## Integration with the engagement workflow

In a full 12-part engagement, this skill plugs in at **Part 11 — AI Creative Instructions output**. After a creative brief is rendered as an actual asset (by your creative tooling or a manual creative process), the resulting file passes through `c2pa-metadata` before being checked in to `engagements/<slug>/11-creative-briefs/signed/`.

The `/digital-marketing-pro:check` pre-publish gate should also verify that all AI-generated assets in an EU-targeted campaign carry a C2PA manifest. v3.4 adds this verification to the EU jurisdiction rule pack in `skills/context-engine/compliance-rules.md`.

## Related

- `/digital-marketing-pro:check` — pre-publish quality gate (now verifies C2PA manifest on AI assets for EU campaigns)
- `skills/context-engine/compliance-rules.md` — EU AI Act Article 50 rule pack
- `skills/influencer-creator/ftc-compliance.md` — FTC endorsement disclosure requirements
- [C2PA Specification 2.4 (April 2026)](https://spec.c2pa.org/specifications/specifications/2.4/specs/C2PA_Specification.html) — defines the `c2pa.ai-disclosure` assertion (Article 50 machine-readable pathway); [Content Credentials 2.3 launch (Feb 2026)](https://c2pa.org/the-c2pa-launches-content-credentials-2-3-and-celebrates-5-years-of-impact-across-the-digital-ecosystem/)
- [Content Authenticity Initiative](https://contentauthenticity.org/)