C2PA · OWG

How OWG records C2PA content credentials on assets, maps manifests and ingredients onto lineage, and earns the attested assurance level only after verification.

Status: buildable on v0.92 with no schema change. The keys inside asset.credentials below are a convention set by this page.

What C2PA is

The Coalition for Content Provenance and Authenticity publishes the Content Credentials specification, currently version 2.4. A content credential is a manifest attached to or referenced by an asset:

Assertions are statements about the asset: what was done to it (actions such as c2pa.created, c2pa.opened and c2pa.edited), which earlier assets went into it (ingredients), and whether it was produced by a generative model.
A claim gathers the assertions and binds them to the content, by a cryptographic hash (a hard binding) or by a watermark or fingerprint (a soft binding).
The claim generator is the software that wrote the claim; the signer holds the key that signed it.
A validator checks the signature, the bindings and the signer's certificate, and reports whether the credential is valid and trusted.

C2PA also publishes guidance on AI and machine-learning content.

Where C2PA and OWG meet

They record provenance at different moments, and a production needs both:

Layer	When	Answers
C2PA	At capture or generation, and at each signed edit	Is this file what its signer says it is?
OWG	Throughout production, as a side effect of running the work	Who made it, from what, under whose authority, after which approvals, at what cost?
Publication labelling (for example the EU AI Act icon set)	At publication	What does the audience need to be told?

A C2PA manifest travels with one file. An OWG graph holds the whole production around it: the brief, the review that approved the image, the person who localized it, the check that verified the credential, the delivery. Each makes the other more useful: the manifest gives OWG's graph its strongest evidence, and the graph explains the manifest.

The hook

C2PA lands on the asset, never on the task, in three existing fields:

{
  "id": "key_art_fr",
  "predecessor": "key_art_base", "version_relation": "alternative",
  "identity": "sha256:…",
  "identifiers": [{ "scope": "c2pa", "id": "urn:c2pa:…" }],
  "credentials": {
    "scheme": "c2pa",
    "manifest": "urn:c2pa:…",
    "signer": "org_studio",
    "actions": ["c2pa.opened", "c2pa.edited"],
    "ingredients": [{ "asset": "key_art_base", "relationship": "parentOf" }],
    "status": "trusted"
  },
  "assurance": "attested"
}

Key in `credentials`	Holds
`scheme`	`c2pa`
`manifest`	The active manifest's identifier. Also listed in `identifiers[]` under scope `c2pa`, so other systems can match on it
`signer`	The organization or participant id whose key signed the claim
`actions`	The C2PA action names in the manifest, as recorded
`ingredients`	`{ asset, relationship }` per ingredient, with C2PA's relationship (`parentOf`, `componentOf`, `inputTo`) and the OWG asset id it resolves to
`ai_generated`	`true` when the manifest declares generative-AI origin
`status`	The last verification result: `unverified`, `valid`, `trusted` or `invalid`

How it maps

C2PA	OWG
Manifest	`credentials.manifest`, and an `identifiers[]` entry with scope `c2pa`
Hard binding (content hash)	`asset.identity`
`parentOf` ingredient	`predecessor` with a `version_relation`
`componentOf` ingredient	an `asset.composes[]` entry
`inputTo` ingredient	the producing task's `used[]`
Actions	The task that `produced` the asset; `credentials.actions` mirrors what the manifest says
Generative-AI origin	The producing task's `ai_role: "generative"`, and `credentials.ai_generated`
Claim generator	The producing task's executor
Signer	`credentials.signer`, an organization or participant
Validation result	A `qc` task that `used` the asset, its report as an asset, and `credentials.status`
Trusted credential	`asset.assurance: "attested"`

attested is earned, not declared. An asset gets assurance: "attested" only after a verification task has found its credential valid and its signer trusted. Until then a manifest is a claim, and the asset stays asserted. This is the rule that keeps OWG's strongest assurance level honest: see Relationships → assurance.

Reference workflow

c2pa-localized-key-art.owg.json: an agent generates base key art through a signing generation service; an art director approves it; a designer adds the French title treatment, producing a new signed asset whose manifest names the base image as its parentOf ingredient; a verifier checks the credential before delivery, and a failed check routes back to approval, at most twice.

curl -O https://openworkflowgraph.org/corpus/c2pa-localized-key-art.owg.json
owg-validate c2pa-localized-key-art.owg.json --json

What to take from it:

The base image is asserted with status unverified; the verified French version is attested. Same scheme, different standing, and the document says why.
The ingredient relationship and the OWG predecessor describe the same edge from two sides. A reconciler can check one against the other.
The generation task declares ai_role: "generative" and its agent traces to the art director through operated_by: the AI disclosure falls out of the graph.

What stays in C2PA

OWG does not sign, embed, strip or validate manifests, and it does not copy their assertions. The manifest store remains the system of record for the credential. OWG records that the credential exists, what it says at the level a production needs, and the result of checking it.

Signing needs a certificate from a certificate authority that C2PA recognizes. An implementation obtains one; it does not need to become one.

Known gaps

The keys inside credentials are a convention on this page. The schema leaves the object open.
No validator rule yet checks that a task with ai_role: "generative" produced an asset whose credential says ai_generated, or the reverse. Both are recorded; their agreement is not checked.
Soft bindings (watermarks, fingerprints) have no field. A soft-binding identifier can go in identifiers[] meanwhile.
No reference signing or verification client ships with OWG.