ManifestBuilder API rebased and updates #7

n8fr8 · 2025-10-30T17:58:53Z

Changes in this pull request

Adds new package to Kotlin code for providing a ManifestBuilder interface for creating valid C2PA JSON Manifests

Types of changes

Bug fix (non-breaking change which fixes an issue)
[ X ] New feature (non-breaking change which adds functionality)
Breaking change (fix or feature that would cause existing functionality to change)

Checklist

All applicable changes have been documented
Any TO DO items (or similar) have been entered as GitHub issues and the link to that issue has been included in a comment

…ation

codecov · 2025-12-04T12:28:02Z

Codecov Report

❌ Patch coverage is 0% with 707 lines in your changes missing coverage. Please review.
✅ Project coverage is 27.61%. Comparing base (ea68831) to head (f73f171).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
...n/org/contentauth/c2pa/manifest/ManifestHelpers.kt	0.00%	281 Missing ⚠️
...rg/contentauth/c2pa/manifest/AttestationBuilder.kt	0.00%	273 Missing ⚠️
...n/org/contentauth/c2pa/manifest/ManifestBuilder.kt	0.00%	153 Missing ⚠️

❗ There is a different number of reports uploaded between BASE (ea68831) and HEAD (f73f171). Click for more details.

HEAD has 2 uploads less than BASE

Flag BASE (ea68831) HEAD (f73f171)

4 2

Additional details and impacted files

@@             Coverage Diff             @@
##             main       #7       +/-   ##
===========================================
- Coverage   53.65%   27.61%   -26.04%     
===========================================
  Files          13       16        +3     
  Lines         863     1503      +640     
  Branches      116      186       +70     
===========================================
- Hits          463      415       -48     
- Misses        327     1015      +688     
  Partials       73       73

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

ok-nick

Looks good, I have a few comments.

ok-nick · 2025-12-04T20:38:05Z

library/src/main/kotlin/org/contentauth/c2pa/manifest/C2PAActions.kt

+    const val OPENED = "c2pa.opened"
+    const val PLACED = "c2pa.placed"
+    const val DRAWING = "c2pa.drawing"
+    const val COLOR_ADJUSTMENTS = "c2pa.color_adjustments"


There are new actions here such as c2pa.adjustedColor and perhaps a few more defined here. We should probably add them upstream in the Rust SDK too.

We kind of went overboard in adding possible actions. We were also considering paring back, to just focus on the typical ones for a mobile app in this release. For now, we can just leave them, and then review and plan after the merge.

ok-nick · 2025-12-04T20:43:53Z

library/src/main/kotlin/org/contentauth/c2pa/manifest/ManifestBuilder.kt

+data class Ingredient(
+    val title: String? = null,
+    val format: String,
+    val instanceId: String = UUID.randomUUID().toString(),


I'd prefer to stick to the default instance ID generation that happens in the Rust SDK. Are there any downsides in doing that?

No I don't think so. We can rely on that. Let me make sure we don't have any other reason to generate it here.

ok-nick · 2025-12-04T20:46:02Z

library/src/main/kotlin/org/contentauth/c2pa/manifest/ManifestBuilder.kt

+    val documentId: String? = null,
+    val provenance: String? = null,
+    val hash: String? = null,
+    val relationship: String = "parentOf",


There can only be 1 parent ingredient in a manifest, thus the Rust SDK defaults to "componentOf." I have the same question if we need to default here or in the Rust SDK.

ok-nick · 2025-12-04T20:47:56Z

library/src/main/kotlin/org/contentauth/c2pa/manifest/ManifestBuilder.kt

+data class Thumbnail(
+    val format: String,
+    val identifier: String,
+    val contentType: String = "image/jpeg"


How come the format and contentType are separate fields? Should we be defaulting to JPEG? The SDK will infer the format from the identifier and may auto-generate PNG, JPEG, or other formats depending on the circumstance.

ok-nick · 2025-12-04T20:49:00Z

library/src/main/kotlin/org/contentauth/c2pa/manifest/ManifestBuilder.kt

+    private var claimGenerator: ClaimGenerator? = null
+    private var format: String? = null
+    private var title: String? = null
+    private var instanceId: String = UUID.randomUUID().toString()


Same question about the UUID default here.

workong on removing these now, and will update with a push soon, once testing is complete.

ok-nick · 2025-12-04T22:17:36Z

library/src/main/kotlin/org/contentauth/c2pa/manifest/ManifestBuilder.kt

+)
+
+class ManifestBuilder {
+    private var claimGenerator: ClaimGenerator? = null


There can be multiple claim generators.

In the case of this generator though, there is only 1 instance active within our builder.

claimGenerator is now an array, and multiple can be added

@ok-nick this was true in C2PA version 1.x (and for that reason, may still be exposed in the core SDK). In C2PA 2.2, there can only be one claim generator. (See https://spec.c2pa.org/specifications/specifications/2.1/specs/C2PA_Specification.html#_schema.)

ok-nick · 2025-12-04T22:17:59Z

library/src/main/kotlin/org/contentauth/c2pa/manifest/ManifestHelpers.kt

+        claimGeneratorName: String = "Android C2PA SDK",
+        claimGeneratorVersion: String = "1.0.0",


In the Rust SDK we inject our Rust SDK specific claim generator into the user-specified list. Maybe we should consider doing that here?

So the Rust SDK specific one would be in addition or included in the name of what the user provides?

@scouten-adobe clarified in #7 (comment) that there's only one claim generator in v2 claims. I agree with what you have implemented here already then.

ok-nick · 2025-12-04T22:20:51Z

library/src/main/kotlin/org/contentauth/c2pa/manifest/ManifestBuilder.kt

Another approach to consider is generating these type definitions automatically from the JSON schemas exported in the Rust SDK. I believe the Node and JS SDK take a similar approach, not sure if that's possible here.

Yes. We did some variation on that at first. I will review and consider. This code is not just type definition however, as there is some additional logic of the builder, I but I understand what you mean. We are trying to keep this Kotlin/Android like while also making it easy to maintain.

ok-nick · 2025-12-04T22:26:35Z

library/src/main/kotlin/org/contentauth/c2pa/manifest/C2PAActions.kt

+    const val DATA_HASH = "c2pa.data_hash"
+    const val HASH_DATA = "c2pa.hash.data"


c2pa.hash.data is the correct label here, I'm not sure if the other one exists.

ok-nick · 2025-12-04T22:28:54Z

library/src/main/kotlin/org/contentauth/c2pa/manifest/C2PAActions.kt

+    }
+}
+
+object C2PAAssertionTypes {


I'm not sure if all of these assertion types are defined in the spec.

n8fr8 added 4 commits October 27, 2025 16:27

add ManifestBuilder package for simple, compliant manifest JSON gener…

1534502

…ation

add new tests for ManifestBuilder package and update sdk to min 28

1e5e115

add support for SoftwareAgent and DigitalSourceType

2cc368e

add new JSON generation for softwareAgent and digitalSourceType

f73f171

scouten-adobe requested a review from ok-nick December 4, 2025 19:24

ok-nick suggested changes Dec 4, 2025

View reviewed changes

n8fr8 added 5 commits December 11, 2025 08:27

refact to improve code using libs toml

29bd48d

improve tests and code coverage for ManifestBuilder and package

28c0d89

remove incorrect Assertion - const val DATA_HASH = "c2pa.data_hash"

b391b36

you can now specify multiple claim generators

49bf22b

fixes issue with duplicate JNA library conflicts

27dab76

		claimGeneratorName: String = "Android C2PA SDK",
		claimGeneratorVersion: String = "1.0.0",

		const val DATA_HASH = "c2pa.data_hash"
		const val HASH_DATA = "c2pa.hash.data"

ManifestBuilder API rebased and updates #7

Are you sure you want to change the base?

ManifestBuilder API rebased and updates #7

Uh oh!

Conversation

n8fr8 commented Oct 30, 2025

Changes in this pull request

Types of changes

Checklist

Uh oh!

codecov bot commented Dec 4, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

ok-nick left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

codecov bot commented Dec 4, 2025 •

edited

Loading