Errors

Every failure throws Automattic\VIP\C2PA\C2paException, which extends \RuntimeException — existing catch (\RuntimeException $e) clauses keep working, and a namespace-wide catch is one class.

use Automattic\VIP\C2PA\C2paException;
use Automattic\VIP\C2PA\Reader;

try {
    $reader = Reader::fromBytes($bytes, 'image/jpeg');
} catch (C2paException $e) {
    // corrupt asset or malformed manifest — not merely "unsigned"
}

What is not an error

The API draws a hard line between verdicts and errors:

No manifest — Reader::fromBytes() returns normally with hasManifest() === false.
Invalid manifest — a manifest that fails validation (tampered bytes, bad signature) returns normally with validationState() === "Invalid".

Exceptions are reserved for inputs and configuration that are actually broken.

Message taxonomy

Messages are prefixed by failure category:

Prefix	Thrown by	Meaning
`c2pa read/validate failed: …`	`Reader::fromBytes()`	The asset is corrupt or its manifest is structurally unreadable
`c2pa signing failed: …`	`Builder::sign()`	Manifest assembly, ingredient embedding, or the signature itself failed
`invalid signer configuration: …`	`Signer::fromPem()`, `generateSelfSigned()`, `sign()`	Unsupported algorithm, empty/invalid PEM, chain–key mismatch
`invalid input: …`	`Builder::addAssertion()`, `addIngredientFromBytes()`	Caller-supplied JSON did not parse

The prefixes are stable enough to branch on for logging/metrics, but prefer structuring your code so the call site tells you the category — each prefix maps 1:1 to the operation you invoked.

Keyboard shortcuts

ext-c2pa

Errors

What is not an error

Message taxonomy