PHP API

Everything lives in the Automattic\VIP\C2PA namespace. This page is the complete surface; stubs/c2pa.stubs.php in the repository mirrors it for IDEs and static analysis.

All $bytes parameters and byte returns are ordinary PHP strings carrying raw binary — no encoding, no base64.

Settings

Trust configuration handed to Reader and Builder. See Trust & Verdicts.

final class Settings
{
    public function __construct();

    /** Set the PEM bundle of trusted C2PA anchors. Empty string clears it. */
    public function withTrustAnchors(string $pem): void;

    /** Whether trust anchors are configured. */
    public function hasTrustAnchors(): bool;
}

Reader

Reads and validates an embedded manifest from image bytes. See Reading & Validating.

final class Reader
{
    /**
     * Validate raw image bytes of the given MIME type. A no-manifest image
     * is not an error: hasManifest() is false, validationState() is "".
     * @throws C2paException on corrupt assets / malformed manifests
     */
    public static function fromBytes(string $bytes, string $mime, ?Settings $settings = null): Reader;

    public function hasManifest(): bool;

    /** "Valid" | "Invalid" | "Trusted" | "" (no manifest). */
    public function validationState(): string;

    /** True for "Valid" or "Trusted". */
    public function isValid(): bool;

    /** True only when the chain verified against configured trust anchors. */
    public function isTrusted(): bool;

    /** Full manifest-store JSON; "" when there was no manifest. */
    public function json(): string;

    /**
     * Compact UI summary JSON: { state, has_manifest, signer,
     * claim_generator, title, format, ai_generated, actions[],
     * ingredients[] }.
     */
    public function summary(): string;
}

Signer

A signing credential. See Signing Identities.

final class Signer
{
    /** Development-only ES256 credential compiled into the extension. */
    public static function selfSigned(): Signer;

    /**
     * BYOK credential. $certChainPem is leaf-first; $privateKeyPem is the
     * matching PKCS#8 key; $alg is one of
     * es256|es384|es512|ps256|ps384|ps512|ed25519.
     * @throws C2paException on unsupported alg / empty PEM
     */
    public static function fromPem(string $certChainPem, string $privateKeyPem, string $alg): Signer;

    /**
     * Generate a fresh ES256 signing identity for $org, as a JSON string
     * { "chain": <leaf+CA PEM>, "key": <PKCS#8 PEM>, "ca": <CA PEM> }.
     * Persist it and anchor "ca"; build a Signer from chain+key via
     * fromPem(). An empty $org defaults to "WordPress".
     */
    public static function generateSelfSigned(string $org): string;

    /** The signing algorithm, lowercased (e.g. "es256"). */
    public function algorithm(): string;
}

Builder

Assembles and embeds a signed manifest into image bytes. See Signing Originals and Derivatives.

final class Builder
{
    /** New original. $sourceType is an IPTC DigitalSourceType URL. */
    public static function create(string $title, string $sourceType, ?Settings $settings = null): Builder;

    /** Edit of a parent asset. Attach the original via addIngredientFromBytes(). */
    public static function edit(string $title, ?Settings $settings = null): Builder;

    /** Override the claim-generator (producer) name; defaults to "wp-c2pa". */
    public function withGenerator(string $name): void;

    /**
     * Add an assertion; $json is the assertion data as a JSON string.
     * @throws C2paException on unparseable JSON
     */
    public function addAssertion(string $label, string $json): void;

    /**
     * Attach an ingredient (e.g. the original as parentOf) from raw bytes.
     * $ingredientJson is e.g. {"title": "...", "relationship": "parentOf"}.
     * @throws C2paException on unparseable JSON
     */
    public function addIngredientFromBytes(string $ingredientJson, string $mime, string $bytes): void;

    /**
     * Sign $bytes and return the signed image bytes.
     * @throws C2paException when manifest assembly or signing fails
     */
    public function sign(string $bytes, string $mime, Signer $signer): string;
}

C2paException

class C2paException extends \RuntimeException {}

The single exception type for every failure — see Errors for the message taxonomy.