/**
 * Attribution Extension Group (org.peacprotocol/attribution)
 *
 * Records credit, obligations, and content signal observations.
 *
 * Design:
 *   - Identifier and reference-based fields; not identity attestation
 *   - Closed enum for content_signal_source (known observation sources)
 *   - SPDX license expressions via parser-grade shared validator
 *   - Observation-only semantics: records events, never enforces policy
 */
import { z } from 'zod';
export declare const ATTRIBUTION_EXTENSION_KEY: "org.peacprotocol/attribution";
/**
 * Content signal observation source.
 *
 * Closed enum: maps to the known observation sources in the
 * content signals precedence chain.
 */
export declare const CONTENT_SIGNAL_SOURCES: readonly ["tdmrep_json", "content_signal_header", "content_usage_header", "robots_txt", "custom"];
export declare const ContentSignalSourceSchema: z.ZodEnum<{
    custom: "custom";
    tdmrep_json: "tdmrep_json";
    content_signal_header: "content_signal_header";
    content_usage_header: "content_usage_header";
    robots_txt: "robots_txt";
}>;
export type ContentSignalSource = z.infer<typeof ContentSignalSourceSchema>;
export declare const AttributionExtensionSchema: z.ZodObject<{
    creator_ref: z.ZodString;
    license_spdx: z.ZodOptional<z.ZodString>;
    obligation_type: z.ZodOptional<z.ZodString>;
    attribution_text: z.ZodOptional<z.ZodString>;
    content_signal_source: z.ZodOptional<z.ZodEnum<{
        custom: "custom";
        tdmrep_json: "tdmrep_json";
        content_signal_header: "content_signal_header";
        content_usage_header: "content_usage_header";
        robots_txt: "robots_txt";
    }>>;
    content_digest: z.ZodOptional<z.ZodString>;
}, z.core.$strict>;
export type AttributionExtension = z.infer<typeof AttributionExtensionSchema>;
//# sourceMappingURL=attribution.d.ts.map