{
    "aiep_version": "2.0.0",
    "type": "schema_reference",
    "title": "AIEP Evidence Rail Schema",
    "description": "Schema definition for an AIEP evidence rail. An evidence rail is an ordered array of evidence artefacts bound to an AI response, enabling full traceability from output claim to hashed source.",
    "fields": {
        "evidence_rail": "Ordered array of AIEP evidence artefact objects",
        "artefact_id": "Unique identifier for this artefact within the rail (e.g. ev_001)",
        "source_url": "URL of the retrieved source document",
        "confidence_tier": "One of: verified | high | medium | low | unverified",
        "content_hash": "SHA-256 hex digest of the retrieved source content",
        "hash_algorithm": "Hash algorithm used — currently always sha256",
        "retrieved_at": "ISO 8601 timestamp of source retrieval",
        "validation_status": "One of: passed | failed | pending",
        "rail_validation": {
            "artefact_count": "Number of artefacts in the rail",
            "all_hashes_present": "Boolean — true if all artefacts carry a content_hash",
            "all_sources_reachable": "Boolean — true if all source_urls resolved at validation time",
            "status": "One of: passed | failed | partial"
        }
    },
    "example_url": "https://aiep.dev/examples/evidence-rail.json",
    "generated_at": "2026-04-29T00:00:00Z",
    "protocol_url": "https://aiep.dev",
    "playground": "https://aiep.dev/playground",
    "machine_endpoint": "https://aiep.dev/.well-known/aiep/",
    "github": "https://github.com/phatfella/AIEP-VALIDATOR"
}