{
  "contract_version": "HRC-API-CONTRACT-v0.3",
  "runtime": "HRC_Heart-rate Resonance Control",
  "ko": "심박 공명 제어 시스템",
  "principle": "HRC is a resonance permission engine. Visuals follow runtime.",
  "source_types": [
    "ENGINE_TEST",
    "LIVE_DEVICE",
    "RECORDED_SESSION"
  ],
  "key_endpoints": [
    "GET /api/health",
    "GET /api/profiles",
    "GET /api/adapters",
    "GET /api/contract",
    "POST /api/session/start",
    "POST /api/session/step",
    "GET /api/session/{id}/manifest",
    "GET /api/session/{id}/verify",
    "GET /api/session/{id}/bundle",
    "POST /api/license/verify",
    "POST /api/benchmark/latency"
  ],
  "core_endpoints": {
    "GET /api/health": "runtime health",
    "GET /api/profiles": "target profile registry",
    "GET /api/adapters": "partner adapter registry",
    "GET /api/contract": "API and packet contract",
    "POST /api/session/start": "start HRC session",
    "POST /api/session/step": "advance HRC session by one packet",
    "GET /api/session/{id}/manifest": "session manifest",
    "GET /api/session/{id}/verify": "hash-chain verification",
    "GET /api/session/{id}/bundle": "license review bundle",
    "POST /api/license/verify": "verify license key and scope",
    "POST /api/license/issue": "admin-only license issuance",
    "POST /api/benchmark/latency": "local runtime latency benchmark",
    "GET /api/benchmark/latest": "latest latency benchmark"
  },
  "packet_contract": {
    "common_required": [
      "source_type",
      "bio_phase_rad",
      "stimulus_phase_rad",
      "quality_score",
      "actuator_latency_ms"
    ],
    "recorded_session_required": [
      "recording_id",
      "anonymized=true"
    ],
    "live_device_required": [
      "integrity.device_id",
      "integrity.timestamp",
      "integrity.nonce",
      "integrity.signature"
    ],
    "optional": [
      "heart_rate_bpm",
      "hrv_rmssd_ms",
      "respiration_phase_rad",
      "interval_ms"
    ]
  },
  "decision_contract": {
    "states": [
      "ASYNC",
      "ENTERING_SYNC",
      "SYNC",
      "EXITING",
      "SAFE_RETURN"
    ],
    "actuation_policies": [
      "L1_BASELINE",
      "KEEP_L1",
      "RAMPING_TO_L2",
      "L2_ALLOWED",
      "SAFE_RETURN_L1"
    ],
    "evidence": "Every decision is chained with SHA-256."
  },
  "live_signature_contract": {
    "algorithm": "HMAC-SHA256",
    "secret": "tenant license key",
    "canonicalization": "JSON canonical form: ensure_ascii=false, sort_keys=true, separators=(comma, colon)",
    "signature_scope": "entire packet except integrity.signature",
    "required_integrity_fields": [
      "device_id",
      "timestamp",
      "nonce",
      "session_id",
      "signature_alg",
      "signature"
    ],
    "session_binding": "integrity.session_id must equal HRC session_id"
  },
  "license_contract": {
    "public_verifier": "ENGINE_TEST and RECORDED_SESSION only",
    "live_device": "requires valid tenant license and signed packet metadata"
  }
}