{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://spec-first.local/contracts/worker-dispatch-host-preflight.schema.json",
  "title": "Worker Dispatch Host Preflight",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "schema_version",
    "artifact_type",
    "gate",
    "status",
    "support_claim",
    "capture_owner",
    "capture_method",
    "captured_at",
    "freshness_expires_at",
    "session_identity",
    "host_identity",
    "host_startup_or_version_ref",
    "dispatch_authorization_receipt",
    "authorization_basis",
    "discovery_surface",
    "schema_excerpt_ref",
    "schema_excerpt",
    "schema_excerpt_sha256",
    "schema_completeness",
    "completeness_basis",
    "redaction_status",
    "capture_limitations",
    "capability_probe",
    "worker_dispatch_capability",
    "eligibility_contract_ref",
    "eligibility_contract_sha256",
    "eligible_candidates",
    "invocation_performed"
  ],
  "properties": {
    "schema_version": { "const": "worker-dispatch-host-preflight/v1" },
    "artifact_type": { "const": "advisory" },
    "gate": { "const": "post-u1-pre-u2-discovery-only" },
    "status": { "enum": ["passed", "failed", "not_run"] },
    "support_claim": { "const": "not_applicable" },
    "capture_owner": { "type": "string", "minLength": 1, "maxLength": 160 },
    "capture_method": {
      "enum": [
        "host-session-tool-registry-api",
        "host-startup-registration-record",
        "equivalent-current-session-source"
      ]
    },
    "captured_at": { "type": "string", "minLength": 20, "maxLength": 40 },
    "freshness_expires_at": { "type": "string", "minLength": 20, "maxLength": 40 },
    "session_identity": { "type": "string", "minLength": 1, "maxLength": 256 },
    "host_identity": { "type": "string", "minLength": 1, "maxLength": 160 },
    "host_startup_or_version_ref": { "type": "string", "minLength": 1, "maxLength": 512 },
    "dispatch_authorization_receipt": { "type": "string", "minLength": 1, "maxLength": 512 },
    "authorization_basis": { "enum": ["explicit-user", "visible-upstream-handoff"] },
    "discovery_surface": { "type": "string", "minLength": 1, "maxLength": 512 },
    "schema_excerpt_ref": { "type": ["string", "null"], "maxLength": 512 },
    "schema_excerpt": { "type": ["string", "null"], "maxLength": 4096 },
    "schema_excerpt_sha256": {
      "type": ["string", "null"],
      "pattern": "^[a-f0-9]{64}$"
    },
    "schema_completeness": { "enum": ["confirmed", "unconfirmed"] },
    "completeness_basis": { "type": ["string", "null"], "maxLength": 512 },
    "redaction_status": { "enum": ["passed", "failed"] },
    "capture_limitations": {
      "type": "array",
      "minItems": 1,
      "maxItems": 20,
      "items": { "type": "string", "minLength": 1, "maxLength": 500 }
    },
    "capability_probe": { "enum": ["attempted", "unavailable"] },
    "worker_dispatch_capability": { "enum": ["available", "missing", "unknown"] },
    "eligibility_contract_ref": {
      "const": "docs/contracts/workflows/worker-dispatch-capability.md#generic-worker-eligibility"
    },
    "eligibility_contract_sha256": { "type": "string", "pattern": "^[a-f0-9]{64}$" },
    "eligible_candidates": {
      "type": "array",
      "maxItems": 8,
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": ["candidate_identity_sha256", "unique", "rationale"],
        "properties": {
          "candidate_identity_sha256": { "type": "string", "pattern": "^[a-f0-9]{64}$" },
          "unique": { "type": "boolean" },
          "rationale": { "type": "string", "minLength": 1, "maxLength": 1000 }
        }
      }
    },
    "invocation_performed": { "const": false }
  }
}