{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://aaep-protocol.org/schemas/v1/handshake/subscription.rejected.schema.json",
  "title": "AAEP Message: subscription.rejected",
  "description": "Producer's rejection of a subscription.request. Carries a machine-readable reason_code and a human-readable reason_message. Producers MUST respond to every subscription.request with either subscription.accepted or subscription.rejected; silent failure is non-conforming. Defined normatively in Chapter 5 §5.5 of the AAEP specification.",

  "type": "object",
  "required": ["type", "reason_code", "reason_message"],

  "properties": {
    "type": {
      "description": "MUST be the literal value 'subscription.rejected'.",
      "const": "subscription.rejected"
    },
    "reason_code": {
      "description": "Machine-readable reason for the rejection. MUST be one of the eight normative codes defined in Chapter 5 §5.5.3.",
      "type": "string",
      "enum": [
        "version_unsupported",
        "manifest_signature_required",
        "capabilities_incompatible",
        "rate_limit",
        "authentication_required",
        "authorization_denied",
        "transport_unavailable",
        "unknown"
      ]
    },
    "reason_message": {
      "description": "Human-readable description of the rejection. SHOULD provide enough detail for the subscriber to understand what went wrong without exposing sensitive details about the producer's internal state.",
      "type": "string",
      "minLength": 1,
      "maxLength": 4096
    },
    "retry_after_seconds": {
      "description": "If the subscriber should try again, after how many seconds. Typically used with reason_code 'rate_limit' or 'transport_unavailable'.",
      "type": "integer",
      "minimum": 0,
      "maximum": 86400
    },
    "alternative_manifest_uri": {
      "description": "URI to a manifest describing what the producer can offer. Useful when reason_code is 'capabilities_incompatible' so the subscriber can adjust its request.",
      "type": "string",
      "format": "uri"
    }
  },

  "additionalProperties": false,

  "examples": [
    {
      "type": "subscription.rejected",
      "reason_code": "version_unsupported",
      "reason_message": "Producer supports AAEP v1.0.0 only; subscriber requested v0.9.0 which is not implemented."
    },
    {
      "type": "subscription.rejected",
      "reason_code": "rate_limit",
      "reason_message": "Producer has reached maximum concurrent subscriptions. Try again later.",
      "retry_after_seconds": 60
    },
    {
      "type": "subscription.rejected",
      "reason_code": "manifest_signature_required",
      "reason_message": "Subscriber requested signed manifests but producer does not currently sign manifests. Update producer configuration or set accept_signed_manifests_only=false.",
      "alternative_manifest_uri": "https://example.com/.well-known/aaep-manifest.json"
    },
    {
      "type": "subscription.rejected",
      "reason_code": "capabilities_incompatible",
      "reason_message": "Subscriber requested only Yoruba, but producer does not have Yoruba translations available. See alternative manifest for supported languages.",
      "alternative_manifest_uri": "https://example.com/.well-known/aaep-manifest.json"
    },
    {
      "type": "subscription.rejected",
      "reason_code": "authentication_required",
      "reason_message": "This producer requires Bearer token authentication. Include an Authorization header on subscription.request."
    }
  ]
}