{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://fluid.dev/schemas/backend-requirement.schema.json",
  "title": "FLUID backend capability requirement",
  "description": "Capability the interface needs but has no authority to build. FLUID escalates rather than crossing the boundary (FluidAPIStandards.md section 30).",
  "type": "object",
  "properties": {
    "fluid_backend_requirement": {
      "type": "object",
      "properties": {
        "schema_version": { "$ref": "common.schema.json#/$defs/schemaVersion" },
        "id": { "$ref": "common.schema.json#/$defs/backendRequirementId" },
        "originating_interface": { "$ref": "common.schema.json#/$defs/interfaceId" },
        "originating_revision": { "oneOf": [{ "$ref": "common.schema.json#/$defs/revisionId" }, { "type": "null" }] },
        "originating_hypothesis": { "oneOf": [{ "$ref": "common.schema.json#/$defs/hypothesisId" }, { "type": "null" }] },
        "backend_service": { "type": "string", "minLength": 1 },

        "capability": {
          "type": "object",
          "properties": {
            "title": { "type": "string", "minLength": 1 },
            "description": { "type": "string", "minLength": 1 }
          },
          "required": ["title", "description"],
          "additionalProperties": false
        },

        "semantics": {
          "type": "object",
          "properties": {
            "consistency": { "type": "string" },
            "required_fields": { "type": "array", "items": { "type": "string" } }
          },
          "additionalProperties": true
        },

        "quality": {
          "type": "object",
          "properties": {
            "p95_latency_ms": { "type": "number", "minimum": 0 },
            "availability": { "$ref": "common.schema.json#/$defs/unitInterval" }
          },
          "additionalProperties": true
        },

        "security": {
          "type": "object",
          "properties": {
            "authorization_scope": { "type": "string" },
            "tenant_isolation": { "type": "string" }
          },
          "additionalProperties": true
        },

        "expected_usage": {
          "type": "object",
          "properties": {
            "requests_per_day": { "type": "integer", "minimum": 0 }
          },
          "additionalProperties": true
        },

        "urgency": { "enum": ["LOW", "MEDIUM", "HIGH"] },

        "disposition": {
          "type": "object",
          "description": "The backend decides. Repeated OUT_OF_SCOPE feeds boundary learning (ArchitectureBlueprint.md section 22).",
          "properties": {
            "state": { "enum": ["OPEN", "ACCEPTED", "PLANNED", "AVAILABLE", "PARTIALLY_AVAILABLE", "OUT_OF_SCOPE", "REJECTED", "SUPERSEDED"] },
            "reason": { "type": ["string", "null"] },
            "target_ref": { "type": ["string", "null"] }
          },
          "required": ["state"],
          "additionalProperties": false
        }
      },
      "required": ["schema_version", "id", "originating_interface", "backend_service", "capability", "disposition"],
      "additionalProperties": false
    }
  },
  "required": ["fluid_backend_requirement"],
  "additionalProperties": false
}