{
  "openapi": "3.0.3",
  "info": {
    "title": "Billing API",
    "description": "API to manage billing data for epilot contracts and orders",
    "version": "1.0.0"
  },
  "tags": [
    {
      "name": "Billing Events",
      "description": "Manage installments, payments and reimbursements"
    },
    {
      "name": "Contracts",
      "description": "Manage contracts within 360"
    },
    {
      "name": "Balance",
      "description": "Get customer balance"
    }
  ],
  "security": [
    {
      "EpilotAuth": []
    }
  ],
  "paths": {
    "/v1/billing/events": {
      "get": {
        "operationId": "getBillingEvents",
        "summary": "getBillingEvents",
        "description": "Get and filter billing events such as installments and reimbursements.",
        "tags": [
          "Billing Events"
        ],
        "parameters": [
          {
            "in": "query",
            "name": "from",
            "required": false,
            "schema": {
              "type": "number",
              "description": "Initial offset to set for the search results",
              "example": 0,
              "default": 0
            }
          },
          {
            "in": "query",
            "name": "size",
            "required": false,
            "schema": {
              "type": "number",
              "description": "Size of the search results",
              "example": 100,
              "default": 100
            }
          },
          {
            "name": "entity_id",
            "in": "query",
            "description": "Entity ID to filter billing events by",
            "required": false,
            "schema": {
              "type": "array",
              "items": {
                "type": "string"
              }
            }
          },
          {
            "name": "event_type",
            "in": "query",
            "schema": {
              "type": "string",
              "enum": [
                "installment",
                "reimbursement"
              ],
              "description": "Type of billing event to filter by"
            }
          },
          {
            "name": "date_after",
            "in": "query",
            "schema": {
              "type": "string",
              "format": "date-time",
              "description": "List billing events after this date"
            }
          },
          {
            "name": "date_before",
            "in": "query",
            "schema": {
              "type": "string",
              "format": "date-time",
              "description": "List billing events before this date"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "List of billing events",
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "properties": {
                    "hits": {
                      "type": "integer"
                    },
                    "results": {
                      "type": "array",
                      "items": {
                        "$ref": "#/components/schemas/BillingEvent"
                      }
                    }
                  }
                }
              }
            }
          }
        }
      },
      "post": {
        "operationId": "createBillingEvent",
        "summary": "createBillingEvent",
        "description": "Create a new billing event.",
        "tags": [
          "Billing Events"
        ],
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "allOf": [
                  {
                    "$ref": "#/components/schemas/BillingEvent"
                  }
                ]
              }
            }
          }
        },
        "responses": {
          "201": {
            "description": "Billing event created successfully",
            "content": {
              "application/json": {
                "schema": {
                  "allOf": [
                    {
                      "$ref": "#/components/schemas/BillingEvent"
                    }
                  ]
                }
              }
            }
          }
        }
      }
    },
    "/v1/billing/events/{id}": {
      "get": {
        "operationId": "getBillingEvent",
        "summary": "getBillingEvent",
        "description": "Get a single billing event by ID.",
        "tags": [
          "Billing Events"
        ],
        "parameters": [
          {
            "name": "id",
            "in": "path",
            "required": true,
            "description": "ID of the billing event to get",
            "schema": {
              "type": "string"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "Billing Event",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/BillingEvent"
                }
              }
            }
          }
        }
      },
      "patch": {
        "operationId": "updateBillingEvent",
        "summary": "updateBillingEvent",
        "description": "Update an existing billing event.",
        "tags": [
          "Billing Events"
        ],
        "parameters": [
          {
            "name": "id",
            "in": "path",
            "required": true,
            "description": "ID of the billing event to update",
            "schema": {
              "type": "string"
            }
          }
        ],
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/BillingEvent"
              }
            }
          }
        },
        "responses": {
          "200": {
            "description": "Billing Event updated successfully",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/BillingEvent"
                }
              }
            }
          }
        }
      },
      "delete": {
        "operationId": "deleteBillingEvent",
        "summary": "deleteBillingEvent",
        "description": "Delete an existing billing event.",
        "tags": [
          "Billing Events"
        ],
        "parameters": [
          {
            "name": "id",
            "in": "path",
            "required": true,
            "description": "ID of the billing event to delete",
            "schema": {
              "type": "string"
            }
          }
        ],
        "responses": {
          "204": {
            "description": "Billing Event deleted successfully"
          }
        }
      }
    },
    "/v1/billing/external/{external_id}": {
      "get": {
        "operationId": "getBillingEventByExternalId",
        "summary": "getBillingEventByExternalId",
        "description": "Get a single billing event by External ID.",
        "tags": [
          "Billing Events"
        ],
        "parameters": [
          {
            "name": "external_id",
            "in": "path",
            "required": true,
            "description": "ID of the billing event to get",
            "schema": {
              "type": "string"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "Billing Event",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/BillingEvent"
                }
              }
            }
          }
        }
      }
    },
    "/v1/billing/contracts": {
      "post": {
        "operationId": "createContractEntity",
        "summary": "createContractEntity",
        "description": "Create a new contract entity.",
        "tags": [
          "Contracts"
        ],
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/Contract"
              }
            }
          }
        },
        "responses": {
          "201": {
            "description": "Contract created successfully",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/ContractItem"
                }
              }
            }
          }
        }
      }
    },
    "/v1/billing/contracts/{id}": {
      "patch": {
        "operationId": "updateContractEntity",
        "summary": "updateContractEntity",
        "description": "Update an existing contract entity.",
        "tags": [
          "Contracts"
        ],
        "parameters": [
          {
            "name": "id",
            "in": "path",
            "required": true,
            "description": "ID of the contract entity to update",
            "schema": {
              "type": "string"
            }
          }
        ],
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/Contract"
              }
            }
          }
        },
        "responses": {
          "200": {
            "description": "Contract updated successfully",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/ContractItem"
                }
              }
            }
          }
        }
      },
      "delete": {
        "operationId": "deleteContractEntity",
        "summary": "deleteContractEntity",
        "description": "Delete an existing contract entity.",
        "tags": [
          "Contracts"
        ],
        "parameters": [
          {
            "name": "id",
            "in": "path",
            "required": true,
            "description": "ID of the contract entity to delete",
            "schema": {
              "type": "string"
            }
          }
        ],
        "responses": {
          "204": {
            "description": "Contract deleted successfully",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/ContractItem"
                }
              }
            }
          }
        }
      }
    },
    "/v1/billing/customers/{id}/balance": {
      "get": {
        "operationId": "getCustomerBalance",
        "summary": "getCustomerBalance",
        "description": "Get total balance across all contracts and orders of a customer entity.",
        "tags": [
          "Balance"
        ],
        "parameters": [
          {
            "name": "id",
            "in": "path",
            "description": "Customer entity ID (contact or account)",
            "required": true,
            "schema": {
              "type": "string",
              "example": "1e3f0d58-69d2-4dbb-9a43-3ee63d862e8e"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "OK",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Balance"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "securitySchemes": {
      "EpilotAuth": {
        "type": "http",
        "scheme": "bearer",
        "description": "Epilot 360 Bearer Token",
        "bearerFormat": "JWT"
      }
    },
    "schemas": {
      "BaseEntity": {
        "type": "object",
        "additionalProperties": true,
        "properties": {
          "_id": {
            "$ref": "#/components/schemas/EntityId"
          },
          "_title": {
            "type": "string",
            "description": "Title of entity"
          },
          "_org": {
            "type": "string",
            "description": "Organization Id the entity belongs to"
          },
          "_schema": {
            "$ref": "#/components/schemas/EntitySlug"
          },
          "_tags": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "_created_at": {
            "type": "string"
          },
          "_updated_at": {
            "type": "string"
          }
        }
      },
      "EntityId": {
        "type": "string",
        "description": "Entity ID",
        "example": "5da0a718-c822-403d-9f5d-20d4584e0528"
      },
      "EntitySlug": {
        "description": "URL-friendly identifier for the entity schema",
        "type": "string",
        "enum": [
          "contact",
          "contract",
          "file",
          "order",
          "opportunity",
          "product",
          "price",
          "meter",
          "meter_counter",
          "billing_event"
        ],
        "example": "contact"
      },
      "EntityRelationItem": {
        "type": "object",
        "properties": {
          "entity_id": {
            "type": "string",
            "description": "Entity ID for the related contract.",
            "example": "f589786b-3024-43cd-9cb3-5a3c953f2896"
          }
        }
      },
      "BaseBillingEvent": {
        "allOf": [
          {
            "$ref": "#/components/schemas/BaseEntity"
          }
        ],
        "description": "A base billing event to be inherited by all billing events.",
        "type": "object",
        "required": [
          "type",
          "contract",
          "billing_amount",
          "billing_amount_decimal",
          "billing_currency"
        ],
        "additionalProperties": true,
        "properties": {
          "billing_amount": {
            "type": "integer",
            "description": "Amount to be paid in cents i.e. precision 2",
            "example": 10050
          },
          "billing_amount_decimal": {
            "type": "string",
            "description": "Amount to be paid in cents in decimal string representation",
            "example": "100.50"
          },
          "billing_currency": {
            "$ref": "#/components/schemas/Currency"
          },
          "external_id": {
            "type": "string",
            "description": "Unique identifier for event, used to reference the event to a 3rd party resource such as a SAP Installment.",
            "example": "d4fb2a4e-3f74-4fc4-8fba-6fdaaaa3b08e"
          },
          "contract": {
            "type": "object",
            "properties": {
              "$relation": {
                "type": "array",
                "items": {
                  "$ref": "#/components/schemas/EntityRelationItem"
                }
              }
            }
          }
        }
      },
      "InstallmentEvent": {
        "description": "An entity that describes an installment billing event.",
        "allOf": [
          {
            "$ref": "#/components/schemas/BaseBillingEvent"
          },
          {
            "type": "object",
            "properties": {
              "type": {
                "type": "string",
                "enum": [
                  "installment"
                ],
                "description": "Type of the billing event.",
                "example": "installment"
              },
              "due_date": {
                "type": "string",
                "format": "date-time",
                "description": "Date on which the installment is due."
              },
              "paid_date": {
                "type": "string",
                "format": "date-time",
                "description": "Date on which the installment is paid by the customer."
              }
            },
            "required": [
              "due_date"
            ]
          }
        ]
      },
      "ReimbursementEvent": {
        "description": "An entity that describes a reimbursement billing event.",
        "allOf": [
          {
            "$ref": "#/components/schemas/BaseBillingEvent"
          },
          {
            "type": "object",
            "properties": {
              "type": {
                "type": "string",
                "enum": [
                  "reimbursement"
                ],
                "description": "Type of the billing event.",
                "example": "reimbursement"
              },
              "paid_date": {
                "type": "string",
                "format": "date-time",
                "description": "Date on which the customer is reimbursed."
              }
            }
          }
        ]
      },
      "BillingEvent": {
        "description": "An entity that describes a billing event such as a future installment or a reimbursement back to the customer.",
        "oneOf": [
          {
            "$ref": "#/components/schemas/InstallmentEvent"
          },
          {
            "$ref": "#/components/schemas/ReimbursementEvent"
          }
        ]
      },
      "Contract": {
        "allOf": [
          {
            "$ref": "#/components/schemas/BaseEntity"
          },
          {
            "type": "object",
            "properties": {
              "contract_name": {
                "type": "string",
                "description": "The name of the contract.",
                "example": "Grid Contract"
              },
              "contract_number": {
                "type": "string",
                "description": "The unique identifier of the contract.",
                "example": "12345"
              },
              "status": {
                "type": "string",
                "enum": [
                  "draft",
                  "in_approval_process",
                  "approved",
                  "active",
                  "deactivated",
                  "revoked",
                  "terminated",
                  "expired"
                ],
                "default": "draft",
                "description": "The status of the contract.",
                "example": "approved"
              },
              "description": {
                "type": "string",
                "description": "A brief description of the contract.",
                "example": "This contract is for the supply of widgets."
              },
              "account_number": {
                "type": "string",
                "description": "The account number associated with the contract.",
                "example": "67890"
              },
              "branch": {
                "type": "string",
                "enum": [
                  "power",
                  "gas",
                  "water",
                  "waste_water",
                  "district_heating"
                ],
                "description": "The branch associated with the contract.",
                "example": "power"
              },
              "billing_address": {
                "type": "string",
                "description": "The billing address associated with the contract.",
                "example": "123 Main St, Anytown"
              },
              "delivery_address": {
                "type": "string",
                "description": "The delivery address associated with the contract.",
                "example": "456 Elm St, Anytown"
              },
              "additional_addresses": {
                "type": "string",
                "description": "Any additional addresses associated with the contract.",
                "example": "789 Oak St, Anytown"
              },
              "termination_date": {
                "type": "string",
                "description": "The date on which the contract was terminated.",
                "example": "2022-01-01"
              },
              "termination_reason": {
                "type": "string",
                "description": "The reason for the termination of the contract.",
                "example": "Non-payment"
              },
              "billing_period": {
                "type": "string",
                "enum": [
                  "weekly",
                  "monthly",
                  "every_quarter",
                  "every_6_months",
                  "yearly"
                ],
                "default": "weekly",
                "description": "The billing period associated with the contract.",
                "example": "monthly"
              },
              "billing_duration_amount": {
                "type": "number",
                "minimum": 0,
                "description": "The duration of the billing period.",
                "example": 30
              },
              "renewal_duration_amount": {
                "type": "number",
                "minimum": 0,
                "description": "The duration of the renewal period.",
                "example": 365
              },
              "renewal_duration_unit": {
                "type": "string",
                "enum": [
                  "weeks",
                  "months",
                  "years"
                ],
                "default": "months",
                "description": "The unit of time for the renewal period.",
                "example": "years"
              },
              "notice_time_amount": {
                "type": "number",
                "minimum": 0,
                "description": "The amount of notice required for termination of the contract.",
                "example": 30
              },
              "notice_time_unit": {
                "type": "string",
                "enum": [
                  "weeks",
                  "months",
                  "years"
                ],
                "default": "months",
                "description": "The unit of time for the notice period.",
                "example": "months"
              },
              "start_date": {
                "type": "string",
                "description": "The start date of the contract.",
                "example": "2021-01-01"
              },
              "billing_due_day": {
                "type": "integer",
                "description": "Defines the day of the month in which the installments are due.",
                "minimum": 1,
                "maximum": 31,
                "example": 2
              },
              "installment_amount": {
                "type": "integer",
                "description": "Set amount for installments in cents. (precision 2)",
                "example": 10050
              },
              "balance": {
                "type": "integer",
                "description": "Current balance of the contract in cents. (precision 2)",
                "example": 8990
              },
              "balance_currency": {
                "$ref": "#/components/schemas/Currency"
              }
            }
          }
        ]
      },
      "ContractItem": {
        "allOf": [
          {
            "$ref": "#/components/schemas/Contract"
          }
        ],
        "required": [
          "_id",
          "_title",
          "_org",
          "_created_at",
          "_updated_at"
        ]
      },
      "Balance": {
        "type": "object",
        "properties": {
          "balance": {
            "type": "integer",
            "description": "Current balance of the customer in cents. (precision 2)",
            "example": 8990
          },
          "balance_decimal": {
            "type": "string",
            "description": "Current balance of the customer in decimal string representation.",
            "example": "89.90"
          },
          "balance_currency": {
            "$ref": "#/components/schemas/Currency"
          }
        }
      },
      "Currency": {
        "type": "string",
        "description": "Currency code in ISO 4217 format",
        "example": "EUR"
      }
    }
  },
  "servers": [
    {
      "url": "https://billing.sls.epilot.io"
    }
  ]
}