{
  "openapi": "3.1.0",
  "info": {
    "title": "ClientBilling API",
    "version": "1.0.0",
    "description": "REST API for scripts and agents operating a merchant account (decisions 0017, 0025, 0026)."
  },
  "servers": [{ "url": "https://www.clientbilling.com" }],
  "components": {
    "securitySchemes": {
      "bearerAuth": {
        "type": "http",
        "scheme": "bearer",
        "bearerFormat": "cb_live_"
      }
    },
    "parameters": {
      "IdempotencyKey": {
        "name": "Idempotency-Key",
        "in": "header",
        "required": true,
        "schema": { "type": "string", "maxLength": 256 },
        "description": "Required on POST and DELETE. Same key and body replays; different body returns 409."
      }
    }
  },
  "security": [{ "bearerAuth": [] }],
  "paths": {
    "/api/v1/clients": {
      "get": {
        "summary": "List clients",
        "responses": { "200": { "description": "Client list" } }
      },
      "post": {
        "summary": "Create a client",
        "parameters": [{ "$ref": "#/components/parameters/IdempotencyKey" }],
        "responses": { "201": { "description": "Created" } }
      }
    },
    "/api/v1/invoices": {
      "get": {
        "summary": "List invoices",
        "parameters": [
          {
            "name": "status",
            "in": "query",
            "schema": {
              "type": "string",
              "enum": ["draft", "sent", "viewed", "overdue", "paid", "void"]
            }
          }
        ],
        "responses": { "200": { "description": "Invoice list" } }
      },
      "post": {
        "summary": "Create a draft invoice",
        "parameters": [{ "$ref": "#/components/parameters/IdempotencyKey" }],
        "responses": { "201": { "description": "Created with actor provenance" } }
      }
    },
    "/api/v1/invoices/{id}": {
      "get": {
        "summary": "Get one invoice",
        "parameters": [{ "name": "id", "in": "path", "required": true, "schema": { "type": "string" } }],
        "responses": { "200": { "description": "Invoice" } }
      }
    },
    "/api/v1/invoices/{id}/send": {
      "post": {
        "summary": "Email the invoice",
        "parameters": [
          { "name": "id", "in": "path", "required": true, "schema": { "type": "string" } },
          { "$ref": "#/components/parameters/IdempotencyKey" }
        ],
        "responses": { "200": { "description": "Sent" } }
      }
    },
    "/api/v1/invoices/{id}/remind": {
      "post": {
        "summary": "Send a reminder",
        "parameters": [
          { "name": "id", "in": "path", "required": true, "schema": { "type": "string" } },
          { "$ref": "#/components/parameters/IdempotencyKey" }
        ],
        "responses": { "200": { "description": "Reminded" } }
      }
    },
    "/api/v1/invoices/{id}/status": {
      "post": {
        "summary": "Change status to sent, paid, or void",
        "parameters": [
          { "name": "id", "in": "path", "required": true, "schema": { "type": "string" } },
          { "$ref": "#/components/parameters/IdempotencyKey" }
        ],
        "responses": { "200": { "description": "Updated" } }
      }
    },
    "/api/v1/invoices/{id}/payments": {
      "get": {
        "summary": "List payments",
        "parameters": [{ "name": "id", "in": "path", "required": true, "schema": { "type": "string" } }],
        "responses": { "200": { "description": "Payments" } }
      },
      "post": {
        "summary": "Record a payment",
        "parameters": [
          { "name": "id", "in": "path", "required": true, "schema": { "type": "string" } },
          { "$ref": "#/components/parameters/IdempotencyKey" }
        ],
        "responses": { "201": { "description": "Recorded" } }
      }
    }
  }
}