{
  "openapi": "3.1.0",
  "info": {
    "title": "AIKloop Payments API (fictional demo)",
    "version": "3.1.0",
    "description": "Send your secret key as a Bearer token in the Authorization header: Authorization: Bearer sk_live_... (or sk_test_... in test mode)."
  },
  "servers": [
    { "url": "https://api.aikloop.example/v3" }
  ],
  "security": [
    { "bearerAuth": [] }
  ],
  "tags": [
    { "name": "Payments" },
    { "name": "Refunds" },
    { "name": "Webhooks" }
  ],
  "paths": {
    "/payments": {
      "post": {
        "tags": ["Payments"],
        "summary": "Create a payment.",
        "parameters": [
          {
            "name": "Idempotency-Key",
            "in": "header",
            "required": true,
            "description": "Required. A unique value, such as a UUID v4. Retry a failed request with the same key. Keys are kept for 1 hour.",
            "schema": { "type": "string" }
          }
        ],
        "requestBody": {
          "required": true,
          "content": {
            "application/x-www-form-urlencoded": {
              "schema": {
                "type": "object",
                "required": ["amount_minor", "currency", "payment_method"],
                "properties": {
                  "amount_minor": {
                    "type": "integer",
                    "description": "Required. Amount in the currency's minor unit, for example 1050 for 10.50 EUR."
                  },
                  "currency": {
                    "type": "string",
                    "description": "Required. Three-letter ISO code, lowercase. No default."
                  },
                  "payment_method": {
                    "type": "string",
                    "description": "Required. Payment method ID from AIKloop.js, for example pm_123."
                  }
                }
              }
            }
          }
        },
        "responses": {
          "201": { "description": "The payment was created." }
        }
      },
      "get": {
        "tags": ["Payments"],
        "summary": "List payments, newest first.",
        "parameters": [
          {
            "name": "limit",
            "in": "query",
            "required": false,
            "description": "1 to 50. Default 10.",
            "schema": { "type": "integer", "minimum": 1, "maximum": 50 }
          },
          {
            "name": "starting_after",
            "in": "query",
            "required": false,
            "description": "ID of the last object from the previous page.",
            "schema": { "type": "string" }
          }
        ],
        "responses": {
          "200": { "description": "A page of payments." }
        }
      }
    },
    "/refunds": {
      "post": {
        "tags": ["Refunds"],
        "summary": "Refund all or part of a payment.",
        "parameters": [
          {
            "name": "Idempotency-Key",
            "in": "header",
            "required": true,
            "description": "Required.",
            "schema": { "type": "string" }
          }
        ],
        "requestBody": {
          "required": true,
          "content": {
            "application/x-www-form-urlencoded": {
              "schema": {
                "type": "object",
                "required": ["payment_id"],
                "properties": {
                  "payment_id": {
                    "type": "string",
                    "description": "Required. The payment to refund, for example pay_123."
                  },
                  "amount_minor": {
                    "type": "integer",
                    "description": "Optional. Partial refund amount in minor units. Leave it out to refund the full amount."
                  }
                }
              }
            }
          }
        },
        "responses": {
          "201": { "description": "The refund was created." }
        }
      }
    }
  },
  "webhooks": {
    "Webhook request": {
      "post": {
        "tags": ["Webhooks"],
        "summary": "Every webhook request is signed.",
        "parameters": [
          {
            "name": "AIKloop-Signature",
            "in": "header",
            "required": true,
            "description": "t=<timestamp>,v1=<signature>. t is the Unix timestamp: reject events older than 3 minutes. v1 is the HMAC-SHA256 of \"{t}.{raw_body}\" with your whsec_ signing secret: compare it in constant time.",
            "schema": { "type": "string" }
          }
        ],
        "responses": {
          "200": { "description": "Return 200 to acknowledge the event." }
        }
      }
    }
  },
  "components": {
    "securitySchemes": {
      "bearerAuth": { "type": "http", "scheme": "bearer" }
    }
  }
}