{
  "openapi": "3.1.0",
  "info": {
    "title": "placeholger — Zero-Disk Dynamic SVG Placeholder API",
    "version": "1.1.0",
    "description": "Generates deterministic, ultra-lightweight SVG wireframe placeholders in memory (<1ms) with custom dimensions (1-2048px), hex colors, and XML-sanitized text overlays.",
    "contact": {
      "url": "https://placeholger.hellinger.wtf"
    },
    "license": {
      "name": "MIT"
    }
  },
  "servers": [
    {
      "url": "https://placeholger.hellinger.wtf",
      "description": "Production Edge Server"
    }
  ],
  "paths": {
    "/{w}/{h}/{bg}/{fg}": {
      "get": {
        "operationId": "getPlaceholderFull",
        "summary": "Generate SVG wireframe with width, height, background hex, and foreground hex",
        "parameters": [
          {
            "name": "w",
            "in": "path",
            "required": true,
            "schema": { "type": "integer", "minimum": 1, "maximum": 2048, "default": 600 },
            "description": "Image width in pixels (1 - 2048)"
          },
          {
            "name": "h",
            "in": "path",
            "required": true,
            "schema": { "type": "integer", "minimum": 1, "maximum": 2048, "default": 400 },
            "description": "Image height in pixels (1 - 2048)"
          },
          {
            "name": "bg",
            "in": "path",
            "required": true,
            "schema": { "type": "string", "pattern": "^[0-9a-fA-F]{3}([0-9a-fA-F]{3})?$", "default": "9e9ea0" },
            "description": "Background hex color without leading #"
          },
          {
            "name": "fg",
            "in": "path",
            "required": true,
            "schema": { "type": "string", "pattern": "^[0-9a-fA-F]{3}([0-9a-fA-F]{3})?$", "default": "ffffff" },
            "description": "Foreground crosshairs & text hex color without leading #"
          },
          {
            "name": "text",
            "in": "query",
            "required": false,
            "schema": { "type": "string", "maxLength": 64, "default": "PLACEHOLGER" },
            "description": "Custom centered label text"
          },
          {
            "name": "dims",
            "in": "query",
            "required": false,
            "schema": { "type": "boolean", "default": false },
            "description": "Append {w} × {h} subtitle below main text"
          }
        ],
        "responses": {
          "200": {
            "description": "SVG wireframe image",
            "headers": {
              "Cache-Control": { "schema": { "type": "string", "example": "public, max-age=31536000, s-maxage=31536000, immutable" } },
              "X-Robots-Tag": { "schema": { "type": "string", "example": "noindex, noimageindex, noarchive, nosnippet" } },
              "ETag": { "schema": { "type": "string" } }
            },
            "content": {
              "image/svg+xml": {
                "schema": { "type": "string" }
              }
            }
          },
          "400": {
            "description": "Dimensions out of range (< 1 or > 2048) or non-integer"
          }
        }
      }
    },
    "/{w}/{h}": {
      "get": {
        "operationId": "getPlaceholderDimensions",
        "summary": "Generate SVG wireframe with width and height using default neutral gray (#9E9EA0 / #FFFFFF)",
        "parameters": [
          { "name": "w", "in": "path", "required": true, "schema": { "type": "integer", "minimum": 1, "maximum": 2048 } },
          { "name": "h", "in": "path", "required": true, "schema": { "type": "integer", "minimum": 1, "maximum": 2048 } },
          { "name": "text", "in": "query", "required": false, "schema": { "type": "string", "maxLength": 64 } },
          { "name": "dims", "in": "query", "required": false, "schema": { "type": "boolean" } }
        ],
        "responses": {
          "200": {
            "description": "SVG wireframe image",
            "content": { "image/svg+xml": { "schema": { "type": "string" } } }
          },
          "400": { "description": "Invalid dimensions" }
        }
      }
    },
    "/{size}": {
      "get": {
        "operationId": "getPlaceholderSquare",
        "summary": "Generate equilateral square SVG wireframe (w = h = size)",
        "parameters": [
          { "name": "size", "in": "path", "required": true, "schema": { "type": "integer", "minimum": 1, "maximum": 2048 } },
          { "name": "bg", "in": "query", "required": false, "schema": { "type": "string" } },
          { "name": "fg", "in": "query", "required": false, "schema": { "type": "string" } },
          { "name": "text", "in": "query", "required": false, "schema": { "type": "string", "maxLength": 64 } },
          { "name": "dims", "in": "query", "required": false, "schema": { "type": "boolean" } }
        ],
        "responses": {
          "200": {
            "description": "Square SVG wireframe image",
            "content": { "image/svg+xml": { "schema": { "type": "string" } } }
          },
          "400": { "description": "Invalid dimension" }
        }
      }
    }
  }
}