{
  "title": "CSS inliner",
  "human_url": "https://happytails.ai/en/developer-tools/css-inliner/",
  "agent_url": "https://happytails.ai/agents/en/developer-tools/css-inliner/",
  "language": "en",
  "markdown_url": "https://happytails.ai/en/developer-tools/css-inliner.md",
  "content": "CSS inliner\nInline supported selectors for email HTML.\nUseful next steps\nHTML formatter\nFormat/minify with options.\nCSS formatter\nFormat/minify CSS with parser-based errors.\nJavascript formatter\nParse and format code without executing it.\nHow to use CSS inliner\nEnter css in the input field.\nReview the settings, then choose Run CSS inliner.\nReview the result, then use Copy result or a download link when available.\nWorking with css inliner\nFormatting makes existing data or code easier to read. Validation checks whether it follows a syntax or schema. Conversion maps it into another representation. Choosing the right operation helps avoid treating a neatly formatted result as proof that the underlying data is correct.\nCommon questions\nDoes valid JSON mean the data is correct?\nSyntax validation only establishes that the text can be parsed as JSON. A schema can check required fields and types, but neither proves that an email address, price or external record is factually correct.\nIs decoding the same as decrypting or verifying?\nNo. Base64 and URL encoding are representations, not encryption. Reading a token payload does not verify its signature. Use the specific validation or verification process required by the system receiving the result.\nContinue your workflow:\nHTML formatter\n,\nCSS formatter\n,\nJavascript formatter\n.",
  "content_format": "text/plain",
  "visibility": "public",
  "links": [
    {
      "name": "HTML formatter Format/minify with options.",
      "url": "https://happytails.ai/en/developer-tools/html-formatter/"
    },
    {
      "name": "CSS formatter Format/minify CSS with parser-based errors.",
      "url": "https://happytails.ai/en/developer-tools/css-formatter/"
    },
    {
      "name": "Javascript formatter Parse and format code without executing it.",
      "url": "https://happytails.ai/en/developer-tools/javascript-formatter/"
    }
  ],
  "tool": {
    "id": "css-inliner",
    "category": "developer-tools",
    "built": true,
    "requirements": "Inline supported selectors for email HTML; preserve unsupported-rule warnings.",
    "implementation": {
      "fields": [
        {
          "key": "css",
          "label": "Additional CSS",
          "value": "",
          "type": "textarea"
        }
      ],
      "note": "Inlines supported rules locally. Media queries, pseudo-class behavior, external stylesheets and email-client rendering need review. External stylesheets are not fetched.",
      "experience": {
        "automatic": false,
        "single": false,
        "label": "CSS",
        "placeholder": "a { color: #3366cc; }",
        "help": "Paste CSS rules, including their selectors. Up to 1,000,000 characters. Review the settings before running.",
        "action": null
      },
      "mode": "explicit",
      "interactive": false
    },
    "execution": "Browser interface",
    "api": null,
    "browser_agent": {
      "supported": true,
      "name": "run_current_tool",
      "discovery": "WebMCP on the human page in a supporting browser",
      "verification": "See audit/API-AUDIT.md; availability is not verification"
    }
  },
  "markdown": "# CSS inliner\n\n- Human page: https://happytails.ai/en/developer-tools/css-inliner/\n- Markdown: https://happytails.ai/en/developer-tools/css-inliner.md\n- Structured JSON: https://happytails.ai/agents/en/developer-tools/css-inliner/index.json\n- Visibility: public\n\n## Tool capabilities\n\n| Property | Value |\n| --- | --- |\n| Tool ID | `css-inliner` |\n| Category | developer-tools |\n| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |\n| Browser execution | Use the visible action or interactive controls. |\n| Browser processing | Browser; see tool notes for network behavior. |\n| HTTP API | Not callable through HTTP. |\n| Browser-agent interface | run_current_tool |\n\n### Implementation notes\n\nInlines supported rules locally. Media queries, pseudo-class behavior, external stylesheets and email-client rendering need review. External stylesheets are not fetched.\n\n### Inputs and settings\n\nText input: CSS.\n\nExample or placeholder shown in the interface (not a validated fixture):\n\n```text\na { color: #3366cc; }\n```\n\nPaste CSS rules, including their selectors. Up to 1,000,000 characters. Review the settings before running.\n\n| Setting | Meaning | Control type | Default | Constraints |\n| --- | --- | --- | --- | --- |\n| `css` | Additional CSS | textarea | \"\" |  |\n\n### Browser-agent workflow\n\n1. Open the human page in a browser that supports WebMCP.\n2. Discover the interface exposed by that page; use its actual schema.\n3. Select files on the page first when the tool requires files.\n4. Call `run_current_tool` with valid input and settings.\n5. Inspect the returned result or error and the displayed output. Retrieve files from the displayed download links.\n\nCalls do not automatically copy or download results. Browser permissions still apply. Interface availability alone is not proof of successful execution.\n\n### Planning specification\n\nInline supported selectors for email HTML; preserve unsupported-rule warnings.\n\nThis describes intended requirements. Use the implementation notes, interface schema and observed output to determine current support.\n\n### Complete machine-readable capability record\n\n```json\n{\n  \"id\": \"css-inliner\",\n  \"category\": \"developer-tools\",\n  \"built\": true,\n  \"requirements\": \"Inline supported selectors for email HTML; preserve unsupported-rule warnings.\",\n  \"implementation\": {\n    \"fields\": [\n      {\n        \"key\": \"css\",\n        \"label\": \"Additional CSS\",\n        \"value\": \"\",\n        \"type\": \"textarea\"\n      }\n    ],\n    \"note\": \"Inlines supported rules locally. Media queries, pseudo-class behavior, external stylesheets and email-client rendering need review. External stylesheets are not fetched.\",\n    \"experience\": {\n      \"automatic\": false,\n      \"single\": false,\n      \"label\": \"CSS\",\n      \"placeholder\": \"a { color: #3366cc; }\",\n      \"help\": \"Paste CSS rules, including their selectors. Up to 1,000,000 characters. Review the settings before running.\",\n      \"action\": null\n    },\n    \"mode\": \"explicit\",\n    \"interactive\": false\n  },\n  \"execution\": \"Browser interface\",\n  \"api\": null,\n  \"browser_agent\": {\n    \"supported\": true,\n    \"name\": \"run_current_tool\",\n    \"discovery\": \"WebMCP on the human page in a supporting browser\",\n    \"verification\": \"See audit/API-AUDIT.md; availability is not verification\"\n  }\n}\n```\n\n## Page guide\n\nInline supported selectors for email HTML.\n\n## Useful next steps\n\n- [HTML formatter](https://happytails.ai/en/developer-tools/html-formatter/): Format/minify with options. ([Markdown](https://happytails.ai/en/developer-tools/html-formatter.md))\n\n- [CSS formatter](https://happytails.ai/en/developer-tools/css-formatter/): Format/minify CSS with parser-based errors. ([Markdown](https://happytails.ai/en/developer-tools/css-formatter.md))\n\n- [Javascript formatter](https://happytails.ai/en/developer-tools/javascript-formatter/): Parse and format code without executing it. ([Markdown](https://happytails.ai/en/developer-tools/javascript-formatter.md))\n\n## How to use CSS inliner\n\n1. Enter css in the input field.\n2. Review the settings, then choose Run CSS inliner.\n3. Review the result, then use Copy result or a download link when available.\n\n## Working with css inliner\n\nFormatting makes existing data or code easier to read. Validation checks whether it follows a syntax or schema. Conversion maps it into another representation. Choosing the right operation helps avoid treating a neatly formatted result as proof that the underlying data is correct.\n\n## Common questions\n\n### Does valid JSON mean the data is correct?\n\nSyntax validation only establishes that the text can be parsed as JSON. A schema can check required fields and types, but neither proves that an email address, price or external record is factually correct.\n\n### Is decoding the same as decrypting or verifying?\n\nNo. Base64 and URL encoding are representations, not encryption. Reading a token payload does not verify its signature. Use the specific validation or verification process required by the system receiving the result.\n\nContinue your workflow: [HTML formatter](https://happytails.ai/en/developer-tools/html-formatter/), [CSS formatter](https://happytails.ai/en/developer-tools/css-formatter/), [Javascript formatter](https://happytails.ai/en/developer-tools/javascript-formatter/).\n"
}