# Web Manifest Validator

- Human page: https://happytails.ai/en/developer-tools/web-manifest-validator/
- Markdown: https://happytails.ai/en/developer-tools/web-manifest-validator.md
- Structured JSON: https://happytails.ai/agents/en/developer-tools/web-manifest-validator/index.json
- Visibility: public

## Tool capabilities

| Property | Value |
| --- | --- |
| Tool ID | `web-manifest-validator` |
| Category | developer-tools |
| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |
| Browser execution | Use the visible action or interactive controls. |
| Browser processing | Browser; see tool notes for network behavior. |
| HTTP API | Not callable through HTTP. |
| Browser-agent interface | run_current_tool |

### Implementation notes

Validate Web App Manifest metadata and icon declarations locally.

### Inputs and settings

Text input: Your text.

Example or placeholder shown in the interface (not a validated fixture):

```text
Type or paste your input…
```

Up to 200,000 characters. Review the settings before running.

No additional settings are declared for this tool.

### Browser-agent workflow

1. Open the human page in a browser that supports WebMCP.
2. Discover the interface exposed by that page; use its actual schema.
3. Select files on the page first when the tool requires files.
4. Call `run_current_tool` with valid input and settings.
5. Inspect the returned result or error and the displayed output. Retrieve files from the displayed download links.

Calls do not automatically copy or download results. Browser permissions still apply. Interface availability alone is not proof of successful execution.

### Planning specification

Input is limited to 200000 characters. Results are computed locally and exported as JSON.

This describes intended requirements. Use the implementation notes, interface schema and observed output to determine current support.

### Complete machine-readable capability record

```json
{
  "id": "web-manifest-validator",
  "category": "developer-tools",
  "built": true,
  "requirements": "Input is limited to 200000 characters. Results are computed locally and exported as JSON.",
  "implementation": {
    "fields": [],
    "inputMaxLength": 200000,
    "inputErrorCode": "STRUCTURED_TEXT_TOO_LONG",
    "registrationFamily": "web-manifest-validator",
    "note": "Validate Web App Manifest metadata and icon declarations locally.",
    "experience": {
      "automatic": false,
      "single": false,
      "inputMaxLength": 200000,
      "inputMode": "text",
      "label": "Your text",
      "placeholder": "Type or paste your input…",
      "help": "Up to 200,000 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"
  }
}
```

## Page guide

Validate Web App Manifest metadata and icon declarations. Runs locally and returns a reviewable report.

How can we improve this tool?

Report a problem or share an idea.

Please leave out private information. Your message and the tool name go to our team via PostHog.

### How to use Web Manifest Validator

1. Paste the manifest JSON.
2. Run the local validator.
3. Review metadata and icon issues and download the report.

## Install metadata

The validator checks common install fields and icon declarations. It does not fetch remote icons.