# YAML Formatter/Validator API

> For the complete documentation index, see [llms.txt](/llms.txt).

Validate, format, minify, or convert YAML to JSON.

Use this endpoint to add the tool to your app, site, workflow, or agent without rebuilding formulas, validation, examples, and docs.

- Slug: `yaml-formatter-validator`
- Category: `developer`
- Version: `2026-04-22`
- Credits per successful call: 1
- Starts on: free
- Max payload: 65536 bytes
- Privacy mode: `no_body_logs`
- Available on: free, starter, pro, business, scale
- Browser tool: https://miniwebtool.com/yaml-formatter-validator/

## Endpoint

`POST https://api.miniwebtool.com/v1/tools/yaml-formatter-validator/run`

## Request body

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `yaml_input` | `str` | yes |  |
| `action` | `str` | no | beautify | minify | validate | to_json Choices: beautify, minify, validate, to_json |
| `indent_size` | `str` | no | 2 | 4 Choices: 2, 4 |
| `sort_keys` | `bool` | no |  |

## Example request

```json
{
  "yaml_input": "name: demo\nitems:\n  - 1\n  - 2",
  "action": "to_json",
  "indent_size": "2",
  "sort_keys": false
}
```

## cURL

```bash
curl -X POST https://api.miniwebtool.com/v1/tools/yaml-formatter-validator/run \
  -H 'Authorization: Bearer mwt_live_YOUR_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"yaml_input":"name: demo\nitems:\n  - 1\n  - 2","action":"to_json","indent_size":"2","sort_keys":false}'
```

## Response envelope

```json
{
  "request_id": "01K...",
  "tool": "yaml-formatter-validator",
  "tool_version": "2026-04-22",
  "credits_used": 1,
  "result": {}
}
```

## Errors

Errors are RFC 7807 `application/problem+json`. Branch on `code`, not `title`.

## MCP

Agents can discover and call this tool through `https://api.miniwebtool.com/mcp` or `https://api.miniwebtool.com/v1/mcp` using MCP `tools/list` and `tools/call`.

## Frequently asked

### What does the YAML Formatter/Validator API do?

Validate, format, minify, or convert YAML to JSON. Use it to add this utility without rebuilding formulas, validation, examples, and documentation.

### How much does one call cost?

1 credit per successful call. Failed calls do not bill.

### What parameters are required?

Required fields: yaml_input. Full schema at `https://api.miniwebtool.com/v1/openapi.json`.

### Is this deterministic?

Yes. Same input, same output. Tool version: 2026-04-22.