# Regex Test — MCP tool `findutils:regex_test`

Test a regex against input text. Returns all matches (up to 1000), their indices, and named groups.

- Category: developer
- MCP server: https://mcp.findutils.com/ (Streamable HTTP, no API keys, 120 req/min per IP)
- REST endpoint: POST https://api.findutils.com/api/tools/regex-test/execute (no API keys, 60 req/min per IP)
- Reference page: https://findutils.com/mcp/regex-test/
- Same tool on the other surface: https://findutils.com/api/regex-test/

## Connect

```bash
claude mcp add findutils --transport http https://mcp.findutils.com/
```

Claude Desktop (`claude_desktop_config.json`):

```json
{
  "mcpServers": {
    "findutils": {
      "url": "https://mcp.findutils.com/"
    }
  }
}
```

## Call the tool (verified example)

```bash
curl -X POST https://mcp.findutils.com/ \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/call",
    "params": {
      "name": "regex_test",
      "arguments": {
        "pattern": "^[a-z]+$",
        "text": "hello"
      }
    }
  }'
```

## Input schema

| Argument | Type | Required | Description |
|---|---|---|---|
| `pattern` | string | yes | Regex pattern (max 500 chars). |
| `input` | string | yes | Text to search. |
| `flags` | string | no | Regex flags (g/i/m/s/u/y). Defaults to "g". Default: `"g"`. |

Example arguments (verified):

```json
{
  "pattern": "^[a-z]+$",
  "text": "hello"
}
```

## Also a REST endpoint

```bash
curl -X POST https://api.findutils.com/api/tools/regex-test/execute \
  -H "Content-Type: application/json" \
  -d '{
    "pattern": "^[a-z]+$",
    "text": "hello"
  }'

# Parameter schema
curl https://api.findutils.com/api/tools/regex-test
```

Full REST reference: https://findutils.com/api/regex-test/ · OpenAPI 3.1 spec: https://findutils.com/api/openapi.json

---
Full catalog: POST https://mcp.findutils.com/ with method `tools/list` · https://findutils.com/mcp/ · https://findutils.com/llms.txt