# Jq Playground — REST API endpoint `jq-playground`

Returns the result of running a jq-style filter over a JSON document. Supports a jq subset: paths (.a.b, .[0], .[1:3], .[]), pipes, map/select/sort_by/group_by/unique_by/min_by/max_by, keys/values/length/type/add/min/max/flatten/unique/reverse/sort, to_entries/from_entries/with_entries, has/contains/del, split/join/ltrimstr/rtrimstr, range/limit, the // fallback, and object/array/string construction. Not a full jq implementation.

- Category: data
- 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/jq-playground/execute (no API keys, 60 req/min per IP)
- Reference page: https://findutils.com/api/jq-playground/
- Same tool on the other surface: https://findutils.com/mcp/jq-playground/

## Call the endpoint (verified example)

```bash
curl -X POST https://api.findutils.com/api/tools/jq-playground/execute \
  -H "Content-Type: application/json" \
  -d '{
    "json": "{\"users\":[{\"name\":\"Ann\",\"age\":31}]}",
    "query": ".users[0].name"
  }'

# Parameter schema
curl https://api.findutils.com/api/tools/jq-playground
```

## Input schema

| Argument | Type | Required | Description |
|---|---|---|---|
| `json` | string | yes | The JSON input document (text). |
| `query` | string | no | The jq filter, e.g. ".users[] \| select(.age > 30) \| .name". Default: "." (identity). Default: `"."`. |

Example arguments (verified):

```json
{
  "json": "{\"users\":[{\"name\":\"Ann\",\"age\":31}]}",
  "query": ".users[0].name"
}
```

Decoded `json` argument (readability only — send it as a string):

```json
{
  "users": [
    {
      "name": "Ann",
      "age": 31
    }
  ]
}
```

OpenAPI 3.1 spec: https://findutils.com/api/openapi.json · Interactive docs: https://findutils.com/api/docs/

## Also an MCP tool

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

Then ask the client to call `findutils:jq_playground`. Full MCP reference: https://findutils.com/mcp/jq-playground/

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