JSON Schema Generator Skill

Overview

JSON Schema Generator works by analyzing the structure and data types in sample JSON to produce a valid JSON Schema. It detects formats like date, email, and URI automatically and marks all fields as required.

Live Test JSON Schema Generator Skill Skill →

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as JSONSchemaGeneratorSkill. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

Tool call

{
  "name": "JSONSchemaGeneratorSkill",
  "arguments": {
    "json": "{\"name\":\"John\",\"age\":30,\"email\":\"[email protected]\"}"
  }
}

You do not name the tool yourself; the model picks it. Asking about {"name":"John","age":30,"email":"[email protected]"} in the terms this skill covers is enough for it to reach for JSONSchemaGeneratorSkill on its own — naming it explicitly also works, and is the way to force the call.

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

Argument	Type	Description
`json`Required	object	The sample JSON data to generate a schema from
`title`Optional	string	The title for the generated schema (default: 'Generated Schema') default Generated Schema
`description`Optional	string	Optional description for the schema

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

Result

{
  "status": "ok",
  "error": null,
  "data": {
    "$schema": "http://json-schema.org/draft-07/schema#",
    "title": "User Schema",
    "type": "object",
    "properties": {
      "name": {
        "type": "string"
      },
      "age": {
        "type": "integer"
      },
      "email": {
        "type": "string",
        "format": "email"
      },
      "active": {
        "type": "boolean"
      }
    },
    "required": [
      "name",
      "age",
      "email",
      "active"
    ]
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`$schema`	string	`http://json-schema.org/draft-07/schema#`	JSON Schema version URI (e.g., Draft-07)
`title`	string	`User Schema`	Title of the generated schema definition
`type`	string	`object`	Root schema type (e.g., object, array)
`properties`	object	`{…}`	Field definitions with inferred types and formats
`properties.name`	object	`{…}`
`properties.name.type`	string	`string`	Root schema type (e.g., object, array)
`properties.age`	object	`{…}`
`properties.age.type`	string	`integer`	Root schema type (e.g., object, array)
`properties.email`	object	`{…}`
`properties.email.type`	string	`string`	Root schema type (e.g., object, array)
`properties.email.format`	string	`email`
`properties.active`	object	`{…}`
`properties.active.type`	string	`boolean`	Root schema type (e.g., object, array)
`required`	array	`["name","age","email"]`	Array of field names marked as required

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

Status	What it means
`400` / `422`	The arguments did not validate. The message names the offending one.
`401`	The OAuth session is invalid or expired — reconnect the server.
`403`	Blocked by a key restriction or an IP allow-list. Never a bad identity.
`404`	This skill is not part of VerveKit. Check the catalog.
`429`	Out of credits, or a brief rate limit. The message tells them apart.

A call costs 2 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

API Documentation: Generate JSON schemas for API request/response documentation automatically from sample data
Data Validation: Create validation schemas for JSON data in applications, APIs, or configuration files
Contract Testing: Generate schemas from API responses to use in contract testing and API monitoring
Code Generation: Use generated schemas as input for code generation tools to create type-safe data models

Other ways to use JSON Schema Generator Skill

Set up JSON Schema Generator Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

Call it as a REST APIOne HTTPS endpoint and an x-api-key header, with SDKs for Node, Python and .NET.APIVerve →Reference →