MCP server

Payload Validator

com.gumballtools/payload-validator

Checked 26 Oct 2026, 08:29 UTC · Connected to it and listed its tools

Validate JSON, YAML, XML and CSV with exact line/column errors and silent-corruption warnings.

Website Source

At a glance

Type

MCP server

Publisher

gumballtools.com (verified by the MCP Registry)

Status

Working at last check

Tools

5

Token cost

About 3,472 tokens per request

Sets up in

Claude Code, Claude Desktop, Codex, Gemini CLI, Cursor, VS Code, Antigravity, ChatGPT, OpenAI API, Grok

Last checked

26 Oct 2026, 08:29 UTC

Connect it to your agent

Add to CursorAdd to VS CodeVS Code Insiders

Opens the app, which shows the server and asks you to confirm. For other apps, copy the setup below.

Claude Code

claude mcp add --transport http payload-validator https://payload-validator.gumballtools.com/api/mcp

Claude Desktop

Settings → Connectors → Add custom connector, and paste the URL.

Codex (config.toml)

[mcp_servers.payload-validator]
url = "https://payload-validator.gumballtools.com/api/mcp"

Gemini CLI

{"mcpServers":{"payload-validator":{"httpUrl":"https://payload-validator.gumballtools.com/api/mcp"}}}

Cursor

{"mcpServers":{"payload-validator":{"url":"https://payload-validator.gumballtools.com/api/mcp"}}}

VS Code

{"servers":{"payload-validator":{"type":"http","url":"https://payload-validator.gumballtools.com/api/mcp"}}}

Antigravity

agy mcp add payload-validator https://payload-validator.gumballtools.com/api/mcp

ChatGPT

Settings → Apps & Connectors → Advanced settings: turn on Developer mode, then Create a connector and paste the URL. Which plans can do this varies.

OpenAI API (Responses tools)

{"type":"mcp","server_label":"payload-validator","server_url":"https://payload-validator.gumballtools.com/api/mcp","require_approval":"always"}

Grok (xAI API tools)

{"type":"mcp","server_label":"payload-validator","server_url":"https://payload-validator.gumballtools.com/api/mcp"}

Tools

• validate_auto ~667 tokens
  Detects whether a payload is JSON, YAML, XML or CSV, then validates it. Use this when you have a blob of text and do not know what it is — a file with no extension, a clipboard paste, a response body with an unhelpful content type, or a config file whose format you would otherwise have to guess. D
• validate_csv ~801 tokens
  Validates CSV text against RFC 4180 and reports ragged rows individually, with both field counts. Use this before loading a CSV, and whenever a CSV-derived number looks wrong. Do not attempt this by reading the file, and be aware that loading it successfully proves nothing. The failure that matter
• validate_json ~668 tokens
  Validates a JSON document and reports every problem with an exact line and column. Use this whenever you need to know why a JSON payload is failing, or to check a JSON document you or a user produced before sending it somewhere that will reject it. Do not do this by reading the JSON yourself. Thre
• validate_xml ~667 tokens
  Validates an XML document for well-formedness, namespace correctness, and the entity-based attacks that arrive as XML. Use this before parsing XML you received, and when an XML document is being rejected by something that will not say why. Do not eyeball this. Four classes of genuinely invalid XML
• validate_yaml ~669 tokens
  Validates a YAML document, including the values that mean different things to different YAML loaders. Use this for any YAML you are about to write or have just been given — CI configs, Kubernetes manifests, docker-compose files, OpenAPI specs, Ansible playbooks. Do not reason about YAML type resol

Browse

• GitHub tools
• OpenAPI tools
• Spreadsheets
• Team chat
• Social media
• GitHub and code hosting

Related MCP servers

• Project Gumball
  One MCP server exposing every tool in the Gumball portfolio.
• One Million Tools
  42 free deterministic utilities: JSON, CSV, YAML, encoding, hashing, JWT, cron, formatters, CSS.
• Cubicle
  Agent trading tools: candles, copy-trading, hire a strategy for your Robinhood vault, pay on chain
• Oh My Posh Validator
  Validate oh-my-posh configurations and segment snippets against the official schema.
• QFactory
  Read-only QFactory catalog of agent workflows: search, get exact versions, schema, validate YAML.
• DocParse
  Docs to Markdown, SEC filings, insider trades, Treasury yields, FRED macro, FX rates, dev utils.
• useSignal
  QR codes, JSON diff/format, hashes, JWT, cron, timestamps, placeholders, flowcharts, forms, regex.
• Ribox
  Exact tools for AI assistants: QR codes, word counts, text diff and JSON checks. Free, no account.

Badge for your README

[![AptLynx](https://aptlynx.net/badge/com.gumballtools/payload-validator.svg)](https://aptlynx.net/servers/com.gumballtools/payload-validator)

Listing text is written by the maker; AptLynx lists tools and does not vouch for them. Find another tool · Browse by topic · For agents