Payload Validator is an MCP server with 5 tools an agent can call, among them validate_auto, validate_csv, validate_json. It answers at https://payload-validator.gumballtools.com/api/mcp over streamable HTTP, and it listed its tools to an anonymous client, so no sign-in was needed for that. Our probes reached it 8 of 8 times since 6 September 2026; the last check, on 17 October 2026, succeeded.
Validate JSON, YAML, XML and CSV with exact line/column errors and silent-corruption warnings.
Description as the publisher wrote it.
| Tool | What it does |
|---|---|
validate_auto | 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 con Inputs: input |
validate_csv | 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 loadi Inputs: input, delimiter, hasHeader |
validate_json | 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 re Inputs: input |
validate_xml | 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. Inputs: input |
validate_yaml | 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 spe Inputs: input |
Every block below points at https://payload-validator.gumballtools.com/api/mcp. Pick your client and copy.
claude mcp add --transport http payload-validator https://payload-validator.gumballtools.com/api/mcp
{
"mcpServers": {
"payload-validator": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://payload-validator.gumballtools.com/api/mcp"]
}
}
}{
"mcpServers": {
"payload-validator": {
"url": "https://payload-validator.gumballtools.com/api/mcp"
}
}
}{
"servers": {
"payload-validator": {
"type": "http",
"url": "https://payload-validator.gumballtools.com/api/mcp"
}
}
}{
"context_servers": {
"payload-validator": {
"url": "https://payload-validator.gumballtools.com/api/mcp"
}
}
}{
"mcpServers": {
"payload-validator": {
"serverUrl": "https://payload-validator.gumballtools.com/api/mcp"
}
}
}{
"mcpServers": {
"payload-validator": {
"url": "https://payload-validator.gumballtools.com/api/mcp"
}
}
}name: Payload Validator
version: 0.0.1
schema: v1
mcpServers:
- name: Payload Validator
type: streamable-http
url: https://payload-validator.gumballtools.com/api/mcp{
"mcpServers": {
"payload-validator": {
"httpUrl": "https://payload-validator.gumballtools.com/api/mcp"
}
}
}{
"mcpServers": {
"payload-validator": {
"type": "http",
"url": "https://payload-validator.gumballtools.com/api/mcp"
}
}
}{
"mcpServers": {
"payload-validator": {
"url": "https://payload-validator.gumballtools.com/api/mcp"
}
}
}goose://extension?url=https%3A%2F%2Fpayload-validator.gumballtools.com%2Fapi%2Fmcp&type=streamable_http&id=payload-validator&name=Payload%20Validator
It answered our last check on 17 October 2026 in 771 ms. Over 8 checks since 6 September 2026 it answered 8. Status here comes from Neuronto's own probes, not from the publisher.
Yes. It is published by gumballtools.com and served from payload-validator.gumballtools.com, the vendor's own domain: https://payload-validator.gumballtools.com/api/mcp.
5, as returned by the server's own tools/list on 6 September 2026: validate_auto, validate_csv, validate_json, validate_xml, validate_yaml.
It answered our last check on 17 October 2026 in 771 ms. Over 8 checks since 6 September 2026 it answered 8.
Put the server under mcpServers in ~/.cursor/mcp.json with the URL https://payload-validator.gumballtools.com/api/mcp. The exact JSON is above, with the same setup for Claude Code, Claude Desktop, VS Code, Windsurf, Zed, Gemini CLI and the rest.
It listed its tools to an anonymous client, so reading the tool list needs no key. Individual tools can still ask for credentials in their own inputs.
Publisher: com.gumballtools. Endpoint host: payload-validator.gumballtools.com. ARD identifier: urn:air:com.gumballtools:mcp:payload-validator.
First indexed 6 September 2026. The tools are exactly what the server returned; nothing on this page
is inferred from its name. Ranking in Neuronto search is never for sale.