Payload Validator vs JSON Validator API
Payload Validator is an MCP server published by gumballtools.com. Marketplaces we read that list it: 1 (Official MCP Registry). JSON Validator API is an MCP server published by Br0ski777. Marketplaces we read that list it: 1 (Official MCP Registry). As of our marketplace pass on 2026-10-29. This pair was picked by a reader, not by our comparison rule, so search engines are asked not to index the page.
Where each is published
| Marketplace |  JSON Validator API | |
|---|---|---|
| Official MCP Registry | Listed Version: 0.1.0 No figure published Not marked · First seen |
Listed Version: 1.1.0 Forks (GitHub): 0 Stars (GitHub): 0 Not marked · First seen |
Each figure is the marketplace's own and is never added up across marketplaces. A marketplace that publishes no figure shows none: no number is not zero.
The facts side by side
| Fact | Payload Validator | JSON Validator API |
|---|---|---|
| Marketplaces that list it | 1 | 1 |
| Stars (GitHub) (differs) | No figure on GitHub | 0 |
| Forks (GitHub) (differs) | No figure on GitHub | 0 |
| Last release | Not published | Not published |
| Where it runs (differs) | Remote server (payload-validator.gumballtools.com/api/mcp) | Remote server (json-validator.api.klymax402.com/mcp) |
| Transport (differs) | Streamable HTTP | SSE |
| Tools it declares | Not published | Not published |
| Environment variables it asks for | Not published | Not published |
| Licence | Not stated | Not stated |
| Repository (differs) | github.com/bwalvoord/gumball | github.com/br0ski777/json-validator-x402 |
| Changes in the last 7 days | 0 | 0 |
| First seen | 2026-10-11 | 2026-10-11 |
| Endpoint at the last check (differs) | Responded 25 h ago | Not responding since 2026-10-13 |
Lines where the two differ have a tinted background and bold values. Where the data itself says which value is better (more marketplaces, a larger figure of the same marketplace, a fresher release, a verified mark on a marketplace that lists both), the better one is also marked green with ▲ and the worse one red with ▼. Where it runs, the transport, the tools, the settings, hooks, the bundle's parts, the licence and the week's changes are marked only as different: more or fewer is not better in itself.
What each says it does
Payload Validator
Validate JSON, YAML, XML and CSV with exact line/column errors and silent-corruption warnings.
JSON Validator API
JSON syntax validation, JSON Schema checking, structure stats. x402 micropayment.
How to run each
Payload Validator As a remote MCP server
claude mcp add --transport http payload-validator https://payload-validator.gumballtools.com/api/mcpJSON Validator API As a remote MCP server
claude mcp add --transport sse json-validator https://json-validator.api.klymax402.com/mcpCommands built only from what the marketplaces declare; the full set for every client is on each card.
Only the endpoint of Payload Validator responded at the last daily check. How we check endpoints
Tools each declares
Neither one's marketplaces publish a list of tools, so there is nothing to compare.
Settings each asks for
Neither one's marketplaces publish the settings it asks for.
What it can do: Payload Validator · What it can do: JSON Validator API · Compare two other plugins
Data comes from the Official MCP Registry (registry.modelcontextprotocol.io), CC0 1.0. Figures come from our own regular passes over the marketplaces, last read on . We publish no contact details for plugin publishers.