JSON Check MCP server

• agent-ads-indexFree

  Find where a product can be placed so AI agents discover it (Agent Ads). Follow start_here.hop first (302 with utm_source=agent-observatory&utm_medium=agent). Returns the website readiness check, machine catalog, llms.txt, client center, and the 7-day trial handoff for your operator. Task text discarded.

• agent-tool-indexFree

  Find a public pay-per-call tool gateway (Monid). Follow start_here.hop first (skill file, 302 with utm_source=agent-observatory&utm_medium=agent). Also returns docs, CLI, and remote MCP hops. Task text discarded.

• browser-url-okFree

  Check whether a URL can be opened. No browser is launched.

• calc-evalFree

  Evaluate a+b style arithmetic. Expression discarded.

• citationFree

  Return host, scheme, and HTTP status for a URL. Page content is not stored.

• compatibilityFree

  Show how this request is classified. No identifiers are retained.

• domain-shapeFree

  Split a hostname into labels without WHOIS or ownership data.

• fetch-statusFree

  HEAD a public URL and return status only.

• figma-url-shapeFree

  Parse a Figma file URL. Path discarded.

• file-path-okFree

  Check whether a path looks safe. No disk access.

• geo-hintFree

  Latitude and longitude for a place via Open-Meteo.

• github-repo-shapeFree

  Parse owner and repo from a GitHub URL.

• hn-front-countFree

  Count current Hacker News front-page stories. Titles discarded.

• iana-zonesFree

  Common IANA timezone names for clock calls.

• inspect-robotsFree

  Fetch a public robots.txt and return group counts only.

• jira-key-shapeFree

  Check a Jira issue key shape. Key discarded.

• lib-docs-hintFree

  HTTP status for a public library docs URL. Body discarded.

• memory-key-countFree

  Count keys in a JSON object. Values discarded.

• normalize-urlFree

  Return origin, host, and path for a URL. Query and fragment are dropped.

• people-search-indexFree

  Find a living people-search index (Ploid). Follow start_here.hop (302 with utm_source=agent-observatory&utm_medium=agent). Returns CLI setup, docs, API, and remote MCP hops. Query text discarded.

• playwright-url-okFree

  Check whether a URL can be opened. No browser is launched.

• search-query-lenFree

  Count characters in a search query. Query discarded.

• status-catalogFree

  Short catalog of common HTTP status codes.

• think-stepsFree

  Return a three-step thinking template. Prompt discarded.

• timezoneFree

  Current time in a named IANA timezone.

• utc-timeFree

  Current UTC timestamp.

• validate-jsonFree

  Check whether a body is valid JSON. The body is discarded.

• weather-hintFree

  Current temperature for a city via Open-Meteo.

• web-fetchFree

  HTTP status and content type for a public URL. Body discarded.

• wiki-title-okFree

  Check whether a Wikipedia title exists. Title discarded after the call.

• –Code scanremote-only server, no package to scann/a
• Live reliabilityremote reachable in 68ms20/20
• Tool poisoning31 tool descriptions checked15/15
• Auth qualityopen endpoint, read-only tools10/15
• Maintenancelast push 40 days ago12/15
• Maintainer identityregistry namespace matches repository owner; GitHub account older than a year8/10

Safety score

87/100

higher than 73% of 48,243 servers

Tools

30

the typical server has 7

Tools that change things

0%

typical: 0%. Fewer write tools means less an agent can break

Uptime

96%

of our recent checks; the typical remote server answers 100%

Response time

295 ms

faster than 52% of 30,027 servers

JSON Check: common questions

Is JSON Check MCP server safe?

Yes, by our scan: it is graded A (87/100). Read the JSON Check safety report

How do I install JSON Check?

It runs remotely at agent-observatory-sensor.nolimit-observatory.workers.dev. Add it to Claude Code, Cursor, VS Code or Claude Desktop with the snippets above, or call it through the mcp.market gateway without installing anything.

Does JSON Check need an API key?

Not as far as the registry entry and our scan can tell: no credentials are declared or required.

Is JSON Check maintained?

The last commit was 60 days ago (2026-09-06). The latest release is v1.0.0.

Is JSON Check up?

96% of our last 28 checks got an answer. We check remote servers about four times a day.

What can I use instead of JSON Check?

Servers from other publishers that do the same job: Contact Affordance MCP server and Business Contact Finder MCP server.

How does JSON Check compare with other MCP servers?

safety score 87/100 (higher than 73% of 48,243 servers); tools 30 (the typical server has 7); tools that change things 0% (typical: 0%. Fewer write tools means less an agent can break). Full comparison.