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Jsonaut MCP Server

by shoggi211 Your server? Claim it
answering

Jsonaut is answering right now. Last checked 3 min ago. It exposes 4 tools. Last commit 6 Jul 2026.

Repair malformed JSON from LLM/agent output; optional JSON Schema coercion. Free + x402 paid.

Uptime history 91 days of history · worst day 92%
91 days agonow
100.0%
Uptime 24h
92 of 92 checks
4
Tools
read from the server
111 ms
Response time
average over 24h
1
Stars
last commit 6 Jul 2026

Nothing serious here today

Today is the operative word: we check Jsonaut every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Three servers free · no card

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 3 min ago.

run in your terminal
claude mcp add jsonaut --transport http https://jsonaut.jsonaut-shaurya.workers.dev/mcp
Settings → Connectors → Add custom connector, then paste this address
https://jsonaut.jsonaut-shaurya.workers.dev/mcp
~/.codex/config.toml
[mcp_servers.jsonaut]
url = "https://jsonaut.jsonaut-shaurya.workers.dev/mcp"
.cursor/mcp.json
{
  "mcpServers": {
    "jsonaut": {
      "url": "https://jsonaut.jsonaut-shaurya.workers.dev/mcp"
    }
  }
}
.vscode/mcp.json
{
  "servers": {
    "jsonaut": {
      "type": "http",
      "url": "https://jsonaut.jsonaut-shaurya.workers.dev/mcp"
    }
  }
}

Available tools 4

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

extract
extract_json
Extract JSON embedded in arbitrary text — LLM prose, chat messages, logs, emails — then repair and validate it. Deterministic extraction is free. If no JSON can be located and allow_llm_fallback is true, a paid LLM extracts structured data from the text (requires x402 payment; charged only on success). Pass a JSON Schema to shape the output.
infer
infer_schema
Infer a JSON Schema (draft 2020-12) from an example JSON value. Free and deterministic. Set as_samples=true when the input is an array of example objects of the same shape to merge them into one schema. Turns sample agent/tool output into a reusable schema.
repair
repair_json
Repair malformed JSON (trailing commas, single quotes, truncation, markdown fences, comments, python literals) and optionally validate/coerce it against a JSON Schema. Deterministic repair is free. If it fails and allow_llm_fallback is true, a paid LLM repair is attempted (requires x402 payment; charged only on success).
validate
validate_json
Validate a JSON string against a JSON Schema. Free. Returns validity and a list of violations.

Endpoints

URLTransportStateLatencyChecked
https://jsonaut.jsonaut-shaurya.workers.dev/mcp streamable-http answering 77 ms 3 min ago

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Jsonaut — questions

Answers built from our own checks of this server.

What can Jsonaut do?
It exposes 4 tools, read directly from the server on our last check. Among them: extract_json, infer_schema, repair_json, validate_json. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →
Is Jsonaut working right now?
We send a real MCP handshake every 15 minutes. Over the last 24 hours 92 of 92 checks got a reply (100.0%), average response time 111 ms. The bar chart above shows every period we have measured.
How do I connect Jsonaut?
Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.
Does Jsonaut need an API key?
No. Jsonaut completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 4 of them are readable on this page. This is what we observed, not what the docs claim.
How fast is Jsonaut?
It answers our handshake in 111 ms on average, which is faster than 92% of all working MCP servers we measure. That puts it in the quick quarter of the ecosystem. The comparison comes from our own checks across the whole registry, every 15 minutes.
Is Jsonaut open source?
We cannot say either way: written in TypeScript and 1 stars on GitHub, but we could not determine the licence, and without one the code is not open source by default.