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Számlázz.hu MCP by usefulapi MCP server

io.usefulapi/szamlazz-hu

We checked this server on 2 November 2026 with McpStamp Check engine 1.2.0. It scored 96 of 100 (grade A), higher than 77.1% of the 33,003 registry servers that responded over HTTPS that day. Ready for Claude, Gemini and MCP Registry. Not ready for ChatGPT.

Measured facts

Score
96A
Sign-in
OAuth
Tools listed
11
Protocol version
2025-11-25
Stores

Store readiness

StoreStatusReason
Claude Connectors Directory Ready No blocking check failed.
ChatGPT app directory Not ready Blocked by Explicit readOnlyHint, destructiveHint and openWorldHint (ChatGPT).
Gemini Connected Apps Ready No blocking check failed.
Official MCP Registry Ready No blocking check failed.

MCP Registry ready means a valid public remote for the registry, not that the server is listed in a store.

Fixes

2 checks to fix

  1. Fails

    Explicit readOnlyHint, destructiveHint and openWorldHint (ChatGPT)

    tool_open_world

    Blocks ChatGPT.

    Measured 11/11 tools miss an explicit hint: szamlazz_get_invoice, szamlazz_get_invoice_pdf, szamlazz_check_taxpayer, szamlazz_get_receipt, szamlazz_create_invoice and 6

    Set readOnlyHint, destructiveHint and openWorldHint to explicit true/false on every tool (OpenAI app review requires all three).

  2. Warning

    JSON-RPC error for unknown method

    jsonrpc_errors

    Measured HTTP 401 instead of a JSON-RPC error

    Route the method first and answer unknown methods with JSON-RPC error -32601 before the auth check, or return a JSON-RPC error body with the 401.

25 checks passed

Passed. Served over HTTPS, initialize over Streamable HTTP, Supported protocol version negotiated, JSON or SSE response Content-Type, GET answers SSE or 405, initialize latency, serverInfo name and version, Server instructions, tools capability declared, Sign-in method the store supports (OAuth or none), 401 carries WWW-Authenticate resource_metadata, Protected resource metadata (RFC 9728), Resource metadata "resource" equals the server URL, Authorization server metadata (RFC 8414 / OIDC), First metadata URL Gemini tries answers 200 with the required fields, issuer equals the authorization_servers entry; token_endpoint_auth_methods_supported (ChatGPT), PKCE S256 advertised, Client registration (DCR or Client ID Metadata Documents), refresh_token grant advertised, tools/list returns tools, inputSchema is an object schema, Tool names are valid and portable, readOnlyHint or destructiveHint on every tool, Human-readable title on every tool, Tool descriptions.

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McpStamp score for Számlázz.hu MCP by usefulapi

Markdown

[![McpStamp score](https://www.mcpstamp.com/badge?url=https%3A%2F%2Fszamlazz-hu.usefulapi.io%2Fmcp)](https://www.mcpstamp.com/r/io-usefulapi-szamlazz-hu/)

HTML

<a href="https://www.mcpstamp.com/r/io-usefulapi-szamlazz-hu/"><img src="https://www.mcpstamp.com/badge?url=https%3A%2F%2Fszamlazz-hu.usefulapi.io%2Fmcp" alt="McpStamp score" height="20"></a>
Registry entry

About this server

Read Számlázz.hu invoices, PDFs, receipts, taxpayers; issue, reverse and pay invoices and receipts.
Registry name
io.usefulapi/szamlazz-hu
Remote URL
https://szamlazz-hu.usefulapi.io/mcp
Version
1.20.0
Source
github.com/m190/usefulapi-mcp
Website
usefulapi.io/szamlazz-hu/
Checked
2 November 2026, engine 1.2.0, no credentials

The description above is the server's own text from the official MCP Registry. If a result looks wrong, run a fresh check and email support@zovo.one with the report link.

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