Home / MCP registry index / io.usefulapi/customer-thermometer

Customer Thermometer MCP by usefulapi

io.usefulapi/customer-thermometer in the official MCP registry. Endpoint https://customer-thermometer.usefulapi.io/mcp. Source: github.com/m190/usefulapi-mcp.

The registry describes it as: Read Thermometers, scores, response rates, survey responses and comments in Customer Thermometer.

We read its 10 tools on 2026-11-02. Nothing in them matched our tool-poisoning rules. It also sets server instructions, text a client puts in front of the model on connect; those were read too.

A clean read means these rules found nothing, not that the server is harmless. A server can change its tools at any time, which is why the index reads it again about every two weeks.

Connect it

The endpoint answers MCP over HTTP; that is how we read it. Add it to your client:

Claude Code

claude mcp add --transport http customer-thermometer https://customer-thermometer.usefulapi.io/mcp

Cursor: ~/.cursor/mcp.json

{
  "mcpServers": {
    "customer-thermometer": {
      "url": "https://customer-thermometer.usefulapi.io/mcp"
    }
  }
}

VS Code

code --add-mcp '{"name":"customer-thermometer","type":"http","url":"https://customer-thermometer.usefulapi.io/mcp"}'

Some servers ask you to sign in the first time a client connects, or want a key from the people who run them; the server's own docs say which.

Let Claude Code check servers as it adds them

With the free lazaretto-guard plugin installed, when Claude Code adds a server for you or writes one into an MCP config, the plugin reads the server's tools first and asks you if one of our rules matches. Install it, restart Claude Code, then ask it to run the command above.

Install lazaretto-guard

claude plugin marketplace add jamesdfinance-dev/lazaretto-plugins
claude plugin install lazaretto-guard@lazaretto-plugins

Tools it advertises

customerthermometer_list_thermometers customerthermometer_list_recipient_lists customerthermometer_get_send_quota customerthermometer_get_happiness_value customerthermometer_get_nps_value customerthermometer_get_temperature_rating customerthermometer_get_response_rate customerthermometer_count_responses customerthermometer_get_blast_results customerthermometer_get_comments

Tool changes

We compare every full read of this server with the one before. No change in what its tools say has been seen since we started keeping this record on 2026-10-30.

Fingerprint of its tools at our last full read (2026-11-02): b3cd667a5727b3a5. A client can hash the tools it is served the same way and compare; the full value and a hash per tool are in this page as JSON.

Rather than checking back: subscribe to this server's tool changes (a feed, no account and no address needed). Tool names and dates only, never what a tool says.

Run this server? Show the check in your README

The badge reflects the latest read:

Markdown

[![MCP tool check](https://lazaretto.dev/mcp-registry/io-usefulapi-customer-thermometer/badge.svg)](https://lazaretto.dev/mcp-registry/io-usefulapi-customer-thermometer)

How this was checked

Lazaretto connects to the endpoint the way any MCP client does, asks the server to introduce itself and list its tools, and reads every name, description, parameter schema and server instruction for tool poisoning: hidden directive blocks, orders to read local secrets, parameters built to carry secrets or the conversation out, orders that redirect another server's tools, and invisible characters. It never calls a tool. What we found across the registry.

To run the same check every time Claude Code adds a server, install the free lazaretto-guard plugin. Browse every server in the index.