check — Claude Code MCP server: verify what your agent did
An MCP server that opens signed records of what an AI agent did on someone's behalf and which commercial influence applied.
claude mcp add --env STUB_REGISTRY=<STUB_REGISTRY> --transport stdio check -- npx -y @getstub/mcp-checkWhat check does
check is a public server from the Stub recipe set, an allegiance receipt registry for AI agents. Ask it for a signed record and you get back who requested the action, what was carried out, what money moved, and any commercial factor that shaped the outcome. The record is checked against a neutral registry rather than the operator's own servers.
It runs through npx as the @getstub/mcp-check package and plugs in as a stdio server across Claude, Codex, Cursor, GitHub Copilot and Gemini CLI. Cursor and Copilot take a config block with the command plus a STUB_REGISTRY variable. The recipes themselves come in JavaScript and Python and talk to the live registry; there is no offline mode, and issuing receipts requires an operator account.
The free tier covers 1,000 stubs a month. Verification stays free, since charging the person being served would defeat the purpose of a registry.
What it helps with
- confirm what an agent actually did for a user
- see whether a commission or paid placement shaped a result
- obtain a signed record anyone can open from a link
- wire registry verification into an agent loop
- sign an empty disclosure as proof nothing applied
Example prompts for the agent
- Add the
checkMCP server so we can read Stub registry receipts. - Use
checkto show which commercial factors influenced this pick. - Pull the receipt for the agent's last action and link me to it.
How to install check
Platform CLI
claude mcp add --env STUB_REGISTRY=<STUB_REGISTRY> --transport stdio check -- npx -y @getstub/mcp-checkReplace <…> with your own values
Platform CLI
codex mcp add check --env STUB_REGISTRY=<STUB_REGISTRY> -- npx -y @getstub/mcp-checkReplace <…> with your own values
Config file
{
"mcpServers": {
"check": {
"command": "npx",
"args": [
"-y",
"@getstub/mcp-check"
],
"env": {
"STUB_REGISTRY": "<STUB_REGISTRY>"
}
}
}
}Replace <…> with your own values
Config file
{
"servers": {
"check": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@getstub/mcp-check"
],
"env": {
"STUB_REGISTRY": "<STUB_REGISTRY>"
}
}
}
}Replace <…> with your own values
Platform CLI
gemini mcp add -e STUB_REGISTRY=<STUB_REGISTRY> check npx -y @getstub/mcp-checkReplace <…> with your own values
Step by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about check
How do I install check in Claude Code?
Run claude mcp add check -- npx -y @getstub/mcp-check, then if needed claude mcp add --env STUB_REGISTRY=<STUB_REGISTRY> --transport stdio check -- npx -y @getstub/mcp-check.
What does check do?
It fetches signed Stub records and verifies them: who asked, what ran, what money moved, and which commercial influence applied.
Do I need an account to issue receipts?
Yes. Receipts are issued under an operator id you pick, and the first run registers it and stores a keypair. Checking records costs nothing.
