three.ws Knock — MCP server for priced doors and messages
A paid line to a real person: the agent checks a door's price, sends one message, then reads the answer. Useful when you want an agent to write to a stranger.
claude mcp add --env THREE_WS_API_KEY=<THREE_WS_API_KEY> --env THREE_WS_BASE=<THREE_WS_BASE> --env THREE_WS_TIMEOUT_MS=<THREE_WS_TIMEOUT_MS> --transport stdio knock-mcp -- npx -y @three-ws/knock-mcpWhat three.ws Knock does
Any three.ws account can publish a door at three.ws/knock/<handle> and name the price of a single message from a stranger. Once that price is paid, the note reaches the recipient's inbox, and their 3D companion speaks it aloud on the site with the sender's name and the amount. USDC settles straight to the recipient.
The server hands your agent six tools. knock_quote reports the price, accepted chains and the length limit; knock_directory lists everyone reachable right now; knock_send pushes a message through; knock_receipt tells you whether a knock is pending, read, answered or dismissed. The other two, knock_inbox and knock_act, manage your own door and need THREE_WS_API_KEY.
No wallet lives in this server. A free door sends at once since there is nothing to pay. A priced door is different: knock_send returns the recipient, amount, token, chain and endpoint, then stops, and a human approves the spend from a wallet they already hold using @three-ws/knock or another x402 client. Node 20+ is required. THREE_WS_BASE and THREE_WS_TIMEOUT_MS set the service address and the per-request timeout.
What it helps with
- check what one message to a given person costs
- list reachable people starting from the cheapest door
- send a single note to a stranger without overspending
- see whether the recipient read your knock and what they replied
- review incoming knocks on your own door with amounts and reply to them
Example prompts for the agent
- Use
knock_directoryto find someone taking questions about x402, then get their price withknock_quote. - Check
knock_receiptand tell me if my last knock got an answer.
How to install three.ws Knock
Platform CLI
claude mcp add --env THREE_WS_API_KEY=<THREE_WS_API_KEY> --env THREE_WS_BASE=<THREE_WS_BASE> --env THREE_WS_TIMEOUT_MS=<THREE_WS_TIMEOUT_MS> --transport stdio knock-mcp -- npx -y @three-ws/knock-mcpReplace <…> with your own values
Platform CLI
codex mcp add knock-mcp --env THREE_WS_API_KEY=<THREE_WS_API_KEY> --env THREE_WS_BASE=<THREE_WS_BASE> --env THREE_WS_TIMEOUT_MS=<THREE_WS_TIMEOUT_MS> -- npx -y @three-ws/knock-mcpReplace <…> with your own values
Config file
{
"mcpServers": {
"knock-mcp": {
"command": "npx",
"args": [
"-y",
"@three-ws/knock-mcp"
],
"env": {
"THREE_WS_API_KEY": "<THREE_WS_API_KEY>",
"THREE_WS_BASE": "<THREE_WS_BASE>",
"THREE_WS_TIMEOUT_MS": "<THREE_WS_TIMEOUT_MS>"
}
}
}
}Replace <…> with your own values
Config file
{
"servers": {
"knock-mcp": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@three-ws/knock-mcp"
],
"env": {
"THREE_WS_API_KEY": "<THREE_WS_API_KEY>",
"THREE_WS_BASE": "<THREE_WS_BASE>",
"THREE_WS_TIMEOUT_MS": "<THREE_WS_TIMEOUT_MS>"
}
}
}
}Replace <…> with your own values
Platform CLI
gemini mcp add -e THREE_WS_API_KEY=<THREE_WS_API_KEY> -e THREE_WS_BASE=<THREE_WS_BASE> -e THREE_WS_TIMEOUT_MS=<THREE_WS_TIMEOUT_MS> knock-mcp npx -y @three-ws/knock-mcpReplace <…> 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 three.ws Knock
How do I install three.ws Knock in Claude Code?
Run claude mcp add knock-mcp -e THREE_WS_API_KEY=<THREE_WS_API_KEY> -- npx -y @three-ws/knock-mcp. The key is only for the tools that manage your own door.
What does three.ws Knock do?
It gives an agent tools to find a person with an open door, look up the price of one message, deliver it and read the reply. Payment on a priced door is made by a human from their own wallet.
Can the server spend money on its own?
No. On a priced door knock_send only returns the recipient, amount, token, chain and endpoint; the payment is approved by a person through @three-ws/knock or another x402 client.
