send21 MCP Server

by send21io Your server? Claim it

answering

send21 is answering right now. Last checked 13 min ago. It exposes 9 tools. Last commit 6 Sep 2026.

Non-custodial payment drafts/pay links for BTC, USDC, USDT, EURC. Never holds keys.

Uptime history 12 days of history

12 days agonow

100.0%

Uptime 24h

91 of 91 checks

Tools

read from the server

176 ms

Response time

average over 24h

Stars

last commit 6 Sep 2026

Nothing serious here today

Today is the operative word: we check send21 every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 13 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add mcp --transport http https://send21.io/mcp

~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "mcp": {
      "url": "https://send21.io/mcp"
    }
  }
}

~/.codex/config.toml

[mcp_servers.mcp]
url = "https://send21.io/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "mcp": {
      "url": "https://send21.io/mcp"
    }
  }
}

.vscode/mcp.json

{
  "mcpServers": {
    "mcp": {
      "url": "https://send21.io/mcp"
    }
  }
}

Available tools 9

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

draft

create_draft

Create a non-custodial payment draft (you are the SENDER paying a receiver address). Amount is either exact base units (sats for BTC, micro-units for stablecoins) via amountBaseUnits, or fiat-pegged via fiatCurrency+fiatAmount with the exchange rate locked at creation. Returns the draft incl. id, amounts, fee, and status. Funds move only when the sender signs in their own wallet — send21 never holds keys. Requires scope drafts:write.

get_draft

Get a payment draft by id, including amounts, fee, quote, and status. Requires scope drafts:read.

get_draft_status

Lightweight status snapshot of a draft: status (AwaitingPayment/Seen/Confirmed/Expired/Cancelled), paying txid, confirmations. Cheap to poll. Requires scope drafts:read.

payment

create_payment_request

Create a payment request / checkout pay link (you are the RECEIVER asking to get paid). Price in any of 165 fiat currencies; the payer opens the returned payPath, picks one of the offered currencies (rate locks then), and pays a single QR-scannable transfer straight to your address. Requires scope drafts:write.

get_payment_request

Get a payment request by id: status (Open/Completed/Cancelled/Expired), pay path, offered currencies, and the underlying draft once the payer committed. Requires scope drafts:read.

address

list_address_book

List the account's saved addresses (label, address, network, direction: Sending = recipients the owner pays, Receiving = the owner's own addresses). Requires scope addressbook:read.

fee

get_fee_schedule

Get the public send21 fee schedule: tiered percent by payment size in USD, min/max fee, and dust limit. No authentication needed.

rate

get_rate

Get the current exchange rate for an asset in a fiat currency (rate = fiat units per 1 whole asset unit, with source provenance). Assets: Btc, Usdc, Usdt, Eurc. 165 ISO-4217 fiat currencies are supported.

transaction

get_transaction_template

Get the multi-output transaction template for a draft: Bitcoin Core walletcreatefundedpsbt arguments and Electrum/Sparrow pay-to-many CSV. The operator's wallet funds, reviews, and signs it — send21 contains no signing code. Requires scope drafts:read.

Endpoints

URL	Transport	State	Latency	Checked
https://send21.io/mcp	streamable-http	answering	115 ms	13 min ago

Alternatives to send21

same job, measured the same way

agentic-pay

by shieldcubed

Non-custodial payment engine for AI agents — BTC, ETH, USDT, USDC, XRP, XMR, ZEC.

31 installs/wk local only

Xenarch MCP

by xenarch-ai

Xenarch — x402 MCP server for AI agent payments. Non-custodial, USDC on Base L2.

120 installs/wk local only

ShieldZCash

by shieldzcash

Keyless non-custodial crypto payments for AI agents: payment links and tip jars, no API key.

34 installs/wk 4 tools answering

Griffnode

by griffnode

Non-custodial crypto payments for AI assistants: balances, payments, and create payment links.

answering

A2AWire

by a2awire

Escrow, reputation, and payments for agent-to-agent commerce. Non-custodial USDC/Base L2.

10 tools answering

agents.u.cash

by uantum

Non-custodial HTTP-402 crypto payments for AI agents. 77-tool MCP server.

local only

agents.u.cash

by udotcash

Non-custodial HTTP-402 crypto payments for AI agents. 86-tool MCP server.

local only

agents.u.cash

by uxdevo

Non-custodial HTTP-402 crypto payments for AI agents. 79-tool MCP server.

local only

send21 — questions

Answers built from our own checks of this server.

What can send21 do?

It exposes 9 tools, read directly from the server on our last check. Among them: create_draft, create_payment_request, get_draft, get_draft_status, get_fee_schedule, get_payment_request and 3 more. 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 →

What is send21 mostly used for?

Its tools cluster around draft and payment. That is what this server is built to work with — the grouping comes from the actual tool names, not from a category we assigned.

Is send21 working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 176 ms. The bar chart above shows every period we have measured.

How do I connect send21?

Copy the ready config from this page — we generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each with the file path that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does send21 need an API key?

No. send21 completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 9 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is send21?

It answers our handshake in 176 ms on average, which is faster than 71% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.

Is send21 open source?

Yes — it is published under the MIT licence and 0 stars on GitHub. The source link is on this page, so you can read exactly what it does with your data before you connect it.