send21

Connect it to your AI

Claude Code

claude mcp add --transport http send21io https://send21.io/mcp

Claude, ChatGPT, Cursor and other apps

Add it as a custom connector with this URL (Streamable HTTP):

https://send21.io/mcp

This server expects extra headers, usually an API key from its maker.

Cursor, VS Code and other apps (mcp.json)

{
  "mcpServers": {
    "send21io": {
      "url": "https://send21.io/mcp"
    }
  }
}

Tools it offers

14 tools, as the server itself reported during our check on Oct 31, 2026.

• get_transaction_templateGet the transaction template for an on-chain draft: every output to pay, plus walletcreatefundedpsbt arguments and a pay-to-many CSV on Bitcoin, or payment URIs (and calldata on EVM chains) on Solana, Ethereum, Base, Arb
• get_fee_scheduleGet the public send21 fee schedule: tiered percent by payment size in USD, min/max fee, and dust limit. No authentication needed.
• create_payment_requestCreate a payment request / checkout pay link (you are the RECEIVER asking to get paid). Price in any of 161 fiat currencies; the payer opens the returned payPath, picks one of the offered currencies (rate locks then), an
• propose_receiving_addressPropose an address for the owner to approve: one of the owner's own receiving addresses (for pay links) or the address of someone the owner pays (for drafts). It is saved unapproved and the owner gets an email. On accoun
• get_account_statusWhat stands between you and a live pay link: whether the owner's email is confirmed, the receiving-address policy, how many addresses are approved or waiting for approval, unsettled fees, your key's scopes, and the next
• list_address_bookList the account's saved addresses (label, address, network, direction: Sending = recipients the owner pays, Receiving = the owner's own addresses). Requires scope addressbook:read.
• get_draftGet a payment draft by id, including amounts, fee, quote, and status. Requires scope drafts:read.
• submit_lightning_proofConfirm a paid Lightning draft with its proof of payment: the 64-character preimage the paying wallet shows after a Lightning payment. Needed for drafts with a pasted bolt11 invoice, and for Lightning addresses whose pro
• create_accountCreate a send21 account for your human owner, without a key. The owner gets an email with a link to take the account over; until they do, nothing can be created. Returns a bootstrap API key ONCE (save it and send it as A
• get_payment_requestGet a payment request by id: status (Open/Completed/Cancelled/Expired), pay path, offered currencies, and the underlying draft once the payer committed. Includes changeSignals and changeNotes: what is unusual compared wi
• get_rateGet 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, Sol, Eth. 161 ISO 4217 fiat currencies are supported. Requi
• create_draftCreate 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, lamports for SOL, gwei for ETH) via amountBaseUnits, or f
• list_draft_quotesList every quote (rate lock) of a fiat-priced draft, oldest first. Quotes never change; a re-quote adds a new one with its own id. Each has a sha256 (RFC 8785 JCS + SHA-256). Requires scope drafts:read.
• get_draft_statusLightweight status snapshot of a draft: status (AwaitingPayment/Seen/Confirmed/Expired/Cancelled), paying txid, confirmations, and reviewState when a transfer with a different amount arrived (pending = needs the receiver

Questions