English Français العربية

send21

Official registry Finance and payments

Crypto pay links and API for people and AI agents. BTC, Lightning, USDC, USDT, EURC, SOL, ETH.

Website

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

Remote (streamable-http)
Claude Code 
claude mcp add --transport http send21 'https://send21.io/mcp' --header 'Authorization: <Bearer s21_<api key>, created by the account owner at https://send21.io/api-keys>'
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "send21": {
            "type": "http",
            "url": "https://send21.io/mcp",
            "headers": {
                "Authorization": "<Bearer s21_<api key>, created by the account owner at https://send21.io/api-keys>"
            }
        }
    }
}
Remote (streamable-http)
Claude Code 
claude mcp add --transport http send21 'https://send21.io/mcp/oauth'
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "send21": {
            "type": "http",
            "url": "https://send21.io/mcp/oauth"
        }
    }
}

Frequently asked questions

What is send21?

Crypto pay links and API for people and AI agents. BTC, Lightning, USDC, USDT, EURC, SOL, ETH.

How do I install send21?

It runs as a remote server. In Claude Code: claude mcp add --transport http send21 'https://send21.io/mcp' --header 'Authorization: <Bearer s21_<api key>, created by the account owner at https://send21.io/api-keys>'. For other clients, paste the JSON configuration from this page into their MCP settings.

Does send21 need an API key?

Yes. It expects Authorization, which you set in its configuration.

Who maintains send21?

It is published by send21io. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.