# About send21

send21 makes crypto pay links and a payment API for people and AI agents. It is non-custodial payment software: it prepares pay links, payment requests and invoices for BTC (on-chain and Lightning), USDC, USDT, EURC, SOL and ETH, then watches the chain until the payment confirms. The money always goes straight from the payer's wallet to the receiver.

## What send21 does

- **Creates pay links and drafts** for a fixed crypto amount, or priced in any of 161 currencies with a locked, recorded exchange rate.

- **Watches the chain** and tells you by email and signed webhook when a payment arrives and confirms.

- **Works for people and AI agents alike.** Everything in the app is also available over the REST API and the MCP server, with scoped keys that can never move funds.

## What send21 is not

send21 is not a custodian, exchange, broker, money transmitter or payment service provider. It never holds, moves or converts funds and never has access to private keys. It has no signing code and never broadcasts transactions: that always happens in the sender's own wallet. Even a full server break-in could not move a single satoshi. The details are in our [terms of service](https://send21.io/terms) .

## How it makes money

One fee per payment, tiered by size: from 0.49% on the smallest payments down to 0.01% above $100,000, capped at $100. No subscription and no spread on exchange rates. See the [pricing page](https://send21.io/pricing) .

## Privacy by default

No KYC, no tracking, no analytics, no ad pixels. send21 stores your email address (encrypted) and little else. The [privacy policy](https://send21.io/privacy) lists exactly what is kept and for how long.

## Contact

- General: [info@send21.io](mailto:info@send21.io)

- Account or payment questions: [support@send21.io](mailto:support@send21.io)

- API and integrations: [integration@send21.io](mailto:integration@send21.io)

- Privacy and GDPR requests: [privacy@send21.io](mailto:privacy@send21.io)

[Create a free account](https://send21.io/login?mode=register) [Try the demo first](https://send21.io/demo)

[Home](https://send21.io/) | [For business](https://send21.io/business) | [Pricing](https://send21.io/pricing) | [Developer docs](https://send21.io/docs) | [llms.txt](https://send21.io/llms.txt)

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Source: https://send21.io/about