Fintech & Payments
send21
Non-custodial crypto payment links and API for people and AI agents
- Votes
- 0
- DR (Ahrefs)
- 6 +2 (up) since last check
Ahrefs Domain Rating reported 28 Oct 2026, restated 28 Oct 2026.
Send crypto payment links or use the REST API to accept BTC, Lightning, USDC, USDT, EURC, SOL and ETH directly to your wallet without intermediaries.
Overview
send21 is non-custodial payment software that creates pay links, payment requests and invoices for cryptocurrency payments. It supports BTC on-chain and over Lightning, plus USDC, USDT, EURC, SOL and ETH across Bitcoin, Solana, Ethereum, Base, Arbitrum and Polygon. Prices can be set in any of 161 currencies with locked exchange rates.
Payment flows directly from the payer's wallet to the receiver. send21 never holds funds, private keys or signing code, and even a full server break-in cannot move money. The software watches the blockchain and notifies the receiver by email and signed webhook when a payment confirms.
The platform works for people and AI agents alike. Everything available in the web app is also accessible via REST API and MCP server, with scoped keys that can never move funds. Payers can use any wallet that scans QR codes using standard formats like BIP-21, Solana Pay, EIP-681 and Lightning invoices.
Feature summary
- REST API with scoped keys and batch drafts up to 25 per call
- Support for Bitcoin PSBT and batching wallets like Safe
- No KYC required, encrypted email storage only
- Idempotency keys for safe retries
- Shopify connection with custom app and setup help
- Fee collected separately on Ethereum and EVM chains via Safe batching
Pricing
Pricing model: Paid
One fee per payment: 0.49% on $0-$10, 0.39% on $10-$50, 0.29% on $50-$100, 0.19% on $100-$500, 0.14% on $500-$2,000, 0.09% on $2,000-$10,000, 0.04% on $10,000-$50,000, 0.02% on $50,000-$100,000, 0.01% above $100,000. Minimum $0.01, maximum $100. No subscription, setup fee or monthly minimum.
send21 metrics
Reported for send21.io: Ahrefs Domain Rating and Majestic link figures, with the movement since the prior report.
- Domain Rating
- 6
- +2 (up) since last check
- Trust Flow
- 15
- no change since last check
- Citation Flow
- 28
- no change since last check
- Referring domains
- 35
- no change since last check
- External backlinks
- 123
- no change since last check
Ahrefs Domain Rating reported 28 Oct 2026, restated 28 Oct 2026. Principal topic: Science/Social Sciences (15). Majestic reported 25 Oct 2026, restated 25 Oct 2026. Link figures sourced from Majestic. Trust Flow, Citation Flow and Topical Trust Flow are trademarks of Majestic-12 Ltd.
send21 domain summary
Show the domain summary
Read from the public RDAP record on 27 Oct 2026, 14:42 UTC.
- Domain age
- 2 months
- Registered
- Expires
- Registrar
- NameCheap, Inc.
- DNSSEC
- Not signed
Compare and explore
See the alternatives to send21, send21 vs FinCobra, send21 vs VoixCall, send21 vs Voyced Hosted IPPBX, PayDD vs send21, send21 vs dasfone, PayBot vs send21, more in Fintech & Payments.
Q&A
- Does send21 hold funds or private keys?
- No. send21 is software that prepares payment instructions with no private keys, no signing code and no way to broadcast. Every payment is signed in the payer's own wallet, and funds move directly from payer to receiver.
- Which currencies and networks are supported?
- BTC on-chain and over Lightning, USDC, USDT, EURC, SOL and ETH across Bitcoin, Solana, Ethereum, Base, Arbitrum and Polygon. Prices can be set in any of 161 world currencies, and the exchange rate locks when the payer picks a currency.
- Which wallets can payers use?
- Any wallet that scans a QR code. Pay links and new drafts are a single payment using standard formats (BIP-21, Solana Pay, EIP-681, Lightning invoices). Batched drafts work with PSBT wallets like Bitcoin Core, Sparrow and Electrum, and batching wallets like Safe.
- What does send21 cost?
- One fee per payment, tiered by size: 0.49% on small payments down to 0.01% above $100,000, with a $0.01 minimum and $100 maximum. There is no subscription, and the receiver always gets the exact billed amount.
- Is there a monthly fee?
- No. send21 has no subscription, setup fee or minimum. You pay only when a payment is made.
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send21 has a free listing. The owner can unlock the full profile with a paid launch for $5:
- Founder story (locked)
- Milestones (locked)
- Demo video (locked)
- Dofollow website link (locked)
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