Drop-in anti-spam powered by Bitcoin micropayments. Replace CAPTCHAs with sats. Humans pay fractions of a cent. Spammers go broke.
Distorted text, image grids, invisible scoring. They break accessibility, frustrate users, and AI solves them with >90% accuracy. The arms race is over. CAPTCHA lost.
The agent economy is exploding. LangChain, CrewAI, autonomous agents — they all need API access. Every CAPTCHA is a wall that blocks legitimate machine traffic.
1 sat per action costs a real user nothing (<$0.001). But a spammer sending 1M requests pays ~$1,000. The economics of spam collapse instantly.
SatCHA doesn't care what you are. Human, bot, AI agent, IoT sensor. If you can pay, you can play. Anti-spam, not anti-bot.
Pay a Lightning invoice once to load an ecash balance. Any amount. Takes seconds from Phoenix, Wallet of Satoshi, Alby, or any Lightning wallet.
Each protected action (form submit, API call, account creation) auto-deducts a tiny amount from the ecash balance. No widget, no popup, no friction.
Legitimate users spend fractions of a cent. Spammers running 100k actions spend real money with zero ROI. The economics make spam irrational.
Deposits sats once,
spends per action
Validates payment,
passes request through
Receives only
paid requests
| Dimension | CAPTCHA | SatCHA |
|---|---|---|
| What it proves | "I am human" | "This action has value to me" |
| AI bypass risk | High — GPT-4V solves 90%+ | Zero — can't fake a payment |
| User friction | Image grids, loading, retries | None — auto-deducted |
| Accessibility | Broken for visually impaired | Universal — money has no language |
| AI agents | Blocked entirely | Welcome — if you can pay, you can play |
| Identity required | Often paired with email/phone | None — bearer ecash is anonymous |
| Cost to spammer (1M actions) | ~$50 (CAPTCHA solving service) | ~$1,000+ (linear, no bulk discount) |
| Scales to machines | No — designed to exclude machines | Yes — designed for anyone who pays |
Attach 1 sat to every email. Auto-accept from contacts. Unknown senders land in a "paid inbox." 1M spam emails = $1,000.
1 sat / emailEvery "Contact Us" form drowns in bot submissions. 10 sats per submit. Real customers don't blink. Bot farms burn cash.
5–50 sats / submitReplace email verification + CAPTCHA with 100 sats. Account instantly active. Throwaway bot accounts cost real money at scale.
50–500 sats / accountFree tier for normal use. Above the limit, each request costs 1 sat. DDoS attackers literally fund your infrastructure.
1–10 sats / request1 sat per post. 1 sat per reply. Free to read. Bot armies, reply spam, and astroturfing become economically irrational.
1–5 sats / post1 sat per vote. Sybil-resistant without KYC. Can't stuff the ballot without spending proportionally. Anonymous by default.
1–100 sats / voteSensors pay 1 sat per publish. No API keys, no OAuth, no device provisioning. If the device can pay, it can publish.
1 sat / publish10 sats to submit a link. Refunded if upvoted. Spam links burn sats. Legitimate content pays for itself.
10–100 sats / submitSubmit URLs to search engines at 1 sat each. Organic crawling stays free. SEO spam farms can't afford to pollute indexes.
1–10 sats / URL10 sats per MB uploaded. Free to download. Malware distribution and throwaway storage become expensive at scale.
10 sats / MBZero-fee transfers inside the mint. No minimum amount. Millions of 1-sat transactions per second. Bearer tokens — anonymous by design.
Deposits and withdrawals via Lightning. Fast, global, permissionless. Works with every Lightning wallet — Phoenix, WoS, Alby, Mutiny.
Each app runs its own Cashu mint. No third-party service. No reCAPTCHA dependency. No data sent to Google. You control the anti-spam layer.
We're building the open-source middleware now. Get early access when it ships. Battle-tested on a production GPU marketplace serving AI agents 24/7.
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