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satring.com now accepts x402 (USDC) payments alongside Lightning: looking for testers

#x402 #api #bitcoin #ai

satring.com is a curated directory of paid APIs that use the HTTP 402 status code for payments. We started as an L402 (Bitcoin Lightning) directory and just shipped dual-protocol support: every paywalled endpoint on satring now accepts both L402 (Lightning sats) and x402 (USDC on Base).

We're looking for testers and early adopters to help us shake out the integration.

What is satring?

A searchable, rated directory of paid API services. Think of it as the quality layer for the paid API economy. Services register with their payment details (L402 or x402), and we provide:

  • Curated listings with human and agent ratings
  • Automated health monitoring (live/confirmed/dead status)
  • Reputation scores based on uptime, ratings, and reliability
  • Protocol-agnostic search (find services by capability, not payment rail)

Browse the directory: satring.com
API docs: satring.com/docs

What changed: dual-protocol x402 support

Every gated endpoint on satring now returns both payment options in its 402 response. Hit any premium endpoint without auth and you'll see:

curl -i https://satring.com/api/v1/services/bulk
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The response includes:

  • WWW-Authenticate: L402 macaroon="...", invoice="..." for Lightning
  • PAYMENT-REQUIRED: <base64 JSON> for x402 (USDC on Base)

Clients pick whichever protocol they support. L402 clients keep working exactly as before. x402 clients (including AI agents with funded USDC wallets) can now pay with stablecoins.

x402 payment details

The x402 challenge follows the v2 spec. Decoded, it looks like:

{
  "x402Version": 2,
  "resource": "https://satring.com/api/v1/services/bulk",
  "description": "satring.com bulk export",
  "mimeType": "application/json",
  "accepts": [{
    "scheme": "exact",
    "network": "eip155:8453",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "2500000",
    "payTo": "0xF182...7562",
    "maxTimeoutSeconds": 300
  }]
}
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Settlement happens through the x402 facilitator. The agent signs an EIP-3009 transferWithAuthorization, and the facilitator submits it on-chain. No API keys, no accounts, no KYC. Just a funded USDC wallet on Base.

Pricing

Every premium endpoint has both a sat price and a USD price:

Endpoint Lightning USDC
Service submission 1,000 sats $0.50
Bulk export 5,000 sats $2.50
Analytics report 500 sats $0.25
Reputation lookup 100 sats $0.05
Rating submission 10 sats $0.01

Free endpoints (search, list, detail, ratings) remain free on both protocols.

How to list your x402 service

If you run an x402-enabled API, you can register it on satring via the web form or the API:

Web: Visit satring.com/submit, select "X402" as the protocol, and fill in your wallet address, network, and asset contract.

API:

curl -X POST https://satring.com/api/v1/services \
  -H "Authorization: L402 <macaroon>:<preimage>" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "My x402 API",
    "url": "https://myapi.com/v1/endpoint",
    "description": "What my API does",
    "protocol": "X402",
    "x402_pay_to": "0xYourWalletAddress",
    "x402_network": "eip155:8453",
    "x402_asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "pricing_usd": "0.01",
    "category_ids": [1]
  }'
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What we need from testers

  1. List your x402 services on satring.com/submit. We want to see how well the directory handles real x402 service metadata.

  2. Try paying with x402 on any premium endpoint. If you have an x402 client or agent with USDC on Base, hit our gated endpoints and let us know if the flow works.

  3. Report bugs and friction. Open an issue on GitHub or comment here. We want to know what breaks, what's confusing, and what's missing.

  4. Rate services you've used. The reputation system is only as good as the data feeding it.

Why this matters

The paid API market is splitting into two camps: Lightning (L402) and stablecoins (x402). Coinbase's Bazaar has 14,000+ auto-indexed x402 services, but zero curation, no ratings, no health checks. The Lightning side has several smaller directories. Nobody aggregates both protocols with quality signals.

Satring's goal is to be the independent trust layer that sits across both ecosystems. We don't intermediate payments (no money transmission). We provide discovery, reputation, and verification so agents and developers can find services worth paying for.

If you're building paid APIs or AI agents that consume them, we'd love your feedback.

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