Last year's L402 thread on SN (#644236) was full of people asking "does anyone actually use this in production?" Fair question. Lightning Labs just shipped lnget and agent commerce tools, Alby's PaidMCP SDK has been live since mid-2025, and there are now dozens of real, working L402 endpoints you can hit right now. The problem is finding them.

The closest things to an L402 directory: awesome-L402 is a GitHub README listing libraries and projects (btw @fewsats open to a PR?). l402.directory is a service registry with the same basic idea but only 4 listings. Fewsats had https://github.com/Fewsats/tools.l402.org but it's down. 402.markets exists but only has a single hello-world example. On the x402 side, Coinbase has x402 Bazaar but it's stablecoin-only and programmatic-only. There's no comprehensive, browsable catalog of Lightning-paywalled services that an agent or a human can just query.

I built satring to fix this. Am I crazy for building on L402? Probably, but I think it finally has real potential, with the coming wave of AI agents needing simple, internet-native, permissionless micropayments.

What it isWhat it is

A searchable catalog of L402 services with a JSON API that agents can query directly. 70+ services listed across 9 categories — AI/ML (none yet), Data, Finance, Identity, Media, Search, Social, Storage, and Tools.

Every listing has a status: confirmed (returns a proper 402 + WWW-Authenticate header), live (server responds), or dead. No guessing whether an endpoint actually works. Domain owners can validate endpoints in <30s.

Try itTry it

Browse the directory: satring.com

Query it from your terminal:

# search for services
curl https://satring.com/api/v1/search?q=satring

# list AI/ML services
curl https://satring.com/api/v1/services?category=search

# get a specific service
curl https://satring.com/api/v1/services/satring-directory-api

Full interactive api docs at satring.com/docs — OpenAPI schema included.

How it worksHow it works

Reading is free. Search, browse, filter by category or status — no payment needed, no auth required. Agents can discover and use free services programmatically without a wallet.

Writing costs sats. Submitting a service is 1,000 sats, leaving a rating is 10 sats. All gated via L402 macaroons. This keeps the catalog clean without needing moderators or accounts.

Domain verification lets service owners prove ownership via a .well-known/satring-verify challenge and manage all their listings with a single edit token.

What's listedWhat's listed

Real endpoints, not demos. Lightning Faucet's ~24 utility APIs (price oracles, sentiment analysis, LLM prompts, mempool data, invoice decoding), WoT Scoring API's 40+ Nostr trust and identity endpoints (PageRank, Sybil detection, spam classification, NIP-05 resolution), and Satring's own L402-gated directory APIs. The catalog is small but everything in it is a live, callable endpoint — not a GitHub link, "coming soon", or 404.

Scraper (still in progress, not open sourced) runs daily to discover and confirm new L402 endpoints. All listed services are rechecked daily for liveness, marked dead on 404, removed if still 404 after 30days.

What it's notWhat it's not

It's early. 70+ listings is a start, not an ecosystem. The rating system is live but thin. I'm not pretending this is finished — I'm shipping it now because builders deploying PaidMCP servers today have literally zero distribution channel, and agents have no clue where to find services.

What's nextWhat's next

• Getting the word out and onboarding primary ecosystem service providers
• MCP server integration so agents can discover services natively?
• x402 service coverage alongside L402?
• other ideas?

Built withBuilt with

FastAPI, SQLite, HTMX. The whole thing is a single lightweight app — no external infra, no accounts, no tracking. Source is on github.

If you're running an L402 service that isn't listed, submit it at satring.com/submit (1,000 sats), or verify your domain if it's been scraped already. If you're building agents that need to find and pay for APIs, I'd love to hear what would make this more useful for your workflows.

What needs adding or improvement?