Introducing Alby Sandbox

What if you could test bitcoin payments over the lightning network without setting up lightning nodes, playing with channels, asking for testnet sats, or depositing real funds? One API call, and you have a working test wallet that acts exactly like a real one.

Today we're launching Alby Sandbox — an interactive playground where you can explore bitcoin payments flows, watch transactions happen in real-time, and copy the code that powers each scenario.

The New Lightning Developer Stack

We've built three tools that work together to eliminate friction from Lightning development:

NWC Faucet — Create a test wallet with a single HTTP request. No signup. No infrastructure. Just a working wallet with 10,000 sats.

Alby Agent Skill — An AI assistant that knows how to build bitcoin apps. It understands Nostr Wallet Connect, lightning addresses, invoices, subscriptions, hold invoices, and more.

Alby Sandbox — A visual playground to see Lightning payments in action across multiple wallets.

Zero-Setup Test Wallets

This is all it takes to create a fully functional Lightning wallet:

curl -X POST https://faucet.nwc.dev

That's it. You get back an NWC connection string with 10,000 sats and a Lightning address. No email signup, no KYC, no node to run, no channels to manage, no testnet faucets to beg from.

These test wallets live in an isolated network—they can send real payments to each other, but they can't interact with the main Lightning Network. This makes them perfect for development and testing.

When you're ready for production? Just swap the connection string for a real wallet like Alby Hub. Your code stays exactly the same.

Why We're Announcing the Sandbox (Not the Agent Skill)

You might wonder why we're leading with the Sandbox instead of the Agent Skill. Here's the thing: the Sandbox was built to dog-food the Agent Skill.

This entire application — all 12+ payment scenarios, the real-time visualizations, the wallet management — was vibe-coded using Claude Code with the Alby Agent Skill installed. Every scenario was 1-shotted.

We didn't want to just tell developers that AI can now build Lightning apps. We wanted to show them. The Sandbox is visual proof that the Agent Skill works. It's not a demo we built to promote a product — it's a product that was built by the thing we're promoting.

What You'll See in the Sandbox

The Sandbox walks you through real Lightning payment scenarios, from simple to complex:

• Simple payments — Create an invoice, pay it, see the funds move

• Lightning addresses — Pay to human-readable addresses like email

• Payment notifications — Subscribe to real-time payment events

• Payment prisms — Split incoming payments across multiple recipients

• Subscription payments — Recurring charges with budgeted wallets

• Hold invoices — Escrow-style payments that can be settled or cancelled

Each scenario runs with real test wallets. You'll watch payments flow between Alice, Bob, Charlie, and David in real-time. Multiple visualization modes let you see the same transaction as a log, a flow diagram, or a balance chart.

And every scenario includes the code that powers it, as well as example prompts — ready to copy into your own app or favorite agent.

E2E Testing Without the Pain

Here's the developer workflow we've enabled:

1. Create test wallets programmatically with the faucet API

2. Build your payment logic (Alby Agent Skill is all you need)

3. Run full end-to-end tests with real payment flows

4. When ready, swap in your production NWC connection

No wallet signups. No node infrastructure. No channel management. No testnet coin hunting. The NWC protocol is the same in test and production—your code doesn't change.

This works beautifully for CI/CD pipelines too. Spin up test wallets, run your payment tests, tear them down. Every test run starts fresh.

Here's where it gets interesting: combine this with Playwright and an AI coding assistant. The AI can build your payment feature, create throwaway test wallets from the faucet, run actual payment flows through the browser, verify the results, and fix any issues — all without human intervention. The AI checks its own work with real transactions.

Try It Now

Launch the Sandbox and run your first Lightning payment in under a minute.

If you're using Claude Code, install the Alby Agent Skill to start building Lightning-powered apps with AI assistance.

When you're ready to go live, Alby Hub gives you a production-ready NWC wallet you can self-host or run in the cloud.

Lightning development just got a lot faster. Go build something.

Powered by a Single Alby Hub

Something that might surprise you: the entire NWC Faucet — all those test wallets paying each other — runs on a single Alby Hub instance with no Lightning channels.

This is possible because of the work we've put into Alby Hub's sub-wallet and self-payment functionality. Each faucet wallet is a sub-wallet of the single Alby Hub instance. When Alice pays Bob, it's an internal transfer that settles instantly. No routing, no fees, no channel liquidity concerns.

Even complex features like HOLD invoices work across sub-wallets. You can create an escrow payment between two test wallets, hold it, then settle or cancel—all within the same Hub.

This architecture means the faucet is fast, reliable, and free to operate. It also showcases what Alby Hub can do: if you're building a platform with multiple users, sub-wallets give each user their own Lightning wallet without the complexity of running separate nodes.

Acknowledgments

Special thanks to Jordan from the Thailand BoB space community, who tested the Agent Skill and came up with the original idea for the Sandbox. His question captured exactly what we were trying to solve:

"What's the quickest and least burdensome way I can get up and running and start shooting sats between Alice & Bob? Let's assume I don't know much about bitcoin, but I know how to code LLMs. Because my code is almost done, and I don't want to do the boring part of setting up a lightning wallet. I just wanna shoot some sats."

This is what it's all about: shrinking the time to that magical moment when a developer sees real value transfer for the first time. That's when the excitement hits—when you realize what's possible with unstoppable, open-source, programmable money.

Also a shout out to hzrd149, who created a completely fake NWC wallet service as part of his Applesauce examples. This in part inspired the NWC faucet: the realization with NWC as an abstraction layer above lightning, no lightning network complexities such as channels, nodes, liquidity, or fees were needed, and that a completely fake wallet (that works just like a real one) is even better than a custodial wallet for testing.