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l402-kit
Add Bitcoin Lightning pay-per-call to any API. 3 lines of code.
   
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▶ Watch end-to-end demo — install → 402 → pay → 200 OK
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Live traction
| SDK | Version | Downloads | |:----|:-------:|----------:| | 📦 TypeScript · npmjs.com/package/l402-kit |  |  | | 🐍 Python · pypi.org/project/l402kit |  |  | | 🦀 Rust · crates.io/crates/l402kit |  |  | | 🔌 VS Code Extension · marketplace |  |  | | 🦫 Go · pkg.go.dev |  |  |
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<details> <summary>🌍 Available in 11 languages — click to expand</summary>
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🇺🇸 Charge for your API in Bitcoin Lightning. 3 lines of code. 🇧🇷 Monetize sua API com Bitcoin Lightning. 3 linhas de código. 🇪🇸 Monetiza tu API con Bitcoin Lightning. 3 líneas de código. 🇨🇳 用 3 行代码，通过比特币闪电网络收费。 🇮🇳 अपने API को Bitcoin Lightning से 3 लाइनों में मोनेटाइज़ करें। 🇸🇦 اكسب من API الخاص بك عبر Bitcoin Lightning. 3 أسطر فقط. 🇫🇷 Monétisez votre API en Bitcoin Lightning. 3 lignes de code. 🇩🇪 Monetarisiere deine API mit Bitcoin Lightning. 3 Zeilen Code. 🇷🇺 Монетизируй свой API через Bitcoin Lightning. 3 строки кода. 🇯🇵 Bitcoin LightningでAPIを3行で収益化。 🇮🇹 Monetizza la tua API con Bitcoin Lightning. 3 righe di codice.
📖 Official docs: 🇺🇸 · 🇧🇷 · 🇪🇸 · 🇨🇳 · 🇮🇳 · 🇸🇦 · 🇫🇷 · 🇩🇪 · 🇷🇺 · 🇯🇵 · 🇮🇹
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Install
npm install l402-kit # TypeScript / Node.js / Express
pip install l402kit # Python / FastAPI / Flask
go get github.com/shinydapps/l402-kit/go@v1.10.0 # Go / net/http / Chi / Gin
cargo add l402kit # Rust / axumAI Agents / LLMs: See
llms.txtfor machine-readable instructions. Agent discovery:/.well-known/agent.json·/.well-known/l402.json
---
For AI Agents
l402-kit is the payment layer for autonomous agents. Agents can pay for APIs without human intervention.
System prompt snippet — add this to any agent to enable L402 payments:
You have access to paid APIs via the L402 protocol.
When you call an API that returns HTTP 402, use the L402Client from l402-kit
to pay automatically with Bitcoin Lightning.
Budget limit: {BUDGET_SATS} sats per session. Never exceed this limit.Agent SDK quickstart:
import { l402Client, buildWallet } from "l402-kit/agent";
const client = l402Client({
wallet: buildWallet(process.env), // auto-detects BLINK_API_KEY or ALBY_TOKEN
budgetSats: 1000,
});
const data = await client.fetch("https://api.example.com/paid-endpoint");MCP Server (for Claude Desktop, Cursor, and any MCP-compatible agent):
{
"mcpServers": {
"l402-kit": {
"command": "npx",
"args": ["l402-kit-mcp"],
"env": { "BLINK_API_KEY": "your-key" }
}
}
}Compatible with: LangChain · OpenAI Agents · CrewAI · Vercel AI SDK · AutoGPT · Any MCP client
Protocol support: L402 (Bitcoin Lightning) · x402 (USDC/Coinbase) compatible
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How it works
1. Client calls your API
↓
2. API returns HTTP 402 + BOLT11 invoice + macaroon
↓
3. Client pays (any Lightning wallet, < 1 second, any country)
↓
4. Client sends Authorization: L402 <macaroon>:<preimage>
↓
5. API verifies SHA256(preimage) == paymentHash ✓
↓
6. HTTP 200 OK + your data
── Fee flow (managed mode) ─────────────────────────────────
Payment → 99.7% → your Lightning Address (instant)
→ 0.3% → ShinyDapps---
Quickstart
TypeScript
import express from "express";
import { l402, AlbyProvider } from "l402-kit";
const app = express();
const lightning = new AlbyProvider(process.env.ALBY_TOKEN!);
app.get("/premium", l402({ priceSats: 100, lightning }), (_req, res) => {
res.json({ data: "Payment confirmed." });
});
app.listen(3000);Python
from fastapi import FastAPI, Request
from l402kit import l402_required
app = FastAPI()
@app.get("/premium")
@l402_required(price_sats=100, owner_lightning_address="you@yourdomain.com")
async def premium(request: Request):
return {"data": "Payment confirmed."}Go
package main
import (
"fmt"
"net/http"
l402kit "github.com/shinydapps/l402-kit/go"
)
func main() {
http.Handle("/premium", l402kit.Middleware(l402kit.Options{
PriceSats: 100,
OwnerLightningAddress: "you@yourdomain.com",
}, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
fmt.Fprintln(w, `{"data": "Payment confirmed."}`)
})))
http.ListenAndServe(":8080", nil)
}Rust
use axum::{middleware, routing::get, Router};
use l402kit::{l402_middleware, Options};
use std::sync::Arc;
#[tokio::main]
async fn main() {
let opts = Arc::new(Options::new(100).with_address("you@yourdomain.com"));
let app = Router::new()
.route("/premium", get(|| async { "Payment confirmed." }))
.route_layer(middleware::from_fn_with_state(opts, l402_middleware));
let listener = tokio::net::TcpListener::bind("0.0.0.0:8080").await.unwrap();
axum::serve(listener, app).await.unwrap();
}---
Test it live
# Step 1 — triggers 402 + returns invoice
curl http://localhost:3000/premium
# ← { "error": "Payment Required", "invoice": "lnbc1u...", "macaroon": "eyJ..." }
# Step 2 — pay the invoice with any Lightning wallet, then:
curl http://localhost:3000/premium \
-H "Authorization: L402 <macaroon>:<preimage>"
# ← { "data": "Payment confirmed." }---
Why not Stripe?
| | Stripe | l402-kit | |--|--------|----------| | Minimum fee | $0.30 | < 1 sat (~$0.001) | | Settlement time | 2–7 days | < 1 second | | Chargebacks | Yes | Impossible — cryptographic proof | | Requires account | Yes | No — any Lightning wallet | | AI agent support | No | Yes — 4 SDKs, native | | Countries blocked | ~50 | 0 — global by default | | Reversible | Yes | No — final on receipt | | Open source | No | Yes — MIT |
---
Providers
import { BlinkProvider, OpenNodeProvider, LNbitsProvider } from "l402-kit";
// Blink (recommended — free, instant setup)
const provider = new BlinkProvider(process.env.BLINK_API_KEY!, process.env.BLINK_WALLET_ID!);
// OpenNode (production, custodial)
const provider = new OpenNodeProvider(process.env.OPENNODE_KEY!);
// LNbits (self-hosted)
const provider = new LNbitsProvider(process.env.LNBITS_KEY!, "https://your.lnbits.host");Bring your own node — implement the LightningProvider interface in 5 lines:
import type { LightningProvider } from "l402-kit";
class MyNode implements LightningProvider {
async createInvoice(amountSats: number) { /* return Invoice */ }
async checkPayment(paymentHash: string) { /* return boolean */ }
}---
Security model
Invoice creation: paymentHash = SHA256(preimage)
Client payment: Lightning Network releases preimage to payer
API verification: SHA256(preimage) == paymentHash ✓
Replay protection: each preimage is marked used — works exactly once
Token expiry: macaroons expire after 1 hour- Unforgeable — SHA256 is a one-way function; you cannot fake a preimage
- No chargebacks — cryptographic settlement, not reversible card auth
- Replay-safe — MemoryReplayAdapter (dev) or RedisReplayAdapter (production, multi-instance)
- 600+ automated tests across 5 runtimes (TS, Python, Go, Rust, Cloudflare Workers) — production-grade reliability for autonomous agent workflows
- Fully auditable — MIT, every line open source
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VS Code Extension
Monitor every sat in real-time without leaving your editor.
- ⚡ Live payment feed per endpoint
- 📊 Bar chart — 1D / 7D (free) · 30D / 1Y / ALL (Pro)
- 🌍 11 languages built-in
- 🎨 Light / dark / auto theme
- 🔧 Zero config — just set your Lightning Address
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Get a Lightning Address (free)
Sign up at dashboard.blink.sv — free, no credit card, instant. Your address: yourname@yourdomain.com
Other wallets: Wallet of Satoshi · Phoenix · Zeus · Alby
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Links
| Resource | URL | |----------|-----| | 📖 Docs (11 languages) | l402kit.com/docs | | 📦 npm | npmjs.com/package/l402-kit | | 🐍 PyPI | pypi.org/project/l402kit | | 🦫 Go | pkg.go.dev/github.com/shinydapps/l402-kit/go | | 🦀 Rust | crates.io/crates/l402kit | | 🔌 VS Code | marketplace.visualstudio.com | | ⚡ Lightning | shinydapps@blink.sv | | 🐙 GitHub | github.com/ShinyDapps/l402-kit |
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MIT — use freely, build freely.
Bitcoin has no borders.
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Built with ⚡ by ShinyDapps
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<a href="https://l402kit.com/docs">Docs</a> · <a href="https://docs.l402kit.com/introduction">Demo</a> · <a href="https://marketplace.visualstudio.com/items?itemName=ShinyDapps.shinydapps-l402">VS Code</a> · <a href="https://npmjs.com/package/l402-kit">npm</a>
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