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Documentation Index

Fetch the complete documentation index at: https://developers.fd.xyz/llms.txt

Use this file to discover all available pages before exploring further.

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Introduction

Finance District provides SDKs for TypeScript, Python, and Java, making it simple to integrate the Prism X402 Payment Protocol into your existing applications. Our SDKs handle authentication, request signing, and payment verification with minimal setup.

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Find Your Integration

Pick the framework you’re already using:

Express

Add payment middleware to Express apps

NestJS

Guards and decorators for NestJS

Next.js

API routes and middleware for Next.js

Fastify

Plugin for Fastify applications

Django (Coming Soon)

Middleware and decorators for Django

FastAPI (Coming Soon)

Dependencies for FastAPI routes

Flask (Coming Soon)

Decorators for Flask routes

Java Servlet (Coming Soon)

Filters for servlet-based apps

Node.js HTTP

Native Node.js HTTP server

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Language SDKs

If you don’t use any of the frameworks above, start with the base SDK for your language:

TypeScript SDK

Node.js and TypeScript applications

Python SDK (Coming Soon)

Python applications

Java SDK (Coming Soon)

Java applications

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What You Get

  • 🔐 Authentication - Project Identify Token management and request signing
  • 💳 Payment Verification - X402 protocol support
  • 🛡️ Error Handling - Proper error types and validation
  • 📝 Type Safety - Full type definitions
  • 🚀 Framework Integration - Drop-in middleware/decorators
  • ⚡ Performance - Production-ready

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Quick Example

Here’s how simple it is to add payment verification to an existing route: 
app.get(
  "/premium-content",
  fdPayment({ amount: 100, currency: "USD" }),
  (req, res) => {
    res.json({ content: "Your premium content" });
  },
);

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Need Help?

GitHub

Report issues or request features
Last modified on May 14, 2026