> For the complete documentation index, see [llms.txt](https://q3labs.gitbook.io/polypay-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://q3labs.gitbook.io/polypay-docs/developer-documentation.md).

# Developer Documentation

Technical documentation for developers who want to understand, contribute to, or integrate with PolyPay.

## Contents

This section covers:

* [Getting Started](/polypay-docs/developer-documentation/getting-started.md) - Prerequisites, setup, and running the project locally
* [Database Connection Guide](/polypay-docs/developer-documentation/database-connection-guide.md) - How to connect and query the PostgreSQL database
* [Circuit Code Walkthrough](/polypay-docs/developer-documentation/circuit-code-walkthrough.md) - Detailed explanation of the Noir ZK circuit

## Tech Stack

| Component          | Technology                                                            |
| ------------------ | --------------------------------------------------------------------- |
| Frontend           | [Next.js](https://nextjs.org) + [wagmi](https://wagmi.sh)             |
| Backend            | [NestJS](https://nestjs.com) + [Prisma](https://prisma.io)            |
| Smart Contract     | [Solidity](https://soliditylang.org) + [Hardhat](https://hardhat.org) |
| ZK Circuit         | [Noir](https://noir-lang.org)                                         |
| Proof Verification | [zkVerify](https://docs.zkverify.io)                                  |
| Database           | [PostgreSQL](https://www.postgresql.org)                              |

## Supported Networks

| Network  | Type                                         | Chain ID | Explorer                                                                              |
| -------- | -------------------------------------------- | -------- | ------------------------------------------------------------------------------------- |
| Horizen  | Mainnet                                      | 26514    | [horizen.calderaexplorer.xyz](https://horizen.calderaexplorer.xyz/)                   |
| Horizen  | Testnet                                      | 2651420  | [horizen-testnet.explorer.caldera.xyz](https://horizen-testnet.explorer.caldera.xyz/) |
| Base     | Mainnet                                      | 8453     | [basescan.org](https://basescan.org/)                                                 |
| Base     | Sepolia                                      | 84532    | [sepolia.basescan.org](https://sepolia.basescan.org/)                                 |
| Arbitrum | Mainnet (Arbitrum One, Stylus WASM contract) | 42161    | [arbiscan.io](https://arbiscan.io/)                                                   |
| Arbitrum | Sepolia (Stylus WASM contract)               | 421614   | [sepolia.arbiscan.io](https://sepolia.arbiscan.io/)                                   |

## Quick Links

* [GitHub Repository](https://github.com/Poly-pay/polypay_app)
* [Smart Contract on Horizen testnet](https://horizen-testnet.explorer.caldera.xyz/)
* [Smart Contract on Base Sepolia](https://sepolia.basescan.org/)