# Adduce — Issue. Prove. Settle.

> The first credential issuer for legal aid on Solana.

## What is Adduce

Adduce digitizes the legal aid eligibility certificate — the single paper artifact that crosses institutional boundaries every time a lawyer gets paid — by issuing it as a cryptographically signed on-chain attestation on Solana with zero-knowledge selective disclosure and instant settlement.

## Key Facts

- 14 on-chain instructions, 4 events, 26 error codes
- Groth16 ZK circuit: 7,883 constraints, 256-byte proofs
- Deployed on Solana Devnet: 3f1yBTY6xb6ESdzzb9LxAozv7uVsj9Y9AMEpnAwKJRNV
- Published SDK: npm install @adduce/sdk
- 9 countries with certificate-based legal aid: Germany, France, Netherlands, Italy, Spain, Austria, Portugal, Canada, Ireland
- 500M+ citizens covered

## Three Pillars

1. Issue: Court authority signs on-chain attestation (SAS). Supports wallet-based and custodial issuance.
2. Prove: 256-byte Groth16 ZK proof. "Jurisdiction is DE, not expired" without revealing other fields.
3. Settle: Credential-gated payment. 400ms USDC or off-chain bank transfer with on-chain reference.

## Tech Stack

- Smart Contracts: Anchor 0.32 / Rust
- ZK Circuits: Circom 2.2 / snarkjs / Groth16 (BN254)
- Identity: Solana Attestation Service (SAS)
- Compression: Light Protocol (98.8% cost savings)
- Document Storage: Arweave + Irys (X25519 + AES-256-GCM encryption)
- Payments: x402 Protocol v2
- SDK: @adduce/sdk on npm

## Links

- Website: https://adduce.vercel.app
- GitHub: https://github.com/SAHU-01/legal_aid
- npm: https://www.npmjs.com/package/@adduce/sdk
- Solana Explorer: https://explorer.solana.com/address/3f1yBTY6xb6ESdzzb9LxAozv7uVsj9Y9AMEpnAwKJRNV?cluster=devnet
- Documentation: https://adduce.vercel.app/docs
- Blog: https://adduce.vercel.app/blog