Polyjuice

🧪 Polyjuice: Soul-Sync AI Powered by Farcaster Snapchain

Polyjuice is a modular, Rust-based framework for building soul-aligned AI agents — systems that can think, speak, and evolve like real Farcaster users. Inspired by the Polyjuice Potion in Harry Potter, it enables AI to “become” someone, capturing their tone, reasoning patterns, and digital identity through on-chain data.

Live Demo

Test it here: https://ai.polyjuice.io/

Warning: The API server is currently running on a local rig and exposed through a Cloudflare Tunnel. Uptime and response speed are not guaranteed — expect occasional downtime or latency during heavy computation or local maintenance.

System Architecture

Polyjuice is composed of several Rust-based components, each serving a distinct role in the soul-sync pipeline:

Module Repository Description Polyjuice Frontend github.com/RyanKung/polyjuice The user interface and orchestration layer for creating and interacting with soul-aligned agents. SnapRAG github.com/RyanKung/snaprag A high-performance RAG (Retrieval-Augmented Generation) engine that vectorizes and indexes Farcaster messages in Postgres via pgvector. Castorix github.com/RyanKung/castorix A CLI and API library for interacting with the Farcaster Snapchain, enabling data synchronization, proof verification, and chain state queries. Rust-x402 github.com/RyanKung/rust-x402 A Rust implementation of the x402 signing and verification protocol used for Snapchain cryptographic primitives.

Together, these modules form a complete stack — from data ingestion and vectorization to soul reconstruction and user simulation.

Technical Highlights

Rust Core — high-performance, memory-safe, parallelized architecture

Modular Design — independently deployable components for maximum flexibility

Postgres + pgvector — scalable vectorized memory for message embeddings

Local GPU Acceleration — native GPU support for embedding and RAG computation, without relying on Ollama or any third-party APIs

x402 Cryptographic Protocol — full support for Farcaster’s signing and verification standard, implemented in pure Rust

On-chain Anchoring — every agent tied to verifiable Farcaster identity

Soul Simulation Layer — reconstructs personality and tone from historical cast data

Vision

Polyjuice envisions a world where AI agents are not generic assistants, but authentic extensions of human identity — autonomous, evolving, and cryptographically sovereign.

“Not just imitation — reincarnation through data.”

Components

Polyjuice Frontend — interactive UI and orchestrator

SnapRAG — RAG and embedding engine

Castorix — Snapchain CLI/API

Rust-x402 — x402 middleware implementation

Polyportal — onchain endpoint router