Mobile-ETH

Problem:

tl;dr: Feature phones (no internet) need secure Ethereum access.

Users in areas with limited internet infrastracture (No internet) need secure access to decentralized finance and Web3 services.

Solution:

An Account Abstraction eSIM ToolKit (eSTK) and USSD Wallet that enables offline User Transaction relays over USSD. (No internet required).

Account Abstraction eSIM Wallet -: USSD → Ethereum → SMS (No internet required)

Demo: Mobile ETH USSD Simulator (Try without setup.)

Setup

1. Install SpacetimeDB CLI

   curl -sSf https://install.spacetimedb.com | sh

2. Start SpacetimeDB

   spacetime start

Deployment

1. Clone the repository

   git clone https://github.com/stk2chain/stk2eth.git  
   cd stk2eth

2. Build and deploy middleware module on SpacetimeDB

   spacetime publish -c --server local --project-path middleware gateway2

   (You may replace gateway2 with any valid URL-safe name.)

3. Start USSD client

   cd ../ussdclient
   python ussdclient.py

4. Start ETH client

   cd ../ethclient
   python ethclient.py

5. Start SMS client

   cd ../client
   python smsclient.py

6. Deploy smart contracts (local)

   cd ../pyethclient/contracts
   anvil &  # Start local Ethereum node
   ape run deploy

Ngrok Callback URL (For Sandbox Testing)

1. Start ngrok to expose ussdclient's HTTP Port

   ngrok http 5000

2. Copy the ngrok URL and configure it in your USSD provider (e.g., Africa's Talking):

   Service Code: *384*6086#	
   Callback URL: https://abc123xyz.ngrok-free.app/ussdeth
   

3. Launch the Simulator and test the flow

Components

Component	Purpose	Technology	Status
middleware	Manages USSD sessions, stores state, and processes transactions	Rust/WASM/SpacetimeDB	✅ Active
ussdclient	Connects USSD gateways to SpacetimeDB and relays response via HTTP/Websocket	Rust/Axum	✅ Active
ethclient	Sends and manages On Chain transactions	Rust	✅ Active
smsclient	Sends transaction notifications via SMS	Rust/WASM	🚧 In Development
contracts	Smart contracts for eSIM registry and account abstraction	Solidity/Ape	✅ Active
eSTK	eSIM JavaCard Applet Wallet over USSD	JavaCard	🚧 In Development

System Architecture