# Modular Rust System: Key-Value Store, Vault, and EVM Client

This repository implements a modular, async, and cross-platform cryptographic stack in Rust. It is designed for use in both native (desktop/server) and WASM (browser) environments, supporting secure storage, cryptographic operations, and EVM (Ethereum) client functionality.

## Crate Overview

- **kvstore/**: Async key-value store trait and implementations (native: `sled`, WASM: IndexedDB).
- **vault/**: Cryptographic vault for managing encrypted keyspaces and key operations. Uses `kvstore` for persistence.
- **evm_client/**: EVM RPC client, integrates with `vault` for signing and secure key management.
- **cli_app/**: (Planned) Command-line interface for scripting and automation.
- **web_app/**: (Planned) WASM web app exposing the same APIs to JavaScript or browser scripting.

## Architecture Highlights
- **Async everywhere:** All APIs are async and runtime-agnostic.
- **Conditional backends:** Uses Cargo features and `cfg` to select the appropriate backend for each environment.
- **Secure by design:** Vault encrypts all key material at rest and leverages modern cryptography.
- **Tested natively and in browser:** WASM and native backends are both covered by tests.

## Building and Testing

### Prerequisites
- Rust (latest stable recommended)
- For WASM: `wasm-pack`, Firefox or Chrome (for browser tests)

### Native
```sh
cargo check --workspace --features kvstore/native
```

### WASM (kvstore only)
```sh
cd kvstore
wasm-pack test --headless --firefox --features web
```

## Directory Structure
```
.
├── kvstore/      # Key-value store trait and backends
├── vault/        # Cryptographic vault
├── evm_client/   # EVM RPC client
├── cli_app/      # CLI (planned)
├── web_app/      # Web app (planned)
├── docs/         # Architecture docs
└── README.md
```

## Roadmap
- [x] Unified async trait for key-value storage
- [x] Native and WASM backends for kvstore
- [ ] Cryptographic vault with password-protected keyspace
- [ ] EVM client with vault integration
- [ ] CLI and web app targets
- [ ] Full end-to-end integration

## License
MIT OR Apache-2.0