This.Wallet.Proxy.Server

A lightweight JSON-RPC proxy for EVM-compatible blockchains (Ethereum, Goerli, Sepolia, BSC, etc.).
Its goal is to safely expose blockchain calls to the frontend without leaking private provider keys, while offering load balancing, caching, rate limiting, and circuit breaking.

✨ Features

Multi-upstream support: routes requests across multiple providers (public RPCs, Infura, Alchemy, etc.)
Round-robin balancing: distributes traffic evenly between available upstreams.
Circuit breaker: skips unreliable upstreams and retries others automatically.
Per-origin rate limiting: avoids abuse by combining origin + ip.
Method allow-list: only expose safe, explicitly permitted JSON-RPC methods.
CORS permissive: designed for dApp frontend integration.
Chain-aware routing: supports multiple EVM chains out-of-the-box.
Caching: short-lived caching for eth_chainId.

⚙️ Configuration

All settings are controlled via environment variables.

🚀 Usage

Start the server

cargo run --release

By default, the server listens at:
http://localhost:7878

Endpoints

`GET /health`

Returns a simple 200 OK with "ok".
Use this for health checks.

curl http://localhost:8080/health
# -> ok

`POST /rpc`

Proxies JSON-RPC requests to the configured upstreams.

Example:

curl -X POST http://localhost:8080/rpc \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}'

Response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x1"
}

Query parameter chain lets you select other EVM chains:

curl -X POST "http://localhost:8080/rpc?chain=sepolia" ...

🛡️ Rate Limiting

Each client is identified by a combination of Origin + real client IP.
Defaults to 120 requests per minute.
Exceeding the limit returns:
```
{
"error": "rate_limited"
}
```

🛠️ JSON-RPC Allow-List

For security, only safe methods are allowed by default:

eth_chainId
eth_getBalance
eth_call
eth_estimateGas
eth_getTransactionCount
eth_sendRawTransaction
net_version
web3_clientVersion

Requests using disallowed methods return:

{
  "error": "method_not_allowed",
  "method": "eth_getLogs"
}

🧠 How It Works

Pick upstreams: based on chain, environment variables, and available providers.
Rate limit: rejects abusive origins/IPs.
Round robin: rotates through upstreams if multiple exist.
Circuit breaker: skips upstreams that recently failed.
Caching: eth_chainId responses are cached for short TTLs.
Proxy request: forwards the request and returns the response unchanged.

Mapa de rutas ⇄ consumidor • GET /health → handlers::health::health Consumido por: checks de infra o curl (para ver que el server vive). • GET /meta → handlers::eth::meta::meta Consumido por: páginas que quieren saber methods, chains, rate_limit. (Útil para poblar UIs sin hardcodear). • GET / → handlers::home::home Consumido por: la portada (home) del sitio. • GET /ethereum → handlers::eth::ethereum::ethereum Consumido por: la página “Ethereum” (intro, allowed methods, enlaces). • GET /json-rpc-overview → handlers::eth::rpc_overview::rpc_overview Consumido por: doc/overview de JSON-RPC (explica requests/responses). • GET /rpc-providers → handlers::eth::rpc_providers::rpc_providers_page Consumido por: doc de proveedores (Infura/Alchemy/Ankr/PublicNode). • GET /dev/eth-upstreams → handlers::eth::dev_upstream::dev_upstreams_page Consumido por: página dev que hace fetch a /meta/upstreams para listar upstreams efectivos. • GET /meta/upstreams → handlers::eth::dev_upstream::meta_upstreams Consumido por: solo dev, la página anterior; devuelve JSON con {url, status, ttl_down_secs, provider}. Requiere EXPOSE_UPSTREAMS=1. • OPTIONS/POST /rpc → handlers::eth::rpc::{rpc_options, rpc} Consumido por: • Tu Playground (/eth-playground) vía fetch al dar “Run”. • Cualquier cliente JSON-RPC (curl/SDK) que pegue a tu proxy. • GET /eth-playground → handlers::eth::eth_playground::eth_playground Consumido por: el navegador. La página incluye JS que: 1. lee ?method= (si viene) 2. prellena el textarea 3. al “Run”, hace POST /rpc?chain=<…> con el body JSON.