# api_gateway

API Gateway service with 6-layer authentication, RBAC, rate limiting, and gRPC proxy routing.

## Key Types

- `ApiGatewayService` -- main service implementation
- `RoleBasedAccessControl` -- RBAC authorization
- `RateLimiter` -- 3-tier rate limiting (auth/trading/compute)
- `CircuitBreaker` -- upstream service protection

## Configuration

- `JWT_SECRET` -- JWT signing secret (min 32 chars)
- `UPSTREAM_TRADING_URL` -- trading service gRPC endpoint
- `UPSTREAM_ML_URL` -- ML service gRPC endpoint

## Features

- `mfa` (default) -- multi-factor authentication support
- Build without: `cargo check -p api_gateway --no-default-features --features minimal`