Circuit breaker pattern implementation

### Current Behavior

I want the implementation of a circuit breaker pattern to be simple.
Rate limiting = “Don’t send too many requests.”
Circuit breaker = “Stop calling something that’s broken.”

Goal: Protect your system (the caller) from repeatedly calling a failing downstream service.

### Expected Behavior

Circuit Breaker, rate-limiting / throtteling op http endpoints.

How it works:

- It monitors calls to a dependent service.
- If failures exceed a certain threshold (e.g., 50% of calls fail), it “opens the circuit” — further calls fail immediately instead of waiting for a timeout.
- After a cooldown, it “half-opens” to test if the service has recovered.

### Example:

Your app calls a payment API that starts timing out.
The circuit breaker detects repeated failures, opens the circuit, and stops calling the API for 30 seconds.

Feature | Rate Limiting | Circuit Breaker
-- | -- | --
Protects | The service from overload | The client from downstream failures
Trigger | Too many requests | Too many failures/timeouts
Action | Reject or delay requests | Stop making calls temporarily
Recovery | Automatic after time window | Half-open test, then close if healthy
Common Response | HTTP 429 | Fast-fail or fallback response