Your Failover Is Lying to You: Why Switching ≠ Verifying

You set up failover for your LLM API. Provider A goes down, it switches to Provider B. Problem solved, right?

Wrong.

Here's what actually happens in production:

Provider A returns a 500 → Failover switches to B → B returns a truncated response → Your app serves garbage to users
Provider A rate-limits you → Failover switches to B → B charges 3x more for the same request → Your bill explodes
Provider A returns a response → No error code → Failover stays put → But the response is a hallucinated mess → Your users get wrong answers

Failover switches. It doesn't verify.

The Problem: Failover Only Checks Transport, Not Semantics

Standard failover logic looks like this:

# Typical failover — only checks HTTP status
if response.status_code >= 500:
    switch_to_next_provider()

This catches server crashes. It misses everything else:

Truncated responses (200 OK, but incomplete)
Schema violations (200 OK, but wrong format)
Cost spikes (200 OK, but 10x the price)
Drift between providers (200 OK, but semantically different)

A 200 status code is not a contract. It's a suggestion.

Introducing Correctover

Correctover is the correct version of failover.

Because failover switches. Correctover verifies.

It adds a 6-dimension contract validation layer on top of traditional failover:

Dimension	What It Checks	Example
Status	HTTP-level health	5xx, timeouts
Schema	Response structure	Missing fields, type mismatches
Completeness	Response truncation	`finish_reason !== "stop"`
Latency	Performance bounds	P99 > threshold
Cost	Token price anomalies	Sudden price spikes
Drift	Provider-to-provider variance	Same prompt, different semantic output

When any dimension fails, Correctover doesn't just switch — it validates the next provider before committing, ensuring you never fall from one broken provider into another.

How It Works

from correctover import CorrectoverEngine

engine = CorrectoverEngine.create({
    "providers": [
        {"name": "openai", "api_key": "sk-...", "model": "gpt-4o"},
        {"name": "anthropic", "api_key": "sk-ant-...", "model": "claude-sonnet-4-20250514"},
    ],
    "contract": {
        "max_latency_ms": 5000,
        "require_complete_response": True,
        "schema": {"type": "object", "required": ["answer"]},
        "max_cost_per_1k_tokens": 0.03,
    }
})

result = await engine.chat("Explain quantum computing in 3 sentences")
# Every response passes 6-dimension validation before reaching your app

The Numbers That Matter

P50 validation overhead: 22µs — less than one network round-trip
333 fault scenarios across 16 failure categories
BYOK direct connection — your keys, your providers, no middleman
Zero token markup — we never touch, log, or proxy your API calls

Failover vs. Correctover

	Failover	Correctover
Detects 5xx errors	✅	✅
Detects truncated responses	❌	✅
Detects schema violations	❌	✅
Detects cost spikes	❌	✅
Detects provider drift	❌	✅
Validates before switching	❌	✅
Adds verification overhead	0ms	22µs (P50)