The proof problem
A router does half the job. The easy half.
What a router hands you
A menu. The rest is on you.
Which model? You pick, from a price list or a leaderboard.
On which prompts? You guess. Benchmarks were not written on your workload.
Did quality hold? You find out when a customer tells you it got worse.
That was never a routing problem. It's a proof problem.
What Parity Layer does instead
The proof, end to end.
We find the cheaper model. Not from a benchmark. By running candidates against your actual production prompts.
We prove it. A blind judge, your own model class judging, decides whether the cheaper output matches or beats your baseline. Your standard, not a vendor's.
You switch in one click. Only once it's proven. Instant fallback the moment quality drifts.
Typically 30 to 60% off, with the receipts.
How the proof works
From logs to verdict, no code changed.
Upload past requests
A JSONL export of real production prompts. No API keys, no code changes, no live traffic.
Cheaper models re-run them
Candidate models answer your actual prompts, not a benchmark's. Same inputs, cheaper engines.
A blind judge scores both
Your own model class judges, blind to which answer came from where. The bar is your baseline's own consistency.
You get the verdict
Which cheaper model held your quality, prompt by prompt, and exactly what it saves. Then one click to switch.
Side by side
A router vs Parity Layer
| A router | Parity Layer | |
|---|---|---|
| Menu of cheap models | Yes | No |
| Finds the cheapest model that works on your prompts | you pick | we test and find it |
| Proves quality held before switching | No | blind judge, your own model class judging |
| Switching | you configure and hope | one click, once proven |
| Fallback | uptime | quality: instant, if it drifts |
| Coding agents | Yes | not our thing |
Where we draw the line honestly: not for coding agents, that isn't our workload. And if you run a router for reasons other than cost, a menu of 300 models to experiment with or multi-provider failover, that's a different job and we're not it. But if you're routing to save money, this replaces that job and does the half nobody does: proving the cheaper model actually held.
The receipts
Where 30 to 60% comes from
The range is what proof runs have shown across prompt types where a cheaper model matched or beat the baseline under a blind judge. It is not a promise that your number lands there: your number comes from your own proof, on your own logs, before you pay anything. If no cheaper model holds your quality bar, nothing switches and you pay nothing.
Free
Routing costs nothing. One key to connect, none to manage, no minimums.
One simple price
A proven switch comes as a single integrated per-token price, below your current bill.
$0 if unproven
Nothing proves out? Nothing switches, and you pay nothing.
The method is inspectable end to end: how the proof works and a worked example report.
Proof, without the theatre.
We're early. No wall of customer logos, and we won't fake one. What we have is a method you can inspect and a proof you can run on your own data before you trust us with a single live request.
Straight answers
Questions teams ask before switching
How is this different from an LLM router?
A router hands you a menu of cheap models and leaves the hard part to you: which model, on which prompts, at what cost to quality. Parity Layer does that job end to end. It tests cheaper models against your actual production prompts, proves quality held with a blind judge, and switches only once it is proven.
Where does 30 to 60% come from?
It is the range proof runs have shown across prompt types where a cheaper model matched or beat the baseline. Your number comes from your own proof on your own logs before you pay anything. If nothing proves out, nothing switches and you pay nothing.
Do I need to change my code or share API keys to see the proof?
No. Upload a JSONL export of past requests. No API keys, no code changes, and your live traffic never touches Parity Layer during the proof.
What happens if quality drifts after switching?
Instant fallback to your baseline model. The judge keeps checking responses after the switch, and the moment quality drifts the traffic goes back.
Does it work for coding agents?
No. Coding agents are not our workload and we say so plainly. If you route for reasons other than cost, like a 300 model menu or multi-provider failover, that is a different job and we are not it.
Prove it on your own prompts. Free.
Upload a JSONL export of your past requests. No API keys. No code. Your live traffic never touches us. We come back with proof that a cheaper model matched or beat your current one, and exactly what it would have saved.
Not for coding agents. Instant fallback if quality ever drifts.