# Polylane for impact analysis

> Catch issues before they break production: Polylane analyses the production impact of every pull request against the live infrastructure it deploys to.

Catch issues before they break production. Polylane analyses the potential impact of every pull request on production. It checks each change against your live infrastructure and tells you what could go wrong before you merge.

- Every pull request analysed against live production
- A comment that explains the risk, shows the evidence and suggests the fix
- A check you can make required, so the risky merge is blocked

## How it plays out

### Polylane analyses every pull request for its impact on production

It reads the change against the infrastructure it deploys to. If production would break, it comments with the cause, the evidence and a fix, and the check fails. Make the check required and the merge is blocked.

### It adds missing observability to your code

When a route can't emit one useful event per request, it adds the instrumentation using the setup you already have, as a small change of its own that can merge first.

### It keeps watching after the merge and finds what broke

Polylane watches production after every deploy. When something regresses, the issue arrives with the change that landed just before it.

## What Polylane analyses in every pull request.

- **Checks against live infrastructure.** Polylane compares each pull request with the config, capacity and dependencies of the resources it deploys to.
- **Uses current production data.** It looks at what your services are doing right now, so the analysis reflects production today.
- **Works on AI-written code.** Hand-written or AI-written, every pull request gets the same analysis.
- **Adds missing observability.** If a route can't emit one useful event per request, Polylane adds the instrumentation as a small change of its own.
- **Explains how it breaks.** Each comment shows what would go wrong, the evidence behind it, and a one-line fix.
- **Blocks risky merges.** The 'Polylane production impact' check fails when production would degrade. Make it required in branch protection to block the merge.

## Learn more

- [What is change intelligence? A production safety guide](https://polylane.com/learn/deployment-safety/what-is-change-intelligence/)
- [How to keep AI coding agents from breaking production](https://polylane.com/learn/ai-in-production/how-to-keep-ai-coding-agents-from-breaking-production/)
- [How to correlate incidents with deploys using evidence](https://polylane.com/learn/deployment-safety/how-to-correlate-incidents-with-deploys/)

## Questions

### How does production impact analysis work?

A GitHub app analyses each pull request against the live infrastructure it deploys to. The result lands as a comment plus a 'Polylane production impact' check.

### Will it block my merges?

Only if you want it to. Require the 'Polylane production impact' check through branch protection and risky merges are blocked. Leave it optional and the verdict is advisory.

### Is this for AI-generated code?

It's for all code, but it matters most when nobody read the change closely. AI-written or hand-written, the same analysis catches the mistake.

### How is this different from CI?

CI runs your tests against the code. Polylane analyses the change against production: the config, capacity and dependencies it lands on, and what they emit right now.

### Will it ever merge or deploy on its own?

Not by default. Every change goes through your review, and anything that merges or touches production on its own is something you switch on.

### How often does it fail a pull request?

Rarely. Pass is the default, and a fail has to name how a line in the diff breaks production. “Might” does not count.

### Does it comment on every push?

One comment, updated in place. Documentation and test-only changes pass straight through without one.

### Does the instrumentation it adds bring new dependencies?

No. It writes with your logger, your OpenTelemetry setup and your conventions, and it never logs a secret.

## More use cases

- [Polylane for DevOps](https://polylane.com/use-cases/devops) ([markdown](https://polylane.com/use-cases/devops.md))
- [Polylane as your AI SRE](https://polylane.com/use-cases/ai-sre) ([markdown](https://polylane.com/use-cases/ai-sre.md))
- [Polylane for Continuous Integration](https://polylane.com/use-cases/continuous-integration) ([markdown](https://polylane.com/use-cases/continuous-integration.md))
- [Polylane for ticket resolution](https://polylane.com/use-cases/ticket-resolution) ([markdown](https://polylane.com/use-cases/ticket-resolution.md))
- [All use cases](https://polylane.com/use-cases) ([markdown](https://polylane.com/use-cases.md))

Merge with confidence. Polylane checks every change against production first. Get started with one command: `curl -fsSL https://polylane.com/setup | bash` installs the CLI, connects your coding agents, and creates the account.