Open Source · Free Beta

APIs change.
Your app stays live.

Poly detects breaking API changes, AI-generates safe fixes, and patches responses before your code sees them — zero proxy, zero deploy, zero downtime.

Your traffic never touches our servers
0+
APIs monitored
0.7%
Drift catch rate
0ms
Latency overhead

Without Poly

Third-party API renames name to full_name. Your app crashes in production at 3 AM.

crash.log
1// API response changed silently
2const user = res.data
3console.log(user.name)
4// → undefined  💥 CRASH
  • ✗Page breaks for all users
  • ✗Emergency deploys at midnight
  • ✗Angry customers, lost revenue

With Poly

Poly's SDK detects the drift, asks AI for a safe mapping, and patches the response before your code even sees it.

output.log
1// Poly patches response in-memory
2const user = res.data
3console.log(user.name)
4// → "John Doe"  ✓ WORKS
  • ✓Zero downtime, instant fix
  • ✓No deploy needed
  • ✓Users never notice anything

See it in action

Watch Poly detect a breaking API change and fix it — step by step, live in your browser.

Click "Run Demo" to see Poly detect and fix a real API breaking change — all before your code notices.

How Poly sits in your stack

Poly runs entirely in your process. Only schema metadata reaches Poly Cloud for AI analysis — never your data.

Your App
Poly SDK
Intercept
Detect Drift
AI Cloud
Patch
Your Code
only schema metadata
01

Detect

SDK intercepts every API response and compares it against the learned schema baseline. Detects 7 types of drift.

02

Analyze

Only schema metadata goes to Poly Cloud. AI generates a safe mapping. Protected fields like prices and tokens are never touched.

03

Patch

Response is transformed locally in-memory before your code sees it. Patch is cached — no repeated AI calls.

Setup in 30 seconds

Wrap your existing HTTP client. That's the only change you need.

app.ts
1import { Poly } from "pritpolytt-sdk"
2import axios from "axios"
3
4// Initialize with your API key
5Poly.init({ apiKey: "poly_live_xxx" })
6
7// Wrap your HTTP client — that's it!
8Poly.wrap(axios)

Built for production

Every design decision prioritizes reliability, security, and developer experience.

7 Drift Types

Auto-detected

Field renames, type changes, removals, additions, nested shifts, enum changes, and structure reordering — caught before they crash your app.

renametyperemovenestedenumorderadd

Protected Fields

Zero data leaks

Mark prices, payments, auth tokens, or any field as protected. Poly will never include them in AI analysis — guaranteed.

protected: ["price", "token", "ssn"]

Zero Proxy

Runs locally

Your traffic never routes through Poly servers. The SDK runs entirely in your process — intercepting and patching locally.

Patch Cache

Instant reuse

Identical drift patterns are fixed instantly from local cache — no repeated AI calls needed.

Confidence Scores

AI-powered

Every patch scored 0–100%. Set thresholds to auto-apply high-confidence patches, review the rest.

Rule Engine

Override AI with custom rules. Force specific field mappings, block changes on critical endpoints, or whitelist trusted APIs — you're in control.

Your data stays yours

Poly was designed with privacy as a first principle. Here's exactly what happens.

Stays in your process

  • ✓ Full API response payloads — never leave your machine
  • ✓ User data, PII, business logic — stays local
  • ✓ Auth tokens, API keys, secrets — never transmitted
  • ✓ Patches apply in-memory — zero latency

Sent to Poly Cloud (only)

  • → Field names and types — full_name → name
  • → Schema structure — nesting, arrays, enums
  • → Drift type classification — rename, remove, etc.
  • → No values, no payloads — just shapes
Free during beta

$0/month

No credit card. No limits. We're building in public and want your feedback.

Unlimited API calls Unlimited endpoints Priority support

Stop fearing API changes.

Install Poly, wrap your HTTP client, and never deal with a breaking API change again.

npm i github:Pritahi/poly-sdk