Know before you ship. Catch breaking API changes before production.

Relion monitors the APIs your code depends on and shows which files are at risk when a vendor changes something important.

Free forever for 1 repo

Without Relion

This is what a silent breaking change looks like.

The vendor changes a field. Your tests pass. Staging is clean. Then production breaks for real users — and you find out from them.

Timeline
  1. 09:14

    Stripe silently removes `source` param from PaymentIntent

  2. 09:31

    Checkout begins returning HTTP 400 errors

  3. 09:47

    On-call paged. Engineers begin triage

  4. 10:22

    Root cause identified: vendor schema change

  5. 10:51

    Outcome: Hotfix deployed. Hours of production pain.

// Stripe API — PaymentIntent schema  "payment_method_types": ["card"]  "automatic_payment_methods": { "enabled": true }  ✗  Your code: still passes `source` param  ✗  Result: 400 Bad Request on every call─── with Relion ──────────────────────  ✓  Change flagged at 09:14 — before your deploy  ✓  PR blocked automatically by relion predeploy  ✓  Zero users hit the 400. Zero on-call pages.
With Relion · how it works

Catch it before it ships. Three steps.

Relion maps the vendor APIs your repo uses, watches for breaking upstream changes, and turns real impact into dashboard alerts or CI failures.

Run a scan

Map every vendor API in your repo

relion scan finds the third-party API calls in your repo and syncs them to the dashboard.

Review impact

See exactly which files are at risk

When a vendor changes an endpoint, schema, or auth rule, Relion shows the files at risk — not just the vendor.

Gate deploys

Block the deploy before it ships

relion predeploy fails CI only when an open vendor change touches code you are shipping. Other PRs flow through untouched.

Where it fits

Slot it into the surfaces you already use.

Same product across four entry points. Pick whichever fits your workflow — or wire up all four.

CLI

Scan from any project directory

One binary. Add it as a dev dep, run via npx, or pin a tagged version.

$ relion scan
CI/CD

Gate every push, every PR

Non-zero exit when an open vendor change touches code in your diff.

✗ exit 1 → push refused
GitHub

Auto-watch every repo in your org

Install once. Every push scans automatically. Alerts route to Slack and email.

auto-scan every push
AI editor

Open risks in Claude, Cursor, Windsurf

Ships as an MCP server. Your AI assistant gets live context on every change.

→ relion.get_open_risks
<0sFirst scan
0+Vendors supported
0Lines of config
0%Code stays local
160+ integrations

Tracks 160+ APIs across your stack.

From payments to AI to observability — Relion watches the APIs your code actually depends on and pings you the moment they change.

Stripe

Payments, billing, and subscriptions.

PayPal

PayPal checkout and payments.

Braintree

Full-stack payment platform (PayPal-owned).

Square

Square payments and point-of-sale.

Adyen

Enterprise global payment processing.

PlPlaid

Bank account linking and financial data.

MoMollie

European payments and SEPA.

Razorpay

India-focused payments and UPI.

Mercado Pago

Latin America payments platform.

ChCheckout.com

Enterprise payments and acquiring.

GoGoCardless

Direct debit and bank-to-bank payments.

ChChargebee

Subscription billing and revenue ops.

Paddle

Merchant-of-record SaaS billing.

Lemon Squeezy

Payments and licensing for digital products.

ReRecurly

Subscription management and recurring billing.

RevenueCat

Mobile in-app purchase and subscription management.

OpOpenAI

GPT, embeddings, and assistants.

Anthropic

Claude family of LLMs.

Don't see your vendor? Request an integration ↗

Pricing

Free for one repo. $25 for a small team. $20/user when you scale.

Scout
Free

No credit card. No expiring trial. Good for solo projects and kicking the tires on a real codebase.

  • 1 repository
  • relion scan
  • Monitoring dashboard
  • 7-day scan history
  • 3 monitored vendors
Get started free
Most popular
Enterprise
$20/user / month

Per-seat billing for larger orgs. Unlimited repos, vendors, and alert rules — scales with the team.

  • Unlimited repositories
  • Unlimited teammates
  • Everything in Sentinel
  • 365-day scan history
  • Unlimited monitored vendors
  • Unlimited custom alert rules
  • Priority support
Start Enterprise
FAQ

Common questions

Does Relion see my source code?

No. The CLI scanner runs entirely on your machine (or CI runner). Only API surface metadata — endpoint paths, HTTP methods, and vendor identifiers — is sent to Relion. Your source code never leaves your environment.

Which CI/CD providers are supported?

Any runner that can execute a Node.js binary. GitHub Actions, GitLab CI, CircleCI, Jenkins, Buildkite, and Railway deploy hooks all work out of the box. Add `relion predeploy` as a pipeline step and it returns a non-zero exit code when a breaking change intersects your diff.

What if my vendor isn't listed?

Relion's scanner uses pattern matching to detect API calls regardless of vendor. If you use a REST or GraphQL API, the scanner will likely detect it. You can also upload OpenAPI specs manually. Request specific vendor support via the dashboard.

How is this different from uptime monitoring?

Uptime monitors tell you an API is down. Relion tells you an API has changed in a way that will break your specific code — before you deploy. It's structural contract diffing at the field level, not a ping.

Can I use Relion with AI coding tools?

Yes. Relion ships an MCP server that connects to Claude Desktop, Cursor, and other AI editors. Your AI assistant can query which APIs are at risk, check scan history, and flag breaking changes — all inside your editor.

Don't learn about the next breaking change from your users.

One command to scan. One flag to gate deploys. One MCP tool for your AI editor. Free for one repo.

Free forever for 1 repo. No credit card required.

Relion