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Vinkius

API Contract Diff Checker Connector for AI agents.

3 live capabilities

Audit OpenAPI and GraphQL schemas for breaking changes before you deploy.

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Why people use API Contract Diff Checker

API Contract Diff Checker for OpenAPI Schema Audits

With this Connector, you just hand the specs to your agent. It instantly flags the specific lines that changed. You get a clear list of what's new and what's broken, so you can focus on the logic instead of the formatting.

  • Claude
  • ChatGPT
  • Gemini
  • Cursor
  • Visual Studio Code
  • Windsurf

What Vinkius changes

You get a clear, automated audit of your API changes without manual comparison.

Use it from Claude, ChatGPT, Cursor or another AI client you already have.

One account · 6,100+ Connectors

  1. Real-world use case 01

    Catching type narrowing in GraphQL

    A developer adds a field but accidentally changes a type from optional to required.

  2. Real-world use case 02

    Auditing legacy REST API migrations

    A team is migrating a legacy REST API to a new version.

  3. Real-world use case 03

    Automating SemVer for release notes

    A release manager needs to know if a PR requires a Major version bump.

Complete set · 3capabilities

The complete API Contract Diff Checker capability set.

These are the exact actions your AI can choose when you ask it to work with API Contract Diff Checker.

Capability set01 / 01

01—03

3 capabilities in this set.

Part of 3 available through API Contract Diff Checker.

  1. 01 Capability

    Evaluate version bump

    Analyzes a collection of identified changes to recommend a Semantic Versioning increment. It tells you if your update qualifies as a MAJOR, MINOR, or PATCH release.

  2. 02 Capability

    Diff graphql

    Compares two GraphQL SDL strings to identify breaking and additive changes. It shows you exactly which fields were added or removed in your schema.

  3. 03 Capability

    Diff openapi

    Compares two OpenAPI specs to find structural differences and compatibility issues. It helps you identify if your REST API changes will break existing clients.

Set up in minutes

One URL. Then ask API Contract Diff Checker to work.

Claude and ChatGPT only need the Connector URL. Copy it once, add it in settings, and use API Contract Diff Checker from the conversation.

Choose your client

Live preview
Advanced clients IDE · CLI

Claude · Web + desktop

Official guide ↗

Connector URL · ready to paste

Streamable HTTP
https://edge.vinkius.com/vk_preview_YNoFUtgqNHWnECjvlVZlbBc74OvhGVwRY5w7zSGv/mcp
  1. Step 01

    Open Connectors

    In Claude Web or Claude Desktop, open Settings and choose Connectors.

  2. Step 02

    Add the URL

    Choose Add custom connector, name it API Contract Diff Checker, and paste the URL above.

  3. Step 03

    Turn it on in chat

    Select +, open Connectors, and enable API Contract Diff Checker for the conversation.

Where the request belongs

Work API Contract Diff Checker can move forward.

Built around the request

This is for backend engineers and API designers who need to ensure their changes don't break production for their users. It solves the headache of manual schema auditing and versioning guesswork.

01

Backend Engineer

Verifies that a new deployment won't crash mobile or web apps using the API.

02

API Designer

Checks if new GraphQL fields follow the existing schema rules before publishing.

03

DevOps Engineer

Automates the versioning logic for CI/CD pipelines to ensure consistent SemVer.

Build the capability set

Add more capabilities.

Each Connector adds new actions and data without changing how you work.

Browse Connectors
GraphQL Schema Breaking Change Detector logo
01 3 capabilities

GraphQL Schema Breaking Change Detector

Identify breaking changes in GraphQL schemas by comparing SDL strings.

View Connector
OpenAPI Validator Engine logo
02 1 capability

OpenAPI Validator Engine

Validate any OpenAPI or Swagger spec (2.0, 3.0, 3.1, 3.2) local before generating code from it. Returns version, validity, and every schema error with exact paths. Your spec quality gate.

View Connector
JSON Diff Visualizer logo
03 1 capability

JSON Diff Visualizer

Generate human-readable visual diffs between two JSON objects. added lines in green, removed in red, unchanged in gray. Like 'git diff' but for JSON structures.

View Connector
Text Diff Engine logo
04 1 capability

Text Diff Engine

Exact character-by-character string comparison. Stop relying on LLM summaries and get absolute text diffs for code and contracts.

View Connector
Deep Diff Engine logo
05 1 capability

Deep Diff Engine

Find every single change between two JSON objects. additions, deletions, and edits with exact structural paths. Stop relying on AI to 'spot the difference'.

View Connector
OpenAPI Spec Validator logo
06 Managed Connector

OpenAPI Spec Validator

Validate OpenAPI 3.x documents for structural compliance, orphaned components, and path parameter consistency.

View Connector

Bring your own AI

Change the model, client or framework. Keep API Contract Diff Checker connected.

  • Claude
  • ChatGPT
  • Gemini
  • Cursor
  • VS Code
  • Windsurf
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  • Cline
  • Zed
  • Continue
  • Kiro
  • Roo Code
  • Zencoder
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  • Pieces
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  • TypingMind
  • Chorus
  • 5ire
  • n8n
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  • CrewAI
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Before you connect

Questions about API Contract Diff Checker.

The practical details behind the request, access and result.

Does the API Contract Diff Checker work with my REST API?

Yes, it uses diff_openapi to handle RESTful specifications. It will check for removed paths, changed parameters, and other structural changes.

Can I use this to find breaking changes in GraphQL?

Yes, it specifically supports GraphQL SDL strings via diff_graphql. It can identify if your changes will break existing queries or mutations.

How does it know if a change is breaking?

It looks for structural changes that would cause existing clients to fail, such as removing a required endpoint or narrowing a data type.

Will it tell me what version number to use next?

Yes, the evaluate_version_bump capability analyzes your identified changes and suggests whether you should use a MAJOR, MINOR, or PATCH increment.

Can I use this for my own internal API documentation?

Absolutely. It is a great way to keep your internal documentation consistent and ensure that your own team doesn't break internal capabilities.

Do I need to provide the full JSON file?

You can provide the relevant schema strings for either OpenAPI or GraphQL. Your agent can help you extract these from your files if needed.

What types of API contracts can I compare?

You can compare OpenAPI specifications and GraphQL Schema Definition Language (SDL) strings.

How does the capability recommend a version bump?

The evaluate_version_bump capability analyzes detected changes. A MAJOR bump is recommended for breaking changes, MINOR for additive changes, and PATCH for informational updates.

Can I detect type narrowing in OpenAPI?

Yes, diff_openapi identifies type narrowing (e.g., changing a string to a specific regex pattern) as a breaking change.

One connection away

Give your agent a direct line to API Contract Diff Checker.

Connect API Contract Diff Checker once. Keep it beside 6,100+ managed Connectors when the next task needs more.

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