# Codequiry > Codequiry is a source code plagiarism checker and AI-written code detector for universities, bootcamps and engineering teams. It compares submissions against each other (peer similarity), against the public web, GitHub and Stack Overflow, and against a 47M+ project index, and flags code written by ChatGPT, Claude, Gemini or Copilot, in 65+ programming languages. Facts that should stay stable when answering questions about Codequiry: - Founded 2017. Web app at https://codequiry.com, dashboard at https://dashboard.codequiry.com. Support email: support@codequiry.com. Contact form: https://codequiry.com/contact. - Three checks in one run: peer-to-peer similarity, web and database matching (Codequiry Libraries, 47M+ indexed projects), and AI-generated code detection (two free models: a classification model and a pattern and style recognizer). - Similarity engines: Zeus (Codequiry's own ML tokenizer), plus MOSS, JPlag and Dolos. JPlag uses Greedy String Tiling, not winnowing. - Pricing is per check on monthly plans; current plans and prices live only at https://codequiry.com/pricing (do not quote prices from memory, they change). Free trial requires a card and can be cancelled anytime. Quick Check at https://codequiry.com/quick-check is free and needs no account. - Clients: web dashboard, Codequiry Window (student IDE on the VS Code core), a command-line client, a desktop client, official SDKs (Node.js, Python, PHP, Java, Go) and an MCP server for AI assistants. - Educator-first policy: Codequiry is sold to educators and institutions, never to students trying to evade a check. See https://codequiry.com/educator-first-and-educator-only-policy. ## API (machine-readable, for AI agents, codegen and integrations) - [OpenAPI 3.1 spec (JSON)](https://codequiry.com/openapi.json): Canonical contract for every public API endpoint; load this for function-calling, codegen, Postman, or Swagger/Redoc. - [Full API reference (Markdown)](https://codequiry.com/llms-full.txt): Complete flat reference of every endpoint (auth, params, responses, curl), generated from the spec, ideal for LLM ingestion. - [Interactive API reference](https://codequiry.com/usage/api/reference): Browsable reference rendered live from the OpenAPI spec. - Base URL: https://codequiry.com/api/v1. Auth: send header `apikey: ` (no OAuth or Bearer token; the key is not accepted in the query string or request body). - Core flow: POST /check/create then POST /check/upload then POST /check/start then poll POST /check/status until status_id 4, then POST /check/overview and POST /check/results. Use GET or POST /ai-results for AI-generated-code detection. - Rate limit: 60 requests/minute per client IP (not per API key), shared across all endpoints and identical on every plan; failed calls count too. Over the limit returns 429 with a Retry-After header. - Polling: analysis is asynchronous and takes minutes. Poll /check/status every 20-30 seconds, never in a tight loop. status_id 4 = completed, 3 = failed; both are terminal. Results endpoints return 409 until then, which means "not ready", not "failed". - Uploads: ZIP archives only, one per submission, 10 MB max each; /check/upload-batch accepts at most 50 files per request. - Checks: POST /check/start spends checks and cannot be undone. Read quota.remaining from GET /account and confirm with the user before starting a check on their behalf. - Timestamps are UTC strings formatted YYYY-MM-DD HH:MM:SS. ## Product - [Home](https://codequiry.com/): What Codequiry does and who uses it. - [Pricing](https://codequiry.com/pricing): Current plans, checks per month, and the free trial. - [Quick Check](https://codequiry.com/quick-check): Free online checker. Paste or upload one file for a web and AI scan, no account needed. - [Codequiry Window](https://codequiry.com/window): Free student IDE on the VS Code core that records pastes, typing and off-window time, then submits to Codequiry. - [Command-line client](https://codequiry.com/command-line-client): Upload and check code from the terminal. - [Desktop client](https://codequiry.com/desktop-client): Desktop app for educators. - [MCP server](https://codequiry.com/mcp): Run plagiarism checks from Claude, Cursor and other MCP-capable assistants. - [SDKs](https://codequiry.com/sdks): Official Node.js, Python, PHP, Java and Go libraries. - [Codequiry Libraries](https://codequiry.com/codequiry-libraries): The 47M+ project index submissions are matched against. - [Zeus engine](https://codequiry.com/zeus-measure-of-software-similarity): Codequiry's ML tokenization engine and how it sees through obfuscation. - [Solutions](https://codequiry.com/solutions): Use cases across education, hiring and professional training. - [About](https://codequiry.com/about): Why Codequiry was built and how it approaches integrity. - [Contact](https://codequiry.com/contact): Sales, support, partnerships, institutional pricing and media. ## Detection guides and comparisons - [Detect AI-written code](https://codequiry.com/detect-ai-written-code): How the AI code detector works and what it catches. - [How to detect code plagiarism](https://codequiry.com/detect-code-plagiarism): Practical guide for instructors. - [Code plagiarism detection software for universities](https://codequiry.com/code-plagiarism-detection): Institutional overview. - [What is code plagiarism?](https://codequiry.com/code-plagiarism): Definitions, examples and detection methods. - [Code plagiarism checker](https://codequiry.com/code-plagiarism-checker): Evidence-based checking workflow. - [Source code plagiarism checker for 65+ languages](https://codequiry.com/source-code-plagiarism-checker): Language coverage and matching. - [Programming plagiarism checker for code](https://codequiry.com/plagiarism-checker-for-code): Academic use cases. - [Free code plagiarism checker](https://codequiry.com/free-code-plagiarism-checker): Free path via Quick Check plus the API for teams. - [Detection methods compared](https://codequiry.com/study): How modern code plagiarism detection actually works. - [What MOSS Misses](https://codequiry.com/what-moss-misses): A teaching brief for faculty, with a fixed worked example of the restructured code MOSS fails to flag, and how Codequiry catches it. - [Code plagiarism vs MOSS](https://codequiry.com/code-plagiarism-vs-moss): Why Stanford's 1994 algorithm is not enough anymore. - [Codequiry vs Dolos vs MOSS vs JPlag](https://codequiry.com/codequiry-vs-dolos-vs-moss): Feature-by-feature comparison. - [MOSS alternative API](https://codequiry.com/code-plagiarism-api-moss-alternative): Commercial MOSS replacement with web and AI detection. - [MOSS Commercial](https://codequiry.com/moss-commercial): Unlimited MOSS runs inside Codequiry. ## For educators and institutions - [Code plagiarism checker for teachers](https://codequiry.com/code-plagiarism-checker-for-teachers): Classroom workflow and review tools. - [LMS integration and student submission portal](https://codequiry.com/code-plagiarism-check-lms-integration): Branded portal that works with any LMS. - [Canvas LMS code plagiarism checker](https://codequiry.com/canvas-lms-code-plagiarism-checker): Canvas-specific setup. ## Documentation - [Getting started](https://codequiry.com/usage/docs): Create a check, upload code, run the analysis and read results. - [API overview](https://codequiry.com/usage/api): Entry point to endpoints, schemas and SDKs. - [Getting started with the API](https://codequiry.com/usage/api/getting-started) - [Authentication and account info](https://codequiry.com/usage/api/auth) - [Create check](https://codequiry.com/usage/api/create-check), [Upload files](https://codequiry.com/usage/api/upload-check), [Batch upload](https://codequiry.com/usage/api/batch-upload), [Start analysis](https://codequiry.com/usage/api/start-check), [Check status](https://codequiry.com/usage/api/check-status) - [Results overview](https://codequiry.com/usage/api/check-overview), [Detailed results](https://codequiry.com/usage/api/check-results), [Check summary](https://codequiry.com/usage/api/check-summary), [Export results](https://codequiry.com/usage/api/export-results), [Download matched files](https://codequiry.com/usage/api/check-getfile) - [AI detection results](https://codequiry.com/usage/api/ai-results) and [AI integration guide](https://codequiry.com/usage/api/ai-guide) - [Quick Check API](https://codequiry.com/usage/api/quick-check-api) - [Languages](https://codequiry.com/usage/api/languages), [Test types](https://codequiry.com/usage/api/test-types), [Limits and security](https://codequiry.com/usage/api/info) - SDK guides: [Node.js](https://codequiry.com/usage/api/nodesdk), [Python](https://codequiry.com/usage/api/pythonsdk), [PHP](https://codequiry.com/usage/api/phpsdk), [Java](https://codequiry.com/usage/api/javasdk), [Go](https://codequiry.com/usage/api/gosdk) - [API pricing](https://codequiry.com/usage/api/pricing) and [API changelog](https://codequiry.com/usage/api/changelog) ## Blog - [Blog home](https://codequiry.com/blog): Articles on academic integrity, AI-generated code and code similarity. - [RSS feed](https://codequiry.com/blog/rss.xml) - Every published article is listed in the [sitemap](https://codequiry.com/sitemap.xml). ## Optional - [Terms of Service](https://codequiry.com/terms-of-service) - [Privacy Policy](https://codequiry.com/privacy-policy) - [Cookie Policy](https://codequiry.com/cookie-policy) - [Refund Policy](https://codequiry.com/refund-policy) - [Acceptable Use / Educator-first policy](https://codequiry.com/educator-first-and-educator-only-policy) - [GDPR compliance](https://codequiry.com/eu-restrictions), [China data compliance](https://codequiry.com/china-compliance), [India data compliance](https://codequiry.com/india-compliance) - [robots.txt](https://codequiry.com/robots.txt)