# OpenPlag Labs

> Originality checks for academic texts. A document is compared with a local index of more than 180 million open-access records (OpenAlex) and the open web, in eight languages: Hebrew, English, Arabic, Russian, French, Spanish, German and Chinese. The report shows verbatim overlap (identical and with changes), whether each shared passage is cited, paraphrase and translation candidates (never counted in the score), an experimental writing indicator, and a check against the OpenPlag Labs standard for the ethical use of AI in academic research.

A similarity report is not a finding of plagiarism. The writing indicator is a probability, not evidence: in our tests it was right in about three cases out of four, measured on Hebrew and English texts. The Chinese search covers open sources only.

## For AI agents: open access, no account

AI agents may check ONE document on behalf of a user, without an account or key.

- MCP server (Streamable HTTP, JSON over POST): https://app.openplaglabs.com/mcp, tools `check_document` and `get_check`
- Plain HTTP: `POST https://app.openplaglabs.com/agent/v1/checks` with a JSON body, then `GET https://app.openplaglabs.com/agent/v1/checks/{token}`

Body of a check: `user_confirmed` (true, only after the user agreed) and exactly one of `content_base64` with `filename`, `text`, or `url` (a public link to a PDF, DOCX or TXT file). Formats: PDF, DOCX, DOC, ODT, RTF, TXT. Up to 10,000 words. A check takes 10 to 20 minutes; the result is a summary and a link to the full report, valid for 24 hours.

Rules for agents:

1. Ask the user before sending their document. It is sent to an external service, checked, and deleted when the check ends.
2. One document per user request. Never send batches, and never split a long document into parts.
3. Poll the result no more often than `poll_after_seconds`.
4. When a call is refused, follow its message. If `retry` is false, do not retry. Pass `tell_user` on to the user.
5. Always pass on the disclaimer that comes with the result.

Limits per network address: one check at a time, growing waiting times between checks (5, 15, 45 and 135 minutes), at most 5 a day. All agents together share a small daily quota, and people's checks run first. Using open access means accepting the terms of service: https://app.openplaglabs.com/terms

Users who need more (documents up to 60,000 words, reports kept for 30 days, a history of checks) can open a free account: https://openplaglabs.com/?src=agent

## Guides

- [How to read a similarity report](https://app.openplaglabs.com/guides/reading-a-report?lang=en)
- [How to disclose the use of AI in a research paper](https://app.openplaglabs.com/guides/ai-disclosure?lang=en)
- [Citation or plagiarism? Where the line runs](https://app.openplaglabs.com/guides/citation-vs-plagiarism?lang=en)
- [Sample report](https://app.openplaglabs.com/sample)