How the checks work
Red, yellow, Spada blue.
SpadaShield is a Chrome extension that checks messages before you send them to AI chat sites and checks citations in their answers.
SpadaShield finds the citations in an AI’s answer, looks each one up in the public source it names, and colors its mark by what that source says. A mark is red only when we can prove the citation is wrong. When in doubt, it’s yellow.
Three colors
Red: we can prove it’s incorrect
The source itself shows the citation is wrong. That’s the only time a mark is red.
Yellow: it needs a stronger, independent review
The source doesn’t settle it, or the lookup couldn’t finish. Read it yourself before you rely on it.
Spada blue: the source was found
A found source means it exists, not that it supports what the answer says. You still read it.
Every mark keeps its words, and the counts under an answer take the worst color among its marks: red if any is red, else yellow if any is yellow, else Spada blue.
What each mark says
Open any mark for every citation in the answer, what the source said, the passage around a quoted line, and a way to report a wrong result.
| The mark says | Color | What it means |
|---|---|---|
| Not found: check it | Red | The lookup finished and the source has no such citation: no DOI registry has the DOI; eCFR has no such CFR section; the linked page says it doesn’t exist, or its web address doesn’t exist; the DOI’s own record is a clearly different paper, with none of the cited authors on it; PubMed has no such ID, or its record is another paper; an ISBN’s check digit doesn’t fit, so it can’t be a real ISBN. |
| Details differ: check it | Yellow | The DOI, PubMed ID or ISBN is real, or a search found a work with that title, but the title, authors, year or journal the answer gives differ from its record. It may be the right work cited sloppily, or the wrong one. |
| Not found in the indexes: check it | Yellow | A reference with no DOI, PubMed ID or ISBN that CrossRef, PubMed and Open Library don’t have, or an ISBN that Open Library and Google Books don’t have. These indexes are large but not complete, so this is never red. |
| Quote not in the source | Yellow | The answer quotes a regulation or a linked page, the source was read, and the quoted words aren’t in it. The quote may come from another version, or the page may load its text later, so this is never red. |
| Not checked | Yellow | A kind of citation we don’t check yet, such as a court case or a statute. |
| Couldn’t check | Yellow | The lookup didn’t finish: the source timed out or wasn’t available, or the check got no answer. Never red. |
| Source found Quote found in the source | Spada blue | The source was found, and the details the answer cites match its record. A quote that was checked is in it. |
What is checked today
Live today- Federal regulationsCFR sections, in eCFR. Each result says the date eCFR shows the section as of, and that eCFR is an unofficial compilation. A quote from a section is looked for in its text.
- DOIsIn CrossRef, and in the other DOI registries when CrossRef doesn’t have it. When the answer cites the DOI with a title, authors, year or journal, those are compared with the DOI’s record, so a real DOI next to an invented title doesn’t pass as found.
- PubMed IDsIn PubMed, with the title, authors and year the answer gives compared with the record.
- ISBNsThe check digit first, then Open Library, then Google Books.
- References with no DOIAn APA reference with no identifier is searched for by its title and authors in CrossRef and PubMed, and in Open Library when it reads as a book.
- LinksWhether the linked page exists. Only a page that says it doesn’t exist, or an address whose site doesn’t exist, is red; a page that times out or can’t be read is yellow. A quote is looked for in the page’s text.
- WhereUp to 25 citations in each answer, on ChatGPT, Claude, Gemini and Microsoft Copilot, in Google Chrome, while you’re signed in to SpadaShield. Each new answer is checked when it finishes.
What isn’t checked today
- Court casesCase citations aren’t looked up today.
- StatutesU.S. Code sections aren’t looked up today.
The limits
What a mark can and can’t tell you.
- Red means provenA mark is red only when the source itself shows the citation is wrong. Anything less is yellow.
- A missing quote is yellowIf the quoted words aren’t in the source, the mark is yellow, never red: the quote may come from another version, or the page may load its text later.
- Not in an index is yellowNot being in an index is never red: the indexes are large, not complete.
- A failed lookup is yellowIf a source times out or can’t be reached, the mark says “Couldn’t check”, in yellow, never red.
- Blue isn’t a verdict on the answerA found source means the source exists, not that it says what the answer claims.
- Only what it can seeIt checks citations in AI answers on ChatGPT, Claude, Gemini and Microsoft Copilot, not your documents, and only the kinds listed above. If a site changes its page and SpadaShield can’t find the answers, it says so instead of checking nothing quietly.
- Your work is yoursSpadaShield doesn’t write or grade your work, or decide what you may hand in. What you submit is still your responsibility.
What is sent
The extension finds the citations on your computer and sends our server only the citations, the words quoted from each, and the AI site’s name, never the answer itself. For a reference, it also sends the title, authors, year and journal the answer gives.
Our server looks each one up in the public source it names: eCFR for a regulation, CrossRef for a DOI, PubMed for a PubMed ID or an article reference, Open Library or Google Books for a book, and the linked website for a link. Those sources see the citation, not who asked. No AI model is asked whether a citation is real. More on the security page.
Questions about AI citations
Can ChatGPT make up references?
Yes. A reference can name a paper nobody published, or pair a real DOI with a title or authors that do not match its record.
How do I check if an AI's citation is real?
SpadaShield looks up citations in public sources and marks them by what those sources say. Open a mark to read the result and the source. A found source means it exists, not that it supports the answer.
What do the red, yellow and blue marks mean?
Red means the source itself shows the citation is wrong. Yellow means it needs a closer look, including when a lookup could not finish. Blue means the source was found; you still need to read it.
Does SpadaShield read my whole conversation?
For a citation check, the extension sends the citations, quoted words, the AI site's name and the cited reference details, never the whole AI answer. Separately, messages you write are sent to the checking service when you pause while typing and on send unless the check is still current. No AI model reads your message to check it.
Does SpadaShield work in the ChatGPT desktop app?
No. SpadaShield works in Chrome on the supported AI chat sites. It does not cover desktop apps or AI built into Office or email programs.