How to use ZTR in Claude

Your name and professional title are recorded when you authorise the connector, and they appear on every receipt you create. State them in the request as well whenever a specific colleague performed the review, or when you want the registration number on the record: what you state in the call always takes precedence.

What the receipt attests — and what it does not

A ZTR receipt attests three things, and only three:

the identity as declared — the name and title the declarant stated at authorisation or in the request. ZTR records that declaration; it does not verify it against any register;
the integrity of the hashed content (anyone can recompute the SHA-256 from their own copy and compare);
the time of the declaration, corroborated by a qualified timestamp from an EU Qualified Trust Service Provider.

It does not attest the accuracy, truthfulness, or predictive value of the content, nor the competence of the declarant in domains outside their stated professional qualification. A receipt issued by a lawyer on a sports forecast is a valid record that the lawyer declared to have reviewed that text at that moment — nothing more. If you use ZTR outside your professional domain, say so in the review_note: it is reproduced verbatim on the PDF.

Verify a document before filing

"I've reviewed this brief and I'm ready to file. Verify it with ZTR.
Reviewer: Marco Bianchi, Avvocato, Ordine di Milano n. 12345."

ZTR computes the SHA-256 of the text, discards the content, and requests a qualified timestamp from an EU Qualified Trust Service Provider. The receipt records who declared the review and when. It does not attest that the review was performed well — that remains the professional's responsibility, and the receipt says so on its face.

Verify a file you have attached

"Verify the attached PDF with ZTR.
Reviewer: Marco Bianchi, Avvocato, Ordine di Milano n. 12345."

Attach the file in Claude and the hash is computed on the file itself, so anyone can later recompute it from their own copy and compare.

Look up a past receipt

"Can you look up receipt ZTR-20260720143022-a7f3c891?"

No authentication is needed to read a receipt: anyone holding the identifier can check it, which is the point.

List your own receipts

"Show me all documents I verified this week."

This returns your receipts only. Each account sees nothing but its own.

Verify something outside your professional domain

"Verify with ZTR that I recorded this forecast today. Context: other.
Reviewer: Marco Bianchi.
Note: I checked the source data, but I cannot guarantee the outcome."

Use context: other when the content does not fall within your professional qualification. The receipt will still carry your registered name and title, so state the limits explicitly in the review_note: the note is reproduced verbatim on the PDF, and it is the only place where a reader will learn that the declaration does not extend to the outcome.

Required fields

Field	Required	Notes
`document_text` or `file_content_base64`	yes	The content is hashed and discarded, never stored.
`reviewer_name`	yes	Taken from your authorisation if omitted in the call. A receipt is never issued without one.
`reviewer_title`	yes	As above.
`reviewer_id`	no	Bar or professional register number. Recommended where the declaration may be relied upon by a third party.
`context`	no	One of: legal_filing, contract_review, legal_research, client_advice, regulatory_submission, internal_memo, other. Defaults to legal_filing. Use `other` outside your professional domain.
`review_note`	no	The reviewer's own declaration, reproduced verbatim on the receipt. Use it to state the limits of what you are declaring.

Limits

Ten receipts per account per day during the technical preview, of which the first five each day carry a qualified timestamp. Beyond that, a receipt is still recorded but marked as carrying no eIDAS timestamp, and the PDF says so. Documents up to 5 MB.