Traceable copies

Send a confidential file to several people so that each one downloads their own watermarked copy. If a copy leaks, detection tells you whose it was.

What you need

• The file in your asset library. Any file you have watermarked is there: its original is the source you share.
• Credits for one embed of the file per recipient. See billing.
• For the API, a key with watermarks:embed, links:write and links:read, and watermarks:detect to check a file later.

Share from the dashboard

Open the original in Assets and choose Share traceable copies. Name the link, paste your recipients' email addresses, one per line, and check the cost shown before you choose Create link.

Copy the link from its page and send it to your recipients in your own email, chat or document system. The link's page in Links shows who has opened it and downloaded their copy.

Share with the API

Watermark the file once to put its original in your library, and keep the X-Source-Asset-ID response header:

curl --fail-with-body https://api.etchv.com/watermarks/documents \
  -H "X-API-Key: $ETCHV_API_KEY" \
  -F 'file=@board-pack.pdf' \
  --form-string 'data={"document":"board-pack-2026-10"}' \
  -D response-headers.txt --output response-body
SOURCE_ASSET_ID=$(awk 'tolower($1)=="x-source-asset-id:" {print $2}' response-headers.txt | tr -d '\r')

response-body is the watermarked PDF. A long PDF may be processed in the background and answer 202 with a job receipt instead; its job status then has source_asset_id. For a file already in your library, list assets with kind=source.

Then create the link and send its url:

curl --fail-with-body https://api.etchv.com/links \
  -H "X-API-Key: $ETCHV_API_KEY" \
  -H 'Idempotency-Key: board-pack-2026-10' \
  -H 'Content-Type: application/json' \
  -d '{
    "asset_id": "'"$SOURCE_ASSET_ID"'",
    "name": "Board pack, October",
    "recipients": ["alex@example.com", "sam@example.com"],
    "download_limit": 3
  }' | jq -r .url

To let anyone at a company open the link, give allowed_domains instead of recipients. See the links reference for every field, and When copies are made for long files.

What recipients see

The link opens a page on etchv.com with the link's name and your workspace's name. The recipient enters their email address and the code Etchv sends to it, then downloads their copy. They don't need an Etchv account. The page reads the same for every address, so it never reveals who else the link was shared with.

Follow opens and stop sharing

Read the link to see each recipient's first open and downloads, or give webhook_id to receive a link.opened event as each one happens.

Revoke the link when you no longer want anyone to open it. Links also expire: by default 30 days after creation, or sooner if the source file expires first.

Trace a leaked copy

When a copy turns up somewhere it shouldn't, check it on Check a file or with the API:

curl --fail-with-body https://api.etchv.com/watermarks/documents/detect \
  -H "X-API-Key: $ETCHV_API_KEY" \
  -F file=@found.pdf

The response's copy names the link, the recipient it was made for and when they first opened it. See detection.