Sign

coss.sign asks people to sign PDFs. They sign inside your app (an embedded signing page) or from a link coss.com emails them, and once everyone has signed you get a sealed PDF with a certificate of completion and a hash-chained audit trail. It uses the same API key, webhooks, logs and sandbox environments as everything else.

const { data: request } = await coss.sign.requests.create({
  title: "Services agreement",
  documents: [{ filename: "agreement.pdf", content: pdfBase64 }],
  signers: [
    {
      name: "Ada Lovelace",
      email: "ada@example.com",
      fields: [{ type: "signature", anchor: "{{signature:signer_1}}" }],
    },
  ],
});

Signatures are simple electronic signatures under the US ESIGN Act and UETA and the EU's eIDAS: each signer agrees to sign electronically, signs with a deliberate act, and is identified by the link they opened or by your app; the audit trail records each step, and the completed PDF is sealed, so any later change shows.

How a request goes

1. Create it with documents (uploaded or inline PDFs) and signers, each with their fields placed by position or by a text anchor in the PDF. It is sent at once, or a draft with send: false.
2. Signers sign. delivery: "email" (the default) signers get an email with their link; "embedded" signers sign in your app, in an iframe you open for them (embedded signing). Before they see a document, each one agrees to sign electronically.
3. It completes. When the last signer signs, coss.com seals the completed document and sends sign_request.completed. Download it with coss.sign.requests.signedDocument(id).

What's in it