# Sign (/docs/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](/docs/webhooks),
[logs](/docs/logs) and sandbox environments as everything else.

```ts twoslash
import { Coss } from "coss";
const coss = new Coss();
declare const pdfBase64: string;
// ---cut---
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 [#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](/docs/sign/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 [#whats-in-it]

<Cards>
  <Card title="Embedded signing" href="/docs/sign/embedded-signing">
    Signing sessions, `mountSigning` and the events your page gets.
  </Card>
  <Card title="Email signing" href="/docs/sign/email-signing">
    Invitations, reminders, expiry and signed copies, from your own address.
  </Card>
  <Card title="Fields and anchors" href="/docs/sign/fields-and-anchors">
    Placing fields by position or text anchor, and what each type does.
  </Card>
  <Card title="Templates" href="/docs/sign/templates">
    Reusable documents with roles and merge fields, and the embedded builder.
  </Card>
  <Card title="Completion and the audit trail" href="/docs/sign/completion-and-audit-trail">
    The sealed PDF, the certificate and the hash chain.
  </Card>
  <Card title="Testing" href="/docs/sign/testing">
    Sandbox requests and what they don't do.
  </Card>
</Cards>