> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getdeckle.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# POST /v1/pdf/sign

> Add a visual signature annotation to a PDF. Not a cryptographic signature.

# Sign PDF

`POST https://api.getdeckle.dev/v1/pdf/sign`

<Warning>
  This endpoint adds a **visual** signature annotation (image overlay +
  reason/location/contact metadata). It is **not** a cryptographic
  digital signature — there is no PAdES/CAdES envelope and the resulting
  PDF is not tamper-evident. The response field is
  `signature_annotation_added`, not `signed`, to make this explicit.
  Cryptographic signing is on the roadmap.
</Warning>

Add a visual signature annotation to a PDF document.

## Request Body

| Parameter | Type | Required | Description |
| - | - | - | - |
| `pdf` | string | Yes | Base64-encoded PDF document |
| `name` | string | Yes | Signer name |
| `reason` | string | No | Reason for signing |
| `location` | string | No | Location of signing |
| `contact` | string | No | Signer contact information |
| `page` | integer | No | Page number for the signature (0-indexed) |
| `x` | number | No | X coordinate for signature placement |
| `y` | number | No | Y coordinate for signature placement |
| `width` | number | No | Width of the signature box |
| `height` | number | No | Height of the signature box |
| `output` | string | No | `"url"` (default) or `"base64"` |

## Example

```bash theme={null}
curl -X POST https://api.getdeckle.dev/v1/pdf/sign \
  -H "Authorization: Bearer dk_live_sk_..." \
  -H "Content-Type: application/json" \
  -d '{
    "pdf": "<base64-encoded-pdf>",
    "name": "Jane Doe",
    "reason": "Contract approval",
    "location": "San Francisco, CA",
    "page": 0,
    "x": 350,
    "y": 50,
    "width": 200,
    "height": 60
  }'
```

## Response (URL mode)

```json theme={null}
{
  "url": "https://cdn.getdeckle.dev/gen_abc123.pdf",
  "file_size": 48200,
  "signed": true
}
```

## Response (base64 mode)

```json theme={null}
{
  "data": "<base64-encoded-signed-pdf>",
  "file_size": 48200,
  "signed": true
}
```

## Errors

| Status | Code | Description |
| - | - | - |
| 400 | `VALIDATION_ERROR` | Missing signer name or PDF exceeds size limit |
| 401 | `UNAUTHORIZED` | Invalid or missing API key |
| 429 | `RATE_LIMITED` | Too many requests |
| 500 | `INTERNAL_ERROR` | Server error during signing |


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.