> ## 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/merge

> Merge multiple PDFs into a single document.

# Merge PDFs

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

Combine two or more PDF documents into a single file. PDFs are merged in the order provided.

## Request Body

| Parameter | Type      | Required | Description                                       |
| --------- | --------- | -------- | ------------------------------------------------- |
| `pdfs`    | string\[] | Yes      | Array of base64-encoded PDF documents (minimum 2) |
| `output`  | string    | No       | `"url"` (default) or `"base64"`                   |

Each PDF must be under \~27MB when decoded.

## Example

```bash theme={null}
curl -X POST https://api.getdeckle.dev/v1/pdf/merge \
  -H "Authorization: Bearer dk_live_sk_..." \
  -H "Content-Type: application/json" \
  -d '{
    "pdfs": [
      "<base64-encoded-pdf-1>",
      "<base64-encoded-pdf-2>"
    ],
    "output": "url"
  }'
```

## Response (URL mode)

```json theme={null}
{
  "url": "https://cdn.getdeckle.dev/gen_abc123.pdf",
  "file_size": 102400
}
```

## Response (base64 mode)

```json theme={null}
{
  "data": "<base64-encoded-merged-pdf>",
  "file_size": 102400
}
```

## Errors

| Status | Code               | Description                                           |
| ------ | ------------------ | ----------------------------------------------------- |
| 400    | `VALIDATION_ERROR` | Fewer than 2 PDFs provided, or PDF exceeds size limit |
| 401    | `UNAUTHORIZED`     | Invalid or missing API key                            |
| 429    | `RATE_LIMITED`     | Too many requests                                     |
| 500    | `INTERNAL_ERROR`   | Server error during merge                             |