> For the complete documentation index, see [llms.txt](https://help.form.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.form.io/deploy/maintenance-and-migration/major-updates/pdf-server-1.x-3.x-to-5.x.md).

# PDF Server 1.x-3.x to 5.x

{% hint style="info" %}
**5.x PDF Serve**r requires an upgrade to **API Server 8.0.0** or higher.
{% endhint %}

If you are using PDF Server APIs directly you need to change the way your application authorizes the requests:

* If you are doing client-to-server requests (your application is working on browser) then you should send requests to API Server's `/pdf-proxy` endpoint using `x-jwt-token` header, see [**PDF API section**](https://apidocs.form.io/#864ccc88-4585-053e-4302-c839d987271a) of API docs.
* If you are doing server-to-server requests (your application is working on the server and request readers cannot be exposed) then you can send requests directly to PDF Server using admin key authorization. To do this you should add the `FORMIO_PDF_ADMINKEY` environment variable to your PDF Server run config. Set it to some secret key. After that, you can authorize your requests using `x-admin-key` header, which should be the same as the environment variable value. See [**PDF Server direct API section**](https://apidocs.form.io/#8e817291-38df-4338-889f-14cf38de5fbd) of API docs.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://help.form.io/deploy/maintenance-and-migration/major-updates/pdf-server-1.x-3.x-to-5.x.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.