# Authentication

You can set a password for accessing pupcloud, by using the `-P` parameter on the commandline. You must provide the SHA-256 sum of the password you want to use, in hex format.

You can provide the whole hash, or just the first part, of any length you want to keep the commandline short. Of course, the longer the hash, the safer the system.

```bash
# Password is "ciao", with 128 bit of strength (truncated at 16 bytes)
pupcloud -r /my/dir -P b133a0c0e9bee3be20163d2ad31d6248
```

You can use [this site](https://emn178.github.io/online-tools/sha256.html) to hash the password, it doesn't send the password on the net (at least at the time I am writing, you may want to check).

{% hint style="danger" %}
The password is sent in clear text over the net, so *always use a HTTPS-capable reverse proxy* if you plan to serve over the public internet.
{% endhint %}


---

# Agent Instructions: 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:

```
GET https://germ.gitbook.io/pupcloud/pupcloud-v0.6/guides/authentication.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
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.