my 404 page will mock you

I believe I have found the killer application for LLMs: automatically generated 404 pages that insult the user for their poor navigational abilities. When a lost visitor tries to access a location that does not exist on this website, the server will give them a harsh reality-check. Have a look at the non-existent pages below to get a taste:

How does it work? When a user requests a page that does not exist, a language model is prompted for an insulting response based on the URI of the requested resource. I use Ollama to self-host a quantized version of Mistral 7B. This allows me to generate responses to prompts by calling a local HTTP API.

The actual HTTP response is assembled by a Bash script that is served via CGI on NGINX using fcgiwrap. In short, CGI executes a program for each request and responds with whatever the program writes to standard output. Here is the script: 

#!/usr/bin/env bash

set -o pipefail

echo "content-type: text/html"
echo "status: 404 not found"
echo "cache-control: max-age=3600"
echo ""

location="$REQUEST_URI"

model="mistral-nemo:latest" #"mistral:latest"
system="You are a web server that is an expert at writing creative and profane insults."
prompt="A visitor tried to access '$location' which does not exist, so they ended up on this 404 page. Respond with an insulting personal letter to the visitor. Guess what they expected to find at '$location' and explain how foolish it was to think that you as a server would respond to such a request. Use markdown to format your message, starting with a 404 heading and ending with a signature."

payload=$(cat << EOF
{
  "model": "$model",
  "system": "$system",
  "prompt": "$prompt",
  "stream": false
}
EOF
)

result=$(curl -X POST "127.0.0.1:11434/api/generate" -d "$payload" | jq -r ".response" | sed 's/&/\&amp;/g; s/</\&lt;/g; s/>/\&gt;/g; s/"/\&quot;/g; s/'"'"'/\&#39;/g' | pandoc -f markdown -t html || echo "Normally I would insult you, but I have better things to do.")

cat << EOF
<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>404 not found - fumlig.se</title>
    <link href="/style.css" rel="stylesheet" type="text/css" />
  </head>
  <body>
    <main>
      <section>
        $result
      </section>
      <footer>
        <hr />
        <nav>
          <ul>
            <li><a href="/">go back home</a></li>
            <li><a href="/insulting-404/">what is this?</a></li>
          </ul>
        </nav>  
      </footer>

      <script src="/oneko.js"></script>
    </main>
  </body>
</html>
EOF

A drawback is that it is a rather expensive response to compute. I have configured caching and rate limiting in NGINX try to prevent people from frying my GPU, but I also ask that you are polite and do not exploit this to spike my energy bill :)

Oskar Lundin
2024-02-25
Stockholm

comments

comment

Epicality

Erik Lundin wrote on :

Now this is epic!

reply

Fun response

Oskar Lundin wrote on :

I liked this one!

reply