<p>I'm searching a wsgi middleware which I can warp around a wsgi applications and which lets me monitor incoming and outgoing http requests and header fields.</p>

<p>Something like firefox live headers, but for the server side.</p>

That shouldn't be too hard to write yourself as long as you only need the headers.  Try that:
```
```
import sys

def log_headers(app, stream=None):
    if stream is None:
        stream = sys.stdout
    def proxy(environ, start_response):
        for key, value in environ.iteritems():
            if key.startswith('HTTP_'):
                stream.write('%s: %s\n' % (key[5:].title().replace('_', '-'), value))
        return app(environ, start_response)
    return proxy
```
```