gistfile1.txt

var proxy = require('express-http-proxy');

var DATA_DIR = '~';
var PouchDB = require('pouchdb').defaults({prefix: DATA_DIR + 'core/'});
var PublicPouchDB = PouchDB.defaults({prefix: DATA_DIR + 'public/'});

var app = require('express')();
 
app.use('/proxy', proxy('www.google.com', {
  forwardPath: function(req, res) {
    return require('url').parse(req.url).path;
  }
}));

// Lets make /db/ admin party access
app.use('/db/', require('pouchdb-express-router')(PouchDB));

// Lets make /public/ a read only instance
function reject(req, res, next) {
  res.status(401).send({error: true, message: 'Unauthorised'});
}

app.post('/public/*', reject);
app.delete('/public/*', reject);
app.put('/public/*', reject);
app.use('/db/public', require('pouchdb-express-router')(PublicPouchDB));

Use this with maximum care. express-http-proxy seems not to pipe, but rather recombine remote server response in memory first, and only then send it to user. In common scenarios this approach might be at least risky.