diff --git a/cellfs.cm b/cellfs.cm
index 2e4f4262..7c95b95b 100644
--- a/cellfs.cm
+++ b/cellfs.cm
@@ -4,10 +4,11 @@ var fd = use('fd')
 var miniz = use('miniz')
 var qop = use('internal/qop')
 var wildstar = use('internal/wildstar')
+var blib = use('blob')
 
 var mounts = []
 
-var writepath = "."
+var write_mount = null
 
 function normalize_path(path) {
   if (!path) return ""
@@ -30,7 +31,7 @@ function mount_exists(mount, path) {
       result = mount.handle.stat(path) != null
     } disruption {}
     _check()
-  } else {
+  } else if (mount.type == 'fs') {
     full_path = fd.join_paths(mount.source, path)
     _check = function() {
       st = fd.stat(full_path)
@@ -119,12 +120,12 @@ function resolve(path, must_exist) {
 }
 
 function mount(source, name) {
-  var st = fd.stat(source)
+  var st = null
   var blob = null
   var qop_archive = null
   var zip = null
-
   var _try_qop = null
+  var http = null
 
   var mount_info = {
     source: source,
@@ -134,6 +135,29 @@ function mount(source, name) {
     zip_blob: null
   }
 
+  if (starts_with(source, 'http://') || starts_with(source, 'https://')) {
+    http = use('http')
+    mount_info.type = 'http'
+    mount_info.handle = {
+      base_url: source,
+      get: function(path, callback) {
+        var url = source + '/' + path
+        $clock(function() {
+          var resp = http.request('GET', url, null, null)
+          if (resp && resp.status == 200) {
+            callback(resp.body)
+          } else {
+            callback(null, "HTTP " + text(resp ? resp.status : 0) + ": " + url)
+          }
+        })
+      }
+    }
+    push(mounts, mount_info)
+    return
+  }
+
+  st = fd.stat(source)
+
   if (st.isDirectory) {
     mount_info.type = 'fs'
   } else if (st.isFile) {
@@ -146,18 +170,18 @@ function mount(source, name) {
     _try_qop()
 
     if (qop_archive) {
-        mount_info.type = 'qop'
-        mount_info.handle = qop_archive
-        mount_info.zip_blob = blob
+      mount_info.type = 'qop'
+      mount_info.handle = qop_archive
+      mount_info.zip_blob = blob
     } else {
-        zip = miniz.read(blob)
-        if (!is_object(zip) || !is_function(zip.count)) {
-          log.error("Invalid archive file (not zip or qop): " + source); disrupt
-        }
+      zip = miniz.read(blob)
+      if (!is_object(zip) || !is_function(zip.count)) {
+        log.error("Invalid archive file (not zip or qop): " + source); disrupt
+      }
 
-        mount_info.type = 'zip'
-        mount_info.handle = zip
-        mount_info.zip_blob = blob
+      mount_info.type = 'zip'
+      mount_info.handle = zip
+      mount_info.zip_blob = blob
     }
   } else {
     log.error("Unsupported mount source type: " + source); disrupt
@@ -191,11 +215,13 @@ function slurp(path) {
 }
 
 function slurpwrite(path, data) {
-  var full_path = writepath + "/" + path
-
-  var f = fd.open(full_path, 'w')
-  fd.write(f, data)
-  fd.close(f)
+  var full_path = null
+  if (write_mount) {
+    full_path = fd.join_paths(write_mount.source, path)
+  } else {
+    full_path = fd.join_paths(".", path)
+  }
+  fd.slurpwrite(full_path, data)
 }
 
 function exists(path) {
@@ -276,12 +302,25 @@ function rm(path) {
 }
 
 function mkdir(path) {
-  var full = fd.join_paths(writepath, path)
+  var full = null
+  if (write_mount) {
+    full = fd.join_paths(write_mount.source, path)
+  } else {
+    full = fd.join_paths(".", path)
+  }
   fd.mkdir(full)
 }
 
-function set_writepath(path) {
-  writepath = path
+function set_writepath(mount_name) {
+  var found = null
+  if (mount_name == null) { write_mount = null; return }
+  arrfor(mounts, function(m) {
+    if (m.name == mount_name) { found = m; return true }
+  }, false, true)
+  if (!found || found.type != 'fs') {
+    log.error("writepath: must be an fs mount"); disrupt
+  }
+  write_mount = found
 }
 
 function basedir() {
@@ -449,6 +488,82 @@ function globfs(globs, _dir) {
    return results
 }
 
+// Requestor factory: returns a requestor for reading a file at path
+function get(path) {
+  return function get_requestor(callback, value) {
+    var res = resolve(path, false)
+    var full = null
+    var f = null
+    var acc = null
+    var cancelled = false
+    var data = null
+    var _close = null
+
+    if (!res) { callback(null, "not found: " + path); return }
+
+    if (res.mount.type == 'zip') {
+      callback(res.mount.handle.slurp(res.path))
+      return
+    }
+    if (res.mount.type == 'qop') {
+      data = res.mount.handle.read(res.path)
+      if (data) {
+        callback(data)
+      } else {
+        callback(null, "not found in qop: " + path)
+      }
+      return
+    }
+    if (res.mount.type == 'http') {
+      res.mount.handle.get(res.path, callback)
+      return
+    }
+
+    full = fd.join_paths(res.mount.source, res.path)
+    f = fd.open(full, 'r')
+    acc = blob()
+
+    function next() {
+      var chunk = null
+      if (cancelled) return
+      chunk = fd.read(f, 65536)
+      if (length(chunk) == 0) {
+        fd.close(f)
+        stone(acc)
+        callback(acc)
+        return
+      }
+      acc.write_blob(chunk)
+      $clock(next)
+    }
+
+    next()
+    return function cancel() {
+      cancelled = true
+      _close = function() { fd.close(f) } disruption {}
+      _close()
+    }
+  }
+}
+
+// Requestor factory: returns a requestor for writing data to path
+function put(path, data) {
+  return function put_requestor(callback, value) {
+    var _data = data != null ? data : value
+    var full = null
+    var _do = null
+    if (!write_mount) { callback(null, "no write mount set"); return }
+    full = fd.join_paths(write_mount.source, path)
+    _do = function() {
+      fd.slurpwrite(full, _data)
+      callback(true)
+    } disruption {
+      callback(null, "write failed: " + path)
+    }
+    _do()
+  }
+}
+
 cellfs.mount = mount
 cellfs.mount_package = mount_package
 cellfs.unmount = unmount
@@ -467,7 +582,8 @@ cellfs.writepath = set_writepath
 cellfs.basedir = basedir
 cellfs.prefdir = prefdir
 cellfs.realdir = realdir
-
-cellfs.mount('.')
+cellfs.get = get
+cellfs.put = put
+cellfs.resolve = resolve
 
 return cellfs
diff --git a/internal/fd.c b/internal/fd.c
index 3563cd03..d9f7eab7 100644
--- a/internal/fd.c
+++ b/internal/fd.c
@@ -761,6 +761,22 @@ JSC_CCALL(fd_readlink,
 #endif
 )
 
+JSC_CCALL(fd_on_readable,
+    int fd = js2fd(js, argv[0]);
+    if (fd < 0) return JS_EXCEPTION;
+    if (!JS_IsFunction(argv[1]))
+        return JS_RaiseDisrupt(js, "on_readable: callback must be a function");
+    actor_watch_readable(js, fd, argv[1]);
+    return JS_NULL;
+)
+
+JSC_CCALL(fd_unwatch,
+    int fd = js2fd(js, argv[0]);
+    if (fd < 0) return JS_EXCEPTION;
+    actor_unwatch(js, fd);
+    return JS_NULL;
+)
+
 static const JSCFunctionListEntry js_fd_funcs[] = {
     MIST_FUNC_DEF(fd, open, 2),
     MIST_FUNC_DEF(fd, write, 2),
@@ -787,6 +803,8 @@ static const JSCFunctionListEntry js_fd_funcs[] = {
     MIST_FUNC_DEF(fd, symlink, 2),
     MIST_FUNC_DEF(fd, realpath, 1),
     MIST_FUNC_DEF(fd, readlink, 1),
+    MIST_FUNC_DEF(fd, on_readable, 2),
+    MIST_FUNC_DEF(fd, unwatch, 1),
 };
 
 JSValue js_core_internal_fd_use(JSContext *js) {