diff --git a/docs/api.rst b/docs/api.rst
index 5d98b8ce..e0ff7ac5 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -41,6 +41,43 @@ Channel Class
    :members:
 
 
+ExternalContext Class
+---------------------
+
+.. class:: econtext.core.ExternalContext
+
+    External context implementation.
+
+    .. attribute:: broker
+
+        The :py:class:`econtext.core.Broker` instance.
+
+    .. attribute:: context
+
+            The :py:class:`econtext.core.Context` instance.
+
+    .. attribute:: channel
+
+            The :py:class:`econtext.core.Channel` over which
+            :py:data:`CALL_FUNCTION` requests are received.
+
+    .. attribute:: stdout_log
+
+        The :py:class:`econtext.core.IoLogger` connected to ``stdout``.
+
+    .. attribute:: importer
+
+        The :py:class:`econtext.core.Importer` instance.
+
+    .. attribute:: stdout_log
+
+        The :py:class:`IoLogger` connected to ``stdout``.
+
+    .. attribute:: stderr_log
+
+        The :py:class:`IoLogger` connected to ``stderr``.
+
+
 econtext.master
 ===============
 
@@ -55,6 +92,13 @@ Helper Functions
 .. autofunction:: econtext.master.minimize_source
 
 
+Context Class
+-------------
+
+.. autoclass:: econtext.master.Context
+   :members:
+
+
 Broker Class
 ------------
 
diff --git a/docs/howitworks.rst b/docs/howitworks.rst
index de1d6646..52cd6c5c 100644
--- a/docs/howitworks.rst
+++ b/docs/howitworks.rst
@@ -120,7 +120,7 @@ Since the bootstrap consists of the :py:mod:`econtext.core` source code, and
 this code is loaded by Python by way of its main script (``__main__`` module),
 initially the module layout in the slave will be incorrect.
 
-The first step taken after bootstrap is to rearrange ``sys.modules`` slightly
+The first step taken after bootstrap is to rearrange :py:data:`sys.modules` slightly
 so that :py:mod:`econtext.core` appears in the correct location, and all
 classes defined in that module have their ``__module__`` attribute fixed up
 such that :py:mod:`cPickle` correctly serializes instance module names.
diff --git a/docs/index.rst b/docs/index.rst
index 7080f005..7f9a44f0 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -56,8 +56,8 @@ connection.
 
     $ python preamble_size.py
     SSH command size: 411
-    Preamble size: 5085 (4.96KiB)
-    econtext.master size: 2403 (2.35KiB)
+    Preamble size: 4892 (4.78KiB)
+    econtext.master size: 2627 (2.57KiB)
 
 Once bootstrapped, the remote process is configured with a customizable
 **argv[0]**, readily visible to system administrators of the remote machine
diff --git a/econtext/core.py b/econtext/core.py
index 963db99e..ac8de96f 100644
--- a/econtext/core.py
+++ b/econtext/core.py
@@ -22,7 +22,6 @@ import sys
 import threading
 import time
 import traceback
-import types
 import zlib
 
 
@@ -471,25 +470,6 @@ class Context(object):
         IOLOG.debug('%r._enqueue_await_reply(): got reply: %r', self, data)
         return data
 
-    def call_with_deadline(self, deadline, with_context, fn, *args, **kwargs):
-        LOG.debug('%r.call_with_deadline(%r, %r, %r, *%r, **%r)',
-                  self, deadline, with_context, fn, args, kwargs)
-
-        if isinstance(fn, types.MethodType) and \
-           isinstance(fn.im_self, (type, types.ClassType)):
-            klass = fn.im_self.__name__
-        else:
-            klass = None
-
-        call = (with_context, fn.__module__, klass, fn.__name__, args, kwargs)
-        result = self.enqueue_await_reply(CALL_FUNCTION, deadline, call)
-        if isinstance(result, CallError):
-            raise result
-        return result
-
-    def call(self, fn, *args, **kwargs):
-        return self.call_with_deadline(None, False, fn, *args, **kwargs)
-
     def __repr__(self):
         bits = filter(None, (self.name, self.hostname, self.username))
         return 'Context(%s)' % ', '.join(map(repr, bits))
diff --git a/econtext/master.py b/econtext/master.py
index 5f22a31a..6a5046a4 100644
--- a/econtext/master.py
+++ b/econtext/master.py
@@ -14,6 +14,7 @@ import re
 import socket
 import sys
 import textwrap
+import types
 import zlib
 
 import econtext.core
@@ -271,3 +272,32 @@ class Context(econtext.core.Context):
 
     def on_disconnect(self):
         self.stream = None
+
+    def call_with_deadline(self, deadline, with_context, fn, *args, **kwargs):
+        """Invoke `fn([context,] *args, **kwargs)` in the external context.
+
+        If `with_context` is True, pass its
+        :py:class:`econtext.core.ExternalContext` instance as first parameter.
+
+        If `deadline` is not ``None``, expire the call after `deadline`
+        seconds. If `deadline` is ``None``, the invocation may block
+        indefinitely."""
+        LOG.debug('%r.call_with_deadline(%r, %r, %r, *%r, **%r)',
+                  self, deadline, with_context, fn, args, kwargs)
+
+        if isinstance(fn, types.MethodType) and \
+           isinstance(fn.im_self, (type, types.ClassType)):
+            klass = fn.im_self.__name__
+        else:
+            klass = None
+
+        call = (with_context, fn.__module__, klass, fn.__name__, args, kwargs)
+        result = self.enqueue_await_reply(econtext.core.CALL_FUNCTION,
+                                          deadline, call)
+        if isinstance(result, econtext.core.CallError):
+            raise result
+        return result
+
+    def call(self, fn, *args, **kwargs):
+        """Invoke `fn(*args, **kwargs)` in the external context."""
+        return self.call_with_deadline(None, False, fn, *args, **kwargs)