diff --git a/.gitignore b/.gitignore
index 48f0ea8..31ae422 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,3 +31,6 @@ nosetests.xml
 .mr.developer.cfg
 .project
 .pydevproject
+
+# ignore virtualenv created by ./tools/provision
+.zulip-api-env
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..2fc7248
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,4 @@
+pycodestyle==2.3.1
+-e ./zulip
+-e ./zulip_bots
+-e ./zulip_botserver
diff --git a/tools/provision b/tools/provision
new file mode 100755
index 0000000..27cdbe3
--- /dev/null
+++ b/tools/provision
@@ -0,0 +1,16 @@
+#!/bin/bash
+
+BASEDIR=`dirname $0`/..
+
+if [ ! -d "$BASEDIR/.zulip-api-env" ]; then
+    virtualenv $BASEDIR/.zulip-api-env
+    echo "Virtualenv created."
+fi
+
+source $BASEDIR/.zulip-api-env/bin/activate
+
+if [ ! -f "$BASEDIR/.zulip-api-env/updated" -o $BASEDIR/requirements.txt -nt $BASEDIR/.zulip-api-env/updated ]; then
+    pip install -r $BASEDIR/requirements.txt
+    touch $BASEDIR/.zulip-api-env/updated
+    echo "Requirements installed."
+fi