diff --git a/front-end/src/components/CustomNodeUpload.js b/front-end/src/components/CustomNodeUpload.js
new file mode 100644
index 0000000..f9a744b
--- /dev/null
+++ b/front-end/src/components/CustomNodeUpload.js
@@ -0,0 +1,48 @@
+import React, {useRef, useState} from "react";
+import * as API from "../API";
+import {Button} from "react-bootstrap";
+
+
+export default function CustomNodeUpload({ onUpload }) {
+
+    const input = useRef(null);
+    const [status, setStatus] = useState("ready");
+
+    const uploadFile = async file => {
+        setStatus("loading");
+        const fd = new FormData();
+        fd.append("file", file);
+        API.uploadDataFile(fd)
+            .then(resp => {
+                onUpload();
+                setStatus("ready");
+            }).catch(() => {
+                setStatus("failed");
+        });
+        input.current.value = null;
+    };
+    const onFileSelect = e => {
+        e.preventDefault();
+        if (!input.current.files) return;
+        uploadFile(input.current.files[0]);
+    };
+
+    let content;
+    if (status === "loading") {
+        content = <div>Uploading file...</div>;
+    } else if (status === "failed") {
+        content = (<div>Upload failed. Try a new file.</div>);
+    }
+    return (
+        <>
+            <input type="file" ref={input} onChange={onFileSelect}
+                   style={{display: "none"}} />
+            <Button size="sm" onClick={() => input.current.click()}
+                    variant="success"
+                    disabled={status === "loading"}>
+                Add Custom Node
+            </Button>
+            {content}
+        </>
+    )
+}
diff --git a/front-end/src/components/NodeMenu.js b/front-end/src/components/NodeMenu.js
index b84d9c0..ac13fa6 100644
--- a/front-end/src/components/NodeMenu.js
+++ b/front-end/src/components/NodeMenu.js
@@ -1,6 +1,7 @@
 import React from 'react';
 import * as _ from 'lodash';
-import { Col } from 'react-bootstrap';
+import { Col, OverlayTrigger, Tooltip } from 'react-bootstrap';
+import CustomNodeUpload from "./CustomNodeUpload";
 
 
 export default function NodeMenu(props) {
@@ -18,28 +19,80 @@ export default function NodeMenu(props) {
                             const config = data.options;
                             delete data.options;
                             return (
-                                <NodeMenuItem key={data.node_key} nodeInfo={data} config={config} />
+                                <NodeMenuItem key={data.node_key || data.filename}
+                                              nodeInfo={data} config={config} />
                             )}
                         )}
                     </ul>
                 </div>
             )}
+            <CustomNodeUpload onUpload={props.onUpload} />
         </Col>
     );
 }
 
 
+/**
+ * Format docstring with newlines into tooltip content
+ * @param string - node docstring
+ * @returns {array} - array of strings and HTML elements
+ */
+function formatTooltip(string) {
+    const split = string.split("\n");
+    const out = [];
+    split.forEach((line, i) => {
+        out.push(line);
+        out.push(<br  key={i} />);
+    });
+    out.pop();
+    return out;
+}
+
+
 function NodeMenuItem(props) {
+    if (!props.nodeInfo.missing_packages) {
+        const tooltip = props.nodeInfo.doc ? formatTooltip(props.nodeInfo.doc) : "This node has no documentation."
+        return (
+            <OverlayTrigger
+                placement="right"
+                delay={{ show: 250, hide: 250 }}
+                overlay={<NodeTooltip message={tooltip} />}>
+                <li className="NodeMenuItem"
+                    draggable={true}
+                    onDragStart={event => {
+                        event.dataTransfer.setData(
+                            'storm-diagram-node',
+                            JSON.stringify(props));
+                    }}
+                    style={{color: props.nodeInfo.color}}>
+                    {props.nodeInfo.name}
+                </li>
+            </OverlayTrigger>
+        )
+    } else {
+        let tooltip = "These Python modules could not be imported:\n\n"
+            + props.nodeInfo.missing_packages.join("\n");
+        tooltip = formatTooltip(tooltip);
+        return (
+            <OverlayTrigger
+                placement="right"
+                delay={{ show: 250, hide: 250 }}
+                overlay={<NodeTooltip message={tooltip} />}>
+                <li className="NodeMenuItem invalid">{props.nodeInfo.filename}</li>
+            </OverlayTrigger>
+        )
+    }
+}
+
+
+// Overlay with props has to use ref forwarding
+const NodeTooltip = React.forwardRef((props, ref) => {
     return (
-        <li className="NodeMenuItem"
-            draggable={true}
-            onDragStart={event => {
-                event.dataTransfer.setData(
-                    'storm-diagram-node',
-                    JSON.stringify(props));
-            }}
-            style={{ color: props.nodeInfo.color }}>
-            {props.nodeInfo.name}
-        </li>
+        <Tooltip {...props} ref={ref}>
+            <div style={{textAlign: "left"}}>
+                {props.message}
+            </div>
+        </Tooltip>
     )
-}
+});
+
diff --git a/front-end/src/components/Workspace.js b/front-end/src/components/Workspace.js
index 57c0f32..32e580a 100644
--- a/front-end/src/components/Workspace.js
+++ b/front-end/src/components/Workspace.js
@@ -22,6 +22,7 @@ class Workspace extends React.Component {
         this.engine.setModel(this.model);
         this.engine.setMaxNumberPointsPerLink(0);
         this.state = {nodes: []};
+        this.getAvailableNodes = this.getAvailableNodes.bind(this);
         this.load = this.load.bind(this);
         this.clear = this.clear.bind(this);
         this.handleNodeCreation = this.handleNodeCreation.bind(this);
@@ -29,10 +30,17 @@ class Workspace extends React.Component {
     }
 
     componentDidMount() {
+        this.getAvailableNodes();
+        API.initWorkflow(this.model).catch(err => console.log(err));
+    }
+
+    /**
+     * Retrieve available nodes from server to display in menu
+     */
+    getAvailableNodes() {
         API.getNodes()
             .then(nodes => this.setState({nodes: nodes}))
             .catch(err => console.log(err));
-        API.initWorkflow(this.model).catch(err => console.log(err));
     }
 
     /**
@@ -107,7 +115,7 @@ class Workspace extends React.Component {
                     </Col>
                 </Row>
                 <Row className="Workspace">
-                    <NodeMenu nodes={this.state.nodes} />
+                    <NodeMenu nodes={this.state.nodes} onUpload={this.getAvailableNodes}/>
                     <Col xs={10}>
                         <div style={{position: 'relative', flexGrow: 1}}
                             onDrop={event => this.handleNodeCreation(event)}
diff --git a/front-end/src/styles/Workspace.css b/front-end/src/styles/Workspace.css
index ee60a27..d448cec 100644
--- a/front-end/src/styles/Workspace.css
+++ b/front-end/src/styles/Workspace.css
@@ -16,14 +16,22 @@
         linear-gradient(to bottom, rgba(54, 169, 231, 0.1) 1px, transparent 1px);
 }
 .NodeMenuItem {
-    cursor: pointer;
     background-color: white;
-    border-radius: 5px;
     margin-bottom: 3px;
+    box-shadow: 0px 2px 4px gray;
+}
+.NodeMenuItem[draggable] {
+    cursor: pointer;
 }
-.NodeMenuItem::before {
+.NodeMenuItem[draggable]::before {
     content: "+";
     padding-right: 10px;
     padding-left: 5px;
     color: black;
 }
+.NodeMenuItem.invalid::before {
+    content: "\26a0";
+    padding-right: 10px;
+    padding-left: 5px;
+    color: red;
+}