Yay a devtools!

devtools/background.js

@@ -0,0 +1,24 @@
+console.log("background.js loaded");
+
+// Listen for messages from the devtools panel
+browser.runtime.onMessage.addListener((message, sender, sendResponse) => {
+  // You could add a check to see if the message is from the devtools panel.
+  if (message.type === "GET_CONTEXT_STACK") {
+    // Forward the message to the content script running in the active tab.
+    browser.tabs.query({ active: true, currentWindow: true }).then((tabs) => {
+      if (tabs.length) {
+        browser.tabs.sendMessage(tabs[0].id, message).then(sendResponse);
+      }
+    });
+    // Return true to indicate you wish to send a response asynchronously
+    return true;
+  } else if (message.type === "UPDATE_CONTEXT_VALUE") {
+    // Forward update messages similarly
+    browser.tabs.query({ active: true, currentWindow: true }).then((tabs) => {
+      if (tabs.length) {
+        browser.tabs.sendMessage(tabs[0].id, message).then(sendResponse);
+      }
+    });
+    return true;
+  }
+});