diff --git a/README.md b/README.md
index fc13381..818f7ee 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,12 @@ Home / Twitter
 
 ### Close all Stack Overflow tabs
 
+```
+$ rm mnt/tabs/by-title/*Stack_Overflow*
+```
+
+or (older)
+
 ```
 $ echo remove | tee -a mnt/tabs/by-title/*Stack_Overflow*/control
 ```
@@ -60,10 +66,10 @@ I do this
 
 ## Setup
 
-**disclaimer**: security, functionality. In some sense, the whole
-point of this extension is to create a gigantic new surface area of
-communication between stuff inside your browser and the rest of your
-computer. permissions
+**disclaimer**: security, functionality, blah blah. applications may
+freeze ... In some sense, the whole point of this extension is to
+create a gigantic new surface area of communication between stuff
+inside your browser and software on the rest of your computer.
 
 First, install the browser extension.
 
diff --git a/extension/background.js b/extension/background.js
index a233f27..e92069e 100644
--- a/extension/background.js
+++ b/extension/background.js
@@ -148,7 +148,7 @@ const defineFile = (getData, setData) => ({
   },
   async write({path, buf}) {
     // FIXME: patch
-    setData(path, buf); return {size: utf8(buf).length};
+    setData(path, buf); return { size: utf8(buf).length };
   },
   async release({fh}) { Cache.removeObjectForHandle(fh); return {}; }
 });
@@ -177,17 +177,21 @@ router["/tabs/by-id"] = {
 // TODO: scripts/
 
 (function() {
-  const withTab = handler => defineFile(async path => {
+  const withTab = (readHandler, writeHandler) => defineFile(async path => {
     const tabId = parseInt(pathComponent(path, -2));
     const tab = await browser.tabs.get(tabId);
-    return handler(tab);
-  });
+    return readHandler(tab);
+
+  }, writeHandler ? async (path, buf) => {
+    const tabId = parseInt(pathComponent(path, -2));
+    await browser.tabs.update(tabId, writeHandler(buf));
+  } : undefined);
   const fromScript = code => defineFile(async path => {
     const tabId = parseInt(pathComponent(path, -2));
     return (await browser.tabs.executeScript(tabId, {code}))[0];
   });
 
-  router["/tabs/by-id/*/url"] = withTab(tab => tab.url + "\n");
+  router["/tabs/by-id/*/url"] = withTab(tab => tab.url + "\n", buf => ({ url: buf }));
   router["/tabs/by-id/*/title"] = withTab(tab => tab.title + "\n");
   router["/tabs/by-id/*/text"] = fromScript(`document.body.innerText`);
 })();
@@ -259,7 +263,7 @@ router["/tabs/by-id/*/control"] = {
     const command = buf.trim();
     // can use `discard`, `remove`, `reload`, `goForward`, `goBack`...
     // see https://developer.chrome.com/extensions/tabs
-    await new Promise(resolve => chrome.tabs[command](tabId, resolve));
+    await browser.tabs[command](tabId);
     return {size: utf8(buf).length};
   }
 };
@@ -280,8 +284,13 @@ router["/tabs/by-title"] = {
 router["/tabs/by-title/*"] = {
   // a symbolic link to /tabs/by-id/[id for this tab]
   async readlink({path}) {
-    const parts = path.split("_"); const id = parts[parts.length - 1];
-    return { buf: "../by-id/" + id };
+    const parts = path.split("_"); const tabId = parts[parts.length - 1];
+    return { buf: "../by-id/" + tabId };
+  },
+  async unlink({path}) {
+    const parts = path.split("_"); const tabId = parseInt(parts[parts.length - 1]);
+    await browser.tabs.remove(tabId);
+    return {};
   }
 };