diff --git a/components/form.js b/components/form.js
index d271da979..2eda65d50 100644
--- a/components/form.js
+++ b/components/form.js
@@ -33,6 +33,7 @@ import EyeClose from '@/svgs/eye-close-line.svg'
 import Info from './info'
 import { InvoiceCanceledError, usePayment } from './payment'
 import { useMe } from './me'
+import { ActCanceledError } from './item-act'
 
 export class SessionRequiredError extends Error {
   constructor () {
@@ -841,7 +842,7 @@ export function Form ({
         }
         let hash, hmac
         if (invoiceable) {
-          revert = optimisticUpdate?.({ amount, ...values }, ...args);
+          revert = await optimisticUpdate?.({ amount, ...values }, ...args);
           [{ hash, hmac }, cancel] = await payment.request(amount)
         }
         await onSubmit({ hash, hmac, amount, ...values }, ...args)
@@ -850,7 +851,7 @@ export function Form ({
       }
     } catch (err) {
       revert?.()
-      if (err instanceof InvoiceCanceledError) {
+      if (err instanceof InvoiceCanceledError || err instanceof ActCanceledError) {
         return
       }
       const msg = err.message || err.toString?.()
diff --git a/components/item-act.js b/components/item-act.js
index 42fc92b82..8505b1187 100644
--- a/components/item-act.js
+++ b/components/item-act.js
@@ -6,7 +6,7 @@ import { useMe } from './me'
 import UpBolt from '@/svgs/bolt.svg'
 import { amountSchema } from '@/lib/validate'
 import { gql, useApolloClient, useMutation } from '@apollo/client'
-import { useToast } from './toast'
+import { TOAST_DEFAULT_DELAY_MS, useToast } from './toast'
 import { useLightning } from './lightning'
 import { nextTip } from './upvote'
 import { InvoiceCanceledError, PaymentProvider, usePayment } from './payment'
@@ -47,6 +47,7 @@ export default function ItemAct ({ onClose, item, down, children }) {
   const [oValue, setOValue] = useState()
   const strike = useLightning()
   const cache = useApolloClient().cache
+  const toaster = useToast()
 
   useEffect(() => {
     inputRef.current?.focus()
@@ -67,10 +68,19 @@ export default function ItemAct ({ onClose, item, down, children }) {
     addCustomTip(Number(amount))
   }, [me, act, down, item.id, strike, onClose])
 
-  const optimisticUpdate = useCallback(({ amount }) => {
+  const optimisticUpdate = useCallback(async ({ amount }) => {
     onClose()
     strike()
-    return actOptimisticUpdate(cache, { ...item, sats: Number(amount), act: down ? 'DONT_LIKE_THIS' : 'TIP' }, { me })
+    const revert = actOptimisticUpdate(cache, { ...item, sats: Number(amount), act: down ? 'DONT_LIKE_THIS' : 'TIP' }, { me })
+    if (zapUndoTrigger(me, amount)) {
+      try {
+        await zapUndo(toaster)
+      } catch (err) {
+        revert()
+        throw err
+      }
+    };
+    return revert
   }, [cache, strike, onClose])
 
   // we need to wrap with PaymentProvider here since modals don't have access to PaymentContext by default
@@ -276,12 +286,15 @@ export function useZap () {
     try {
       const variables = { path: item.path, id: item.id, sats, act: 'TIP' }
       revert = zapOptimisticUpdate(cache, variables)
-      strike();
+      strike()
+      if (zapUndoTrigger(me, sats)) {
+        await zapUndo(toaster)
+      };
       [{ hash, hmac }, cancel] = await payment.request(sats - meSats)
       await zap({ variables: { ...variables, hash, hmac } })
     } catch (error) {
       revert?.()
-      if (error instanceof InvoiceCanceledError) {
+      if (error instanceof InvoiceCanceledError || error instanceof ActCanceledError) {
         return
       }
       console.error(error)
@@ -290,3 +303,24 @@ export function useZap () {
     }
   }, [strike, payment])
 }
+
+export class ActCanceledError extends Error {
+  constructor () {
+    super('act canceled')
+    this.name = 'ActCanceledError'
+  }
+}
+
+const zapUndoTrigger = (me, amount) => {
+  if (!me) return false
+  const enabled = me.privates.zapUndos !== null
+  return enabled ? amount >= me.privates.zapUndos : false
+}
+
+const zapUndo = async (toaster) => {
+  return await new Promise((resolve, reject) => {
+    const delay = TOAST_DEFAULT_DELAY_MS
+    toaster.undo({ onClick: () => reject(new ActCanceledError()) })
+    setTimeout(resolve, delay)
+  })
+}
diff --git a/components/toast.js b/components/toast.js
index e71548306..8ecfc9ed6 100644
--- a/components/toast.js
+++ b/components/toast.js
@@ -75,6 +75,16 @@ export const ToastProvider = ({ children }) => {
         ...options
       }
       return dispatchToast(toast)
+    },
+    undo: (options) => {
+      const toast = {
+        body: (onClose) => <ToastUndo handleClick={options.onClick} onClose={onClose} />,
+        variant: 'undo',
+        autohide: true,
+        delay: TOAST_DEFAULT_DELAY_MS,
+        ...options
+      }
+      return dispatchToast(toast)
     }
   }), [dispatchToast, removeToast])
 
@@ -137,18 +147,22 @@ export const ToastProvider = ({ children }) => {
               key={toast.id} bg={toast.variant} show autohide={toast.autohide}
               delay={toast.delay} className={`${styles.toast} ${styles[toast.variant]} ${textStyle}`} onClose={() => removeToast(toast)}
             >
-              <ToastBody>
-                <div className='d-flex align-items-center'>
-                  <div className='flex-grow-1'>{toast.body}</div>
-                  <Button
-                    variant={null}
-                    className='p-0 ps-2'
-                    aria-label='close'
-                    onClick={onClose}
-                  ><div className={`${styles.toastClose} ${textStyle}`}>X</div>
-                  </Button>
-                </div>
-              </ToastBody>
+              {typeof toast.body === 'function'
+                ? toast.body(onClose)
+                : (
+                  <ToastBody>
+                    <div className='d-flex align-items-center'>
+                      <div className='flex-grow-1'>{toast.body}</div>
+                      <Button
+                        variant={null}
+                        className='p-0 ps-2'
+                        aria-label='close'
+                        onClick={onClose}
+                      ><div className={`${styles.toastClose} ${textStyle}`}>X</div>
+                      </Button>
+                    </div>
+                  </ToastBody>
+                  )}
               {toast.progressBar && <div className={`${styles.progressBar} ${styles[toast.variant]}`} style={{ animationDuration, animationDelay }} />}
             </Toast>
           )
@@ -160,3 +174,19 @@ export const ToastProvider = ({ children }) => {
 }
 
 export const useToast = () => useContext(ToastContext)
+
+const ToastUndo = ({ handleClick, onClose }) => {
+  // TODO: make more pretty
+  return (
+    <ToastBody
+      onClick={() => {
+        handleClick()
+        onClose()
+      }}
+    >
+      <div className='d-flex fw-bold align-items-center flex-right'>
+        undo
+      </div>
+    </ToastBody>
+  )
+}
diff --git a/components/toast.module.css b/components/toast.module.css
index 2223f7cf7..9808b74f0 100644
--- a/components/toast.module.css
+++ b/components/toast.module.css
@@ -1,5 +1,6 @@
 .toastContainer {
   transform: translate3d(0, 0, 0);
+  margin-bottom: 53px; /* padding for bottom nav bar on mobile */
 }
 
 .toast {
@@ -32,6 +33,12 @@
   align-items: center;
 }
 
+.undo {
+  background-color:  var(--bs-warning);
+  border-width: 0px;
+  color: black;
+}
+
 .progressBar {
   width: 0;
   height: 5px;
@@ -54,8 +61,6 @@
   background-color: var(--bs-warning);
 }
 
-
-
 @keyframes progressBar {
   0% {
     width: 0;
@@ -71,7 +76,7 @@
 }
 
 @media screen and (min-width: 400px) {
-  .toast {
-    width: var(--bs-toast-max-width);
+  .toastContainer {
+    margin-bottom: 0px;
   }
 }
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