diff --git a/frontend/common/Binder.js b/frontend/common/Binder.js
index e907a83815..c897d402be 100644
--- a/frontend/common/Binder.js
+++ b/frontend/common/Binder.js
@@ -1,5 +1,6 @@
 import immer from "../imports/immer.js"
 import { timeout_promise, ws_address_from_base } from "./PlutoConnection.js"
+import { alert, confirm } from "./alert_confirm.js"
 
 export const BinderPhase = {
     wait_for_user: 0,
diff --git a/frontend/common/Feedback.js b/frontend/common/Feedback.js
index 0d074f2851..06f6931994 100644
--- a/frontend/common/Feedback.js
+++ b/frontend/common/Feedback.js
@@ -2,6 +2,7 @@ import { timeout_promise } from "./PlutoConnection.js"
 
 // Sorry Fons, even this part of the code is now unnessarily overengineered.
 // But at least, I overengineered this on purpose. - DRAL
+import { alert, confirm } from "./alert_confirm.js"
 
 let async = async (async) => async()
 
diff --git a/frontend/common/PlutoConnection.js b/frontend/common/PlutoConnection.js
index 0cf400e352..a9aead455e 100644
--- a/frontend/common/PlutoConnection.js
+++ b/frontend/common/PlutoConnection.js
@@ -1,6 +1,9 @@
 import { Promises } from "../common/SetupCellEnvironment.js"
 import { pack, unpack } from "./MsgPack.js"
+import { base64_arraybuffer, decode_base64_to_arraybuffer } from "./PlutoHash.js"
 import "./Polyfill.js"
+import { available as vscode_available, api as vscode_api } from "./VSCodeApi.js"
+import { alert, confirm } from "./alert_confirm.js"
 
 // https://github.com/denysdovhan/wtfjs/issues/61
 const different_Infinity_because_js_is_yuck = 2147483646
@@ -62,7 +65,7 @@ export const resolvable_promise = () => {
 /**
  * @returns {string}
  */
-const get_unique_short_id = () => crypto.getRandomValues(new Uint32Array(1))[0].toString(36)
+export const get_unique_short_id = () => crypto.getRandomValues(new Uint32Array(1))[0].toString(36)
 
 const socket_is_alright = (socket) => socket.readyState == WebSocket.OPEN || socket.readyState == WebSocket.CONNECTING
 
@@ -179,6 +182,54 @@ const create_ws_connection = (address, { on_message, on_socket_close }, timeout_
     })
 }
 
+const create_vscode_connection = (address, { on_message, on_socket_close }, timeout_s = 30) => {
+    return new Promise((resolve, reject) => {
+        window.addEventListener("message", (event) => {
+            // we read and deserialize the incoming messages asynchronously
+            // they arrive in order (WS guarantees this), i.e. this socket.onmessage event gets fired with the message events in the right order
+            // but some message are read and deserialized much faster than others, because of varying sizes, so _after_ async read & deserialization, messages are no longer guaranteed to be in order
+            //
+            // the solution is a task queue, where each task includes the deserialization and the update handler
+            last_task = last_task.then(async () => {
+                try {
+                    const raw = event.data // The json-encoded data that the extension sent
+                    if (raw.type === "ws_proxy") {
+                        const buffer = await decode_base64_to_arraybuffer(raw.base64_encoded)
+                        const message = unpack(new Uint8Array(buffer))
+
+                        try {
+                            window.DEBUG && console.info("message received!", message)
+                            on_message(message)
+                        } catch (process_err) {
+                            console.error("Failed to process message from websocket", process_err, { message })
+                            // prettier-ignore
+                            alert(`Something went wrong! You might need to refresh the page.\n\nPlease open an issue on https://github.com/fonsp/Pluto.jl with this info:\n\nFailed to process update\n${process_err.message}\n\n${JSON.stringify(event)}`)
+                        }
+                    }
+                } catch (unpack_err) {
+                    console.error("Failed to unpack message from websocket", unpack_err, { event })
+
+                    // prettier-ignore
+                    alert(`Something went wrong! You might need to refresh the page.\n\nPlease open an issue on https://github.com/fonsp/Pluto.jl with this info:\n\nFailed to unpack message\n${unpack_err}\n\n${JSON.stringify(event)}`)
+                }
+            })
+        })
+
+        const send_encoded = async (message) => {
+            window.DEBUG && console.log("Sending message!", message)
+            const encoded = pack(message)
+            await vscode_api.postMessage({ type: "ws_proxy", base64_encoded: await base64_arraybuffer(encoded) })
+        }
+
+        let last_task = Promise.resolve()
+
+        resolve({
+            socket: {},
+            send: send_encoded,
+        })
+    })
+}
+
 let next_tick_promise = () => {
     return new Promise((resolve) => setTimeout(resolve, 0))
 }
@@ -275,7 +326,7 @@ export const create_pluto_connection = async ({
     connect_metadata = {},
     ws_address = default_ws_address(),
 }) => {
-    var ws_connection = null // will be defined later i promise
+    let ws_connection = null // will be defined later i promise
     const client = {
         send: null,
         session_options: null,
@@ -346,11 +397,16 @@ export const create_pluto_connection = async ({
         update_url_with_binder_token()
 
         try {
-            ws_connection = await create_ws_connection(String(ws_address), {
+            ws_connection = await (vscode_available ? create_vscode_connection : create_ws_connection)(String(ws_address), {
                 on_message: (update) => {
-                    const by_me = update.initiator_id == client_id
+                    const for_me = update.recipient_id === client_id
+                    const by_me = update.initiator_id === client_id
                     const request_id = update.request_id
 
+                    if (!for_me) {
+                        return
+                    }
+
                     if (by_me && request_id) {
                         const request = sent_requests.get(request_id)
                         if (request) {
@@ -389,7 +445,7 @@ export const create_pluto_connection = async ({
 
             if (connect_metadata.notebook_id != null && !u.message.notebook_exists) {
                 // https://github.com/fonsp/Pluto.jl/issues/55
-                if (confirm("A new server was started - this notebook session is no longer running.\n\nWould you like to go back to the main menu?")) {
+                if (await confirm("A new server was started - this notebook session is no longer running.\n\nWould you like to go back to the main menu?")) {
                     window.location.href = "./"
                 }
                 on_connection_status(false)
diff --git a/frontend/common/PlutoHash.js b/frontend/common/PlutoHash.js
index 8c8333738a..3ce93c30ea 100644
--- a/frontend/common/PlutoHash.js
+++ b/frontend/common/PlutoHash.js
@@ -10,6 +10,11 @@ export const base64_arraybuffer = async (/** @type {BufferSource} */ data) => {
     return base64url.split(",", 2)[1]
 }
 
+export const decode_base64_to_arraybuffer = async (/** @type {string} */ data) => {
+    let r = await fetch(`data:;base64,${data}`)
+    return await r.arrayBuffer()
+}
+
 export const hash_arraybuffer = async (/** @type {BufferSource} */ data) => {
     // @ts-ignore
     const hashed_buffer = await window.crypto.subtle.digest("SHA-256", data)
diff --git a/frontend/common/VSCodeApi.js b/frontend/common/VSCodeApi.js
new file mode 100644
index 0000000000..64532936fa
--- /dev/null
+++ b/frontend/common/VSCodeApi.js
@@ -0,0 +1,28 @@
+// If we are running inside a VS Code WebView, then this exposes the API.
+
+// @ts-ignore
+export const available = window.acquireVsCodeApi != null
+// @ts-ignore
+const vscode = window.acquireVsCodeApi?.() ?? {}
+const store_cell_input_in_vscode_state = (cell_id, new_val) => {
+    if (available) {
+        const currentVSCodeState = vscode.getState() ?? {}
+        const { cell_inputs_local, ...rest } = currentVSCodeState ?? {}
+        api.setState({ cell_inputs_local: { ...(cell_inputs_local || {}), [cell_id]: { code: new_val } }, ...(rest ?? {}) })
+    }
+}
+
+const load_cell_inputs_from_vscode_state = () => {
+    if (available) {
+        const state = vscode.getState() ?? {}
+        return state.cell_inputs_local ?? {}
+    }
+    return {}
+}
+
+export const api = {
+    postMessage: console.error,
+    ...vscode,
+    store_cell_input_in_vscode_state,
+    load_cell_inputs_from_vscode_state,
+}
diff --git a/frontend/common/alert_confirm.js b/frontend/common/alert_confirm.js
new file mode 100644
index 0000000000..f8cf5e007a
--- /dev/null
+++ b/frontend/common/alert_confirm.js
@@ -0,0 +1,35 @@
+import { available, api } from "../common/VSCodeApi.js"
+import { resolvable_promise, get_unique_short_id } from "./PlutoConnection.js"
+
+const sent_requests = new Map()
+
+if (available) {
+    window.addEventListener("message", (event) => {
+        const raw = event.data
+
+        if (raw.type === "alert_confirm_callback") {
+            const request = sent_requests.get(raw.token)
+            if (request) {
+                request(raw.value)
+                sent_requests.delete(raw.token)
+            }
+        }
+    })
+}
+
+const create_alert_confirm = (name) => (x) =>
+    new Promise((resolve) => {
+        let request_id = get_unique_short_id()
+
+        sent_requests.set(request_id, (response_message) => {
+            resolve(response_message)
+        })
+        api.postMessage({
+            type: name,
+            text: x,
+            token: request_id,
+        })
+    })
+
+export const alert = available ? create_alert_confirm("alert") : window.alert
+export const confirm = available ? create_alert_confirm("confirm") : window.confirm
diff --git a/frontend/components/Editor.js b/frontend/components/Editor.js
index 5402d0f2e4..64bae347a0 100644
--- a/frontend/components/Editor.js
+++ b/frontend/components/Editor.js
@@ -30,10 +30,13 @@ import { BinderButton } from "./BinderButton.js"
 import { slider_server_actions, nothing_actions } from "../common/SliderServerClient.js"
 import { ProgressBar } from "./ProgressBar.js"
 import { IsolatedCell } from "./Cell.js"
+import { available as vscode_available, api as vscode } from "../common/VSCodeApi.js"
 import { RawHTMLContainer } from "./CellOutput.js"
 import { RecordingPlaybackUI, RecordingUI } from "./RecordingUI.js"
 
 const default_path = "..."
+import { alert, confirm } from "../common/alert_confirm.js"
+
 const DEBUG_DIFFING = false
 let pending_local_updates = 0
 // from our friends at https://stackoverflow.com/a/2117523
@@ -161,7 +164,7 @@ const url_logo_small = document.head.querySelector("link[rel='pluto-logo-small']
 const url_params = new URLSearchParams(window.location.search)
 const launch_params = {
     //@ts-ignore
-    notebook_id: url_params.get("id") ?? window.pluto_notebook_id,
+    notebook_id: (vscode_available ? null : url_params.get("id")) ?? window.pluto_notebook_id,
     //@ts-ignore
     statefile: url_params.get("statefile") ?? window.pluto_statefile,
     //@ts-ignore
@@ -211,7 +214,7 @@ export class Editor extends Component {
 
         this.state = {
             notebook: /** @type {NotebookData} */ initial_notebook(),
-            cell_inputs_local: /** @type {{ [id: string]: CellInputData }} */ ({}),
+            cell_inputs_local: /** @type {{ [id: string]: CellInputData }} */ vscode.load_cell_inputs_from_vscode_state(),
             desired_doc_query: null,
             recently_deleted: /** @type {Array<{ index: number, cell: CellInputData }>} */ (null),
             last_update_time: 0,
@@ -253,6 +256,7 @@ export class Editor extends Component {
             update_notebook: (...args) => this.update_notebook(...args),
             set_doc_query: (query) => this.setState({ desired_doc_query: query }),
             set_local_cell: (cell_id, new_val) => {
+                vscode.store_cell_input_in_vscode_state(cell_id, new_val)
                 return this.setStatePromise(
                     immer((state) => {
                         state.cell_inputs_local[cell_id] = {
@@ -439,9 +443,9 @@ export class Editor extends Component {
                 return await this.actions.add_remote_cell_at(index + delta, code)
             },
             confirm_delete_multiple: async (verb, cell_ids) => {
-                if (cell_ids.length <= 1 || confirm(`${verb} ${cell_ids.length} cells?`)) {
+                if (cell_ids.length <= 1 || (await confirm(`${verb} ${cell_ids.length} cells?`))) {
                     if (cell_ids.some((cell_id) => this.state.notebook.cell_results[cell_id].running || this.state.notebook.cell_results[cell_id].queued)) {
-                        if (confirm("This cell is still running - would you like to interrupt the notebook?")) {
+                        if (await confirm("This cell is still running - would you like to interrupt the notebook?")) {
                             this.actions.interrupt_remote(cell_ids[0])
                         }
                     } else {
@@ -854,7 +858,7 @@ patch: ${JSON.stringify(
                 return
             }
             if (!this.state.notebook.in_temp_dir) {
-                if (!confirm("Are you sure? Will move from\n\n" + old_path + "\n\nto\n\n" + new_path)) {
+                if (!(await confirm("Are you sure? Will move from\n\n" + old_path + "\n\nto\n\n" + new_path))) {
                     throw new Error("Declined by user")
                 }
             }
@@ -1171,6 +1175,8 @@ patch: ${JSON.stringify(
                             ${
                                 status.binder
                                     ? html`<pluto-filepicker><a href=${this.export_url("notebookfile")} target="_blank">Save notebook...</a></pluto-filepicker>`
+                                    : vscode_available
+                                    ? null
                                     : html`<${FilePicker}
                                           client=${this.client}
                                           value=${notebook.in_temp_dir ? "" : notebook.path}
diff --git a/frontend/components/LiveDocs.js b/frontend/components/LiveDocs.js
index 3e5559b4f2..0ee3d8acf7 100644
--- a/frontend/components/LiveDocs.js
+++ b/frontend/components/LiveDocs.js
@@ -2,6 +2,7 @@ import { html, useState, useRef, useLayoutEffect, useEffect, useMemo, useContext
 import immer from "../imports/immer.js"
 import observablehq from "../common/SetupCellEnvironment.js"
 import { cl } from "../common/ClassTable.js"
+import { alert, confirm } from "../common/alert_confirm.js"
 
 import { RawHTMLContainer, highlight } from "./CellOutput.js"
 import { PlutoContext } from "../common/PlutoContext.js"
diff --git a/frontend/components/PkgPopup.js b/frontend/components/PkgPopup.js
index ea25cc6fdf..67cd25358d 100644
--- a/frontend/components/PkgPopup.js
+++ b/frontend/components/PkgPopup.js
@@ -8,6 +8,7 @@ import { PlutoContext } from "../common/PlutoContext.js"
 import { package_status, nbpkg_fingerprint_without_terminal } from "./PkgStatusMark.js"
 import { PkgTerminalView } from "./PkgTerminalView.js"
 import { useDebouncedTruth } from "./RunArea.js"
+import { alert, confirm } from "../common/alert_confirm.js"
 
 export const PkgPopup = ({ notebook }) => {
     let pluto_actions = useContext(PlutoContext)
@@ -115,11 +116,11 @@ export const PkgPopup = ({ notebook }) => {
                 title="Update packages"
                 style=${(!!showupdate ? "" : "opacity: .4;") + (recent_event?.is_disable_pkg ? "display: none;" : "")}
                 href="#"
-                onClick=${(e) => {
+                onClick=${async (e) => {
                     if (busy) {
                         alert("Pkg is currently busy with other packages... come back later!")
                     } else {
-                        if (confirm("Would you like to check for updates and install them? A backup of the notebook file will be created.")) {
+                        if (await confirm("Would you like to check for updates and install them? A backup of the notebook file will be created.")) {
                             console.warn("Pkg.updating!")
                             pluto_actions.send("pkg_update", {}, { notebook_id: notebook.notebook_id })
                         }
diff --git a/frontend/components/Welcome.js b/frontend/components/Welcome.js
index c58ac800a1..f06d8a9c01 100644
--- a/frontend/components/Welcome.js
+++ b/frontend/components/Welcome.js
@@ -5,6 +5,7 @@ import { FilePicker } from "./FilePicker.js"
 import { create_pluto_connection, fetch_pluto_releases } from "../common/PlutoConnection.js"
 import { cl } from "../common/ClassTable.js"
 import { PasteHandler } from "./PasteHandler.js"
+import { alert, confirm } from "../common/alert_confirm.js"
 
 /**
  * @typedef CombinedNotebook
@@ -237,20 +238,20 @@ export class Welcome extends Component {
                 document.body.classList.add("loading")
                 window.location.href = link_open_path(processed.path_or_url)
             } else {
-                if (confirm("Are you sure? This will download and run the file at\n\n" + processed.path_or_url)) {
+                if (await confirm("Are you sure? This will download and run the file at\n\n" + processed.path_or_url)) {
                     document.body.classList.add("loading")
                     window.location.href = link_open_url(processed.path_or_url)
                 }
             }
         }
 
-        this.on_session_click = (nb) => {
+        this.on_session_click = async (nb) => {
             if (nb.transitioning) {
                 return
             }
             const running = nb.notebook_id != null
             if (running) {
-                if (confirm("Shut down notebook process?")) {
+                if (await confirm("Shut down notebook process?")) {
                     set_notebook_state(nb.path, {
                         running: false,
                         transitioning: true,
diff --git a/frontend/editor.css b/frontend/editor.css
index 9ce8caff2d..8798e86ee7 100644
--- a/frontend/editor.css
+++ b/frontend/editor.css
@@ -39,6 +39,7 @@ html {
 
 body {
     margin: 0px;
+    padding: 0px;
     overflow-anchor: none;
     overflow-x: hidden;
     position: relative;
@@ -66,6 +67,7 @@ body:not(.disable_ui) main {
 
 body:not(.disable_ui) {
     overscroll-behavior-x: contain;
+    background: white;
 }
 
 /* | main=25px+700px+6px=731px | pluto-helpbox=350px - 500px | */
diff --git a/frontend/editor.js b/frontend/editor.js
index 7ee766bedd..2d34473896 100644
--- a/frontend/editor.js
+++ b/frontend/editor.js
@@ -2,6 +2,12 @@ import { html, render } from "./imports/Preact.js"
 import "./common/NodejsCompatibilityPolyfill.js"
 
 import { Editor } from "./components/Editor.js"
+import { available as vscode_available } from "./common/VSCodeApi.js"
+
+// remove default stylesheet inserted by VS Code
+if (vscode_available) {
+    document.head.querySelector("style#_defaultStyles").remove()
+}
 
 // it's like a Rube Goldberg machine
 render(html`<${Editor} />`, document.body)
diff --git a/src/webserver/Dynamic.jl b/src/webserver/Dynamic.jl
index 7860f35033..832569cb56 100644
--- a/src/webserver/Dynamic.jl
+++ b/src/webserver/Dynamic.jl
@@ -174,6 +174,7 @@ Update the local state of all clients connected to this notebook.
 """
 function send_notebook_changes!(🙋::ClientRequest; commentary::Any=nothing)
     notebook_dict = notebook_to_js(🙋.notebook)
+    # @info "Connected clients" length(🙋.session.connected_clients) Set(c -> c.stream for c in 🙋.session.connected_clients)
     for (_, client) in 🙋.session.connected_clients
         if client.connected_notebook !== nothing && client.connected_notebook.notebook_id == 🙋.notebook.notebook_id
             current_dict = get(current_state_for_clients, client, :empty)
@@ -183,6 +184,7 @@ function send_notebook_changes!(🙋::ClientRequest; commentary::Any=nothing)
 
             # Make sure we do send a confirmation to the client who made the request, even without changes
             is_response = 🙋.initiator !== nothing && client == 🙋.initiator.client
+            # @info "Responding" is_response (🙋.initiator !== nothing) (commentary === nothing)    
 
             if !isempty(patches) || is_response
                 response = Dict(
@@ -278,6 +280,7 @@ responses[:update_notebook] = function response_update_notebook(🙋::ClientRequ
         patches = (Base.convert(Firebasey.JSONPatch, update) for update in 🙋.body["updates"])
 
         if length(patches) == 0
+            # @info "Empty patches"
             send_notebook_changes!(🙋)
             return nothing
         end
diff --git a/src/webserver/PutUpdates.jl b/src/webserver/PutUpdates.jl
index ea541777d0..dcac8e9dd5 100644
--- a/src/webserver/PutUpdates.jl
+++ b/src/webserver/PutUpdates.jl
@@ -1,6 +1,10 @@
 
-function serialize_message_to_stream(io::IO, message::UpdateMessage)
-    to_send = Dict(:type => message.type, :message => message.message)
+function serialize_message_to_stream(io::IO, message::UpdateMessage, recipient::ClientSession)
+    to_send = Dict{Symbol,Any}(
+        :type => message.type, 
+        :message => message.message,
+        :recipient_id => recipient.id,
+    )
     if message.notebook !== nothing
         to_send[:notebook_id] = message.notebook.notebook_id
     end
@@ -15,8 +19,8 @@ function serialize_message_to_stream(io::IO, message::UpdateMessage)
     pack(io, to_send)
 end
 
-function serialize_message(message::UpdateMessage)
-    sprint(serialize_message_to_stream, message)
+function serialize_message(message::UpdateMessage, recipient::ClientSession)
+    sprint(serialize_message_to_stream, message, recipient)
 end
 
 "Send `messages` to all clients connected to the `notebook`."
@@ -76,7 +80,7 @@ function flushclient(client::ClientSession)
                     if client.stream isa HTTP.WebSockets.WebSocket
                         client.stream.frame_type = HTTP.WebSockets.WS_BINARY
                     end
-                    write(client.stream, serialize_message(next_to_send))
+                    write(client.stream, serialize_message(next_to_send, client))
                 else
                     put!(flushtoken)
                     return false