feat: v0.8.1 answer sessions from the inbox: allow/deny, peek & reply

- PermissionRequest hook: the state file records tool, detail and description of a pending permission; Notification keeps it. - devdesk attach --answer (presses 1/Esc only if the same wait is on and the prompt is visible), --peek (last exchange from the transcript), --reply (bracketed paste + Enter, streamed like uploads). - Inbox: Allow/Deny/Open for permission waits; Peek & reply for other waits and finished sessions. Matrix messages include the command. Closes #22 Closes #23 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
feat: v0.8.0 edit and save files with conflict detection
2026-10-10 20:22:37 -04:00 · 2026-10-10 20:10:45 -04:00 · 2026-10-10 19:57:52 -04:00
18 changed files with 1044 additions and 60 deletions
@@ -41,7 +41,7 @@ install: all
 	install -m 0755 libexec/devdesk-picker libexec/devdesk-claude-run libexec/devdesk-session-hook \
 		libexec/devdesk-tmux-ready libexec/devdesk-serve libexec/devdesk-statusline \
 		libexec/devdesk-deploy libexec/devdesk-state-hook libexec/devdesk-notify-matrix $(DESTDIR)$(LIBDIR)/
-	install -m 0644 libexec/devdesk-files.sh $(DESTDIR)$(LIBDIR)/devdesk-files.sh
+	install -m 0644 libexec/devdesk-files.sh libexec/devdesk-inbox.sh $(DESTDIR)$(LIBDIR)/
 	install -m 0755 build/ttyd $(DESTDIR)$(LIBDIR)/bin/ttyd
 	install -m 0644 dist/index.html share/tmux.conf share/claude-settings.json $(DESTDIR)$(SHAREDIR)/
 	install -d $(DESTDIR)$(SHAREDIR)/assets
@@ -38,6 +38,7 @@ The tmux server runs in its own unit, so every Claude process lives in **that**
  - The sidebar shows it with context % and a context bar; the session chip's dot shows the current session's state.
  - A "… needs you" chip jumps to other sessions that are waiting, and a desktop notification fires when one starts waiting.
  - The **🔔 inbox** lists what needs you (waiting sessions, firing Grafana alerts) and what happened while you were away (a background session finished or started waiting, CI passed or failed); its badge counts them.
+  - **Answer from the inbox:** a session waiting on a permission shows the exact command/file and **Allow / Deny** (the key is pressed only if that prompt is still on screen); other waits and finished sessions offer **Peek & reply**: the last exchange and a reply box.
 - **Matrix "Claude needs you":** when a session has waited for `DEVDESK_MATRIX_DELAY` seconds (30) and no browser tab or SSH client is attached to it, `devdesk-notify-matrix` posts one message per wait, with a link, to the hookshot webhook URL in `/etc/devdesk/matrix-webhook` (mode 600; no file = off).
 - **File & image drop:** drag files onto the terminal or paste a screenshot.
  - They're uploaded through ttyd to `/var/lib/devdesk/uploads/<session>/` (25 MB max, pruned after 7 days), and the path is pasted into Claude.
@@ -46,7 +47,8 @@ The tmux server runs in its own unit, so every Claude process lives in **that**
  - **Ask Claude** types an investigation prompt into the current session without sending it.
  - Configure `DEVDESK_GRAFANA_URL`, plus a Viewer token in `DEVDESK_GRAFANA_TOKEN_FILE`.
 - **Repo / CI panel:** branch, ahead/behind, uncommitted changes, HEAD's Gitea CI status and open PRs for the session's folder. When CI fails, **Ask Claude to fix CI** types a prompt to read the failed job's log.
- **Files** (Ctrl+Shift+E), laid out like VS Code: an explorer tree (git colours, gitignored entries dimmed) and an editor with tabs (a click opens a preview tab, a double-click keeps it), **Go to file** (Ctrl+P in the pane), markdown previews (sanitized, with relative images), images, and a Changes view of uncommitted files with line counts, a **C** badge on files Claude edited, and diffs against HEAD. **@Claude** types `@path` into the prompt. Tabs and open folders are remembered per session. Read-only for now. Paths can't leave the session folder. The editor bundle (`/usr/share/devdesk/assets/editor.js`) loads over ttyd the first time and is cached by the browser.
+- **Files** (Ctrl+Shift+E), laid out like VS Code: an explorer tree (git colours, gitignored entries dimmed) and an editor with tabs (a click opens a preview tab, a double-click keeps it), **Go to file** (Ctrl+P in the pane), markdown previews (sanitized, with relative images), images, and a Changes view of uncommitted files with line counts, a **C** badge on files Claude edited, and diffs against HEAD. **@Claude** types `@path` into the prompt. Tabs and open folders are remembered per session. Paths can't leave the session folder.
+  - **Editing:** text files are editable; ● marks unsaved tabs; Ctrl+S (or Save) writes atomically and keeps the file's mode and owner. If the file changed on disk since you opened it (Claude edited it), saving asks: Compare (a diff of disk vs yours), Overwrite or Cancel; a change on disk while you edit shows a banner instead of replacing your text. Unsaved edits are kept as drafts in the browser, so a reload or a session switch doesn't lose them. ＋ creates a file (folders as needed). The editor bundle (`/usr/share/devdesk/assets/editor.js`) loads over ttyd the first time and is cached by the browser.
 - **Context:** a Claude `statusLine` command (`devdesk-statusline`) snapshots each session's model, context-window use and cost to `/var/lib/devdesk/context/<session>.json`. The Sessions panel shows it as a bar (cost in the tooltip), and Claude's own footer shows a one-line summary.
 - **Light mode:** the terminal switches palettes with the page. DevDesk starts Claude with its `dark-ansi` theme so Claude draws with the terminal's 16 colours, and the light palette maps bright white to ink; tmux and the status line use ANSI colours too. A session picks up Claude's theme the next time Claude starts in it (`/exit`, then ⏎ resumes the same conversation).
 - **Phone:** a key bar replaces the shortcut hints (Esc, Tab, ⇧Tab, ^C, ↑, ↓, ⏎, Claude/Shell window), and the panels open as a drawer.
@@ -19,6 +19,8 @@ set -euo pipefail
 . "${DEVDESK_LIBEXEC:-/usr/lib/devdesk}/devdesk-lib.sh"
 # shellcheck source=libexec/devdesk-files.sh
 . "$DEVDESK_LIBEXEC/devdesk-files.sh"
+# shellcheck source=libexec/devdesk-inbox.sh
+. "$DEVDESK_LIBEXEC/devdesk-inbox.sh"

 usage() {
    sed -n '2,12s/^# \{0,1\}//p' "$0"
@@ -318,13 +320,27 @@ cmd_attach() {
        dd_linger
        return
        ;;
-    --fs-list | --fs-find | --fs-read | --git-status | --git-show | --asset)
+    --fs-list | --fs-find | --fs-read | --fs-write | --git-status | --git-show | --asset)
        local action=${1#--}
        shift
        "cmd_${action//-/_}" "$@"
        dd_linger
        return
        ;;
+    --peek)
+        shift
+        cmd_peek "$@"
+        dd_linger
+        return
+        ;;
+    --answer | --reply)
+        local action=${1#--}
+        shift
+        "cmd_$action" "$@"
+        ok_json
+        dd_linger
+        return
+        ;;
    --new | --rename | --end)
        local action=${1#--}
        shift
@@ -1,3 +1,59 @@
+devdesk (0.8.1) bookworm; urgency=medium
+
+  * Answer sessions from the 🔔 inbox without switching to them:
+    - Allow / Deny (#22): a PermissionRequest hook records what Claude wants
+      to run (tool, command/file/URL, Claude's description); the inbox shows
+      it with Allow, Deny and Open. The key is pressed in that session's
+      Claude window only if the same wait is still on and the permission
+      prompt is on screen, so a stale button never types into Claude.
+    - Peek & reply (#23): the last thing you asked and Claude's latest answer
+      (from the session's transcript), and a reply box; the reply is pasted
+      as one bracketed paste and sent. Available for sessions that wait for
+      input and from "finished" entries.
+    - Matrix "needs you" messages include the command.
+  * New attach commands: --answer SESSION SINCE allow|deny, --peek SESSION,
+    --reply SESSION BYTES (text streamed like uploads).
+  * Sessions pick up the new PermissionRequest hook when Claude next starts
+    (/exit, then ⏎).
+
+ -- Jared Vititoe <jjvititoe1@gmail.com>  Sat, 10 Oct 2026 20:22:37 -0400
+
+devdesk (0.8.0) bookworm; urgency=medium
+
+  * Edit and save files in the Files pane (#20):
+    - Text files open editable; ● marks unsaved tabs; Ctrl+S or Save writes
+      through `devdesk attach --fs-write`: a temp file in the same folder,
+      mode and owner kept, swapped in with mv.
+    - Conflict detection: the save carries the sha256 of the version you
+      opened; if Claude (or anyone) changed the file since, nothing is written
+      and you choose Compare (diff of disk vs yours), Overwrite or Cancel.
+    - A file that changes on disk while you edit it shows a banner (Compare,
+      Reload, Keep mine) instead of replacing your text; clean files still
+      reload in place.
+    - Unsaved edits are mirrored to the browser as drafts (flushed when the
+      page closes), so a reload, a crash or a session switch doesn't lose
+      them; a draft for a file that changed since offers Compare/Restore/
+      Discard.
+    - Closing a tab with unsaved changes asks Save / Don't save / Cancel;
+      leaving the page warns.
+    - ＋ New file (missing folders are created; never outside the session
+      folder, and never through a symlink out of it).
+    - Markdown previews show unsaved Source edits. Latin-1 files stay
+      read-only.
+
+ -- Jared Vititoe <jjvititoe1@gmail.com>  Sat, 10 Oct 2026 20:09:49 -0400
+
+devdesk (0.7.3) bookworm; urgency=medium
+
+  * Fix (#38): links that mean "go to that session" no longer re-create one
+    that was ended. The 🔔 inbox, the session switcher, palette switches, the
+    "needs you" chip and Matrix links (now ?arg=NAME&existing=1) open sessions
+    existing-only; an ended one shows "NAME has ended" with an explicit
+    "Start NAME again". Inbox entries for ended sessions are marked as such,
+    and entries older than 7 days are dropped.
+
+ -- Jared Vititoe <jjvititoe1@gmail.com>  Sat, 10 Oct 2026 19:57:52 -0400
+
 devdesk (0.7.2) bookworm; urgency=medium

  * Fix: Go to file failed in big non-git folders such as /root/code: the
@@ -190,6 +190,81 @@ cmd_git_show() {
    rm -f "$tmp"
 }

+# --fs-write SESSION REL BYTES BASE (devdesk#20): save a file from the editor.
+# The content arrives as base64 on stdin after the READY line (like uploads).
+# BASE is the sha256 the editor loaded: if the file changed since, nothing is
+# written and the reply is {conflict: true, sha: <current>}. BASE "new" creates
+# a file (and missing folders) and refuses to overwrite one. Writes go to a
+# temp file in the same folder, keep the mode and owner, and land with mv.
+cmd_fs_write() {
+    [ $# -eq 4 ] || dd_die "usage: devdesk attach --fs-write SESSION PATH BYTES BASESHA|new"
+    local root rel=$2 size=$3 base=$4 target dir name tmp b64len actual current sha mtime
+    root=$(dd_session_root "$1")
+    if ! [[ $size =~ ^[0-9]+$ ]] || [ "$size" -gt "$DEVDESK_FS_MAX" ]; then
+        dd_die "too large: the editor saves files up to $((DEVDESK_FS_MAX / 1024)) KiB"
+    fi
+    [[ $base =~ ^([0-9a-f]{64}|new)$ ]] || dd_die "bad base: $base"
+    case $rel in /* | *$'\n'* | *$'\r'* | '' | */ | . | ..) dd_die "bad path: $rel" ;; esac
+    name=${rel##*/}
+    if [ "$name" = . ] || [ "$name" = .. ]; then dd_die "bad path: $rel"; fi
+    if [ "$base" = new ]; then
+        if [ -e "$root/$rel" ] || [ -L "$root/$rel" ]; then dd_die "already exists: $rel"; fi
+        case $rel in */*) dir=$root/${rel%/*} ;; *) dir=$root ;; esac
+        # Missing folders are created, but never through a symlink out of the
+        # root: check the deepest folder that exists before creating any.
+        local existing=$dir
+        while [ ! -e "$existing" ]; do existing=${existing%/*}; done
+        existing=${existing#"$root"}
+        dd_fs_path "$root" "${existing#/}" >/dev/null
+        mkdir -p -- "$dir" || dd_die "cannot create folder for $rel"
+        dir=${dir#"$root"}
+        dir=$(dd_fs_path "$root" "${dir#/}")
+        target="$dir/$name"
+    else
+        target=$(dd_fs_path "$root" "$rel")
+        [ -f "$target" ] || dd_die "not a file: $rel"
+        dir=${target%/*}
+    fi
+    tmp=$(mktemp --tmpdir="$dir" ".${name}.devdesk-XXXXXX") || dd_die "cannot write in ${dir#"$root"/}"
+    trap 'rm -f "$tmp"' HUP INT TERM
+    # shellcheck disable=SC2017 # integer ceil(size/3)*4: the base64 length, on purpose
+    b64len=$(((size + 2) / 3 * 4))
+    stty raw -echo 2>/dev/null || true
+    printf 'DEVDESK-WRITE-READY\r\n'
+    if [ "$b64len" -gt 0 ]; then
+        head -c "$b64len" | base64 -d >"$tmp" 2>/dev/null || true
+    fi
+    stty sane 2>/dev/null || true
+    actual=$(stat -c %s "$tmp" 2>/dev/null || echo 0)
+    if [ "$actual" != "$size" ]; then
+        rm -f "$tmp"
+        dd_die "save incomplete ($actual of $size bytes)"
+    fi
+    if [ "$base" = new ]; then
+        if [ -e "$target" ]; then
+            rm -f "$tmp"
+            dd_die "already exists: $rel"
+        fi
+        chmod 0644 "$tmp"
+    else
+        current=$(sha256sum -- "$target" | cut -d' ' -f1)
+        if [ "$current" != "$base" ]; then
+            rm -f "$tmp"
+            trap - HUP INT TERM
+            jq -cMn --arg p "$rel" --arg h "$current" '{ok: false, conflict: true, path: $p, sha: $h}'
+            return
+        fi
+        chmod --reference="$target" "$tmp" 2>/dev/null || true
+        chown --reference="$target" "$tmp" 2>/dev/null || true
+    fi
+    mv -f -- "$tmp" "$target" || { rm -f "$tmp"; dd_die "cannot replace $rel"; }
+    trap - HUP INT TERM
+    sha=$(sha256sum -- "$target" | cut -d' ' -f1)
+    mtime=$(stat -c %Y -- "$target")
+    jq -cMn --arg p "${target#"$root"/}" --arg h "$sha" --argjson s "$size" --argjson m "$mtime" \
+        '{ok: true, path: $p, sha: $h, size: $s, mtime: $m}'
+}
+
 # --asset NAME: a lazily loaded part of the web UI (the file viewer's editor),
 # shipped in $DEVDESK_ASSETS and cached by the browser.
 cmd_asset() {
@@ -0,0 +1,111 @@
+# shellcheck shell=bash disable=SC2016 # single-quoted jq filters use jq variables
+# Answer a session without switching to it (devdesk#22, #23), sourced by
+# bin/devdesk and reached through `devdesk attach --answer|--peek|--reply`.
+
+dd_state_file() {
+    printf '%s/%s.json\n' "$DEVDESK_STATUS_DIR" "$1"
+}
+
+# The Claude window's visible screen (not the scrollback).
+dd_claude_screen() {
+    dd_tmux capture-pane -p -J -t "=$1:claude" 2>/dev/null
+}
+
+# --answer SESSION SINCE allow|deny: press the permission prompt's key in that
+# session's Claude window. Only when the same wait is still on (SINCE) and the
+# prompt is actually on screen, so a stale button never types into Claude.
+cmd_answer() {
+    [ $# -eq 3 ] || dd_die "usage: devdesk attach --answer SESSION SINCE allow|deny"
+    local session=$1 since=$2 choice=$3 file
+    dd_valid_name "$session" || dd_die "invalid session name: $session"
+    [[ $since =~ ^[0-9]+$ ]] || dd_die "bad wait id: $since"
+    case $choice in allow | deny) ;; *) dd_die "answer allow or deny" ;; esac
+    if ! { dd_server_up && dd_tmux has-session -t "=$session" 2>/dev/null; }; then dd_die "session '$session' isn't running"; fi
+    file=$(dd_state_file "$session")
+    if [ "$(jq -rM '"\(.state) \(.since) \(.request != null)"' "$file" 2>/dev/null)" != "waiting $since true" ]; then
+        dd_die "nothing to answer: it was already answered"
+    fi
+    # Every permission prompt lists "1. Yes" first (Bash, edits, fetches, MCP).
+    if ! dd_claude_screen "$session" | tail -n 40 | grep -Eq '^[[:space:]]*(❯[[:space:]]*)?1\.[[:space:]]+Yes'; then
+        dd_die "the permission prompt isn't on screen any more"
+    fi
+    if [ "$choice" = allow ]; then
+        dd_tmux send-keys -t "=$session:claude" 1
+    else
+        dd_tmux send-keys -t "=$session:claude" Escape
+    fi
+    # A denial doesn't fire a hook; the turn ends there. An approval is followed
+    # by PostToolUse, which takes it from here.
+    local tmp
+    tmp=$(mktemp "$DEVDESK_STATUS_DIR/.$session.XXXXXX") || return 0
+    if jq -cMn --arg s "$([ "$choice" = allow ] && echo working || echo idle)" --arg m "$([ "$choice" = allow ] && echo "Allowed from DevDesk" || echo "Denied from DevDesk")" \
+        '{state: $s, since: (now | floor), event: "DevDeskAnswer", message: $m}' >"$tmp"; then
+        mv -f "$tmp" "$file"
+    else
+        rm -f "$tmp"
+    fi
+}
+
+# The session's conversation file, from the id the SessionStart hook recorded.
+dd_transcript() {
+    local id
+    id=$(dd_registry_get "$1" claude_session_id)
+    [[ $id =~ ^[0-9a-f-]{36}$ ]] || return 1
+    compgen -G "${CLAUDE_CONFIG_DIR:-$HOME/.claude}/projects/*/$id.jsonl" | head -n1
+}
+
+# --peek SESSION: what the session is doing and the last exchange, from the end
+# of its transcript (the last assistant text and the last thing you asked).
+cmd_peek() {
+    [ $# -eq 1 ] || dd_die "usage: devdesk attach --peek SESSION"
+    local session=$1 transcript status
+    dd_valid_name "$session" || dd_die "invalid session name: $session"
+    status=$(jq -cM . "$(dd_state_file "$session")" 2>/dev/null) || status=null
+    transcript=$(dd_transcript "$session") || transcript=""
+    if [ -z "$transcript" ] || [ ! -r "$transcript" ]; then
+        jq -cMn --arg s "$session" --argjson st "${status:-null}" '{session: $s, status: $st, assistant: null, user: null}'
+        return
+    fi
+    tail -n 400 -- "$transcript" | jq -cMs --arg s "$session" --argjson st "${status:-null}" '
+        def text: if type == "string" then . else ([.[]? | select(.type == "text") | .text] | join("\n")) end;
+        [.[] | select(.isSidechain != true and .isMeta != true)] as $all
+        | ([$all[] | select(.type == "assistant") | {text: (.message.content | text), at: .timestamp} | select(.text != "")] | last) as $a
+        | ([$all[] | select(.type == "user" and (.message.content | type == "string" or (any(.[]?; .type == "text"))))
+              | {text: (.message.content | text), at: .timestamp}
+              | select(.text != "" and (.text | startswith("<") | not))] | last) as $u
+        | {session: $s, status: $st,
+           assistant: (if $a then {text: ($a.text | .[-4000:]), at: $a.at, truncated: ($a.text | length > 4000)} else null end),
+           user: (if $u then {text: ($u.text | .[-600:]), at: $u.at} else null end)}' 2>/dev/null ||
+        jq -cMn --arg s "$session" --argjson st "${status:-null}" '{session: $s, status: $st, assistant: null, user: null}'
+}
+
+# --reply SESSION BYTES: type a message into the session's Claude prompt and
+# send it. The text arrives as base64 after the READY line (like uploads) and is
+# pasted as one bracketed paste, so newlines in it don't send it early.
+cmd_reply() {
+    [ $# -eq 2 ] || dd_die "usage: devdesk attach --reply SESSION BYTES"
+    local session=$1 size=$2 file tmp b64len
+    dd_valid_name "$session" || dd_die "invalid session name: $session"
+    if ! [[ $size =~ ^[0-9]+$ ]] || [ "$size" -lt 1 ] || [ "$size" -gt 16384 ]; then dd_die "a reply is 1 to 16384 bytes"; fi
+    if ! { dd_server_up && dd_tmux has-session -t "=$session" 2>/dev/null; }; then dd_die "session '$session' isn't running"; fi
+    file=$(dd_state_file "$session")
+    if [ "$(jq -rM '"\(.state) \(.request != null)"' "$file" 2>/dev/null)" = "waiting true" ]; then
+        dd_die "Claude is asking for a permission: answer that first"
+    fi
+    tmp=$(mktemp)
+    trap 'rm -f "$tmp"' HUP INT TERM
+    # shellcheck disable=SC2017 # integer ceil(size/3)*4: the base64 length, on purpose
+    b64len=$(((size + 2) / 3 * 4))
+    stty raw -echo 2>/dev/null || true
+    printf 'DEVDESK-REPLY-READY\r\n'
+    head -c "$b64len" | base64 -d >"$tmp" 2>/dev/null || true
+    stty sane 2>/dev/null || true
+    if [ "$(stat -c %s "$tmp")" != "$size" ]; then
+        rm -f "$tmp"
+        dd_die "reply incomplete"
+    fi
+    dd_tmux load-buffer -b devdesk-reply "$tmp" && dd_tmux paste-buffer -p -d -b devdesk-reply -t "=$session:claude" &&
+        sleep 0.2 && dd_tmux send-keys -t "=$session:claude" Enter
+    rm -f "$tmp"
+    trap - HUP INT TERM
+}
@@ -27,8 +27,12 @@ attached=$(dd_tmux list-sessions -F '#{session_name} #{session_attached}' 2>/dev
 [ "${attached:-0}" = 0 ] || exit 0

 message=$(jq -rM '.message // "Claude is waiting for your input"' "$state_file" 2>/dev/null)
+detail=$(jq -rM '.request.detail // empty' "$state_file" 2>/dev/null)
+[ -z "$detail" ] || message="$message: ${detail:0:300}"
 url=""
-[ -z "$DEVDESK_PUBLIC_URL" ] || url="${DEVDESK_PUBLIC_URL%/}/?arg=$session"
+# existing=1: if the session was ended by the time you tap, say so instead of
+# starting a new Claude there (devdesk#38).
+[ -z "$DEVDESK_PUBLIC_URL" ] || url="${DEVDESK_PUBLIC_URL%/}/?arg=$session&existing=1"
 body=$(jq -cMn --arg s "$session" --arg m "$message" --arg u "$url" --arg h "$(hostname)" \
    '{session: $s, message: $m, url: (if $u == "" then null else $u end), host: $h,
      text: ("Claude needs you in " + $s + ": " + $m + (if $u == "" then "" else " — " + $u end))}')
@@ -2,6 +2,9 @@
 # Claude Code hook (wired in via claude-settings.json) that tracks what Claude is
 # doing in each DevDesk session, for the sidebar's at-a-glance status:
 #   UserPromptSubmit, PostToolUse -> working
+#   PermissionRequest             -> waiting, with what Claude wants to run
+#                                    (tool + command/file/URL), for the inbox's
+#                                    Allow/Deny (devdesk#22)
 #   Notification                  -> waiting (Claude needs input or a permission)
 #   Stop, SessionStart            -> idle
 #   SessionEnd                    -> exited
@@ -35,7 +38,7 @@ PostToolUse:Edit | PostToolUse:Write | PostToolUse:MultiEdit | PostToolUse:Noteb
 esac
 case $event in
 UserPromptSubmit | PostToolUse) state=working ;;
-Notification) state=waiting ;;
+Notification | PermissionRequest) state=waiting ;;
 Stop | SessionStart) state=idle ;;
 SessionEnd) state=exited ;;
 *) exit 0 ;;
@@ -47,19 +50,33 @@ file="$dir/$session.json"
 if [ "$state" != waiting ] && [ -f "$file" ] && grep -q "\"state\":\"$state\"" "$file"; then
    exit 0
 fi
+# What a permission prompt is about. tool_use_id is null in PermissionRequest,
+# so a wait is identified by its `since` instead.
+request=null
+if [ "$event" = PermissionRequest ]; then
+    request=$(jq -cM '(.tool_input // {}) as $i | {tool: (.tool_name // "a tool"),
+        detail: (($i.command // $i.file_path // $i.notebook_path // $i.url // $i.pattern // $i.query // $i.path // ($i | tostring)) | tostring | .[0:600]),
+        description: ($i.description // null)}' <<<"$input" 2>/dev/null) || request=null
+    message="Claude wants to use ${tool:-a tool}"
+fi
 # A second Notification during the same wait updates the message but keeps
-# `since`, so the wait stays one wait (one Matrix message at most).
+# `since` (and what the wait is about), so the wait stays one wait (one Matrix
+# message at most).
 since=$(date +%s)
 was_waiting=0
 if [ "$state" = waiting ] && grep -q '"state":"waiting"' "$file" 2>/dev/null; then
    was_waiting=1
    since=$(jq -rM '.since // empty' "$file" 2>/dev/null) || since=$(date +%s)
    [[ $since =~ ^[0-9]+$ ]] || since=$(date +%s)
+    if [ "$request" = null ]; then
+        request=$(jq -cM '.request // null' "$file" 2>/dev/null) || request=null
+        [ "$request" = null ] || message=$(jq -rM '.message // empty' "$file" 2>/dev/null)
+    fi
 fi
 mkdir -p "$dir" 2>/dev/null || exit 0
 tmp=$(mktemp "$dir/.$session.XXXXXX" 2>/dev/null) || exit 0
-if jq -cMn --arg s "$state" --arg m "$message" --arg e "$event" --argjson t "$since" \
-    '{state: $s, since: $t, event: $e, message: (if $m == "" then null else $m end)}' >"$tmp"; then
+if jq -cMn --arg s "$state" --arg m "$message" --arg e "$event" --argjson t "$since" --argjson r "${request:-null}" \
+    '{state: $s, since: $t, event: $e, message: (if $m == "" then null else $m end)} + (if $r then {request: $r} else {} end)' >"$tmp"; then
    mv -f "$tmp" "$file"
 else
    rm -f "$tmp"
@@ -73,6 +73,17 @@
          }
        ]
      }
+    ],
+    "PermissionRequest": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "/usr/lib/devdesk/devdesk-state-hook",
+            "timeout": 5
+          }
+        ]
+      }
    ]
  },
  "statusLine": {
@@ -310,7 +310,7 @@ posts() { [ -f "$TMP/posts" ] && wc -l <"$TMP/posts" || echo 0; }
    sleep 2.5
    [ "$(posts)" -eq 1 ]
    run jq -r '[.session, .url, (.text | test("Claude needs you in alpha"))] | @tsv' "$TMP/posts"
-    [ "$output" = "$(printf 'alpha\thttps://dev.example.org/?arg=alpha\ttrue')" ]
+    [ "$output" = "$(printf 'alpha\thttps://dev.example.org/?arg=alpha&existing=1\ttrue')" ]

    # answered within the delay: nothing is posted
    echo '{"hook_event_name":"PostToolUse"}' | hook
@@ -620,3 +620,123 @@ blob_body() {
    [ "$status" -eq 0 ]
    [ "$(jq -r '[(.entries | length), .truncated] | @tsv' <<<"$output")" = "$(printf '5\ttrue')" ]
 }
+
+# Save through --fs-write the way the browser does: content as base64 on stdin.
+fs_write() { # SESSION PATH BASE CONTENT-FILE
+    local size
+    size=$(stat -c %s "$4")
+    base64 -w0 "$4" | devdesk attach --fs-write "$1" "$2" "$size" "$3"
+}
+
+@test "fs-write saves atomically, keeps the mode, and refuses stale bases (#20)" {
+    p="$DEVDESK_PROJECTS_ROOT/alpha"
+    printf 'v1\n' >"$p/conf.sh"
+    chmod 0750 "$p/conf.sh"
+    base=$(sha256sum "$p/conf.sh" | cut -d' ' -f1)
+    printf 'v2\n' >"$TMP/new"
+    run fs_write alpha conf.sh "$base" "$TMP/new"
+    [ "$status" -eq 0 ]
+    [ "$(tail -n1 <<<"$output" | jq -r '.ok')" = true ]
+    [ "$(cat "$p/conf.sh")" = v2 ]
+    [ "$(stat -c %a "$p/conf.sh")" = 750 ]
+    [ "$(tail -n1 <<<"$output" | jq -r '.sha')" = "$(sha256sum "$p/conf.sh" | cut -d' ' -f1)" ]
+    # Someone (Claude) changed it since: the old base no longer matches.
+    printf 'v3 from me\n' >"$TMP/mine"
+    run fs_write alpha conf.sh "$base" "$TMP/mine"
+    [ "$(tail -n1 <<<"$output" | jq -r '[.ok, .conflict] | @tsv')" = "$(printf 'false\ttrue')" ]
+    [ "$(cat "$p/conf.sh")" = v2 ]
+    # No temp files left behind
+    [ -z "$(find "$p" -name '*.devdesk-*')" ]
+    # Empty files are fine
+    : >"$TMP/empty"
+    base=$(sha256sum "$p/conf.sh" | cut -d' ' -f1)
+    run fs_write alpha conf.sh "$base" "$TMP/empty"
+    [ "$(tail -n1 <<<"$output" | jq -r '.ok')" = true ]
+    [ ! -s "$p/conf.sh" ]
+}
+
+@test "fs-write creates new files (and folders) but never overwrites or escapes (#20)" {
+    p="$DEVDESK_PROJECTS_ROOT/alpha"
+    printf 'hello\n' >"$TMP/c"
+    run fs_write alpha docs/notes/new.md new "$TMP/c"
+    [ "$(tail -n1 <<<"$output" | jq -r '[.ok, .path] | @tsv')" = "$(printf 'true\tdocs/notes/new.md')" ]
+    [ "$(cat "$p/docs/notes/new.md")" = hello ]
+    run fs_write alpha docs/notes/new.md new "$TMP/c"
+    [ "$status" -ne 0 ]
+    [[ $output == *"already exists"* ]]
+    ln -s "$TMP/outside" "$p/out"
+    for bad in ../escape.txt /etc/x out/pwned.txt out/newdir/x.txt docs/ ""; do
+        run fs_write alpha "$bad" new "$TMP/c"
+        [ "$status" -ne 0 ]
+    done
+    [ ! -e "$TMP/outside/pwned.txt" ] && [ ! -e "$TMP/outside/newdir" ] && [ ! -e "$DEVDESK_PROJECTS_ROOT/escape.txt" ]
+    # A short stream fails without touching anything
+    run bash -c "printf aGVs | '$REPO/bin/devdesk' attach --fs-write alpha docs/notes/new.md 6 $(sha256sum "$p/docs/notes/new.md" | cut -d' ' -f1)"
+    [ "$status" -ne 0 ]
+    [ "$(cat "$p/docs/notes/new.md")" = hello ]
+}
+
+@test "permission requests are recorded and answered only while their prompt shows (#22)" {
+    start_server
+    devdesk new alpha
+    claude_args alpha >/dev/null
+    pane=$(tmux -S "$DEVDESK_SOCKET" display -p -t =alpha:shell '#{pane_id}')
+    hook() { TMUX="$DEVDESK_SOCKET,1,0" TMUX_PANE="$pane" "$REPO/libexec/devdesk-state-hook"; }
+    echo '{"hook_event_name":"PermissionRequest","tool_name":"Bash","tool_input":{"command":"rm -rf /tmp/x","description":"Remove x"}}' | hook
+    echo '{"hook_event_name":"Notification","message":"Claude needs your permission","notification_type":"permission_prompt"}' | hook
+    st="$DEVDESK_STATE_DIR/state/alpha.json"
+    [ "$(jq -r '[.state, .request.tool, .request.detail, .request.description, .message] | @tsv' "$st")" = \
+        "$(printf 'waiting\tBash\trm -rf /tmp/x\tRemove x\tClaude wants to use Bash')" ]
+    since=$(jq -r .since "$st")
+    # The fake Claude window shows no prompt: refused, nothing typed.
+    run devdesk attach --answer alpha "$since" allow
+    [ "$status" -ne 0 ]
+    [[ $output == *"isn't on screen"* ]]
+    # Put a prompt on screen (what Claude draws), then allow.
+    tmux -S "$DEVDESK_SOCKET" respawn-window -k -t =alpha:claude "printf ' Do you want to proceed?\n ❯ 1. Yes\n   2. No\n'; read -r -n1 k; echo \"got:\$k\" > '$TMP/key'; sleep 30"
+    sleep 0.5
+    run devdesk attach --answer alpha 999 allow
+    [ "$status" -ne 0 ]
+    [[ $output == *"already answered"* ]]
+    run devdesk attach --answer alpha "$since" allow
+    [ "$status" -eq 0 ]
+    sleep 0.5
+    [ "$(cat "$TMP/key")" = "got:1" ]
+    [ "$(jq -r .state "$st")" = working ]
+    # Answered: a second click is refused.
+    run devdesk attach --answer alpha "$since" deny
+    [ "$status" -ne 0 ]
+}
+
+@test "peek shows the last exchange; reply pastes into the Claude window (#23)" {
+    start_server
+    devdesk new alpha
+    claude_args alpha >/dev/null
+    export CLAUDE_CONFIG_DIR="$TMP/claude"
+    id=11111111-2222-3333-4444-555555555555
+    mkdir -p "$CLAUDE_CONFIG_DIR/projects/-x"
+    cat >"$CLAUDE_CONFIG_DIR/projects/-x/$id.jsonl" <<'JSONL'
+{"type":"user","message":{"role":"user","content":"Please upgrade PBS"},"timestamp":"2026-10-10T10:00:00Z"}
+{"type":"assistant","message":{"role":"assistant","content":[{"type":"tool_use","name":"Bash","input":{}}]},"timestamp":"2026-10-10T10:00:05Z"}
+{"type":"user","message":{"role":"user","content":[{"type":"tool_result","content":"ok"}]},"timestamp":"2026-10-10T10:00:06Z"}
+{"type":"assistant","message":{"role":"assistant","content":[{"type":"text","text":"PBS is on 4.1. Reboot now?"}]},"timestamp":"2026-10-10T10:00:09Z"}
+JSONL
+    jq --arg id "$id" '.sessions.alpha.claude_session_id = $id' "$DEVDESK_STATE_DIR/registry.json" >"$TMP/r" && mv "$TMP/r" "$DEVDESK_STATE_DIR/registry.json"
+    run devdesk attach --peek alpha
+    [ "$status" -eq 0 ]
+    [ "$(jq -r '[.assistant.text, .user.text] | @tsv' <<<"$output")" = "$(printf 'PBS is on 4.1. Reboot now?\tPlease upgrade PBS')" ]
+    # reply: lands in the Claude window as one paste + Enter
+    tmux -S "$DEVDESK_SOCKET" respawn-window -k -t =alpha:claude "IFS= read -r line; printf '%s' \"\$line\" > '$TMP/got'; sleep 30"
+    sleep 0.3
+    printf 'yes, reboot it' >"$TMP/msg"
+    run bash -c "base64 -w0 '$TMP/msg' | '$REPO/bin/devdesk' attach --reply alpha 14"
+    [ "$status" -eq 0 ]
+    sleep 0.5
+    [ "$(cat "$TMP/got")" = "yes, reboot it" ]
+    # not while a permission prompt waits
+    mkdir -p "$DEVDESK_STATE_DIR/state"
+    printf '{"state":"waiting","since":1,"request":{"tool":"Bash"}}\n' >"$DEVDESK_STATE_DIR/state/alpha.json"
+    run bash -c "base64 -w0 '$TMP/msg' | '$REPO/bin/devdesk' attach --reply alpha 14"
+    [ "$status" -ne 0 ]
+    [[ $output == *"answer that first"* ]]
+}
@@ -4,7 +4,7 @@
 // the first time the Files pane opens, so the page itself stays small.
 import { EditorView, keymap, lineNumbers, highlightActiveLine, highlightActiveLineGutter, drawSelection, highlightSpecialChars } from '@codemirror/view';
 import { EditorState } from '@codemirror/state';
-import { defaultKeymap, history, historyKeymap } from '@codemirror/commands';
+import { defaultKeymap, history, historyKeymap, indentWithTab } from '@codemirror/commands';
 import { syntaxHighlighting, HighlightStyle, StreamLanguage, bracketMatching, foldGutter, foldKeymap } from '@codemirror/language';
 import { search, searchKeymap, highlightSelectionMatches } from '@codemirror/search';
 import { markdownLanguage } from '@codemirror/lang-markdown';
@@ -135,12 +135,40 @@ function baseExtensions(path, { readOnly = true, wrap = false } = {}) {
  ];
 }

-// Read-only (v1) view of a file.
+// Read-only view of a file.
 export function viewer(parent, { doc, path, wrap }) {
  const view = new EditorView({ parent, state: EditorState.create({ doc, extensions: baseExtensions(path, { wrap }) }) });
  return { view, destroy: () => view.destroy() };
 }

+// Editable file (devdesk#20): onChange(text) after every edit, onSave() on
+// Ctrl/Cmd+S (which never reaches the browser or the terminal).
+export function editor(parent, { doc, path, wrap, onChange, onSave }) {
+  const view = new EditorView({
+    parent,
+    state: EditorState.create({
+      doc,
+      extensions: [
+        keymap.of([{ key: 'Mod-s', preventDefault: true, run: () => { onSave?.(); return true; } }, indentWithTab]),
+        baseExtensions(path, { readOnly: false, wrap }),
+        EditorView.updateListener.of((update) => {
+          if (update.docChanged) onChange?.(update.state.doc.toString());
+        }),
+      ],
+    }),
+  });
+  return {
+    view,
+    text: () => view.state.doc.toString(),
+    // Replace the whole document (reload from disk) keeping the cursor roughly where it was.
+    setText: (text) => {
+      const pos = Math.min(view.state.selection.main.head, text.length);
+      view.dispatch({ changes: { from: 0, to: view.state.doc.length, insert: text }, selection: { anchor: pos } });
+    },
+    destroy: () => view.destroy(),
+  };
+}
+
 // Unified diff of the HEAD version against the working copy.
 export function diff(parent, { original, modified, path, wrap }) {
  const view = new EditorView({
@@ -96,6 +96,7 @@
      <button type="button" class="dd-icon-btn dd-explorer-toggle" title="Show / hide the explorer" aria-label="Toggle explorer">☰</button>
      <div class="dd-tabs" role="tablist" aria-label="Open files"></div>
      <span class="dd-files-actions">
+        <button type="button" class="dd-icon-btn dd-files-new" title="New file" aria-label="New file">＋</button>
        <button type="button" class="dd-icon-btn dd-files-find" title="Go to file (Ctrl+P)" aria-label="Go to file">⌕</button>
        <button type="button" class="dd-icon-btn dd-files-refresh" title="Refresh" aria-label="Refresh">↻</button>
        <button type="button" class="dd-icon-btn dd-files-close" title="Close (Esc)" aria-label="Close files">✕</button>
@@ -209,11 +209,43 @@ export function uploadFile(session, file, onProgress) {
 }

 async function uploadNow(session, file, onProgress) {
-  const token = await fetchToken();
  const name = (file.name || 'pasted-image.png').slice(-100);
+  const result = await streamIn(['--upload', session, name, String(file.size)], 'DEVDESK-UPLOAD-READY', file, onProgress);
+  if (!result.ok || !result.path) throw new Error('upload failed');
+  return result.path;
+}
+
+// Answer a session from the inbox (devdesk#22, #23).
+export function answerPrompt(session, since, choice) {
+  return sessionAction('answer', session, String(since), choice);
+}
+
+export async function peekSession(session) {
+  return parseListOutput(await runCommand(['--peek', session], 15000));
+}
+
+export async function replyTo(session, text) {
+  const bytes = new TextEncoder().encode(text);
+  const result = await limited(() => streamIn(['--reply', session, String(bytes.length)], 'DEVDESK-REPLY-READY', new Blob([bytes])));
+  if (!result.ok) throw new Error('not sent');
+}
+
+// Save a file from the editor (devdesk#20): `--fs-write SESSION PATH BYTES BASE`
+// with the content streamed after the ready line. Resolves the server's JSON:
+// {ok: true, sha, size, mtime} or {ok: false, conflict: true, sha} when the file
+// changed since `base` (a sha256, or "new" to create).
+export function writeFile(session, path, bytes, base) {
+  return limited(() => streamIn(['--fs-write', session, path, String(bytes.length), base], 'DEVDESK-WRITE-READY', new Blob([bytes])));
+}
+
+// Run a devdesk command that reads base64 from the terminal after printing
+// `ready`: stream `blob` in slices (never all in memory), then resolve the JSON
+// reply. Fails on 20 s of inactivity rather than a fixed total (devdesk#9).
+async function streamIn(args, ready, blob, onProgress) {
+  const token = await fetchToken();
  const slice = 3 * 16 * 1024; // multiple of 3: base64 of slices concatenates cleanly
  return new Promise((resolve, reject) => {
-    const socket = new WebSocket(wsUrl(window.location, ['--upload', session, name, String(file.size)]), ['tty']);
+    const socket = new WebSocket(wsUrl(window.location, args), ['tty']);
    socket.binaryType = 'arraybuffer';
    const decoder = new TextDecoder();
    let output = '';
@@ -224,15 +256,16 @@ async function uploadNow(session, file, onProgress) {
      idle = setTimeout(() => socket.close(), 20000);
    };
    const send = async () => {
-      for (let offset = 0; offset < file.size; offset += slice) {
+      for (let offset = 0; offset < blob.size; offset += slice) {
        while (socket.bufferedAmount > 1 << 20) await sleep(20);
        if (socket.readyState !== WebSocket.OPEN) return;
-        const bytes = new Uint8Array(await file.slice(offset, offset + slice).arrayBuffer());
+        const bytes = new Uint8Array(await blob.slice(offset, offset + slice).arrayBuffer());
        socket.send(encodeInput(toBase64(bytes)));
        touch();
-        onProgress?.(Math.min(1, (offset + slice) / file.size));
+        onProgress?.(Math.min(1, (offset + slice) / blob.size));
      }
    };
+    const after = () => output.slice(output.indexOf(ready) + ready.length);
    touch();
    socket.onopen = () => socket.send(encodeInit(token, 240, 24));
    socket.onmessage = (event) => {
@@ -240,28 +273,26 @@ async function uploadNow(session, file, onProgress) {
      const { type, payload } = decodeServer(event.data);
      if (type !== Server.OUTPUT) return;
      output += decoder.decode(payload, { stream: true });
-      if (!sending && output.includes('DEVDESK-UPLOAD-READY')) {
+      if (!sending && output.includes(ready)) {
        sending = true;
        send();
-      } else if (sending && isComplete(output.replace(/^[\s\S]*DEVDESK-UPLOAD-READY/, ''))) {
+      }
+      if (sending && isComplete(after())) {
        socket.close(); // the reply is in; let devdesk exit (devdesk#35)
      }
    };
    socket.onerror = () => {};
    socket.onclose = () => {
      clearTimeout(idle);
-      const text = stripAnsi(output.replace(/^[\s\S]*DEVDESK-UPLOAD-READY/, ''));
+      const text = stripAnsi(output.includes(ready) ? after() : output);
      try {
-        const result = parseListOutput(text);
-        if (result.ok && result.path) {
-          resolve(result.path);
-          return;
-        }
+        resolve(parseListOutput(text));
+        return;
      } catch {
        // fall through to the error message
      }
      const message = text.split(/\r?\n/).map((l) => l.trim()).filter(Boolean).pop();
-      reject(new Error((message || 'upload failed').replace(/^devdesk:\s*/, '')));
+      reject(new Error((message || 'no reply').replace(/^devdesk:\s*/, '')));
    };
  });
 }
@@ -5,11 +5,11 @@
 // see what Claude edited, and jump to any file by name. Read-only for now.
 // Everything goes through `devdesk attach --fs-*` over ttyd.

-import { runBlob, runCommand } from './connection.js';
+import { runBlob, runCommand, writeFile } from './connection.js';
 import { parseListOutput } from './protocol.js';
 import { el } from './dom.js';
 import { ago } from './sessions.js';
-import { CommandPalette, toast } from './ui.js';
+import { CommandPalette, openDialog, toast } from './ui.js';

 // ---------------------------------------------------------------- editor bundle

@@ -164,6 +164,27 @@ function writeJson(key, value) {
  }
 }

+// Unsaved edits survive a reload, a session switch or a crash (devdesk#20):
+// each dirty buffer is mirrored to localStorage with the sha it was based on.
+const draftKey = (session, path) => `devdesk.draft.${session}:${path}`;
+
+function readDraft(session, path) {
+  try {
+    return JSON.parse(localStorage.getItem(draftKey(session, path)));
+  } catch {
+    return null;
+  }
+}
+
+function writeDraft(session, path, draft) {
+  try {
+    if (draft) localStorage.setItem(draftKey(session, path), JSON.stringify(draft));
+    else localStorage.removeItem(draftKey(session, path));
+  } catch {
+    // Quota or private mode: the edit just isn't backed up.
+  }
+}
+
 // ---------------------------------------------------------------- icons

 // A two-character badge per file type (VS Code's icon idea, in the terminal style).
@@ -249,6 +270,7 @@ export class FilesPane {
    root.querySelector('.dd-files-refresh').addEventListener('click', () => this.refresh());
    root.querySelector('.dd-files-close').addEventListener('click', () => this.close());
    root.querySelector('.dd-files-find').addEventListener('click', () => this.quickOpen.open());
+    root.querySelector('.dd-files-new').addEventListener('click', () => this.newFile());
    root.querySelector('.dd-explorer-toggle').addEventListener('click', () => this.setExplorer(!this.explorerShown()));
    this.explorer.addEventListener('keydown', (event) => this.treeKey(event));
    root.addEventListener('keydown', (event) => {
@@ -256,8 +278,15 @@ export class FilesPane {
        event.preventDefault();
        this.quickOpen.open();
      }
+      if ((event.ctrlKey || event.metaKey) && !event.shiftKey && !event.altKey && event.code === 'KeyS') {
+        event.preventDefault();
+        if (this.active) this.save(this.active);
+      }
    });
    this.wireExplorerResize();
+    // Leaving or reloading the page: write pending drafts now, not in 400 ms.
+    window.addEventListener('pagehide', () => this.flushDrafts());
+    window.addEventListener('beforeunload', () => this.flushDrafts());
    // Narrow pane (phone, or dragged small): the explorer slides over the editor.
    new ResizeObserver(() => root.classList.toggle('is-narrow', root.clientWidth < 680)).observe(root);
    this.quickOpen = new CommandPalette(() => this.loadFileList(), {
@@ -343,6 +372,7 @@ export class FilesPane {
  syncSession() {
    const session = this.hooks.session();
    if (session === this.session) return false;
+    this.flushDrafts();
    for (const v of this.views.values()) v.editor?.destroy();
    this.views.clear();
    this.listings.clear();
@@ -689,7 +719,11 @@ export class FilesPane {
        this.tabs[preview] = tab;
      } else {
        this.tabs.push(tab);
-        while (this.tabs.length > 12) this.closeTab(this.tabs.find((t) => t.key !== key).key, { render: false });
+        while (this.tabs.length > 12) {
+          const victim = this.tabs.find((t) => t.key !== key && !this.views.get(t.key)?.dirty);
+          if (!victim) break;
+          this.closeTab(victim.key, { render: false, force: true });
+        }
      }
    } else if (pin) {
      tab.pinned = true;
@@ -716,7 +750,34 @@ export class FilesPane {
    this.renderExplorer();
  }

-  closeTab(key, { render = true } = {}) {
+  flushDrafts() {
+    for (const [key, view] of this.views) {
+      if (!view.editable || !view.draftTimer) continue;
+      clearTimeout(view.draftTimer);
+      view.draftTimer = 0;
+      const tab = this.tabs.find((t) => t.key === key);
+      if (tab) writeDraft(this.session, tab.path, view.dirty ? { text: view.editor.text(), base: view.base, at: Date.now() } : null);
+    }
+  }
+
+  hasDirty() {
+    return [...this.views.values()].some((v) => v.dirty);
+  }
+
+  async closeTab(key, { render = true, force = false } = {}) {
+    const view = this.views.get(key);
+    const tab = this.tabs.find((t) => t.key === key);
+    if (!force && view?.dirty && tab) {
+      const choice = await openDialog({
+        title: `Save changes to ${base(tab.path)}?`,
+        size: 'sm',
+        body: el('p', { class: 'dd-dialog-text' }, `${tab.path} has unsaved changes.`),
+        actions: [{ label: 'Cancel', value: null }, { label: 'Don\'t save', value: 'discard' }, { label: 'Save', primary: true }],
+      });
+      if (!choice) return;
+      if (choice === 'discard') writeDraft(this.session, tab.path, null);
+      else if (!(await this.save(key))) return;
+    }
    const i = this.tabs.findIndex((t) => t.key === key);
    if (i < 0) return;
    this.tabs.splice(i, 1);
@@ -731,6 +792,7 @@ export class FilesPane {
  }

  dropView(key) {
+    clearTimeout(this.views.get(key)?.draftTimer);
    this.views.get(key)?.editor?.destroy();
    this.views.get(key)?.node.remove();
    this.views.delete(key);
@@ -742,7 +804,7 @@ export class FilesPane {
      const change = this.changeFor(tab.path);
      const status = change ? statusOf(change) : null;
      return el('div', {
-        class: `dd-tab${tab.key === this.active ? ' is-active' : ''}${tab.pinned ? '' : ' is-preview'}${status ? ` git-${status[2]}` : ''}`,
+        class: `dd-tab${tab.key === this.active ? ' is-active' : ''}${tab.pinned ? '' : ' is-preview'}${status ? ` git-${status[2]}` : ''}${this.views.get(tab.key)?.dirty ? ' is-dirty' : ''}`,
        role: 'tab', 'aria-selected': String(tab.key === this.active), tabindex: tab.key === this.active ? '0' : '-1',
        title: `${tab.path}${tab.mode === 'diff' ? ' (diff against HEAD)' : ''}${tab.pinned ? '' : ' · preview: the next file replaces it; double-click to keep'}`,
        onclick: () => this.activate(tab.key),
@@ -758,12 +820,12 @@ export class FilesPane {
      el('span', { class: 'dd-tab-name' }, name),
      tab.mode === 'diff' ? el('span', { class: 'dd-tab-tag' }, 'diff') : null,
      el('button', {
-        type: 'button', class: 'dd-tab-close', 'aria-label': `Close ${name}`, title: 'Close',
+        type: 'button', class: 'dd-tab-close', 'aria-label': `Close ${name}`, title: this.views.get(tab.key)?.dirty ? 'Unsaved changes: close…' : 'Close',
        onclick: (event) => {
          event.stopPropagation();
          this.closeTab(tab.key);
        },
-      }, '×'));
+      }, this.views.get(tab.key)?.dirty ? '●' : '×'));
    });
    this.tabStrip.replaceChildren(...nodes);
    this.tabStrip.querySelector('.is-active')?.scrollIntoView({ block: 'nearest', inline: 'nearest' });
@@ -851,6 +913,10 @@ export class FilesPane {
      const [{ blob, original }, editor] = await Promise.all([this.fetchTab(tab), loadEditor().catch((error) => ({ error }))]);
      if (session !== this.session || this.views.get(key) !== view) return;
      if (blob.header.sha && blob.header.sha === view.header?.sha && tab.mode !== 'diff') return;
+      if (view.dirty) {
+        if (blob.header.sha !== view.base) this.changedOnDisk(key);
+        return;
+      }
      const scroller = view.node.querySelector('.cm-scroller');
      const top = scroller?.scrollTop ?? 0;
      view.editor?.destroy();
@@ -863,7 +929,7 @@ export class FilesPane {
    }
  }

-  bar(tab, header) {
+  bar(tab, header, view) {
    const change = this.changeFor(tab.path);
    const meta = header ? [
      size(header.size ?? 0),
@@ -876,6 +942,10 @@ export class FilesPane {
    const button = (label, run, extra = {}) => el('button', { type: 'button', class: 'dd-viewer-btn', onclick: run, ...extra }, label);
    const switchMode = (mode) => this.openFile(tab.path, { mode, pin: true });
    const actions = [];
+    if (view?.editable) {
+      actions.push(button('Save', () => this.save(tab.key), { class: 'dd-viewer-btn is-primary dd-dirty-only', title: 'Save (Ctrl+S)' }));
+      actions.push(button('Revert', () => this.revert(tab.key), { class: 'dd-viewer-btn dd-dirty-only', title: 'Discard your changes' }));
+    }
    if (tab.mode !== 'diff' && isMarkdown(tab.path)) actions.push(button(tab.mode === 'preview' ? 'Source' : 'Preview', () => switchMode(tab.mode === 'preview' ? 'view' : 'preview')));
    if (change && change.x !== '?' && change.y !== '?' && this.changes?.git) {
      actions.push(button(tab.mode === 'diff' ? 'File' : 'Diff', () => switchMode(tab.mode === 'diff' ? (isMarkdown(tab.path) ? 'preview' : 'view') : 'diff')));
@@ -897,7 +967,8 @@ export class FilesPane {
    return el('div', { class: 'dd-viewer-bar' },
      el('span', { class: 'dd-viewer-where', title: [tab.path, meta].filter(Boolean).join('\n') },
        el('span', { class: 'dd-viewer-path' }, tab.path),
-        meta ? el('span', { class: 'dd-viewer-meta' }, ` · ${meta}`) : null),
+        meta ? el('span', { class: 'dd-viewer-meta' }, ` · ${meta}`) : null,
+        view?.editable ? el('span', { class: 'dd-unsaved dd-dirty-only' }, ' · unsaved') : null),
      el('span', { class: 'dd-viewer-actions' }, ...actions));
  }

@@ -917,20 +988,261 @@ export class FilesPane {
      content.append(el('pre', { class: 'dd-plain' }, text(base64, header.utf8)));
    } else if (tab.mode === 'preview') {
      content.classList.add('is-preview');
+      // Unsaved edits in the Source tab show in the preview too.
+      const source = this.views.get(`view:${tab.path}`);
+      const md = source?.dirty ? source.editor.text() : text(base64);
      const frame = el('iframe', {
        class: 'dd-md-frame', title: `Preview of ${tab.path}`,
-        sandbox: 'allow-popups allow-popups-to-escape-sandbox', srcdoc: previewDocument(editor.markdown(text(base64))),
+        sandbox: 'allow-popups allow-popups-to-escape-sandbox', srcdoc: previewDocument(editor.markdown(md)),
      });
      content.append(frame);
-      inlineImages(editor.markdown(text(base64)), this.session, tab.path).then((html) => {
+      inlineImages(editor.markdown(md), this.session, tab.path).then((html) => {
        if (frame.isConnected) frame.srcdoc = previewDocument(html);
      });
    } else if (tab.mode === 'diff') {
      view.editor = editor.diff(content, { original: text(original?.base64), modified: text(base64), path: tab.path, wrap: this.wrap });
+    } else if (header.utf8 === false) {
+      // Not UTF-8: shown as Latin-1, read-only (saving would change the bytes).
+      view.editor = editor.viewer(content, { doc: text(base64, false), path: tab.path, wrap: this.wrap });
    } else {
-      view.editor = editor.viewer(content, { doc: text(base64, header.utf8), path: tab.path, wrap: this.wrap });
+      const disk = text(base64);
+      const draft = readDraft(this.session, tab.path);
+      let doc = disk;
+      let banner = null;
+      if (draft && draft.text !== disk) {
+        if (draft.base === header.sha) {
+          doc = draft.text;
+          toast.info(`Restored your unsaved changes to ${tab.path}`);
+        } else {
+          banner = draft;
+        }
+      }
+      view.editable = true;
+      view.saved = disk;
+      view.base = header.sha;
+      view.editor = editor.editor(content, {
+        doc, path: tab.path, wrap: this.wrap,
+        onChange: (now) => this.edited(tab.key, now),
+        onSave: () => this.save(tab.key),
+      });
+      view.dirty = doc !== disk;
+      view.node.classList.toggle('is-dirty', view.dirty);
+      view.node.replaceChildren(this.bar(tab, header, view), content);
+      if (banner) this.oldDraft(tab.key, banner);
+      if (view.dirty) this.renderTabs();
+      return;
+    }
+    view.node.replaceChildren(this.bar(tab, header, view), content);
+  }
+
+  // ------------------------------------------------------------ editing (devdesk#20)
+
+  edited(key, now) {
+    const view = this.views.get(key);
+    const tab = this.tabs.find((t) => t.key === key);
+    if (!view || !tab) return;
+    const dirty = now !== view.saved;
+    if (dirty && !tab.pinned) {
+      tab.pinned = true; // editing keeps a preview tab
+      this.saveState();
+    }
+    clearTimeout(view.draftTimer);
+    view.draftTimer = setTimeout(() => writeDraft(this.session, tab.path, dirty ? { text: now, base: view.base, at: Date.now() } : null), 400);
+    if (dirty !== view.dirty) {
+      view.dirty = dirty;
+      view.node.classList.toggle('is-dirty', dirty);
+      this.renderTabs();
+    }
+  }
+
+  // Resolves true when saved. A conflict (the file changed on disk since it was
+  // opened) asks before overwriting.
+  async save(key, { base: forced } = {}) {
+    const view = this.views.get(key);
+    const tab = this.tabs.find((t) => t.key === key);
+    if (!view?.editable || !tab || view.saving) return false;
+    if (!view.dirty && !forced) return true;
+    const now = view.editor.text();
+    view.saving = true;
+    try {
+      const result = await writeFile(this.session, tab.path, new TextEncoder().encode(now), forced ?? view.base ?? 'new');
+      if (result.conflict) return this.conflict(key, result.sha);
+      if (!result.ok) throw new Error('not saved');
+      view.saved = now;
+      view.base = result.sha;
+      view.header = { ...view.header, sha: result.sha, size: result.size, mtime: result.mtime };
+      clearTimeout(view.draftTimer);
+      writeDraft(this.session, tab.path, null);
+      this.edited(key, view.editor.text());
+      view.node.querySelector('.dd-viewer-banner')?.remove();
+      toast.success(`Saved ${tab.path}`);
+      this.loadChanges();
+      this.fileList = null;
+      return true;
+    } catch (error) {
+      toast.error(`Could not save ${tab.path}: ${error.message}`);
+      return false;
+    } finally {
+      view.saving = false;
+    }
+  }
+
+  revert(key) {
+    const view = this.views.get(key);
+    const tab = this.tabs.find((t) => t.key === key);
+    if (!view?.editable || !tab) return;
+    clearTimeout(view.draftTimer);
+    writeDraft(this.session, tab.path, null);
+    view.editor.setText(view.saved);
+    view.node.querySelector('.dd-viewer-banner')?.remove();
+  }
+
+  async diskText(path) {
+    const { header, base64 } = await runBlob(['--fs-read', this.session, path]);
+    return { sha: header.sha, text: new TextDecoder().decode(decodeBase64(base64 || '')) };
+  }
+
+  async conflict(key, diskSha) {
+    const tab = this.tabs.find((t) => t.key === key);
+    const choice = await openDialog({
+      title: `${base(tab.path)} changed on disk`,
+      size: 'sm',
+      body: el('p', { class: 'dd-dialog-text' }, `Someone (probably Claude) changed ${tab.path} after you opened it. Saving now would overwrite that.`),
+      actions: [{ label: 'Cancel', value: null }, { label: 'Compare', value: 'compare' }, { label: 'Overwrite', primary: true, danger: true }],
+      danger: true,
+    });
+    if (choice === 'compare') return this.compare(key);
+    if (choice) return this.save(key, { base: diskSha });
+    return false;
+  }
+
+  // Disk version vs yours, side by side in a unified diff; pick one.
+  async compare(key) {
+    const view = this.views.get(key);
+    const tab = this.tabs.find((t) => t.key === key);
+    if (!view || !tab) return false;
+    let disk;
+    let editor;
+    try {
+      [disk, editor] = await Promise.all([this.diskText(tab.path), loadEditor()]);
+    } catch (error) {
+      toast.error(error.message);
+      return false;
+    }
+    const holder = el('div', { class: 'dd-compare' });
+    let diffView = null;
+    const choice = await openDialog({
+      title: `${tab.path}: disk (red) vs yours (green)`,
+      className: 'is-wide',
+      body: holder,
+      onOpen: () => {
+        diffView = editor.diff(holder, { original: disk.text, modified: view.editor.text(), path: tab.path, wrap: this.wrap });
+        return holder.querySelector('.cm-content');
+      },
+      actions: [{ label: 'Close', value: null }, { label: 'Take the disk version', value: 'disk' }, { label: 'Save mine', primary: true }],
+    });
+    diffView?.destroy();
+    if (choice === 'disk') {
+      view.saved = disk.text;
+      view.base = disk.sha;
+      view.header = { ...view.header, sha: disk.sha };
+      view.editor.setText(disk.text);
+      writeDraft(this.session, tab.path, null);
+      view.node.querySelector('.dd-viewer-banner')?.remove();
+      return false;
+    }
+    if (choice) return this.save(key, { base: disk.sha });
+    return false;
+  }
+
+  banner(key, text, actions) {
+    const view = this.views.get(key);
+    if (!view) return;
+    view.node.querySelector('.dd-viewer-banner')?.remove();
+    const node = el('div', { class: 'dd-viewer-banner', role: 'alert' }, el('span', {}, text),
+      ...actions.map(([label, run]) => el('button', { type: 'button', class: 'dd-viewer-btn', onclick: run }, label)));
+    view.node.querySelector('.dd-viewer-bar')?.after(node);
+  }
+
+  // Claude changed a file you're editing: nothing is replaced until you choose.
+  changedOnDisk(key) {
+    this.banner(key, 'This file changed on disk while you were editing it.', [
+      ['Compare', () => this.compare(key)],
+      ['Reload (discard mine)', () => {
+        this.revert(key);
+        this.dropView(key);
+        this.renderEditor();
+      }],
+      ['Keep mine', () => this.views.get(key)?.node.querySelector('.dd-viewer-banner')?.remove()],
+    ]);
+  }
+
+  // Unsaved changes from an earlier visit, but the file changed since.
+  oldDraft(key, draft) {
+    const view = this.views.get(key);
+    const tab = this.tabs.find((t) => t.key === key);
+    const age = ago(Math.floor(draft.at / 1000));
+    this.banner(key, `You have unsaved changes from ${age === 'now' ? 'a moment ago' : `${age} ago`}, but the file changed on disk since.`, [
+      ['Compare', async () => {
+        view.editor.setText(draft.text);
+        await this.compare(key);
+      }],
+      ['Restore mine', () => {
+        view.editor.setText(draft.text);
+        view.node.querySelector('.dd-viewer-banner')?.remove();
+      }],
+      ['Discard', () => {
+        writeDraft(this.session, tab.path, null);
+        view.node.querySelector('.dd-viewer-banner')?.remove();
+      }],
+    ]);
+  }
+
+  // New file in the folder you're looking at (folders are created as needed).
+  async newFile() {
+    if (!this.session) return;
+    const activePath = this.tabs.find((t) => t.key === this.active)?.path;
+    const row = this.treeRows?.[this.focusIndex];
+    const folder = row?.kind === 'dir' ? row.path : parent(row?.path ?? activePath ?? '');
+    const input = el('input', { class: 'lt-input', value: folder ? `${folder}/` : '', spellcheck: 'false', autocomplete: 'off', 'aria-describedby': 'dd-newfile-hint' });
+    const hint = el('p', { class: 'dd-dialog-hint', id: 'dd-newfile-hint' }, `Relative to ${this.listings.get('')?.root ?? 'the session folder'}. Missing folders are created.`);
+    const path = await openDialog({
+      title: 'New file',
+      size: 'sm',
+      body: el('div', { class: 'dd-dialog-fields' }, el('label', { class: 'dd-field' }, el('span', {}, 'Path'), input), hint),
+      actions: [{ label: 'Cancel' }, { label: 'Create', primary: true }],
+      onOpen: () => {
+        input.setSelectionRange(input.value.length, input.value.length);
+        return input;
+      },
+      submit: () => {
+        const value = input.value.trim().replace(/^\/+/, '');
+        if (!value || value.endsWith('/') || value.split('/').some((part) => part === '..' || part === '.')) {
+          hint.textContent = 'Type a file name (no .. or trailing /).';
+          hint.classList.add('is-error');
+          return null;
+        }
+        return value;
+      },
+    });
+    if (!path) return;
+    try {
+      const result = await writeFile(this.session, path, new Uint8Array(0), 'new');
+      if (!result.ok) throw new Error('not created');
+      // Show it: re-list every folder above the new file and open them.
+      const parts = result.path.split('/').slice(0, -1);
+      for (let i = 0; i <= parts.length; i += 1) {
+        const dir = parts.slice(0, i).join('/');
+        if (dir) this.expanded.add(dir);
+        this.listDir(dir);
+      }
+      this.saveState();
+      this.fileList = null;
+      this.openFile(result.path, { mode: 'view', pin: true });
+      toast.success(`Created ${result.path}`);
+    } catch (error) {
+      toast.error(`Could not create ${path}: ${error.message}`);
    }
-    view.node.replaceChildren(this.bar(tab, header), content);
  }

  // Theme switch: the editor follows CSS variables; previews need a re-render.
@@ -5,14 +5,17 @@

 import { el } from './dom.js';
 import { ago } from './sessions.js';
+import { answerPrompt, peekSession, replyTo } from './connection.js';
+import { toast } from './ui.js';

 const KEY = 'devdesk.inbox';
 const MAX = 30;
+const MAX_AGE = 7 * 86400 * 1000;

 function load() {
  try {
    const list = JSON.parse(localStorage.getItem(KEY) || '[]');
-    return Array.isArray(list) ? list : [];
+    return Array.isArray(list) ? list.filter((e) => Date.now() - e.at < MAX_AGE) : [];
  } catch {
    return [];
  }
@@ -45,6 +48,7 @@ export class Inbox {
    this.events = load();
    this.waiting = [];
    this.alerts = [];
+    this.known = null; // session names that exist, once the list has loaded
    this.list = panel.querySelector('.lt-notif-panel-list');
    panel.querySelector('.lt-notif-panel-clear').addEventListener('click', () => this.markAllRead());
    window.addEventListener('storage', (event) => {
@@ -63,6 +67,8 @@ export class Inbox {
    if (open) this.panel.removeAttribute('aria-hidden');
    else this.panel.setAttribute('aria-hidden', 'true');
    this.button.setAttribute('aria-expanded', String(open));
+    if (!open) this.peeking = null;
+    this.panel.classList.toggle('is-peek', false);
    if (open) this.render();
  }

@@ -78,9 +84,10 @@ export class Inbox {
  }

  // Live state: other sessions waiting on you, firing alerts.
-  setLive({ waiting, alerts }) {
+  setLive({ waiting, alerts, sessions }) {
    if (waiting) this.waiting = waiting;
    if (alerts) this.alerts = alerts;
+    if (sessions) this.known = new Set(sessions);
    this.render();
  }

@@ -91,7 +98,7 @@ export class Inbox {
  }

  unread() {
-    return this.events.filter((e) => !e.read && e.kind !== 'waiting').length;
+    return this.events.filter((e) => !e.read && e.kind !== 'waiting' && !(this.known && e.session && !e.url && !this.known.has(e.session))).length;
  }

  render() {
@@ -110,7 +117,84 @@ export class Inbox {
    if (this.isOpen) this.renderPanel();
  }

+  // ------------------------------------------------------------ answer from here
+
+  async answer(session, since, choice, button) {
+    button.disabled = true;
+    try {
+      await answerPrompt(session, since, choice);
+      toast.success(choice === 'allow' ? `Allowed in ${session}` : `Denied in ${session}`);
+      this.hooks.refresh?.();
+    } catch (error) {
+      toast.error(`${session}: ${error.message}`);
+      this.hooks.refresh?.();
+    } finally {
+      button.disabled = false;
+    }
+  }
+
+  // Peek: the last exchange of a session, and a reply box.
+  async peek(session) {
+    this.peeking = session;
+    this.panel.classList.add('is-peek');
+    const body = el('div', { class: 'dd-peek' }, el('div', { class: 'dd-notif-empty' }, 'Loading…'));
+    this.list.replaceChildren(body);
+    let data;
+    try {
+      data = await peekSession(session);
+    } catch (error) {
+      body.replaceChildren(el('div', { class: 'dd-notif-empty' }, error.message));
+      return;
+    }
+    if (this.peeking !== session) return;
+    const input = el('textarea', { class: 'lt-input dd-peek-input', rows: '3', placeholder: `Reply to ${session}… (Ctrl+Enter sends)`, 'aria-label': `Reply to ${session}` });
+    const send = el('button', { type: 'button', class: 'lt-btn lt-btn-primary lt-btn-sm' }, 'Send');
+    const submit = async () => {
+      const text = input.value.trim();
+      if (!text) return;
+      send.disabled = true;
+      try {
+        await replyTo(session, text);
+        toast.success(`Sent to ${session}`);
+        this.peeking = null;
+        this.setOpen(false);
+        this.hooks.refresh?.();
+      } catch (error) {
+        toast.error(`${session}: ${error.message}`);
+      } finally {
+        send.disabled = false;
+      }
+    };
+    send.addEventListener('click', submit);
+    input.addEventListener('keydown', (event) => {
+      if (event.key === 'Enter' && (event.ctrlKey || event.metaKey)) {
+        event.preventDefault();
+        submit();
+      }
+      event.stopPropagation(); // keys belong to the reply box, not the terminal or shortcuts
+    });
+    const status = data.status;
+    const waitingRequest = status?.state === 'waiting' && status.request;
+    body.replaceChildren(
+      el('div', { class: 'dd-peek-head' },
+        el('button', { type: 'button', class: 'dd-peek-back', onclick: () => { this.peeking = null; this.panel.classList.remove('is-peek'); this.renderPanel(); } }, '←'),
+        el('span', { class: 'dd-peek-title' }, session),
+        el('span', { class: 'dd-peek-state' }, status?.state ? `${status.state}${status.since ? ` · ${ago(status.since)}` : ''}` : '')),
+      data.user ? el('div', { class: 'dd-peek-user' }, el('span', { class: 'dd-peek-label' }, 'You'), data.user.text) : null,
+      el('div', { class: 'dd-peek-assistant' },
+        el('span', { class: 'dd-peek-label' }, 'Claude'),
+        data.assistant ? `${data.assistant.truncated ? '…' : ''}${data.assistant.text}` : 'Nothing yet.'),
+      waitingRequest
+        ? el('div', { class: 'dd-notif-empty' }, 'Claude is asking for a permission: answer it from the list, or open the session.')
+        : el('div', { class: 'dd-peek-reply' }, input, el('div', { class: 'dd-peek-actions' },
+          el('button', { type: 'button', class: 'lt-btn lt-btn-ghost lt-btn-sm', onclick: () => { this.setOpen(false); this.hooks.openSession(session); } }, 'Open session'),
+          send)));
+    if (!waitingRequest) input.focus();
+    body.querySelector('.dd-peek-assistant').scrollTop = 1e9;
+  }
+
  renderPanel() {
+    if (this.peeking) return; // the peek view stays until you go back
    const close = (run) => () => {
      this.setOpen(false);
      run();
@@ -133,11 +217,31 @@ export class Inbox {
    if (this.waiting.length) {
      nodes.push(el('div', { class: 'dd-notif-section' }, 'Needs you'));
      for (const s of this.waiting) {
-        nodes.push(item({
+        const request = s.status?.request;
+        const node = item({
          dot: 'red', unread: true, title: `${s.name}: ${s.status?.message || 'Claude is waiting for your input'}`,
          meta: s.status?.since ? `waiting ${ago(s.status.since)}` : 'waiting',
          onclick: close(() => this.hooks.openSession(s.name)),
-        }));
+        });
+        const stop = (run) => (event) => {
+          event.stopPropagation();
+          run(event.currentTarget);
+        };
+        const body = node.querySelector('.lt-notif-item-body');
+        if (request) {
+          body.append(
+            request.description ? el('div', { class: 'dd-request-desc' }, request.description) : null,
+            el('code', { class: 'dd-request' }, request.detail || request.tool),
+            el('div', { class: 'dd-request-actions' },
+              el('button', { type: 'button', class: 'lt-btn lt-btn-primary lt-btn-sm', onclick: stop((b) => this.answer(s.name, s.status.since, 'allow', b)) }, 'Allow'),
+              el('button', { type: 'button', class: 'lt-btn lt-btn-danger lt-btn-sm', onclick: stop((b) => this.answer(s.name, s.status.since, 'deny', b)) }, 'Deny'),
+              el('button', { type: 'button', class: 'lt-btn lt-btn-ghost lt-btn-sm', onclick: stop(() => { this.setOpen(false); this.hooks.openSession(s.name); }) }, 'Open')));
+        } else {
+          body.append(el('div', { class: 'dd-request-actions' },
+            el('button', { type: 'button', class: 'lt-btn lt-btn-sm', onclick: stop(() => this.peek(s.name)) }, 'Peek & reply'),
+            el('button', { type: 'button', class: 'lt-btn lt-btn-ghost lt-btn-sm', onclick: stop(() => { this.setOpen(false); this.hooks.openSession(s.name); }) }, 'Open')));
+        }
+        nodes.push(node);
      }
    }
    if (this.alerts.length) {
@@ -155,15 +259,24 @@ export class Inbox {
      nodes.push(el('div', { class: 'dd-notif-section' }, 'Recent'));
      for (const e of recent.slice(0, 12)) {
        const kind = KINDS[e.kind] ?? { tone: 'cyan' };
-        nodes.push(item({
-          dot: e.read ? 'read' : kind.tone, unread: !e.read, title: e.text, meta: when(e.at),
+        // An entry about a session that has since ended must not bring it back (devdesk#38).
+        const ended = !e.url && e.session && this.known && !this.known.has(e.session);
+        const recentNode = item({
+          dot: e.read || ended ? 'read' : kind.tone, unread: !e.read && !ended, title: e.text,
+          meta: `${when(e.at)}${ended ? ' · session ended' : ''}`,
          onclick: close(() => {
            this.events = this.events.map((x) => (x.id === e.id ? { ...x, read: true } : x));
            save(this.events);
            if (e.url) window.open(e.url, '_blank', 'noopener');
+            else if (ended) this.hooks.ended?.(e.session);
            else if (e.session) this.hooks.openSession(e.session);
          }),
-        }));
+        });
+        if (e.kind === 'finished' && !ended) {
+          recentNode.querySelector('.lt-notif-item-body').append(el('div', { class: 'dd-request-actions' },
+            el('button', { type: 'button', class: 'lt-btn lt-btn-ghost lt-btn-sm', onclick: (event) => { event.stopPropagation(); this.peek(e.session); } }, 'Peek & reply')));
+        }
+        nodes.push(recentNode);
      }
    }
    if (!nodes.length) nodes.push(el('div', { class: 'dd-notif-empty' }, 'Nothing needs you. Sessions that finish or wait while you\'re elsewhere show up here.'));
@@ -58,6 +58,8 @@ const ui = {
 };

 const urlSession = sessionFromSearch(window.location.search);
+// Notification links (Matrix) add existing=1: open, never re-create (devdesk#38).
+const urlExisting = new URLSearchParams(window.location.search).get('existing') === '1';
 const state = {
  session: urlSession, // null = picker
  conn: null,
@@ -169,7 +171,11 @@ function recordTransitions(sessions) {
 }

 function renderPanelsBadge() {
-  inbox?.setLive({ waiting: waitingOthers, alerts: lastAlerts?.alerts ?? [] });
+  inbox?.setLive({
+    waiting: waitingOthers,
+    alerts: lastAlerts?.alerts ?? [],
+    sessions: sessionsPanel?.data ? sessionsPanel.data.sessions.map((x) => x.name) : null,
+  });
 }

 function onSessionData({ fetched = false } = {}) {
@@ -316,14 +322,19 @@ function updateUrl(session) {
  const url = new URL(window.location.href);
  if (session) url.searchParams.set('arg', session);
  else url.searchParams.delete('arg');
+  url.searchParams.delete('existing');
  if (url.href !== window.location.href) window.history.replaceState(null, '', url);
 }

 // ---------------------------------------------------------------- connection

-// reconnect: automatic re-attach after a drop. It must not re-create a session
-// that was ended or renamed meanwhile, so it asks for --existing (devdesk#4).
-function connect(session, { reconnect = false } = {}) {
+// existing: go to a session that should already exist (reconnects, the
+// switcher, inbox entries, notification links). It must not re-create one that
+// was ended or renamed meanwhile, so it asks for --existing (devdesk#4, #38).
+// Creating is explicit: a typed name, the New dialog, the picker, recents.
+function connect(session, { existing = false, reconnect = false } = {}) {
+  const existingOnly = Boolean(session) && (existing || reconnect);
+  state.existingOnly = existingOnly;
  clearTimeout(state.retryTimer);
  state.conn?.dispose();
  state.session = session;
@@ -339,7 +350,7 @@ function connect(session, { reconnect = false } = {}) {
  term.reset();

  const conn = new TtydConnection({
-    arg: session && reconnect ? ['--existing', session] : session,
+    arg: existingOnly ? ['--existing', session] : session,
    size: () => ({ cols: term.cols, rows: term.rows }),
    onOpen: () => {
      state.openedAt = Date.now();
@@ -373,6 +384,25 @@ function onClosed(code) {
  // few seconds of opening means the session could not start (the reason is
  // printed in the terminal), so don't retry forever.
  const failedFast = code !== 1000 && Date.now() - state.openedAt < 4000;
+  if (failedFast && state.existingOnly) {
+    // Most likely ended or renamed since the link was made: say so, and only
+    // start it again when asked.
+    const name = state.session;
+    sessionsPanel?.reload().then(() => {
+      const known = sessionsPanel.data?.sessions?.some((x) => x.name === name);
+      if (known) {
+        scheduleReconnect();
+        return;
+      }
+      setWsState('disconnected', 'ended');
+      showOverlay({
+        title: `${name} has ended`,
+        text: `The session "${name}" no longer exists: it was ended or renamed. Its conversation is still in Claude's history.`,
+        actions: [pickerAction, { label: `Start ${name} again`, run: () => connect(name) }],
+      });
+    });
+    return;
+  }
  if (failedFast) {
    showOverlay({
      title: 'Session did not start',
@@ -515,7 +545,7 @@ function renderSwitcher() {
    return el('button', {
      type: 'button', role: 'menuitem',
      class: `dd-menu-item dd-switch-item is-${status.key}${s.name === state.session ? ' is-current' : ''}`,
-      title: s.dir || '', onclick: choose(() => connect(s.name)),
+      title: s.dir || '', onclick: choose(() => connect(s.name, { existing: true })),
    },
    el('span', { class: `lt-dot ${status.dot}` }),
    el('span', { class: 'dd-switch-name' }, s.name),
@@ -591,7 +621,7 @@ function buildCommands() {
    const status = sessionStatus(s);
    add({
      id: `switch:${s.name}`, group: 'Sessions', label: `Switch to ${s.name}`, hint: status.label, keywords: s.dir,
-      icon: status.key === 'waiting' ? '!' : s.running ? '●' : '○', run: () => connect(s.name),
+      icon: status.key === 'waiting' ? '!' : s.running ? '●' : '○', run: () => connect(s.name, { existing: true }),
    });
  }
  add({ id: 'new', group: 'Sessions', icon: '+', label: 'New session…', keywords: 'create open project', run: () => sessionsPanel.newDialog() });
@@ -682,7 +712,9 @@ const KEY_HELP = [
  ]],
  ['DevDesk', [
    ['Ctrl+⇧ P', 'Command palette'],
-    ['Ctrl+⇧ E', 'Files: browse, preview, diff (Esc closes)'],
+    ['Ctrl+⇧ E', 'Files: browse, preview, diff, edit (Esc closes)'],
+    ['Ctrl+P', 'Files: go to file'],
+    ['Ctrl+S', 'Files: save the open file'],
    ['Ctrl+⇧ C / V', 'Copy selection / paste'],
    ['⇧ drag', 'Select text in the browser'],
    ['Drop or paste a file', 'Upload it and attach it for Claude'],
@@ -866,7 +898,9 @@ function wireChrome() {
    badge: $('inbox-badge'),
    panel: $('inbox-panel'),
    hooks: {
-      openSession: (name) => connect(name),
+      openSession: (name) => connect(name, { existing: true }),
+      ended: (name) => toast.info(`${name} has ended; its conversation is still in Claude's history`),
+      refresh: () => sessionsPanel.reload(),
      showAlerts: () => {
        setSidebar(true);
        $('widget-alerts').scrollIntoView({ block: 'start', behavior: 'smooth' });
@@ -921,7 +955,7 @@ function wireChrome() {

  // Ctrl+W closes the tab before the terminal sees it; ask first.
  window.addEventListener('beforeunload', (event) => {
-    if (state.conn?.isOpen && state.session) {
+    if ((state.conn?.isOpen && state.session) || files?.hasDirty()) {
      event.preventDefault();
      event.returnValue = '';
    }
@@ -957,7 +991,7 @@ function wireChrome() {
    if (!document.hidden && ui.body.classList.contains('dd-sidebar-open')) refreshRepo();
  }, 60 * 1000);
  ui.attention.addEventListener('click', () => {
-    if (ui.attention.dataset.target) connect(ui.attention.dataset.target);
+    if (ui.attention.dataset.target) connect(ui.attention.dataset.target, { existing: true });
  });
 }

@@ -1057,7 +1091,8 @@ async function boot() {
  wireUploads();
  refreshAlerts();
  await sessionsPanel.refresh();
-  connect(urlSession ?? defaultSession(sessionsPanel.data));
+  if (urlSession) connect(urlSession, { existing: urlExisting });
+  else connect(defaultSession(sessionsPanel.data), { existing: true });
 }

 boot();
@@ -52,7 +52,7 @@ export const dialogOpen = () => openDialogs > 0 || !!document.querySelector('.lt
 // A .lt-modal dialog. `body` is a node; `actions` are { label, value, primary,
 // danger }. Resolves with the chosen action's value (or `submit()`'s value when
 // a form is submitted), or null when dismissed (✕, Esc, backdrop).
-export function openDialog({ title, body, actions = [], danger = false, size = '', onOpen, submit }) {
+export function openDialog({ title, body, actions = [], danger = false, size = '', className = '', onOpen, submit }) {
  return new Promise((resolve) => {
    const opener = document.activeElement;
    let done = false;
@@ -81,7 +81,7 @@ export function openDialog({ title, body, actions = [], danger = false, size = '
      if (button.type === 'submit') button.setAttribute('form', titleId);
    }
    form.id = titleId;
-    const overlay = el('div', { class: 'lt-modal-overlay is-open dd-dialog', role: 'dialog', 'aria-modal': 'true', 'aria-labelledby': `${titleId}-title` },
+    const overlay = el('div', { class: `lt-modal-overlay is-open dd-dialog${className ? ` ${className}` : ''}`, role: 'dialog', 'aria-modal': 'true', 'aria-labelledby': `${titleId}-title` },
      el('div', { class: `lt-modal${size ? ` lt-modal-${size}` : ''}` },
        el('div', { class: `lt-modal-header${danger ? ' lt-modal-header--danger' : ''}` },
          el('h2', { class: 'lt-modal-title', id: `${titleId}-title` }, title),
@@ -924,3 +924,55 @@ html[data-theme="light"] .dd-files.is-narrow .dd-explorer { box-shadow: 8px 0 24
  .dd-tree-row { min-height: 34px; }
  .dd-tab-close { opacity: 0.7; width: 28px; height: 28px; }
 }
+
+/* ---- editing (devdesk#20) ------------------------------------------------------------- */
+.dd-tab-view:not(.is-dirty) .dd-dirty-only { display: none; }
+.dd-unsaved { color: var(--accent-amber); }
+.dd-tab.is-dirty .dd-tab-close { opacity: 1; color: var(--accent-amber); }
+.dd-tab.is-dirty .dd-tab-close:hover { color: var(--accent-red); }
+.dd-viewer-btn.is-primary { border-color: var(--accent-orange); color: var(--accent-orange); }
+.dd-viewer-btn.is-primary:hover { background: var(--accent-orange-dim); }
+.dd-viewer-banner {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 6px 10px;
+  padding: 5px 10px;
+  border-bottom: 1px solid var(--accent-amber-dim);
+  background: var(--accent-amber-dim);
+  color: var(--accent-amber);
+  font-size: 0.72rem;
+}
+.dd-dialog.is-wide .lt-modal { width: min(1100px, 94vw); max-height: 88vh; }
+.dd-dialog.is-wide .lt-modal-body { padding: 0; }
+.dd-compare { display: flex; height: min(64vh, 640px); }
+.dd-compare > .cm-editor { flex: 1; min-width: 0; }
+
+/* ---- inbox: answer & peek (devdesk#22, #23) --------------------------------------------- */
+.dd-inbox-panel.is-peek { width: min(460px, calc(100vw - 16px)); }
+.dd-request-desc { margin-top: 4px; color: var(--text-secondary); font-size: 0.7rem; }
+.dd-request {
+  display: block;
+  max-height: 7.5em;
+  margin-top: 4px;
+  padding: 4px 6px;
+  overflow: auto;
+  border-left: 2px solid var(--accent-amber);
+  background: var(--bg-terminal);
+  color: var(--text-primary);
+  font-family: var(--font-mono);
+  font-size: 0.7rem;
+  white-space: pre-wrap;
+  overflow-wrap: anywhere;
+}
+.dd-request-actions { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 6px; }
+.dd-peek { display: flex; flex-direction: column; gap: 8px; padding: 8px 10px 10px; }
+.dd-peek-head { display: flex; align-items: center; gap: 8px; }
+.dd-peek-back { padding: 0 6px; border: 1px solid var(--border-color); background: none; color: var(--accent-cyan); cursor: pointer; }
+.dd-peek-title { flex: 1; color: var(--text-primary); font-weight: 700; font-size: 0.8rem; }
+.dd-peek-state { color: var(--text-muted); font-size: 0.66rem; }
+.dd-peek-label { display: block; margin-bottom: 2px; color: var(--accent-orange); font-size: 0.6rem; letter-spacing: 0.1em; text-transform: uppercase; }
+.dd-peek-user { padding: 6px 8px; border-left: 2px solid var(--border-color); color: var(--text-secondary); font-size: 0.72rem; white-space: pre-wrap; overflow-wrap: anywhere; }
+.dd-peek-assistant { max-height: 38vh; padding: 6px 8px; overflow: auto; border-left: 2px solid var(--accent-cyan); background: var(--bg-terminal); color: var(--text-primary); font-size: 0.74rem; line-height: 1.5; white-space: pre-wrap; overflow-wrap: anywhere; }
+.dd-peek-input { width: 100%; min-height: 4.5em; resize: vertical; font-family: var(--font-mono); font-size: 0.76rem; }
+.dd-peek-actions { display: flex; justify-content: flex-end; gap: 6px; margin-top: 6px; }