Add in-app edit UI for dashboard config

A web editor at /edit for managing pages and widgets without hand-editing YAML:

- Page list and per-page widget views with breadcrumb navigation
- Add/delete pages, add/delete/reorder widgets within a column
- Per-widget textarea editor with curated starter templates, widget-specific
  help (example, full field reference, link to upstream docs), and inline
  error rendering that preserves the user's edits on validation failure
- Pre-save validation via newConfigFromYAML; atomic temp+rename writes with
  .bak backup; YAML edits go through yaml.Node so comments and unresolved
  ${env:X}/${secret:X} tokens survive round-trips
- Auth gate: editing requires auth.users to be configured, or
  admin.allow-without-auth: true as an explicit opt-in for trusted networks
- Pencil button on the dashboard near the theme picker for quick access
- Admin views read fresh from disk so the list updates immediately after
  saves rather than lagging the fsnotify watcher

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitignore

@@ -3,3 +3,4 @@
 /playground
 /.idea
 /glance*.yml
+*.yml.bak

docs/glance.yml

@@ -1,105 +1,119 @@
+# --- Edit access ---
+# /edit is locked down by default. Pick ONE of the two blocks below.
+#
+# Option A (recommended): require login.
+#   Generate values with:
+#     go run . secret:make
+#     go run . password:hash <your-password>
+#
+# auth:
+#   secret-key: <paste base64 secret here>
+#   users:
+#     yourname:
+#       password-hash: <paste bcrypt hash here>
+#
+# Option B: open /edit without authentication. ONLY on a trusted network —
+# anyone who can reach this server can rewrite your config.
+# (The config key is still named `admin` for backward compatibility.)
+#
+admin:
+    allow-without-auth: true
 pages:
-  - name: Home
+    - name: Home
-    # Optionally, if you only have a single page you can hide the desktop navigation for a cleaner look
+      # Optionally, if you only have a single page you can hide the desktop navigation for a cleaner look
-    # hide-desktop-navigation: true
+      # hide-desktop-navigation: true
-    columns:
+      columns:
-      - size: small
+        - size: small
-        widgets:
+          widgets:
-          - type: calendar
+            - type: calendar
-            first-day-of-week: monday
+              first-day-of-week: monday
+            - type: rss
+              limit: 10
+              collapse-after: 3
+              cache: 12h
+              feeds:
+                - url: https://selfh.st/rss/
+                  title: selfh.st
+                  limit: 4
+                - url: https://ciechanow.ski/atom.xml
+                - url: https://www.joshwcomeau.com/rss.xml
+                  title: Josh Comeau
+                - url: https://samwho.dev/rss.xml
+                - url: https://ishadeed.com/feed.xml
+                  title: Ahmad Shadeed
+                - url: https://www.techmeme.com/feed.xml
+                  title: TechMeme
+            - type: twitch-channels
+              channels:
+                - theprimeagen
+                - j_blow
+                - giantwaffle
+                - cohhcarnage
+                - christitustech
+                - EJ_SA
+        - size: full
+          widgets:
+            - type: group
+              widgets:
+                - type: hacker-news
+                - type: lobsters
+            - type: videos
+              channels:
+                - UCXuqSBlHAE6Xw-yeJA0Tunw # Linus Tech Tips
+                - UCR-DXc1voovS8nhAvccRZhg # Jeff Geerling
+                - UCsBjURrPoezykLs9EqgamOA # Fireship
+                - UCBJycsmduvYEL83R_U4JriQ # Marques Brownlee
+                - UCHnyfMqiRRG1u-2MsSQLbXA # Veritasium
+            - type: group
+              widgets:
+                - type: reddit
+                  subreddit: technology
+                  show-thumbnails: true
+                - type: reddit
+                  subreddit: selfhosted
+                  show-thumbnails: true
+        - size: small
+          widgets:
+            - type: weather
+              location: London, United Kingdom
+              units: metric # alternatively "imperial"
+              hour-format: 12h # alternatively "24h"
+              # Optionally hide the location from being displayed in the widget
+              # hide-location: true
+            - type: markets
+              markets:
+                - symbol: SPY
+                  name: S&P 500
+                - symbol: BTC-USD
+                  name: Bitcoin
+                - symbol: NVDA
+                  name: NVIDIA
+                - symbol: AAPL
+                  name: Apple
+                - symbol: MSFT
+                  name: Microsoft
+            - type: releases
+              cache: 1d
+              # Without authentication the Github API allows for up to 60 requests per hour. You can create a
+              # read-only token from your Github account settings and use it here to increase the limit.
+              # token: ...
+              repositories:
+                - glanceapp/glance
+                - go-gitea/gitea
+                - immich-app/immich
+                - syncthing/syncthing
 
-          - type: rss
+# Add more pages here:
-            limit: 10
+# - name: Your page name
-            collapse-after: 3
+#   columns:
-            cache: 12h
+#     - size: small
-            feeds:
+#       widgets:
-              - url: https://selfh.st/rss/
+#         # Add widgets here
-                title: selfh.st
-                limit: 4
-              - url: https://ciechanow.ski/atom.xml
-              - url: https://www.joshwcomeau.com/rss.xml
-                title: Josh Comeau
-              - url: https://samwho.dev/rss.xml
-              - url: https://ishadeed.com/feed.xml
-                title: Ahmad Shadeed
 
-          - type: twitch-channels
+#     - size: full
-            channels:
+#       widgets:
-              - theprimeagen
+#         # Add widgets here
-              - j_blow
-              - giantwaffle
-              - cohhcarnage
-              - christitustech
-              - EJ_SA
 
-      - size: full
+#     - size: small
-        widgets:
+#       widgets:
-          - type: group
+#         # Add widgets here
-            widgets:
-              - type: hacker-news
-              - type: lobsters
-
-          - type: videos
-            channels:
-              - UCXuqSBlHAE6Xw-yeJA0Tunw # Linus Tech Tips
-              - UCR-DXc1voovS8nhAvccRZhg # Jeff Geerling
-              - UCsBjURrPoezykLs9EqgamOA # Fireship
-              - UCBJycsmduvYEL83R_U4JriQ # Marques Brownlee
-              - UCHnyfMqiRRG1u-2MsSQLbXA # Veritasium
-
-          - type: group
-            widgets:
-              - type: reddit
-                subreddit: technology
-                show-thumbnails: true
-              - type: reddit
-                subreddit: selfhosted
-                show-thumbnails: true
-
-      - size: small
-        widgets:
-          - type: weather
-            location: London, United Kingdom
-            units: metric # alternatively "imperial"
-            hour-format: 12h # alternatively "24h"
-            # Optionally hide the location from being displayed in the widget
-            # hide-location: true
-
-          - type: markets
-            markets:
-              - symbol: SPY
-                name: S&P 500
-              - symbol: BTC-USD
-                name: Bitcoin
-              - symbol: NVDA
-                name: NVIDIA
-              - symbol: AAPL
-                name: Apple
-              - symbol: MSFT
-                name: Microsoft
-
-          - type: releases
-            cache: 1d
-            # Without authentication the Github API allows for up to 60 requests per hour. You can create a
-            # read-only token from your Github account settings and use it here to increase the limit.
-            # token: ...
-            repositories:
-              - glanceapp/glance
-              - go-gitea/gitea
-              - immich-app/immich
-              - syncthing/syncthing
-
-  # Add more pages here:
-  # - name: Your page name
-  #   columns:
-  #     - size: small
-  #       widgets:
-  #         # Add widgets here
-
-  #     - size: full
-  #       widgets:
-  #         # Add widgets here
-
-  #     - size: small
-  #       widgets:
-  #         # Add widgets here

internal/glance/admin-edit.go

@@ -0,0 +1,555 @@
+package glance
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"strconv"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
+
+// configEditor manipulates glance.yml as a yaml.Node tree, preserving
+// comments, ordering, and unresolved ${env:X}/${secret:X} tokens that
+// would be destroyed by round-tripping through the parsed config struct.
+type configEditor struct {
+	path string
+	root yaml.Node
+}
+
+func loadConfigEditor(path string) (*configEditor, error) {
+	_, includes, err := parseYAMLIncludes(path)
+	if err != nil {
+		return nil, fmt.Errorf("parsing config: %w", err)
+	}
+	if len(includes) > 0 {
+		return nil, fmt.Errorf("admin editing is not supported when the config uses include directives — edit included files manually for now")
+	}
+
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("reading config: %w", err)
+	}
+
+	e := &configEditor{path: path}
+	if err := yaml.Unmarshal(raw, &e.root); err != nil {
+		return nil, fmt.Errorf("parsing config yaml: %w", err)
+	}
+	if e.root.Kind != yaml.DocumentNode || len(e.root.Content) == 0 {
+		return nil, fmt.Errorf("config has no document content")
+	}
+	if e.root.Content[0].Kind != yaml.MappingNode {
+		return nil, fmt.Errorf("config top-level is not a mapping")
+	}
+	return e, nil
+}
+
+// save validates the edited tree against newConfigFromYAML, writes a
+// .bak of the previous file, then writes via temp+rename for atomicity.
+func (e *configEditor) save() error {
+	out, err := yaml.Marshal(&e.root)
+	if err != nil {
+		return fmt.Errorf("marshaling config: %w", err)
+	}
+
+	if _, err := newConfigFromYAML(out); err != nil {
+		return fmt.Errorf("edited config is invalid: %w", err)
+	}
+
+	if existing, err := os.ReadFile(e.path); err == nil {
+		if werr := os.WriteFile(e.path+".bak", existing, 0644); werr != nil {
+			log.Printf("admin: failed to write backup: %v", werr)
+		}
+	}
+
+	tmpPath := e.path + ".tmp"
+	if err := os.WriteFile(tmpPath, out, 0644); err != nil {
+		return fmt.Errorf("writing temp file: %w", err)
+	}
+	if err := os.Rename(tmpPath, e.path); err != nil {
+		os.Remove(tmpPath)
+		return fmt.Errorf("renaming temp file into place: %w", err)
+	}
+	return nil
+}
+
+func (e *configEditor) topMapping() *yaml.Node {
+	return e.root.Content[0]
+}
+
+// findOrCreateKey returns the value node for the given key under a mapping.
+// If create is true and the key does not exist, it is appended with a fresh
+// value node of the given kind.
+func findOrCreateKey(m *yaml.Node, key string, create bool, valueKind yaml.Kind) (*yaml.Node, error) {
+	if m.Kind != yaml.MappingNode {
+		return nil, fmt.Errorf("node is not a mapping")
+	}
+	for i := 0; i+1 < len(m.Content); i += 2 {
+		if m.Content[i].Value == key {
+			return m.Content[i+1], nil
+		}
+	}
+	if !create {
+		return nil, fmt.Errorf("key %q not found", key)
+	}
+	keyNode := &yaml.Node{Kind: yaml.ScalarNode, Value: key}
+	valNode := &yaml.Node{Kind: valueKind}
+	m.Content = append(m.Content, keyNode, valNode)
+	return valNode, nil
+}
+
+func (e *configEditor) pagesNode(create bool) (*yaml.Node, error) {
+	return findOrCreateKey(e.topMapping(), "pages", create, yaml.SequenceNode)
+}
+
+// widgetSlot returns the sequence node holding the widget and the widget's
+// position within it. Caller can read via seq.Content[pos] or replace by
+// assigning to seq.Content[pos]. Use colIdx = -1 for head widgets.
+func (e *configEditor) widgetSlot(pageIdx, colIdx, widgetIdx int) (*yaml.Node, int, error) {
+	pageNode, err := e.pageNodeAt(pageIdx)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	var seq *yaml.Node
+	if colIdx == -1 {
+		seq, err = findOrCreateKey(pageNode, "head-widgets", false, yaml.SequenceNode)
+		if err != nil {
+			return nil, 0, err
+		}
+	} else {
+		columns, err := columnsOf(pageNode)
+		if err != nil {
+			return nil, 0, err
+		}
+		if colIdx < 0 || colIdx >= len(columns.Content) {
+			return nil, 0, fmt.Errorf("column index out of range")
+		}
+		seq, err = widgetsOf(columns.Content[colIdx])
+		if err != nil {
+			return nil, 0, err
+		}
+	}
+
+	if widgetIdx < 0 || widgetIdx >= len(seq.Content) {
+		return nil, 0, fmt.Errorf("widget index out of range")
+	}
+	return seq, widgetIdx, nil
+}
+
+func (e *configEditor) pageNodeAt(idx int) (*yaml.Node, error) {
+	pages, err := e.pagesNode(false)
+	if err != nil {
+		return nil, err
+	}
+	if pages.Kind != yaml.SequenceNode {
+		return nil, fmt.Errorf("pages is not a sequence")
+	}
+	if idx < 0 || idx >= len(pages.Content) {
+		return nil, fmt.Errorf("page index %d out of range", idx)
+	}
+	return pages.Content[idx], nil
+}
+
+func columnsOf(pageNode *yaml.Node) (*yaml.Node, error) {
+	return findOrCreateKey(pageNode, "columns", false, yaml.SequenceNode)
+}
+
+func widgetsOf(columnNode *yaml.Node) (*yaml.Node, error) {
+	return findOrCreateKey(columnNode, "widgets", true, yaml.SequenceNode)
+}
+
+func newPageNode(title string) *yaml.Node {
+	return &yaml.Node{
+		Kind: yaml.MappingNode,
+		Content: []*yaml.Node{
+			{Kind: yaml.ScalarNode, Value: "name"},
+			{Kind: yaml.ScalarNode, Value: title},
+			{Kind: yaml.ScalarNode, Value: "columns"},
+			{Kind: yaml.SequenceNode, Content: []*yaml.Node{
+				{Kind: yaml.MappingNode, Content: []*yaml.Node{
+					{Kind: yaml.ScalarNode, Value: "size"},
+					{Kind: yaml.ScalarNode, Value: "full"},
+					{Kind: yaml.ScalarNode, Value: "widgets"},
+					{Kind: yaml.SequenceNode},
+				}},
+			}},
+		},
+	}
+}
+
+// adminError renders a minimal HTML error page so failed mutations don't
+// leave the user staring at a blank screen. The hot-reload watcher will
+// still pick up any successful intermediate save state.
+func adminError(w http.ResponseWriter, status int, msg string) {
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	w.WriteHeader(status)
+	w.Write([]byte("<!doctype html><meta charset=utf-8><title>Edit error</title><body style=\"font-family:sans-serif;padding:2rem;max-width:50rem\"><h1>Couldn't save</h1><p>The change wasn't applied. Your config file is unchanged.</p><pre style=\"white-space:pre-wrap;background:#f4f4f4;padding:1rem;border-radius:4px\">"))
+	w.Write([]byte(htmlEscape(msg)))
+	w.Write([]byte("</pre><p><a href=\"javascript:history.back()\">Back</a></p>"))
+}
+
+func htmlEscape(s string) string {
+	r := strings.NewReplacer("&", "&amp;", "<", "&lt;", ">", "&gt;", "\"", "&quot;", "'", "&#39;")
+	return r.Replace(s)
+}
+
+// ---- handlers ----
+
+func (a *application) handleAdminAddPage(w http.ResponseWriter, r *http.Request) {
+	if !a.adminAccessAllowed(w, r) {
+		return
+	}
+	if err := r.ParseForm(); err != nil {
+		adminError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	title := strings.TrimSpace(r.FormValue("title"))
+	if title == "" {
+		adminError(w, http.StatusBadRequest, "page title is required")
+		return
+	}
+
+	editor, err := loadConfigEditor(a.ConfigPath)
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	pages, err := editor.pagesNode(true)
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	pages.Content = append(pages.Content, newPageNode(title))
+
+	if err := editor.save(); err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	http.Redirect(w, r, a.Config.Server.BaseURL+"/edit", http.StatusSeeOther)
+}
+
+func (a *application) handleAdminDeletePage(w http.ResponseWriter, r *http.Request) {
+	if !a.adminAccessAllowed(w, r) {
+		return
+	}
+	slug := r.PathValue("page")
+	idx, ok := a.freshPageIndexBySlug(slug)
+	if !ok {
+		a.handleNotFound(w, r)
+		return
+	}
+
+	editor, err := loadConfigEditor(a.ConfigPath)
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	pages, err := editor.pagesNode(false)
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if idx >= len(pages.Content) {
+		adminError(w, http.StatusInternalServerError, "page index out of range — config may have been edited externally")
+		return
+	}
+	if len(pages.Content) <= 1 {
+		adminError(w, http.StatusBadRequest, "cannot delete the last remaining page")
+		return
+	}
+	pages.Content = append(pages.Content[:idx], pages.Content[idx+1:]...)
+
+	if err := editor.save(); err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	http.Redirect(w, r, a.Config.Server.BaseURL+"/edit", http.StatusSeeOther)
+}
+
+func (a *application) handleAdminDeleteWidget(w http.ResponseWriter, r *http.Request) {
+	if !a.adminAccessAllowed(w, r) {
+		return
+	}
+	slug := r.PathValue("page")
+	pageIdx, ok := a.freshPageIndexBySlug(slug)
+	if !ok {
+		a.handleNotFound(w, r)
+		return
+	}
+	col, err := strconv.Atoi(r.PathValue("col"))
+	if err != nil {
+		a.handleNotFound(w, r)
+		return
+	}
+	idx, err := strconv.Atoi(r.PathValue("idx"))
+	if err != nil {
+		a.handleNotFound(w, r)
+		return
+	}
+
+	editor, err := loadConfigEditor(a.ConfigPath)
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	pageNode, err := editor.pageNodeAt(pageIdx)
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	columns, err := columnsOf(pageNode)
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if col < 0 || col >= len(columns.Content) {
+		adminError(w, http.StatusBadRequest, "column index out of range")
+		return
+	}
+	widgets, err := widgetsOf(columns.Content[col])
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if idx < 0 || idx >= len(widgets.Content) {
+		adminError(w, http.StatusBadRequest, "widget index out of range")
+		return
+	}
+	widgets.Content = append(widgets.Content[:idx], widgets.Content[idx+1:]...)
+
+	if err := editor.save(); err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	http.Redirect(w, r, a.Config.Server.BaseURL+"/edit/pages/"+slug, http.StatusSeeOther)
+}
+
+func (a *application) handleAdminMoveWidget(w http.ResponseWriter, r *http.Request) {
+	if !a.adminAccessAllowed(w, r) {
+		return
+	}
+	slug := r.PathValue("page")
+	pageIdx, ok := a.freshPageIndexBySlug(slug)
+	if !ok {
+		a.handleNotFound(w, r)
+		return
+	}
+	col, err := strconv.Atoi(r.PathValue("col"))
+	if err != nil {
+		a.handleNotFound(w, r)
+		return
+	}
+	idx, err := strconv.Atoi(r.PathValue("idx"))
+	if err != nil {
+		a.handleNotFound(w, r)
+		return
+	}
+
+	dir := r.URL.Query().Get("dir")
+	delta := 0
+	switch dir {
+	case "up":
+		delta = -1
+	case "down":
+		delta = 1
+	default:
+		adminError(w, http.StatusBadRequest, "dir must be 'up' or 'down'")
+		return
+	}
+
+	editor, err := loadConfigEditor(a.ConfigPath)
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	pageNode, err := editor.pageNodeAt(pageIdx)
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	columns, err := columnsOf(pageNode)
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	if col < 0 || col >= len(columns.Content) {
+		adminError(w, http.StatusBadRequest, "column index out of range")
+		return
+	}
+	widgets, err := widgetsOf(columns.Content[col])
+	if err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	target := idx + delta
+	if idx < 0 || idx >= len(widgets.Content) || target < 0 || target >= len(widgets.Content) {
+		adminError(w, http.StatusBadRequest, "cannot move further in that direction")
+		return
+	}
+	widgets.Content[idx], widgets.Content[target] = widgets.Content[target], widgets.Content[idx]
+
+	if err := editor.save(); err != nil {
+		adminError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	http.Redirect(w, r, a.Config.Server.BaseURL+"/edit/pages/"+slug, http.StatusSeeOther)
+}
+
+func (a *application) handleAdminEditWidget(w http.ResponseWriter, r *http.Request) {
+	if !a.adminAccessAllowed(w, r) {
+		return
+	}
+	if err := r.ParseForm(); err != nil {
+		adminError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	slug := r.PathValue("page")
+	page, pageIdx, exists := findPageBySlug(a.freshPagesFromDisk(), slug)
+	if !exists {
+		a.handleNotFound(w, r)
+		return
+	}
+	col, err := strconv.Atoi(r.PathValue("col"))
+	if err != nil {
+		a.handleNotFound(w, r)
+		return
+	}
+	idx, err := strconv.Atoi(r.PathValue("idx"))
+	if err != nil {
+		a.handleNotFound(w, r)
+		return
+	}
+
+	yamlText := r.FormValue("yaml")
+
+	rerenderError := func(msg string) {
+		a.renderWidgetEditor(w, r, editorRenderInput{
+			pageTitle:    page.Title,
+			pageSlug:     page.Slug,
+			col:          col,
+			idx:          idx,
+			widgetType:   widgetTypeFromYAML(yamlText),
+			yamlText:     yamlText,
+			errorMessage: msg,
+		})
+	}
+
+	newNode, err := parseWidgetYAML(yamlText)
+	if err != nil {
+		rerenderError(err.Error())
+		return
+	}
+
+	editor, err := loadConfigEditor(a.ConfigPath)
+	if err != nil {
+		rerenderError(err.Error())
+		return
+	}
+	seq, pos, err := editor.widgetSlot(pageIdx, col, idx)
+	if err != nil {
+		rerenderError(err.Error())
+		return
+	}
+	seq.Content[pos] = newNode
+
+	if err := editor.save(); err != nil {
+		rerenderError(err.Error())
+		return
+	}
+	http.Redirect(w, r,
+		fmt.Sprintf("%s/edit/pages/%s/widgets/%d/%d", a.Config.Server.BaseURL, slug, col, idx),
+		http.StatusSeeOther)
+}
+
+// parseWidgetYAML parses the editor's submitted text into a single mapping
+// node suitable for splicing into the config tree.
+func parseWidgetYAML(yamlText string) (*yaml.Node, error) {
+	var doc yaml.Node
+	if err := yaml.Unmarshal([]byte(yamlText), &doc); err != nil {
+		return nil, fmt.Errorf("YAML parse error: %w", err)
+	}
+	if doc.Kind != yaml.DocumentNode || len(doc.Content) == 0 {
+		return nil, fmt.Errorf("submitted YAML is empty")
+	}
+	node := doc.Content[0]
+	if node.Kind != yaml.MappingNode {
+		return nil, fmt.Errorf("widget YAML must be a mapping (key: value pairs)")
+	}
+	return node, nil
+}
+
+func (a *application) handleAdminCreateWidget(w http.ResponseWriter, r *http.Request) {
+	if !a.adminAccessAllowed(w, r) {
+		return
+	}
+	if err := r.ParseForm(); err != nil {
+		adminError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	slug := r.PathValue("page")
+	page, pageIdx, exists := findPageBySlug(a.freshPagesFromDisk(), slug)
+	if !exists {
+		a.handleNotFound(w, r)
+		return
+	}
+	col, err := strconv.Atoi(r.PathValue("col"))
+	if err != nil {
+		a.handleNotFound(w, r)
+		return
+	}
+
+	yamlText := r.FormValue("yaml")
+
+	rerenderError := func(msg string) {
+		a.renderWidgetEditor(w, r, editorRenderInput{
+			pageTitle:    page.Title,
+			pageSlug:     page.Slug,
+			isNew:        true,
+			col:          col,
+			widgetType:   widgetTypeFromYAML(yamlText),
+			yamlText:     yamlText,
+			errorMessage: msg,
+		})
+	}
+
+	newNode, err := parseWidgetYAML(yamlText)
+	if err != nil {
+		rerenderError(err.Error())
+		return
+	}
+
+	editor, err := loadConfigEditor(a.ConfigPath)
+	if err != nil {
+		rerenderError(err.Error())
+		return
+	}
+	pageNode, err := editor.pageNodeAt(pageIdx)
+	if err != nil {
+		rerenderError(err.Error())
+		return
+	}
+	columns, err := columnsOf(pageNode)
+	if err != nil {
+		rerenderError("page has no columns; add a column first")
+		return
+	}
+	if col < 0 || col >= len(columns.Content) {
+		rerenderError("column index out of range")
+		return
+	}
+	widgets, err := widgetsOf(columns.Content[col])
+	if err != nil {
+		rerenderError(err.Error())
+		return
+	}
+	widgets.Content = append(widgets.Content, newNode)
+
+	if err := editor.save(); err != nil {
+		rerenderError(err.Error())
+		return
+	}
+	http.Redirect(w, r, a.Config.Server.BaseURL+"/edit/pages/"+slug, http.StatusSeeOther)
+}

internal/glance/admin.go

@@ -0,0 +1,537 @@
+package glance
+
+import (
+	"bytes"
+	"html/template"
+	"net/http"
+	"strconv"
+
+	"gopkg.in/yaml.v3"
+)
+
+var (
+	adminIndexTemplate  = mustParseTemplate("admin.html", "document.html", "footer.html")
+	adminPageTemplate   = mustParseTemplate("admin-page.html", "document.html", "footer.html")
+	adminWidgetTemplate = mustParseTemplate("admin-widget.html", "document.html", "footer.html")
+)
+
+// allWidgetTypes mirrors the switch in newWidget(). Aliases ("stocks") omitted.
+var allWidgetTypes = []string{
+	"bookmarks", "calendar", "change-detection", "clock", "custom-api",
+	"dns-stats", "docker-containers", "extension", "group", "hacker-news",
+	"html", "iframe", "lobsters", "markets", "monitor", "reddit",
+	"releases", "repository", "rss", "search", "server-stats",
+	"split-column", "to-do", "twitch-channels", "twitch-top-games",
+	"videos", "weather",
+}
+
+// widgetFieldReferences caches the marshaled YAML of an empty instance of
+// each widget type, used to show users what fields are available when
+// editing. Computed once at startup.
+var widgetFieldReferences = func() map[string]string {
+	out := make(map[string]string, len(allWidgetTypes))
+	for _, t := range allWidgetTypes {
+		w, err := newWidget(t)
+		if err != nil {
+			continue
+		}
+		b, err := yaml.Marshal(w)
+		if err != nil {
+			continue
+		}
+		out[t] = string(b)
+	}
+	return out
+}()
+
+// widgetDocsAnchors maps a widget type to its anchor in upstream Glance docs.
+// Anchors are GitHub-rendered from the headings in docs/configuration.md.
+var widgetDocsAnchors = map[string]string{
+	"bookmarks":         "bookmarks",
+	"calendar":          "calendar",
+	"calendar-legacy":   "calendar-legacy",
+	"change-detection":  "changedetectionio",
+	"clock":             "clock",
+	"custom-api":        "custom-api",
+	"dns-stats":         "dns-stats",
+	"docker-containers": "docker-containers",
+	"extension":         "extension",
+	"group":             "group",
+	"hacker-news":       "hacker-news",
+	"lobsters":          "lobsters",
+	"markets":           "markets",
+	"monitor":           "monitor",
+	"reddit":            "reddit",
+	"releases":          "releases",
+	"repository":        "repository",
+	"rss":               "rss",
+	"search":            "search-widget",
+	"server-stats":      "server-stats",
+	"split-column":      "split-column",
+	"to-do":             "todo",
+	"twitch-channels":   "twitch-channels",
+	"twitch-top-games":  "twitch-top-games",
+	"videos":            "videos",
+	"weather":           "weather",
+}
+
+func widgetDocsURL(widgetType string) string {
+	anchor, ok := widgetDocsAnchors[widgetType]
+	if !ok {
+		return "https://github.com/glanceapp/glance/blob/main/docs/configuration.md#widgets"
+	}
+	return "https://github.com/glanceapp/glance/blob/main/docs/configuration.md#" + anchor
+}
+
+// widgetStarters provides hand-curated minimal-but-meaningful YAML for each
+// widget type, drawn from the upstream docs. Used to pre-fill the editor
+// when adding a new widget so users see a working shape they can adapt.
+var widgetStarters = map[string]string{
+	"bookmarks": `type: bookmarks
+groups:
+  - title: Sites
+    links:
+      - title: Glance
+        url: https://github.com/glanceapp/glance
+`,
+	"calendar":         "type: calendar\n",
+	"calendar-legacy":  "type: calendar-legacy\n",
+	"change-detection": `type: change-detection
+instance-url: https://changedetection.example.com/
+token: ${CHANGE_DETECTION_TOKEN}
+`,
+	"clock": "type: clock\n",
+	"custom-api": `type: custom-api
+url: https://api.example.com/data
+template: |
+  <p>Replace with a Go template that renders the JSON response.</p>
+`,
+	"dns-stats": `type: dns-stats
+service: pihole
+url: http://pi.hole
+allow-insecure: true
+username: admin
+password: ${DNS_PASSWORD}
+`,
+	"docker-containers": "type: docker-containers\n",
+	"extension": `type: extension
+url: https://example.com/extension
+`,
+	"group": `type: group
+widgets:
+  - type: hacker-news
+  - type: lobsters
+`,
+	"hacker-news": "type: hacker-news\n",
+	"html": `type: html
+source: |
+  <p>Hello from a custom HTML widget.</p>
+`,
+	"iframe": `type: iframe
+source: https://example.com
+`,
+	"lobsters": "type: lobsters\n",
+	"markets": `type: markets
+markets:
+  - symbol: SPY
+    name: S&P 500
+  - symbol: BTC-USD
+    name: Bitcoin
+`,
+	"monitor": `type: monitor
+title: Services
+sites:
+  - title: Example
+    url: https://example.com
+`,
+	"reddit": `type: reddit
+subreddit: technology
+`,
+	"releases": `type: releases
+repositories:
+  - glanceapp/glance
+`,
+	"repository": `type: repository
+repository: glanceapp/glance
+`,
+	"rss": `type: rss
+feeds:
+  - url: https://www.theverge.com/rss/index.xml
+    title: The Verge
+`,
+	"search":       "type: search\n",
+	"server-stats": "type: server-stats\n",
+	"split-column": `type: split-column
+widgets:
+  - type: clock
+  - type: search
+`,
+	"to-do": "type: to-do\n",
+	"twitch-channels": `type: twitch-channels
+channels:
+  - shroud
+`,
+	"twitch-top-games": "type: twitch-top-games\n",
+	"videos": `type: videos
+channels:
+  - UCXuqSBlHAE6Xw-yeJA0Tunw
+`,
+	"weather": `type: weather
+location: London, GB
+`,
+}
+
+func widgetStarterYAML(widgetType string) string {
+	if s, ok := widgetStarters[widgetType]; ok {
+		return s
+	}
+	return "type: " + widgetType + "\n"
+}
+
+type adminWidgetView struct {
+	ColumnIndex int
+	WidgetIndex int
+	ID          uint64
+	Title       string
+	Type        string
+	IsFirst     bool
+	IsLast      bool
+}
+
+type adminColumnView struct {
+	Index   int
+	Size    string
+	Widgets []adminWidgetView
+}
+
+type adminPageSummary struct {
+	Title       string
+	Slug        string
+	WidgetCount int
+}
+
+type adminPageDetail struct {
+	Title       string
+	Slug        string
+	HeadWidgets []adminWidgetView
+	Columns     []adminColumnView
+}
+
+type adminTemplateData struct {
+	App     *application
+	Request templateRequestData
+
+	Pages          []adminPageSummary
+	Page           *adminPageDetail
+	Widget         *adminWidgetView
+	WidgetTypes    []string
+	WidgetYAML     string
+	LoadError      string
+	FieldReference string
+	WidgetExample  string
+	DocsURL        string
+	IsNew          bool
+	ErrorMessage   string
+}
+
+func (a *application) handleAdminIndex(w http.ResponseWriter, r *http.Request) {
+	if !a.adminAccessAllowed(w, r) {
+		return
+	}
+
+	pages := a.freshPagesFromDisk()
+	summaries := make([]adminPageSummary, 0, len(pages))
+	for p := range pages {
+		page := &pages[p]
+		count := len(page.HeadWidgets)
+		for c := range page.Columns {
+			count += len(page.Columns[c].Widgets)
+		}
+		summaries = append(summaries, adminPageSummary{
+			Title:       page.Title,
+			Slug:        page.Slug,
+			WidgetCount: count,
+		})
+	}
+
+	data := adminTemplateData{App: a, Pages: summaries}
+	a.populateTemplateRequestData(&data.Request, r)
+	renderAdminTemplate(w, adminIndexTemplate, data)
+}
+
+func (a *application) handleAdminPage(w http.ResponseWriter, r *http.Request) {
+	if !a.adminAccessAllowed(w, r) {
+		return
+	}
+
+	pages := a.freshPagesFromDisk()
+	page, _, exists := findPageBySlug(pages, r.PathValue("page"))
+	if !exists {
+		a.handleNotFound(w, r)
+		return
+	}
+
+	detail := adminPageDetail{Title: page.Title, Slug: page.Slug}
+
+	for i, widget := range page.HeadWidgets {
+		detail.HeadWidgets = append(detail.HeadWidgets, adminWidgetView{
+			ColumnIndex: -1,
+			WidgetIndex: i,
+			ID:          widget.GetID(),
+			Title:       widget.GetTitle(),
+			Type:        widget.GetType(),
+		})
+	}
+
+	for c := range page.Columns {
+		col := &page.Columns[c]
+		view := adminColumnView{Index: c, Size: col.Size}
+		last := len(col.Widgets) - 1
+		for w, widget := range col.Widgets {
+			view.Widgets = append(view.Widgets, adminWidgetView{
+				ColumnIndex: c,
+				WidgetIndex: w,
+				ID:          widget.GetID(),
+				Title:       widget.GetTitle(),
+				Type:        widget.GetType(),
+				IsFirst:     w == 0,
+				IsLast:      w == last,
+			})
+		}
+		detail.Columns = append(detail.Columns, view)
+	}
+
+	data := adminTemplateData{App: a, Page: &detail, WidgetTypes: allWidgetTypes}
+	a.populateTemplateRequestData(&data.Request, r)
+	renderAdminTemplate(w, adminPageTemplate, data)
+}
+
+func (a *application) handleAdminWidget(w http.ResponseWriter, r *http.Request) {
+	if !a.adminAccessAllowed(w, r) {
+		return
+	}
+
+	pages := a.freshPagesFromDisk()
+	page, pageIdx, exists := findPageBySlug(pages, r.PathValue("page"))
+	if !exists {
+		a.handleNotFound(w, r)
+		return
+	}
+
+	col, err := strconv.Atoi(r.PathValue("col"))
+	if err != nil {
+		a.handleNotFound(w, r)
+		return
+	}
+	idx, err := strconv.Atoi(r.PathValue("idx"))
+	if err != nil {
+		a.handleNotFound(w, r)
+		return
+	}
+
+	var widget widget
+	if col == -1 {
+		if idx < 0 || idx >= len(page.HeadWidgets) {
+			a.handleNotFound(w, r)
+			return
+		}
+		widget = page.HeadWidgets[idx]
+	} else {
+		if col < 0 || col >= len(page.Columns) {
+			a.handleNotFound(w, r)
+			return
+		}
+		column := &page.Columns[col]
+		if idx < 0 || idx >= len(column.Widgets) {
+			a.handleNotFound(w, r)
+			return
+		}
+		widget = column.Widgets[idx]
+	}
+
+	yamlText, loadErr := loadWidgetYAML(a.ConfigPath, pageIdx, col, idx)
+
+	a.renderWidgetEditor(w, r, editorRenderInput{
+		pageTitle:   page.Title,
+		pageSlug:    page.Slug,
+		col:         col,
+		idx:         idx,
+		widgetType:  widget.GetType(),
+		widgetTitle: widget.GetTitle(),
+		yamlText:    yamlText,
+		loadError:   loadErr,
+	})
+}
+
+func (a *application) handleAdminNewWidget(w http.ResponseWriter, r *http.Request) {
+	if !a.adminAccessAllowed(w, r) {
+		return
+	}
+
+	pages := a.freshPagesFromDisk()
+	page, _, exists := findPageBySlug(pages, r.PathValue("page"))
+	if !exists {
+		a.handleNotFound(w, r)
+		return
+	}
+	col, err := strconv.Atoi(r.PathValue("col"))
+	if err != nil || col < 0 || col >= len(page.Columns) {
+		a.handleNotFound(w, r)
+		return
+	}
+	widgetType := r.URL.Query().Get("type")
+	if _, err := newWidget(widgetType); err != nil {
+		adminError(w, http.StatusBadRequest, "unknown widget type: "+widgetType)
+		return
+	}
+
+	a.renderWidgetEditor(w, r, editorRenderInput{
+		pageTitle:  page.Title,
+		pageSlug:   page.Slug,
+		isNew:      true,
+		col:        col,
+		widgetType: widgetType,
+		yamlText:   widgetStarterYAML(widgetType),
+	})
+}
+
+type editorRenderInput struct {
+	pageTitle    string
+	pageSlug     string
+	isNew        bool
+	col          int
+	idx          int
+	widgetType   string
+	widgetTitle  string
+	yamlText     string
+	loadError    string
+	errorMessage string
+}
+
+func (a *application) renderWidgetEditor(w http.ResponseWriter, r *http.Request, in editorRenderInput) {
+	view := adminWidgetView{
+		ColumnIndex: in.col,
+		WidgetIndex: in.idx,
+		Title:       in.widgetTitle,
+		Type:        in.widgetType,
+	}
+	detail := adminPageDetail{Title: in.pageTitle, Slug: in.pageSlug}
+
+	data := adminTemplateData{
+		App:            a,
+		Page:           &detail,
+		Widget:         &view,
+		IsNew:          in.isNew,
+		WidgetYAML:     in.yamlText,
+		LoadError:      in.loadError,
+		ErrorMessage:   in.errorMessage,
+		FieldReference: widgetFieldReferences[in.widgetType],
+		WidgetExample:  widgetStarters[in.widgetType],
+		DocsURL:        widgetDocsURL(in.widgetType),
+	}
+	a.populateTemplateRequestData(&data.Request, r)
+	renderAdminTemplate(w, adminWidgetTemplate, data)
+}
+
+// widgetTypeFromYAML extracts just the `type:` field from a YAML mapping.
+// Used when re-rendering the editor after a save error so docs/reference
+// match what the user is actually editing.
+func widgetTypeFromYAML(yamlText string) string {
+	var probe struct {
+		Type string `yaml:"type"`
+	}
+	_ = yaml.Unmarshal([]byte(yamlText), &probe)
+	return probe.Type
+}
+
+// freshPagesFromDisk reads the on-disk config and returns the parsed pages
+// with slugs auto-generated. Admin views use this instead of a.Config.Pages
+// because the fsnotify watcher debounces 500ms after a save, and during that
+// window a.Config still reflects the pre-save state. Falls back to a copy
+// of the cached config on any error.
+func (a *application) freshPagesFromDisk() []page {
+	contents, _, err := parseYAMLIncludes(a.ConfigPath)
+	if err != nil {
+		return a.Config.Pages
+	}
+	cfg, err := newConfigFromYAML(contents)
+	if err != nil {
+		return a.Config.Pages
+	}
+	for p := range cfg.Pages {
+		if cfg.Pages[p].Slug == "" {
+			cfg.Pages[p].Slug = titleToSlug(cfg.Pages[p].Title)
+		}
+	}
+	return cfg.Pages
+}
+
+func findPageBySlug(pages []page, slug string) (*page, int, bool) {
+	for i := range pages {
+		if pages[i].Slug == slug {
+			return &pages[i], i, true
+		}
+	}
+	return nil, -1, false
+}
+
+// freshPageIndexBySlug looks up the on-disk page index by slug. Mutating
+// handlers must use this rather than a.pageIndexBySlug because the cached
+// a.Config can lag the file by up to ~500ms after a save.
+func (a *application) freshPageIndexBySlug(slug string) (int, bool) {
+	_, idx, ok := findPageBySlug(a.freshPagesFromDisk(), slug)
+	return idx, ok
+}
+
+// loadWidgetYAML reads the on-disk config and returns the marshaled YAML for
+// one widget. Errors are returned as a string so the template can show them
+// without preventing the page from rendering.
+func loadWidgetYAML(path string, pageIdx, col, idx int) (string, string) {
+	editor, err := loadConfigEditor(path)
+	if err != nil {
+		return "", err.Error()
+	}
+	seq, pos, err := editor.widgetSlot(pageIdx, col, idx)
+	if err != nil {
+		return "", err.Error()
+	}
+	out, err := yaml.Marshal(seq.Content[pos])
+	if err != nil {
+		return "", err.Error()
+	}
+	return string(out), ""
+}
+
+// adminAccessAllowed enforces that admin endpoints either require auth, or
+// have been explicitly opted into without auth via config.admin.allow-without-auth.
+// Returns false if the response has been written and the caller should bail.
+func (a *application) adminAccessAllowed(w http.ResponseWriter, r *http.Request) bool {
+	if !a.RequiresAuth && !a.Config.Admin.AllowWithoutAuth {
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		w.WriteHeader(http.StatusForbidden)
+		w.Write([]byte(`<!doctype html><meta charset=utf-8><title>Editing disabled</title>` +
+			`<body style="font-family:sans-serif;padding:2rem;max-width:50rem;line-height:1.5">` +
+			`<h1>Editing is disabled</h1>` +
+			`<p>The edit UI requires authentication. Either:</p>` +
+			`<ul>` +
+			`<li>Configure <code>auth.users</code> in your config (recommended), or</li>` +
+			`<li>Set <code>admin.allow-without-auth: true</code> in your config if you accept that anyone reachable on the network can edit it. (The legacy <code>admin</code> key still works for this option.)</li>` +
+			`</ul>` +
+			`</body>`))
+		return false
+	}
+	if a.handleUnauthorizedResponse(w, r, redirectToLogin) {
+		return false
+	}
+	return true
+}
+
+func renderAdminTemplate(w http.ResponseWriter, t *template.Template, data adminTemplateData) {
+	var buf bytes.Buffer
+	if err := t.Execute(&buf, data); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		w.Write([]byte(err.Error()))
+		return
+	}
+	w.Write(buf.Bytes())
+}

internal/glance/config.go

@@ -65,6 +65,12 @@ type config struct {
 		AppBackgroundColor string        `yaml:"app-background-color"`
 	} `yaml:"branding"`
 
+	Admin struct {
+		// AllowWithoutAuth permits access to /admin even when auth.users is empty.
+		// Off by default because admin can rewrite the config file.
+		AllowWithoutAuth bool `yaml:"allow-without-auth"`
+	} `yaml:"admin"`
+
 	Pages []page `yaml:"pages"`
 }
 

internal/glance/glance.go

@@ -28,9 +28,10 @@ const STATIC_ASSETS_CACHE_DURATION = 24 * time.Hour
 var reservedPageSlugs = []string{"login", "logout"}
 
 type application struct {
-	Version   string
+	Version    string
-	CreatedAt time.Time
+	CreatedAt  time.Time
-	Config    config
+	Config     config
+	ConfigPath string
 
 	parsedManifest []byte
 
@@ -44,11 +45,12 @@ type application struct {
 	failedAuthAttempts     map[string]*failedAuthAttempt
 }
 
-func newApplication(c *config) (*application, error) {
+func newApplication(c *config, configPath string) (*application, error) {
 	app := &application{
 		Version:    buildVersion,
 		CreatedAt:  time.Now(),
 		Config:     *c,
+		ConfigPath: configPath,
 		slugToPage: make(map[string]*page),
 		widgetByID: make(map[uint64]widget),
 	}
@@ -450,6 +452,18 @@ func (a *application) server() (func() error, func() error) {
 		w.WriteHeader(http.StatusOK)
 	})
 
+	mux.HandleFunc("GET /edit", a.handleAdminIndex)
+	mux.HandleFunc("GET /edit/pages/{page}", a.handleAdminPage)
+	mux.HandleFunc("GET /edit/pages/{page}/widgets/{col}/{idx}", a.handleAdminWidget)
+
+	mux.HandleFunc("POST /edit/api/pages", a.handleAdminAddPage)
+	mux.HandleFunc("POST /edit/api/pages/{page}/delete", a.handleAdminDeletePage)
+	mux.HandleFunc("GET /edit/pages/{page}/widgets/{col}/new", a.handleAdminNewWidget)
+	mux.HandleFunc("POST /edit/api/pages/{page}/widgets/{col}/new", a.handleAdminCreateWidget)
+	mux.HandleFunc("POST /edit/api/pages/{page}/widgets/{col}/{idx}", a.handleAdminEditWidget)
+	mux.HandleFunc("POST /edit/api/pages/{page}/widgets/{col}/{idx}/delete", a.handleAdminDeleteWidget)
+	mux.HandleFunc("POST /edit/api/pages/{page}/widgets/{col}/{idx}/move", a.handleAdminMoveWidget)
+
 	if a.RequiresAuth {
 		mux.HandleFunc("GET /login", a.handleLoginPageRequest)
 		mux.HandleFunc("GET /logout", a.handleLogoutRequest)

internal/glance/main.go

@@ -114,7 +114,7 @@ func serveApp(configPath string) error {
 			return
 		}
 
-		app, err := newApplication(config)
+		app, err := newApplication(config, configPath)
 		if err != nil {
 			log.Printf("Failed to create application: %v", err)
 
@@ -165,7 +165,7 @@ func serveApp(configPath string) error {
 			return fmt.Errorf("validating config file: %w", err)
 		}
 
-		app, err := newApplication(config)
+		app, err := newApplication(config, configPath)
 		if err != nil {
 			return fmt.Errorf("creating application: %w", err)
 		}

internal/glance/templates/admin-page.html

@@ -0,0 +1,79 @@
+{{- template "document.html" . }}
+
+{{- define "document-title" }}Edit {{ .Page.Title }} - {{ .App.Config.Branding.AppName }}{{ end }}
+
+{{- define "document-body" }}
+<div class="flex flex-column body-content">
+    <main class="content-bounds" style="padding-block: 2rem;">
+        <div class="margin-bottom-15">
+            <a class="color-subdue" href="{{ .App.Config.Server.BaseURL }}/edit">← Edit</a>
+        </div>
+        <h1 class="size-h1">{{ .Page.Title }}</h1>
+        <p class="color-subdue margin-bottom-25">/{{ .Page.Slug }}</p>
+
+        {{- if .Page.HeadWidgets }}
+        <h2 class="size-h2 margin-bottom-10">Head widgets</h2>
+        <ul class="list list-gap-10 margin-bottom-25">
+            {{- range .Page.HeadWidgets }}
+            <li>
+                <a class="color-primary" href="{{ $.App.Config.Server.BaseURL }}/edit/pages/{{ $.Page.Slug }}/widgets/-1/{{ .WidgetIndex }}">
+                    {{ if .Title }}{{ .Title }}{{ else }}<em>(untitled)</em>{{ end }}
+                </a>
+                <span class="color-subdue"> — {{ .Type }}</span>
+            </li>
+            {{- end }}
+        </ul>
+        {{- end }}
+
+        <h2 class="size-h2 margin-bottom-10">Columns</h2>
+        {{- if not .Page.Columns }}
+        <p class="color-subdue">No columns configured on this page. Edit the YAML manually to add columns — column editing comes in a later phase.</p>
+        {{- end }}
+        {{- range $colIdx, $col := .Page.Columns }}
+        <section class="margin-bottom-25">
+            <h3 class="size-h3 margin-bottom-10">
+                Column {{ $col.Index }}
+                <span class="color-subdue size-h5">({{ if $col.Size }}{{ $col.Size }}{{ else }}default{{ end }})</span>
+            </h3>
+            {{- if not $col.Widgets }}
+            <p class="color-subdue">No widgets in this column.</p>
+            {{- else }}
+            <ul class="list list-gap-10 margin-bottom-15">
+                {{- range $col.Widgets }}
+                <li class="flex items-center gap-10">
+                    <div class="grow">
+                        <a class="color-primary" href="{{ $.App.Config.Server.BaseURL }}/edit/pages/{{ $.Page.Slug }}/widgets/{{ .ColumnIndex }}/{{ .WidgetIndex }}">
+                            {{ if .Title }}{{ .Title }}{{ else }}<em>(untitled)</em>{{ end }}
+                        </a>
+                        <span class="color-subdue"> — {{ .Type }}</span>
+                    </div>
+                    <form method="post" action="{{ $.App.Config.Server.BaseURL }}/edit/api/pages/{{ $.Page.Slug }}/widgets/{{ .ColumnIndex }}/{{ .WidgetIndex }}/move?dir=up">
+                        <button type="submit" {{ if .IsFirst }}disabled{{ end }}>↑</button>
+                    </form>
+                    <form method="post" action="{{ $.App.Config.Server.BaseURL }}/edit/api/pages/{{ $.Page.Slug }}/widgets/{{ .ColumnIndex }}/{{ .WidgetIndex }}/move?dir=down">
+                        <button type="submit" {{ if .IsLast }}disabled{{ end }}>↓</button>
+                    </form>
+                    <form method="post" action="{{ $.App.Config.Server.BaseURL }}/edit/api/pages/{{ $.Page.Slug }}/widgets/{{ .ColumnIndex }}/{{ .WidgetIndex }}/delete"
+                          onsubmit="return confirm('Delete this widget?');">
+                        <button type="submit" class="color-negative">Delete</button>
+                    </form>
+                </li>
+                {{- end }}
+            </ul>
+            {{- end }}
+
+            <form method="get" action="{{ $.App.Config.Server.BaseURL }}/edit/pages/{{ $.Page.Slug }}/widgets/{{ $col.Index }}/new" class="flex gap-10 items-center">
+                <select name="type" required>
+                    <option value="">— add widget —</option>
+                    {{- range $.WidgetTypes }}
+                    <option value="{{ . }}">{{ . }}</option>
+                    {{- end }}
+                </select>
+                <button type="submit">Configure & add</button>
+            </form>
+        </section>
+        {{- end }}
+    </main>
+    {{ template "footer.html" . }}
+</div>
+{{- end }}

internal/glance/templates/admin-widget.html

@@ -0,0 +1,94 @@
+{{- template "document.html" . }}
+
+{{- define "document-title" }}{{ if .IsNew }}Add {{ .Widget.Type }}{{ else }}Edit {{ if .Widget.Title }}{{ .Widget.Title }}{{ else }}{{ .Widget.Type }}{{ end }}{{ end }} - {{ .App.Config.Branding.AppName }}{{ end }}
+
+{{- define "document-body" }}
+<div class="flex flex-column body-content">
+    <main class="content-bounds" style="padding-block: 2rem;">
+        <div class="margin-bottom-15">
+            <a class="color-subdue" href="{{ .App.Config.Server.BaseURL }}/edit">← Edit</a>
+            <span class="color-subdue"> / </span>
+            <a class="color-subdue" href="{{ .App.Config.Server.BaseURL }}/edit/pages/{{ .Page.Slug }}">{{ .Page.Title }}</a>
+        </div>
+        <h1 class="size-h1">
+            {{- if .IsNew -}}
+            Add widget <span class="color-subdue size-h4">— {{ .Widget.Type }}</span>
+            {{- else -}}
+            {{ if .Widget.Title }}{{ .Widget.Title }}{{ else }}<em>(untitled)</em>{{ end }}
+            <span class="color-subdue size-h4">— {{ .Widget.Type }}</span>
+            {{- end }}
+        </h1>
+        <p class="color-subdue margin-bottom-25">
+            {{- if .IsNew -}}
+            New widget for column {{ .Widget.ColumnIndex }}
+            {{- else if eq .Widget.ColumnIndex -1 -}}
+            head widget #{{ .Widget.WidgetIndex }}
+            {{- else -}}
+            column {{ .Widget.ColumnIndex }}, widget #{{ .Widget.WidgetIndex }}
+            {{- end }}
+        </p>
+
+        {{- if .ErrorMessage }}
+        <div class="margin-bottom-15" style="padding:1rem;background:#fee;border:1px solid #c00;border-radius:4px;color:#700;">
+            <strong>Couldn't save:</strong>
+            <pre style="white-space:pre-wrap;margin:0.5rem 0 0;">{{ .ErrorMessage }}</pre>
+        </div>
+        {{- end }}
+
+        {{- if .LoadError }}
+        <div class="margin-bottom-15" style="padding:1rem;background:#fee;border:1px solid #c00;border-radius:4px;">
+            <strong>Can't load YAML:</strong>
+            <pre style="white-space:pre-wrap;margin-top:0.5rem;">{{ .LoadError }}</pre>
+        </div>
+        {{- end }}
+
+        {{- if or .WidgetYAML .IsNew }}
+        <details class="margin-bottom-15" style="background:var(--color-widget-content-frame-background);border:1px solid var(--color-widget-content-border);border-radius:4px;padding:0.75rem;" {{ if .IsNew }}open{{ end }}>
+            <summary style="cursor:pointer;font-weight:bold;">How to edit a {{ if .Widget.Type }}<code>{{ .Widget.Type }}</code>{{ else }}widget{{ end }}</summary>
+            <div style="margin-top:0.75rem;line-height:1.6;">
+                {{- if .WidgetExample }}
+                <p style="margin-bottom:0.25rem;">A working example of a <code>{{ .Widget.Type }}</code> widget:</p>
+                <pre style="margin:0 0 0.75rem;padding:0.5rem;background:rgba(0,0,0,0.15);border-radius:3px;font-size:0.85rem;overflow:auto;">{{- .WidgetExample -}}</pre>
+                {{- end }}
+                {{- if .FieldReference }}
+                <p style="margin-bottom:0.25rem;">All fields supported by <code>{{ .Widget.Type }}</code> (defaults shown — fields with <code>yaml:"-"</code> tags or empty defaults still apply):</p>
+                <pre style="margin:0 0 0.75rem;padding:0.5rem;background:rgba(0,0,0,0.15);border-radius:3px;font-size:0.85rem;overflow:auto;max-height:18rem;">{{- .FieldReference -}}</pre>
+                {{- end }}
+                <p style="margin-bottom:0.25rem;">YAML quick tips:</p>
+                <ul style="padding-left:1.5rem;margin:0 0 0.75rem;">
+                    <li>Indentation matters — use two spaces per level, never tabs.</li>
+                    <li>Strings, numbers, booleans go inline: <code>limit: 10</code>, <code>hide-header: true</code>.</li>
+                    <li>List items start with <code>-</code> and align under the parent key.</li>
+                    <li>Pull secrets from the environment: <code>token: ${env:MY_TOKEN}</code>.</li>
+                </ul>
+                <p>Validation runs before saving — if the YAML is invalid, your file isn't touched and the error appears above.</p>
+                {{- if .Widget.Type }}
+                <p>Full upstream reference: <a href="{{ .DocsURL }}" target="_blank" rel="noreferrer">{{ .Widget.Type }} docs ↗</a></p>
+                {{- end }}
+            </div>
+        </details>
+
+        <form method="post"
+              action="{{- if .IsNew -}}
+                  {{ .App.Config.Server.BaseURL }}/edit/api/pages/{{ .Page.Slug }}/widgets/{{ .Widget.ColumnIndex }}/new
+              {{- else -}}
+                  {{ .App.Config.Server.BaseURL }}/edit/api/pages/{{ .Page.Slug }}/widgets/{{ .Widget.ColumnIndex }}/{{ .Widget.WidgetIndex }}
+              {{- end }}">
+            <label for="widget-yaml" class="form-label widget-header margin-bottom-10">Widget YAML</label>
+            <textarea id="widget-yaml" name="yaml" rows="20" spellcheck="false"
+                      style="width:100%;font-family:monospace;font-size:0.9rem;padding:0.75rem;background:var(--color-widget-content-frame-background);color:var(--color-text-base);border:1px solid var(--color-widget-content-border);border-radius:4px;">{{- .WidgetYAML -}}</textarea>
+            <div class="flex gap-10 margin-top-10">
+                <button type="submit">{{ if .IsNew }}Create{{ else }}Save{{ end }}</button>
+                <a href="{{ .App.Config.Server.BaseURL }}/edit/pages/{{ .Page.Slug }}" class="color-subdue" style="align-self:center;">Cancel</a>
+            </div>
+            {{- if not .IsNew }}
+            <p class="color-subdue size-h5" style="margin-top:0.5rem;">
+                You can change <code>type:</code> here to convert this widget to any type.
+            </p>
+            {{- end }}
+        </form>
+        {{- end }}
+    </main>
+    {{ template "footer.html" . }}
+</div>
+{{- end }}

internal/glance/templates/admin.html

@@ -0,0 +1,40 @@
+{{- template "document.html" . }}
+
+{{- define "document-title" }}Edit - {{ .App.Config.Branding.AppName }}{{ end }}
+
+{{- define "document-body" }}
+<div class="flex flex-column body-content">
+    <main class="content-bounds" style="padding-block: 2rem;">
+        <h1 class="size-h1 margin-bottom-15">Edit</h1>
+        <p class="color-subdue margin-bottom-25">
+            Editing <code>{{ .App.ConfigPath }}</code>. Changes take effect via hot-reload.
+        </p>
+
+        <h2 class="size-h2 margin-bottom-10">Pages</h2>
+        <ul class="list list-gap-10 margin-bottom-25">
+            {{- range .Pages }}
+            <li class="flex items-center gap-10">
+                <div class="grow">
+                    <a class="color-primary" href="{{ $.App.Config.Server.BaseURL }}/edit/pages/{{ .Slug }}">
+                        {{ .Title }}
+                    </a>
+                    <span class="color-subdue"> — {{ .WidgetCount }} widget{{ if ne .WidgetCount 1 }}s{{ end }}</span>
+                    <div class="color-subdue size-h5">/{{ .Slug }}</div>
+                </div>
+                <form method="post" action="{{ $.App.Config.Server.BaseURL }}/edit/api/pages/{{ .Slug }}/delete"
+                      onsubmit="return confirm('Delete page &quot;{{ .Title }}&quot; and all its widgets?');">
+                    <button type="submit" class="color-negative">Delete</button>
+                </form>
+            </li>
+            {{- end }}
+        </ul>
+
+        <h3 class="size-h3 margin-bottom-10">Add a page</h3>
+        <form method="post" action="{{ .App.Config.Server.BaseURL }}/edit/api/pages" class="flex gap-10 items-center">
+            <input type="text" name="title" required placeholder="Page title" class="input grow">
+            <button type="submit">Add page</button>
+        </form>
+    </main>
+    {{ template "footer.html" . }}
+</div>
+{{- end }}

internal/glance/templates/page.html

@@ -43,6 +43,13 @@
                 </div>
             </div>
             {{ end }}
+            {{- if or .App.RequiresAuth .App.Config.Admin.AllowWithoutAuth }}
+            <a class="block self-center" href="{{ .App.Config.Server.BaseURL }}/edit" title="Edit dashboard">
+                <svg class="logout-button" stroke="var(--color-text-subdue)" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="1.5">
+                    <path stroke-linecap="round" stroke-linejoin="round" d="m16.862 4.487 1.687-1.688a1.875 1.875 0 1 1 2.652 2.652L6.832 19.82a4.5 4.5 0 0 1-1.897 1.13l-2.685.8.8-2.685a4.5 4.5 0 0 1 1.13-1.897L16.863 4.487Zm0 0L19.5 7.125" />
+                </svg>
+            </a>
+            {{- end }}
             {{- if .App.RequiresAuth }}
             <a class="block self-center" href="{{ .App.Config.Server.BaseURL }}/logout" title="Logout">
                 <svg class="logout-button" stroke="var(--color-text-subdue)" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="1.5">
@@ -92,6 +99,15 @@
             </div>
             {{ end }}
 
+            {{ if or .App.RequiresAuth .App.Config.Admin.AllowWithoutAuth }}
+            <a href="{{ .App.Config.Server.BaseURL }}/edit" class="flex justify-between items-center">
+                <div class="size-h3">Edit dashboard</div>
+                <svg class="ui-icon" stroke="var(--color-text-subdue)" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="1.5">
+                    <path stroke-linecap="round" stroke-linejoin="round" d="m16.862 4.487 1.687-1.688a1.875 1.875 0 1 1 2.652 2.652L6.832 19.82a4.5 4.5 0 0 1-1.897 1.13l-2.685.8.8-2.685a4.5 4.5 0 0 1 1.13-1.897L16.863 4.487Zm0 0L19.5 7.125" />
+                </svg>
+            </a>
+            {{ end }}
+
             {{ if .App.RequiresAuth }}
             <a href="{{ .App.Config.Server.BaseURL }}/logout" class="flex justify-between items-center">
                 <div class="size-h3">Logout</div>

internal/glance/widget.go

@@ -128,6 +128,7 @@ type widget interface {
 	Render() template.HTML
 	GetType() string
 	GetID() uint64
+	GetTitle() string
 
 	initialize() error
 	requiresUpdate(*time.Time) bool
@@ -210,6 +211,10 @@ func (w *widgetBase) GetType() string {
 	return w.Type
 }
 
+func (w *widgetBase) GetTitle() string {
+	return w.Title
+}
+
 func (w *widgetBase) setProviders(providers *widgetProviders) {
 	w.Providers = providers
 }