diff --git a/etaf-ui-data.el b/etaf-ui-data.el
new file mode 100644
index 0000000..d5dc267
--- /dev/null
+++ b/etaf-ui-data.el
@@ -0,0 +1,342 @@
+;;; etaf-ui-data.el --- Data-aware ETAF UI Components -*- lexical-binding: t; -*-
+
+;; SPDX-License-Identifier: GPL-3.0-or-later
+
+;;; Commentary:
+
+;; DataGrid and Pagination adapt ETAF Data Controller state onto basic
+;; Components.  They do not duplicate Table or Button behavior.
+
+;;; Code:
+
+(require 'etaf-ui-table)
+
+(declare-function etaf-data-status "etaf-data" (controller))
+(declare-function etaf-data-items "etaf-data" (controller))
+(declare-function etaf-data-page "etaf-data" (controller))
+(declare-function etaf-data-page-size "etaf-data" (controller))
+(declare-function etaf-data-total "etaf-data" (controller))
+(declare-function etaf-data-previous-page "etaf-data" (controller))
+(declare-function etaf-data-next-page "etaf-data" (controller))
+(declare-function etaf-data-selected-ref "etaf-data" (controller identity))
+(declare-function etaf-data-item-identity "etaf-data" (controller item))
+
+(defun etaf-ui--data-grid-default-row-ref (controller row)
+  "Return a stable internal Host reference for CONTROLLER ROW.
+
+DataGrid owns this fallback so the presentational Table can keep its stricter
+interactive-row contract.  The controller's validated item identity is the
+only input, making the reference stable across keyed Range updates."
+  (intern (format "etaf-data-grid-row-%s"
+                 (etaf-data-item-identity
+                  controller row))))
+
+(defun etaf-ui--data-grid-row-ref (row-ref on-row-press controller row)
+  "Return a validated stable Host reference for interactive ROW.
+
+An explicit ROW-REF remains caller-owned.  Interactive grids without one use
+the CONTROLLER identity fallback; when ON-ROW-PRESS is nil, rows have no Host
+reference."
+  (when on-row-press
+    (let ((ref (if row-ref
+                   (funcall row-ref row)
+                 (etaf-ui--data-grid-default-row-ref controller row))))
+      (unless ref
+        (error "ETAF DataGrid :row-ref must return a non-nil stable ref"))
+      ref)))
+
+(defun etaf-ui--data-grid-row-action (cache key row callback)
+  "Return CACHE's stable press action for row KEY.
+
+The vector is retained by DataGrid setup state; only its current ROW and
+CALLBACK change across renders.  Unchanged keyed rows therefore keep the same
+handler identity and avoid rebuilding behavior resources."
+  (let ((entry (gethash key cache)))
+    (unless entry
+      (setq entry (vector row callback nil))
+      (aset entry 2
+         (lambda ()
+              (let ((current (aref entry 1)))
+                (when current
+                  (funcall current (aref entry 0))))))
+      (puthash key entry cache))
+    (aset entry 0 row)
+    (aset entry 1 callback)
+    (aref entry 2)))
+
+(defun etaf-ui--data-grid-row-selected-p (controller row row-selected-p)
+  "Return whether ROW is selected in CONTROLLER or by ROW-SELECTED-P."
+  (or (and row-selected-p (funcall row-selected-p row))
+      (etaf-value
+       (etaf-data-selected-ref
+        controller (etaf-data-item-identity controller row)))))
+
+(defun etaf-ui--data-grid-row
+    (controller entry columns row-ref on-row-press row-selected-p row-actions
+                theme)
+  "Return one retained DataGrid row for keyed ENTRY.
+CONTROLLER owns selection identity; ROW-REF, ON-ROW-PRESS, and ROW-SELECTED-P
+define the interaction contract.  ROW-ACTIONS retains callback identity, and
+THEME is the resolved table-paint snapshot for this item."
+  (let* ((key (car entry))
+         (row (cdr entry))
+         (border-color (plist-get theme :ui-table-border))
+         (selected-p
+          (etaf-ui--data-grid-row-selected-p
+           controller row row-selected-p)))
+    (unless key
+      (error "ETAF DataGrid row-key must return a non-nil stable scalar"))
+    (etaf-node
+     'row
+     (list :key key
+           :class (concat "etaf-table-row" (when selected-p " selected"))
+           :ref (etaf-ui--data-grid-row-ref
+                 row-ref on-row-press controller row)
+           :role (when on-row-press 'button)
+           :tab-index (when on-row-press 0)
+           :color (when selected-p
+                    (plist-get theme :ui-table-selected-fg))
+           :background-color (when selected-p
+                               (plist-get theme :ui-table-selected-bg))
+           :border-bottom-width 1
+           :border-bottom-style 'solid
+           :border-bottom-color border-color
+           :on-press
+           (and on-row-press
+                (etaf-ui--data-grid-row-action
+                 row-actions key row on-row-press)))
+     (etaf-ui--table-cells row columns border-color))))
+
+(defun etaf-ui--data-grid-state-label (key text &optional class color)
+  "Return TEXT as a non-row DataGrid state label identified by KEY.
+CLASS and COLOR optionally style the label."
+  (etaf-node 'etaf-label
+             (list :key key :text text :class class :color color)
+             nil))
+
+(defun etaf-ui--data-grid-body-entries
+    (controller row-key loading-label error-label empty-label)
+  "Return public keyed Range entries for CONTROLLER and labels.
+ROW-KEY identifies successful rows.  Loading, error, and empty states use one
+stable sentinel entry so every body state remains below the same Range.
+LOADING-LABEL, ERROR-LABEL, and EMPTY-LABEL override default state text."
+  (let* ((status (etaf-value (etaf-data-status controller)))
+         (items (etaf-value (etaf-data-items controller))))
+    (cond
+     ((and (eq status 'success) items)
+      (etaf-ui--table-entries items row-key))
+     ((and (eq status 'loading) (null items))
+      (list (cons 'loading
+                  (list :etaf-data-grid-state 'loading
+                        :text (or loading-label "Loading...")))))
+     ((and (eq status 'error) (null items))
+      (list (cons 'error
+                  (list :etaf-data-grid-state 'error
+                        :text (or error-label "Unable to load data.")))))
+     (t
+      (list (cons 'empty
+                  (list :etaf-data-grid-state 'empty
+                        :text (or empty-label "No data."))))))))
+
+(defun etaf-ui--data-grid-state-entry-node (entry)
+  "Return the state label View represented by keyed ENTRY."
+  (let* ((state (cdr entry))
+         (kind (plist-get state :etaf-data-grid-state))
+         (theme (and (eq kind 'error)
+                     (etaf-ui--style-tokens :ui-data-grid-error-fg))))
+    (etaf-ui--data-grid-state-label
+     kind (plist-get state :text)
+     (when (eq kind 'error) "etaf-data-grid-error")
+     (and theme (plist-get theme :ui-data-grid-error-fg)))))
+
+(etaf-define-component etaf-ui--data-grid-body-item
+    (&key controller entry columns row-ref on-row-press row-selected-p
+          row-actions)
+  "Render one retained keyed DataGrid ENTRY with a cached row action."
+  :view
+  (expr
+   (if (plist-get (cdr entry) :etaf-data-grid-state)
+       (etaf-ui--data-grid-state-entry-node entry)
+     (etaf-ui--data-grid-row
+      controller entry columns row-ref on-row-press row-selected-p row-actions
+      (etaf-ui--style-tokens
+       :ui-table-border :ui-table-selected-fg :ui-table-selected-bg)))))
+
+;;;###autoload
+(etaf-define-component etaf-data-grid
+    (&key controller columns row-key on-row-press row-ref row-selected-p
+          loading-label error-label empty-label)
+  "Render DATA CONTROLLER state through the public Component DSL.
+
+DataGrid owns loading, error, empty, and controller-selection adaptation.
+Its keyed Range retains row identity across insert, reorder, and update; setup
+state only caches stable row action closures."
+  :setup (list :row-actions (make-hash-table :test #'equal))
+  :view
+  (column
+   :class "etaf-data-grid etaf-table"
+   :color (plist-get (etaf-ui--style-tokens :ui-fg) :ui-fg)
+   (etaf-ui--table-header :columns columns)
+   (column
+    :class "etaf-table-body"
+    (etaf-ui--data-grid-body-item
+     :for (entry
+           (etaf-ui--data-grid-body-entries
+            controller row-key loading-label error-label empty-label))
+     :key (car entry)
+     :controller controller :entry entry :columns columns
+     :row-ref row-ref :on-row-press on-row-press
+     :row-selected-p row-selected-p
+     :row-actions (plist-get (etaf-state) :row-actions)))
+   (slot :name 'footer)))
+
+;;;###autoload
+(etaf-define-component etaf-pagination
+    (&key controller previous-ref next-ref class color bgcolor border padding
+          aria-label)
+  "Render a controlled pager for DATA CONTROLLER with retained controls."
+  :setup
+  (let* ((state (list :controller nil))
+         (page-value
+          (lambda ()
+            (let ((controller (plist-get state :controller)))
+              (max 1 (or (and controller
+                               (etaf-value (etaf-data-page controller)))
+                          1)))))
+         (page-size-value
+          (lambda ()
+            (let ((controller (plist-get state :controller)))
+              (max 1 (or (and controller
+                               (etaf-value (etaf-data-page-size controller)))
+                          1)))))
+         (total-value
+          (lambda ()
+            (let ((controller (plist-get state :controller)))
+              (max 0 (or (and controller
+                               (etaf-value (etaf-data-total controller)))
+                          0)))))
+         (pages-value
+          (lambda ()
+            (max 1 (ceiling (/ (float (funcall total-value))
+                               (funcall page-size-value))))))
+         (loading-p
+          (lambda ()
+            (let ((controller (plist-get state :controller)))
+              (and controller
+                   (eq (etaf-value (etaf-data-status controller))
+                       'loading)))))
+         (previous-disabled
+          (lambda ()
+            (or (funcall loading-p) (<= (funcall page-value) 1))))
+         (next-disabled
+          (lambda ()
+            (or (funcall loading-p)
+                (>= (funcall page-value) (funcall pages-value)))))
+         (previous
+          (lambda ()
+            (let ((controller (plist-get state :controller)))
+              (when (and controller
+                         (not (funcall previous-disabled)))
+                (etaf-data-previous-page controller)))))
+         (next
+          (lambda ()
+            (let ((controller (plist-get state :controller)))
+              (when (and controller
+                         (not (funcall next-disabled)))
+                (etaf-data-next-page controller))))))
+    (plist-put state :page-value page-value)
+    (plist-put state :page-size-value page-size-value)
+    (plist-put state :total-value total-value)
+    (plist-put state :pages-value pages-value)
+    (plist-put state :loading-p loading-p)
+    (plist-put state :previous-disabled previous-disabled)
+    (plist-put state :next-disabled next-disabled)
+    (plist-put state :previous previous)
+    (plist-put state :next next)
+    state)
+  :render
+  (let* ((state (etaf-state))
+         (controller-value controller))
+    (setf (plist-get state :controller) controller-value)
+    (let* ((theme (etaf-ui--style-tokens
+                   :ui-fg :ui-bg :ui-disabled-fg
+                   :ui-pagination-muted-fg))
+           (parent-color (or color (plist-get theme :ui-fg)))
+           (parent-bgcolor (or bgcolor (plist-get theme :ui-bg)))
+           (arrow-border (or border '(0 solid "transparent")))
+           (page (funcall (plist-get state :page-value)))
+           (page-size (funcall (plist-get state :page-size-value)))
+           (total (funcall (plist-get state :total-value)))
+           (pages (funcall (plist-get state :pages-value)))
+           (previous-disabled
+            (funcall (plist-get state :previous-disabled)))
+           (next-disabled
+            (funcall (plist-get state :next-disabled)))
+           (first-item (if (zerop total) 0
+                         (1+ (* (1- page) page-size))))
+           (last-item (min total (* page page-size))))
+      (etaf-node
+       'flex
+       (list :class (etaf-ui--class-value "etaf-pagination" nil class)
+             :width 'stretch :flex-direction 'row :align-items 'center
+             :role 'navigation :aria-label (or aria-label "Pagination")
+             :color parent-color :background-color parent-bgcolor
+             :box-sizing 'border-box :padding (or padding '(0 1))
+             :gap '(0 (1)))
+       (list
+        (etaf-node
+         'column
+         (list :width 'max-content
+               :flex-grow 0 :flex-shrink 0 :flex-basis 'auto)
+         (list
+          (etaf-node
+           'etaf-button
+           (list :label "←" :ref previous-ref
+                 :aria-label "Previous page"
+                 :disabled previous-disabled :padding '(0 0)
+                 :border arrow-border
+                 :color (if previous-disabled
+                            (plist-get theme :ui-disabled-fg)
+                          parent-color)
+                 :background-color parent-bgcolor :font-weight 'bold
+                 :on-press (plist-get state :previous))
+           nil)))
+        (etaf-node
+         'column
+         (list :flex-grow 1 :flex-shrink 1 :flex-basis '(0) :min-width 0)
+         (list
+          (etaf-node
+           'box
+           (list :class "etaf-pagination-label" :text-align 'center
+                 :wrap-mode 'none :min-width 'max-content)
+           (list (format "Page %d / %d" page pages)))
+          (etaf-node
+           'box
+           (list :class "etaf-pagination-summary" :text-align 'center
+                 :color (plist-get theme :ui-pagination-muted-fg)
+                 :wrap-mode 'none :min-width 'max-content)
+           (list (format "%d–%d of %d" first-item last-item total)))))
+        (etaf-node
+         'column
+         (list :width 'max-content
+               :flex-grow 0 :flex-shrink 0 :flex-basis 'auto)
+         (list
+          (etaf-node
+           'etaf-button
+           (list :label "→" :ref next-ref
+                 :aria-label "Next page"
+                 :disabled next-disabled :padding '(0 0)
+                 :border arrow-border
+                 :color (if next-disabled
+                            (plist-get theme :ui-disabled-fg)
+                          parent-color)
+                 :background-color parent-bgcolor :font-weight 'bold
+                 :on-press (plist-get state :next))
+           nil)))))))
+  :styles
+  (styles
+   ("&" :width stretch)
+   (".etaf-pagination-label" :font-weight bold)))
+
+(provide 'etaf-ui-data)
+;;; etaf-ui-data.el ends here
diff --git a/scripts/etaf-ui-m0a-inventory.el b/scripts/etaf-ui-m0a-inventory.el
new file mode 100644
index 0000000..3bb7f50
--- /dev/null
+++ b/scripts/etaf-ui-m0a-inventory.el
@@ -0,0 +1,267 @@
+;;; etaf-ui-m0a-inventory.el --- M0a Component inventory -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Machine-readable current-behavior inventory.  This file deliberately
+;; records private consumers as drift; M0a does not turn the M0b target into a
+;; failing current gate.
+
+;;; Code:
+(require 'cl-lib)
+(require 'seq)
+
+(defconst etaf-ui-m0a--package-root
+  (file-name-directory
+   (directory-file-name
+    (file-name-directory (or load-file-name buffer-file-name))))
+  "Absolute etaf-ui package root used by the inventory.")
+
+(defconst etaf-ui-m0a-public-component-contracts
+  '((:name etaf-label
+     :business-props (text variant)
+     :forwarded-host-attrs all-valid-host-attrs
+     :root-guarantee single-host-root
+     :definition "etaf-ui-basic.el")
+    (:name etaf-button
+     :business-props (label on-press disabled ref class color bgcolor border
+                            padding font-weight tab-index aria-label use variant)
+     :forwarded-host-attrs all-valid-host-attrs
+     :root-guarantee single-host-root
+     :definition "etaf-ui-basic.el")
+    (:name etaf-checkbox
+     :business-props (checked label on-change disabled)
+     :forwarded-host-attrs all-valid-host-attrs
+     :root-guarantee single-host-root
+     :definition "etaf-ui-basic.el")
+    (:name etaf-panel
+     :business-props (title variant)
+     :forwarded-host-attrs all-valid-host-attrs
+     :root-guarantee single-host-root
+     :definition "etaf-ui-basic.el")
+    (:name etaf-number-input
+     :business-props (value label on-change disabled min max)
+     :forwarded-host-attrs all-valid-host-attrs
+     :root-guarantee single-host-root
+     :definition "etaf-ui-basic.el")
+    (:name etaf-table
+     :business-props (columns rows row-key row-ref on-row-press row-selected-p)
+     :forwarded-host-attrs all-valid-host-attrs
+     :root-guarantee single-host-root
+     :definition "etaf-ui-table.el")
+    (:name etaf-data-grid
+     :business-props (controller columns row-key on-row-press row-ref
+                                 row-selected-p loading-label error-label
+                                 empty-label)
+     :forwarded-host-attrs all-valid-host-attrs
+     :root-guarantee single-host-root
+     :definition "etaf-ui-data.el")
+    (:name etaf-pagination
+     :business-props (controller previous-ref next-ref class color bgcolor
+                                 border padding aria-label)
+     :forwarded-host-attrs all-valid-host-attrs
+     :root-guarantee single-host-root
+     :definition "etaf-ui-data.el"))
+  "Observed contracts of the eight public etaf-ui Components.
+
+`all-valid-host-attrs' names the core single-root Component forwarding rule;
+it is not a claim that every attribute is a declared business prop.")
+
+(defconst etaf-ui-m0a-private-production-callsites
+  '((:symbol etaf--expr-create :scope production
+     :file "etaf-ui-data.el" :line 93)
+    (:symbol etaf--expr-create :scope production
+     :file "etaf-ui-data.el" :line 106)
+    (:symbol etaf--expr-create :scope production
+     :file "etaf-ui-data.el" :line 114)
+    (:symbol etaf--expr-create :scope production
+     :file "etaf-ui-data.el" :line 234)
+    (:symbol etaf--view-call :scope production
+     :file "etaf-ui-data.el" :line 278)
+    (:symbol etaf--view-call :scope production
+     :file "etaf-ui-data.el" :line 284)
+    (:symbol etaf--slot-projection-create :scope production
+     :file "etaf-ui-data.el" :line 286))
+  "Exact M0a baseline of production calls into private ETAF functions.")
+
+(defconst etaf-ui-m0b-private-production-callsites nil
+  "M0b target and current production calls into private ETAF functions.")
+
+(defun etaf-ui-m0a--read-top-level-forms (file)
+  "Return top-level forms and source lines read from FILE."
+  (with-temp-buffer
+    (insert-file-contents file)
+    (goto-char (point-min))
+    (let (forms form start)
+      (condition-case nil
+          (while t
+            (setq start (point)
+                  form (read (current-buffer)))
+            (push (list :form form :line (line-number-at-pos start)) forms))
+        (end-of-file nil))
+      (nreverse forms))))
+
+(defun etaf-ui-m0a--component-definitions ()
+  "Return public Component definitions observed in package product files."
+  (let (result)
+    (dolist (file (directory-files etaf-ui-m0a--package-root t
+                                   "\\`etaf-ui-.*\\.el\\'"))
+      (dolist (entry (etaf-ui-m0a--read-top-level-forms file))
+        (let ((form (plist-get entry :form)))
+          (when (and (eq (car-safe form) 'etaf-define-component)
+                     (symbolp (cadr form))
+                     (not (string-prefix-p "etaf-ui--"
+                                           (symbol-name (cadr form)))))
+            (let ((arguments (nth 2 form)))
+              (push (list :name (cadr form)
+                          :business-props
+                          (seq-filter #'symbolp
+                                      (cdr (memq '&key arguments)))
+                          :definition
+                          (file-relative-name file etaf-ui-m0a--package-root)
+                          :line (plist-get entry :line))
+                    result))))))
+    (sort result (lambda (left right)
+                   (string< (symbol-name (plist-get left :name))
+                            (symbol-name (plist-get right :name)))))))
+
+(defun etaf-ui-m0a-component-inventory ()
+  "Return the current eight-Component contract with observed source lines."
+  (let ((definitions (etaf-ui-m0a--component-definitions)))
+    (mapcar
+     (lambda (contract)
+       (let* ((name (plist-get contract :name))
+              (observed (seq-find
+                         (lambda (entry) (eq name (plist-get entry :name)))
+                         definitions)))
+         (append (copy-sequence contract)
+                 (list :observed-business-props
+                       (plist-get observed :business-props)
+                       :observed-definition (plist-get observed :definition)
+                       :line (plist-get observed :line)
+                       :drift
+                       (unless (and observed
+                                    (equal (plist-get contract :business-props)
+                                           (plist-get observed :business-props))
+                                    (equal (plist-get contract :definition)
+                                           (plist-get observed :definition)))
+                         'contract-mismatch)))))
+     etaf-ui-m0a-public-component-contracts)))
+
+(defun etaf-ui-m0a--private-occurrences-in-file (file scope root call-only)
+  "Return active private occurrences in FILE under SCOPE and ROOT.
+
+When CALL-ONLY is non-nil, record only symbols in function-call position.
+The linear scanner excludes strings and both line and block comments."
+  (with-temp-buffer
+    (insert-file-contents file)
+    (goto-char (point-min))
+    (let ((block-depth 0)
+          in-string
+          escaped
+          result)
+      (while (< (point) (point-max))
+        (cond
+         ((> block-depth 0)
+          (cond ((looking-at "#|")
+                 (setq block-depth (1+ block-depth))
+                 (forward-char 2))
+                ((looking-at "|#")
+                 (setq block-depth (1- block-depth))
+                 (forward-char 2))
+                (t (forward-char 1))))
+         (in-string
+          (let ((character (char-after)))
+            (forward-char 1)
+            (cond (escaped (setq escaped nil))
+                  ((eq character ?\\) (setq escaped t))
+                  ((eq character ?\") (setq in-string nil)))))
+         ((looking-at "#|")
+          (setq block-depth 1)
+          (forward-char 2))
+         ((eq (char-after) ?\;)
+          (forward-line 1))
+         ((eq (char-after) ?\")
+          (setq in-string t)
+          (forward-char 1))
+         ((eq (char-after) ??)
+          ;; Skip an Emacs Lisp character literal, including ?\\X.
+          (forward-char (min (if (eq (char-after (1+ (point))) ?\\) 3 2)
+                             (- (point-max) (point)))))
+         ((and call-only (eq (char-after) ?\())
+          (forward-char 1)
+          (skip-chars-forward " \t\r\n")
+          (when (looking-at "\\(etaf--[[:alnum:]-]+\\)\\_>")
+            (push (list :symbol (intern (match-string-no-properties 1))
+                        :scope scope
+                        :file (file-relative-name file root)
+                        :line (line-number-at-pos (point)))
+                  result)))
+         ((and (not call-only)
+               (looking-at "\\_<\\(etaf--[[:alnum:]-]+\\)\\_>"))
+          (push (list :symbol (intern (match-string-no-properties 1))
+                      :scope scope
+                      :file (file-relative-name file root)
+                      :line (line-number-at-pos (point)))
+                result)
+          (goto-char (match-end 1)))
+         (t (forward-char 1))))
+      (nreverse result))))
+
+(defun etaf-ui-m0a-private-consumers (&optional root)
+  "Return active core-private consumers below ROOT.
+
+ROOT defaults to the etaf-ui package root."
+  (let* ((root (file-name-as-directory
+                (or root etaf-ui-m0a--package-root)))
+         (tests-directory (expand-file-name "tests" root))
+         (files (append
+                 (directory-files root t
+                                  "\\`etaf-ui-.*\\.el\\'")
+                 (when (file-directory-p tests-directory)
+                   (directory-files tests-directory t "\\.el\\'"))))
+        result)
+    (dolist (file files)
+      ;; The inventory's own expectation literals are evidence vocabulary,
+      ;; not calls into the private API under inventory.
+      (unless (string-suffix-p "etaf-ui-m0a-inventory-tests.el" file)
+        (setq result
+              (nconc result
+                     (if (string-match-p "/tests/" file)
+                         (etaf-ui-m0a--private-occurrences-in-file
+                          file 'test root nil)
+                       (etaf-ui-m0a--private-occurrences-in-file
+                        file 'production root t))))))
+    result))
+
+(defun etaf-ui-m0a-private-consumer-drift (&optional root)
+  "Return current M0b production private-call drift below optional ROOT."
+  (let ((observed
+         (seq-filter
+          (lambda (entry) (eq 'production (plist-get entry :scope)))
+          (etaf-ui-m0a-private-consumers root))))
+    (list :expected etaf-ui-m0b-private-production-callsites
+          :observed observed
+          :missing (seq-remove (lambda (entry) (member entry observed))
+                               etaf-ui-m0b-private-production-callsites)
+          :unexpected
+          (seq-remove (lambda (entry)
+                        (member entry etaf-ui-m0b-private-production-callsites))
+                      observed))))
+
+(defun etaf-ui-m0a-inventory ()
+  "Return the complete machine-readable etaf-ui M0a inventory."
+  (list :schema-version 1
+        :milestone 'M0b
+        :evidence-mode 'migrated-public-extension-seam
+        :components (etaf-ui-m0a-component-inventory)
+        :m0a-private-production-baseline
+        etaf-ui-m0a-private-production-callsites
+        :private-consumers (etaf-ui-m0a-private-consumers)
+        :private-production-drift (etaf-ui-m0a-private-consumer-drift)))
+
+(defun etaf-ui-m0a-inventory-batch ()
+  "Print `etaf-ui-m0a-inventory' for a batch evidence run."
+  (prin1 (etaf-ui-m0a-inventory))
+  (terpri))
+
+(provide 'etaf-ui-m0a-inventory)
+;;; etaf-ui-m0a-inventory.el ends here
diff --git a/tests/etaf-ui-m0a-inventory-tests.el b/tests/etaf-ui-m0a-inventory-tests.el
new file mode 100644
index 0000000..7533522
--- /dev/null
+++ b/tests/etaf-ui-m0a-inventory-tests.el
@@ -0,0 +1,182 @@
+;;; etaf-ui-m0a-inventory-tests.el --- M0a inventory tests -*- lexical-binding: t; -*-
+
+;;; Code:
+(require 'ert)
+(require 'seq)
+(require 'etaf-ui)
+(declare-function etaf-ui-m0a-component-inventory
+                  "../scripts/etaf-ui-m0a-inventory")
+(declare-function etaf-ui-m0a-private-consumers
+                  "../scripts/etaf-ui-m0a-inventory")
+(declare-function etaf-ui-m0a-private-consumer-drift
+                  "../scripts/etaf-ui-m0a-inventory")
+(declare-function etaf-ui-m0a-inventory
+                  "../scripts/etaf-ui-m0a-inventory")
+(load-file (expand-file-name "scripts/etaf-ui-m0a-inventory.el"
+                            default-directory))
+
+(ert-deftest etaf-ui-m0a-inventory-records-eight-public-components ()
+  "Record exactly the eight current public etaf-ui Components."
+  (let ((components (etaf-ui-m0a-component-inventory)))
+    (should (= 8 (length components)))
+    (should
+     (equal '(etaf-button etaf-checkbox etaf-data-grid etaf-label
+                          etaf-number-input etaf-pagination etaf-panel etaf-table)
+            (sort (mapcar (lambda (entry) (plist-get entry :name)) components)
+                  (lambda (left right)
+                    (string< (symbol-name left) (symbol-name right))))))))
+
+(ert-deftest etaf-ui-m0a-inventory-matches-current-business-props ()
+  "Match each declared business prop list to its source definition."
+  (dolist (component (etaf-ui-m0a-component-inventory))
+    (should (equal (plist-get component :business-props)
+                   (plist-get component :observed-business-props)))
+    (should-not (plist-get component :drift))))
+
+(ert-deftest etaf-ui-m0a-inventory-separates-host-forwarding-from-props ()
+  "Record Host forwarding and single-root guarantees separately from props."
+  (dolist (component (etaf-ui-m0a-component-inventory))
+    (should (eq 'all-valid-host-attrs
+                (plist-get component :forwarded-host-attrs)))
+    (should (eq 'single-host-root
+                (plist-get component :root-guarantee)))))
+
+(ert-deftest etaf-ui-m0a-components-forward-host-attrs-to-one-mounted-root ()
+  "Forward ref, class, and aria-label through every public Component root."
+  (let* ((source (etaf-data-memory-source
+                  '((:id 1 :name "Ada")) :id-key :id))
+         (controller (etaf-data-controller source :auto-load t))
+         (buffer (generate-new-buffer-name " *etaf-ui-m0a-forwarding*"))
+         (components (etaf-ui-m0a-component-inventory)))
+    (unwind-protect
+        (progn
+          (etaf-mount
+           buffer
+           (etaf-view
+            (column
+             (etaf-label :text "Label" :ref 'm0a-label
+                         :class "m0a-forwarded" :aria-label "m0a-label")
+             (etaf-button :label "Button" :ref 'm0a-button
+                          :class "m0a-forwarded" :aria-label "m0a-button")
+             (etaf-checkbox :checked nil :label "Checkbox"
+                            :ref 'm0a-checkbox :class "m0a-forwarded"
+                            :aria-label "m0a-checkbox")
+             (etaf-panel :title "Panel" :ref 'm0a-panel
+                         :class "m0a-forwarded" :aria-label "m0a-panel"
+               (etaf-label :text "Nested"))
+             (etaf-number-input :value 1 :label "Number"
+                                :ref 'm0a-number-input
+                                :class "m0a-forwarded"
+                                :aria-label "m0a-number-input")
+             (etaf-table :columns '((:key :name :label "Name"))
+                         :rows '((:id 1 :name "Ada"))
+                         :row-key (lambda (row) (plist-get row :id))
+                         :ref 'm0a-table :class "m0a-forwarded"
+                         :aria-label "m0a-table")
+             (etaf-data-grid
+              :controller controller
+              :columns '((:key :name :label "Name"))
+              :row-key (lambda (row) (plist-get row :id))
+              :ref 'm0a-data-grid :class "m0a-forwarded"
+              :aria-label "m0a-data-grid")
+             (etaf-pagination :controller controller
+                              :ref 'm0a-pagination
+                              :class "m0a-forwarded"
+                              :aria-label "m0a-pagination"))))
+          (let ((runtime (etaf-runtime-for-buffer buffer)))
+            (should (= 8 (length components)))
+            (dolist (component components)
+              (let* ((name (plist-get component :name))
+                     (suffix (string-remove-prefix "etaf-"
+                                                   (symbol-name name)))
+                     (ref (intern (concat "m0a-" suffix)))
+                     (props (etaf-runtime-host-props-for runtime ref)))
+                (should props)
+                (should (eq ref (plist-get props :ref)))
+                (should (member "m0a-forwarded"
+                                (etaf--class-tokens
+                                 (plist-get props :class))))
+                (should (equal (symbol-name ref)
+                               (plist-get props :aria-label)))))))
+      (when-let* ((runtime (etaf-runtime-for-buffer buffer)))
+        (etaf-unmount runtime))
+      (when (get-buffer buffer) (kill-buffer buffer))
+      (etaf-data-stop controller))))
+
+(ert-deftest etaf-ui-m0b-inventory-records-private-production-closure ()
+  "Record zero current production private consumers and retain M0a history."
+  (let* ((entries (seq-filter
+                   (lambda (entry) (eq 'production (plist-get entry :scope)))
+                   (etaf-ui-m0a-private-consumers)))
+         (symbols (delete-dups
+                   (mapcar (lambda (entry) (plist-get entry :symbol)) entries))))
+    (should-not entries)
+    (should-not symbols)
+    (should (cl-every (lambda (entry)
+                        (and (stringp (plist-get entry :file))
+                             (integerp (plist-get entry :line))))
+                      entries))
+    (let ((drift (etaf-ui-m0a-private-consumer-drift)))
+      (should-not (plist-get drift :missing))
+      (should-not (plist-get drift :unexpected)))
+    (should (= 7 (length etaf-ui-m0a-private-production-callsites)))))
+
+(ert-deftest etaf-ui-m0a-inventory-rejects-an-undeclared-production-callsite ()
+  "Report a newly added private production call even when its symbol is known."
+  (let ((temporary-root (make-temp-file "etaf-ui-m0a-private-" t)))
+    (unwind-protect
+        (progn
+          (copy-file (expand-file-name "etaf-ui-data.el" default-directory)
+                     (expand-file-name "etaf-ui-data.el" temporary-root))
+          (with-temp-buffer
+            (insert "\n(etaf--expr-create 'undeclared-callsite)\n")
+            (append-to-file (point-min) (point-max)
+                            (expand-file-name "etaf-ui-data.el"
+                                              temporary-root)))
+          (should (plist-get
+                   (etaf-ui-m0a-private-consumer-drift temporary-root)
+                   :unexpected)))
+      (delete-directory temporary-root t))))
+
+(ert-deftest etaf-ui-m0a-inventory-records-current-test-consumers ()
+  "Record existing private test consumers without counting inventory data."
+  (let* ((entries (seq-filter
+                   (lambda (entry) (eq 'test (plist-get entry :scope)))
+                   (etaf-ui-m0a-private-consumers)))
+         (symbols (delete-dups
+                   (mapcar (lambda (entry) (plist-get entry :symbol)) entries))))
+    (should (= 10 (length entries)))
+    (should (= 2 (cl-count 'etaf--class-tokens entries
+                           :key (lambda (entry)
+                                  (plist-get entry :symbol)))))
+    (should (= 4 (cl-count 'etaf--runtime-render-dirty-component entries
+                           :key (lambda (entry)
+                                  (plist-get entry :symbol)))))
+    (should (= 2 (cl-count 'etaf--ebox-box-node entries
+                           :key (lambda (entry)
+                                  (plist-get entry :symbol)))))
+    (should (= 2 (cl-count 'etaf--ebox-text-node entries
+                           :key (lambda (entry)
+                                  (plist-get entry :symbol)))))
+    (should (equal '(etaf--class-tokens etaf--ebox-box-node
+                     etaf--ebox-text-node
+                     etaf--runtime-render-dirty-component)
+                   (sort symbols (lambda (left right)
+                                   (string< (symbol-name left)
+                                            (symbol-name right))))))))
+
+(ert-deftest etaf-ui-m0b-inventory-labels-public-seam-migration ()
+  "Label the zero-private-consumer state as the completed M0b migration."
+  (let ((inventory (etaf-ui-m0a-inventory)))
+    (should (eq 'M0b (plist-get inventory :milestone)))
+    (should (eq 'migrated-public-extension-seam
+                (plist-get inventory :evidence-mode)))
+    (should (= 7 (length (plist-get inventory
+                                    :m0a-private-production-baseline))))
+    (should-not
+     (seq-filter
+      (lambda (entry) (eq 'production (plist-get entry :scope)))
+      (plist-get inventory :private-consumers)))))
+
+(provide 'etaf-ui-m0a-inventory-tests)
+;;; etaf-ui-m0a-inventory-tests.el ends here
diff --git a/tests/etaf-ui-m0b-extension-tests.el b/tests/etaf-ui-m0b-extension-tests.el
new file mode 100644
index 0000000..7c7b565
--- /dev/null
+++ b/tests/etaf-ui-m0b-extension-tests.el
@@ -0,0 +1,204 @@
+;;; etaf-ui-m0b-extension-tests.el --- M0b public extension seam -*- lexical-binding: t; -*-
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+(require 'etaf-ui)
+
+(defconst etaf-ui-m0b--data-source-file
+  (expand-file-name "../etaf-ui-data.el"
+                    (file-name-directory (or load-file-name buffer-file-name)))
+  "DataGrid production source inspected by the M0b seam tests.")
+
+(defun etaf-ui-m0b--walk (form predicate)
+  "Return non-nil when PREDICATE matches FORM or one of its children."
+  (or (funcall predicate form)
+      (and (consp form)
+           (or (etaf-ui-m0b--walk (car form) predicate)
+               (etaf-ui-m0b--walk (cdr form) predicate)))))
+
+(defun etaf-ui-m0b--source-forms (file)
+  "Read and return every Lisp form in FILE."
+  (with-temp-buffer
+    (insert-file-contents file)
+    (let (forms form)
+      (condition-case nil
+          (while t
+            (setq form (read (current-buffer)))
+            (push form forms))
+        (end-of-file (nreverse forms))))))
+
+(ert-deftest etaf-ui-m0b-data-grid-production-uses-public-extension-seam ()
+  "DataGrid production code contains no ETAF private API call."
+  (let ((private
+          (cl-loop for form in (etaf-ui-m0b--source-forms
+                                etaf-ui-m0b--data-source-file)
+                   when (etaf-ui-m0b--walk
+                         form
+                         (lambda (node)
+                           (and (symbolp node)
+                                (string-prefix-p "etaf--" (symbol-name node)))))
+                   collect form)))
+    (should-not private)))
+
+(ert-deftest etaf-ui-m0b-data-grid-public-range-retains-handler-and-root ()
+  "Insert/reorder/update retain handlers and avoid a root replacement."
+  (let* ((rows (cl-loop for id from 1 to 12
+                        collect (list :id id :name (format "Row %d" id))))
+         (source (etaf-data-memory-source rows :id-key :id))
+         (controller (etaf-data-controller source :page-size 120 :auto-load t))
+         (buffer-name " *etaf-ui-m0b-grid-retention*")
+         (root-replacements 0)
+         (materialized 0)
+         update-materialized
+         pressed)
+    (unwind-protect
+        (progn
+          (etaf-mount
+           buffer-name
+           (etaf-view
+            (etaf-data-grid
+             :controller controller
+             :columns '((:key :id :label "ID")
+                        (:key :name :label "Name"))
+             :row-key (lambda (row) (plist-get row :id))
+             :row-ref (lambda (row)
+                        (intern (format "m0b-row-%d" (plist-get row :id))))
+             :on-row-press (lambda (row) (setq pressed row)))))
+          (let* ((runtime (etaf-runtime-for-buffer buffer-name))
+                 (handler
+                  (cdr (assq 'press
+                             (etaf-runtime-handler-for runtime 'm0b-row-6))))
+                 (old-root (symbol-function 'ebox-candidate-replace-root))
+                 (old-box (symbol-function 'etaf--ebox-box-node))
+                 (old-text (symbol-function 'etaf--ebox-text-node)))
+            (cl-letf (((symbol-function 'ebox-candidate-replace-root)
+                       (lambda (&rest arguments)
+                         (cl-incf root-replacements)
+                         (apply old-root arguments)))
+                      ((symbol-function 'etaf--ebox-box-node)
+                       (lambda (&rest arguments)
+                         (cl-incf materialized)
+                         (apply old-box arguments)))
+                      ((symbol-function 'etaf--ebox-text-node)
+                       (lambda (&rest arguments)
+                         (cl-incf materialized)
+                         (apply old-text arguments))))
+              (setf (etaf-value (etaf-data-items controller))
+                    (cl-loop for row in rows
+                             if (= 6 (plist-get row :id))
+                             collect '(:id 6 :name "Row six updated")
+                             else collect row))
+              (setq update-materialized materialized)
+              (etaf-data-mutate controller 'insert
+                                '(:id 13 :name "Row 13"))
+              (etaf-data-mutate controller 'update
+                                '(:id 6 :name "Row six updated")))
+            (should (zerop root-replacements))
+            ;; One local update stays well below materializing all 12 rows and
+            ;; their two cells (at least 60 Ebox nodes).
+            (should (< update-materialized 30))
+            (should (eq handler
+                        (cdr (assq
+                              'press
+                              (etaf-runtime-handler-for runtime 'm0b-row-6)))))
+            (etaf-dispatch-event runtime 'm0b-row-6 'press)
+            (should (equal "Row six updated" (plist-get pressed :name)))
+            (should (string-match-p
+                     "Row six updated"
+                     (with-current-buffer buffer-name
+                       (substring-no-properties (buffer-string)))))))
+      (when-let* ((runtime (etaf-runtime-for-buffer buffer-name)))
+        (etaf-unmount runtime))
+      (etaf-data-stop controller)
+      (when-let* ((buffer (get-buffer buffer-name)))
+        (kill-buffer buffer)))))
+
+(ert-deftest etaf-ui-m0b-data-grid-enumerates-120-items-once-per-turn ()
+  "A 120-row update enumerates the public Range once and stays item-local."
+  (let* ((row-key-calls 0)
+         (rows (cl-loop for id from 1 to 120
+                        collect (list :id id :name (format "Row %d" id))))
+         (source (etaf-data-memory-source rows :id-key :id))
+         (controller (etaf-data-controller source :page-size 120 :auto-load t))
+         (buffer-name " *etaf-ui-m0b-grid-scale*"))
+    (unwind-protect
+        (progn
+          (etaf-mount
+           buffer-name
+           (etaf-view
+            (etaf-data-grid
+             :controller controller
+             :columns '((:key :id :label "ID"))
+             :row-key (lambda (row)
+                        (cl-incf row-key-calls)
+                        (plist-get row :id)))))
+          (setq row-key-calls 0)
+          (etaf-data-mutate controller 'update
+                            '(:id 60 :name "Changed"))
+          (should (= 120 row-key-calls)))
+      (when-let* ((runtime (etaf-runtime-for-buffer buffer-name)))
+        (etaf-unmount runtime))
+      (etaf-data-stop controller)
+      (when-let* ((buffer (get-buffer buffer-name)))
+        (kill-buffer buffer)))))
+
+(ert-deftest etaf-ui-m0b-data-grid-footer-reorder-and-key-rollback ()
+  "Public slot projection and keyed rollback preserve the committed grid."
+  (let* ((rows '((:id 1 :name "Ada") (:id 2 :name "Grace")))
+         (source (etaf-data-memory-source rows :id-key :id))
+         (controller (etaf-data-controller source :page-size 10 :auto-load t))
+         (buffer-name " *etaf-ui-m0b-grid-footer*")
+         pressed)
+    (unwind-protect
+        (progn
+          (etaf-mount
+           buffer-name
+           (etaf-view
+            (etaf-data-grid
+             :controller controller
+             :columns '((:key :name :label "Name"))
+             :row-key (lambda (row) (plist-get row :id))
+             :row-ref (lambda (row)
+                        (intern (format "m0b-footer-row-%d"
+                                        (plist-get row :id))))
+             :on-row-press (lambda (row) (setq pressed row))
+             (slot :name 'footer (etaf-label :text "Grid footer")))))
+          (let* ((runtime (etaf-runtime-for-buffer buffer-name))
+                 (handler
+                  (cdr (assq 'press
+                             (etaf-runtime-handler-for
+                              runtime 'm0b-footer-row-1)))))
+            (should (string-match-p
+                     "Grid footer"
+                     (with-current-buffer buffer-name
+                       (substring-no-properties (buffer-string)))))
+            (setf (etaf-value (etaf-data-items controller))
+                  (reverse rows))
+            (should (eq handler
+                        (cdr (assq
+                              'press
+                              (etaf-runtime-handler-for
+                               runtime 'm0b-footer-row-1)))))
+            (etaf-dispatch-event runtime 'm0b-footer-row-1 'press)
+            (should (= 1 (plist-get pressed :id)))
+            (let ((generation (etaf-runtime-current-generation runtime))
+                  (text (with-current-buffer buffer-name (buffer-string))))
+              (should-error
+               (setf (etaf-value (etaf-data-items controller))
+                     '((:id 1 :name "A") (:id 1 :name "duplicate")))
+               :type 'etaf-component-call-error)
+              (should (eq generation
+                          (etaf-runtime-current-generation runtime)))
+              (should (equal-including-properties
+                       text (with-current-buffer buffer-name
+                              (buffer-string)))))))
+      (when-let* ((runtime (etaf-runtime-for-buffer buffer-name)))
+        (etaf-unmount runtime))
+      (etaf-data-stop controller)
+      (when-let* ((buffer (get-buffer buffer-name)))
+        (kill-buffer buffer)))))
+
+(provide 'etaf-ui-m0b-extension-tests)
+;;; etaf-ui-m0b-extension-tests.el ends here