@@ -50,6 +50,7 @@
     "rules/validate-imported-mesh-scale.mdc",
     "rules/no-unapplied-modifiers-on-export.mdc",
     "rules/use-correct-axis-rna-per-exporter.mdc",
-    "rules/no-bgl.mdc"
+    "rules/no-bgl.mdc",
+    "rules/no-removed-normals-api.mdc"
   ]
 }
@@ -20,7 +20,7 @@ a `.cursor-plugin/plugin.json` manifest so the ecosystem drift checker
 classifies it as a `cursor-plugin`. This is content the AI loads when the user
 asks Blender questions or works on Blender add-ons in Cursor or Claude Code.
 
-The content base is 19 skills, 10 rules, 3 templates, 29 snippets, 66
+The content base is 19 skills, 11 rules, 3 templates, 29 snippets, 66
 examples, and 80 showcase pieces (counts are CI-enforced across README.md, the agent docs, ROADMAP.md,
 `site.json` and the site templates). The full inventory tables and per-item purposes live in
 `CLAUDE.md`. Example anatomy and authoring rules: copy `examples/bmesh-gear/`;
@@ -33,10 +33,10 @@ in `docs/VISUAL-STYLE.md`; the canonical run prompt is
 ```
 Blender-Developer-Tools/
   skills/<skill-name>/SKILL.md   # 19 skill files
-  rules/<rule-name>.mdc          # 10 rule files
+  rules/<rule-name>.mdc          # 11 rule files
   templates/<template-name>/     # 3 starter templates
   snippets/<snippet-name>.py     # 29 standalone Python snippets
-  examples/<name>/               # 67 runnable smoke-gated examples (+ gallery.json)
+  examples/<name>/               # 68 runnable smoke-gated examples (+ gallery.json)
   examples/gallery_framing.py    # shared Layer 1 framing measurement (render path only)
   showcase/<name>/               # budget-conformance props (sibling of examples/)
   showcase/gallery.json          # this tree's gallery index; merged into docs/gallery/
 
@@ -18,10 +18,10 @@ The **Blender Developer Tools** repository is at **v0.154.0**. It packages skill
 
 ```
 skills/<skill-name>/SKILL.md   - AI workflow definitions, 19 total
-rules/<rule-name>.mdc          - Anti-pattern rules, 10 total
+rules/<rule-name>.mdc          - Anti-pattern rules, 11 total
 templates/<template-name>/     - Starter projects, 3 total
 snippets/<snippet-name>.py     - Standalone code patterns, 29 total
-examples/<name>/               - Runnable smoke-gated examples, 67 total (+ gallery.json)
+examples/<name>/               - Runnable smoke-gated examples, 68 total (+ gallery.json)
 showcase/<name>/               - Budget-conformance props, 80 pieces, each with a gallery `category` (sibling of examples/; see showcase/README.md § Categories)
 scripts/build_gallery.py       - Regenerates docs/gallery/ from examples/gallery.json + showcase/gallery.json
 scripts/site/                  - Vendored landing-page build (Jinja2); tokens.css is the shared palette
@@ -54,7 +54,7 @@ VERSION                        - Source of truth for the repo version
 | timers-modal-and-threading | `bpy.app.timers` return values and `persistent`, modal operators on `event_timer_add`, worker thread + queue + main-thread drain, no timers in `--background` |
 | gpu-drawing-and-overlays | `gpu` instead of the removed `bgl`: `draw_handler_add`/`remove`, builtin shader names, `gpu.state` blending and depth, `POLYLINE_*` line width, `blf` text, `GPUOffScreen` with 5.2's `gpu.init()` headless |
 
-## Rules (10)
+## Rules (11)
 
 Every rule sets `alwaysApply: false`, so the Scope column below is the rule's
 actual load condition, not a description: a rule enters context only when a file
@@ -72,6 +72,7 @@ matching its `globs` does. Changing a glob changes when the rule fires.
 | no-unapplied-modifiers-on-export | `*.py` | Export with live modifiers when the export does not request evaluated geometry |
 | use-correct-axis-rna-per-exporter | `*.py` | `export_scene.gltf` with FBX `axis_forward`/`axis_up`, or `export_scene.fbx` with glTF `export_yup` |
 | no-bgl | `*.py` | `import bgl` or any `bgl.` call (removed in 5.x; the add-on fails to register) |
+| no-removed-normals-api | `*.py` | `use_auto_smooth`, `auto_smooth_angle`, `calc_normals_split()` and the other normals calls removed in 4.1 |
 
 ## Templates (3)
 
@@ -111,13 +112,13 @@ AI asset pipeline track: `decimate_to_budget.py`, `convex_hull_collider.py`, `lo
 
 Extensions runtime: `extension-user-data.py` (`extension_path_user` settings file and an `online_access` guard). Long-running work: `thread-queue-timer.py` (worker thread, `queue.Queue`, main-thread drain timer).
 
-## Examples (67)
+## Examples (68)
 
 Runnable scripts at `examples/<name>/`, each asserting a real API contract with
 deterministic checks (exit non-zero on failure) and optionally rendering a still via
 `--output`. All of them run headless on Blender 5.2 LTS and 4.5 LTS in `blender-smoke.yml` (5.1 on the weekly cron, the `needs-5.1` PR label, or manual dispatch);
-**56 of the 67 ship a render in the site gallery** at `docs/gallery/`. The other
-eleven are **check-only**: they carry no `--output` path, no gallery entry, and no
+**56 of the 68 ship a render in the site gallery** at `docs/gallery/`. The other
+twelve are **check-only**: they carry no `--output` path, no gallery entry, and no
 hero asset. The criterion is whether the contract is expressible in pixels. An
 example is check-only when its witness is a data or state fact that no scene
 redesign can make visible — a datablock name, an RNA attribute's presence, a
 
@@ -288,7 +288,7 @@ The drift-check workflow enforces these on every push and PR.
 
 ## Aggregate Counts
 
-`README.md` declares aggregate counts (e.g. "19 skills, 10 rules, 3 templates, 29 snippets, 67 examples, and 80 showcase pieces"). The `validate-counts` job in `.github/workflows/validate.yml` enforces these substrings against the filesystem on every push and PR. Showcase pieces are counted separately from examples. When you add or remove content, update the README counts in the same commit.
+`README.md` declares aggregate counts (e.g. "19 skills, 11 rules, 3 templates, 29 snippets, 68 examples, and 80 showcase pieces"). The `validate-counts` job in `.github/workflows/validate.yml` enforces these substrings against the filesystem on every push and PR. Showcase pieces are counted separately from examples. When you add or remove content, update the README counts in the same commit.
 
 ## Pull Request Process
 
 
@@ -25,7 +25,7 @@
 </p>
 
 <p align="center">
-  <strong>19 skills</strong> &nbsp;&bull;&nbsp; <strong>10 rules</strong> &nbsp;&bull;&nbsp; <strong>3 templates</strong> &nbsp;&bull;&nbsp; <strong>29 snippets</strong> &nbsp;&bull;&nbsp; <strong>67 examples</strong> &nbsp;&bull;&nbsp; <strong>80 showcase pieces</strong>
+  <strong>19 skills</strong> &nbsp;&bull;&nbsp; <strong>11 rules</strong> &nbsp;&bull;&nbsp; <strong>3 templates</strong> &nbsp;&bull;&nbsp; <strong>29 snippets</strong> &nbsp;&bull;&nbsp; <strong>68 examples</strong> &nbsp;&bull;&nbsp; <strong>80 showcase pieces</strong>
 </p>
 
 <p align="center">
@@ -44,7 +44,7 @@
 
 ## Overview
 
-This repository ships **19 skills, 10 rules, 3 templates, 29 snippets, 67 examples, and 80 showcase pieces** for Blender Python development targeting Blender 5.2 LTS (current stable) with Blender 4.5 LTS fallback support. Blender 5.1 is prior stable.
+This repository ships **19 skills, 11 rules, 3 templates, 29 snippets, 68 examples, and 80 showcase pieces** for Blender Python development targeting Blender 5.2 LTS (current stable) with Blender 4.5 LTS fallback support. Blender 5.1 is prior stable.
 
 The content is consumed by AI coding agents, installed as a plugin or read from a checkout. An optional second plugin registers the official [Blender Lab MCP server](https://www.blender.org/lab/mcp-server/) for live sessions (see [Live Blender session](#live-blender-session-mcp)); the server is referenced from upstream, not part of this repository, and nothing else depends on it. Cursor and Claude Code both install it as a plugin (see [Quick start](#quick-start)): Cursor loads the skills and applies `rules/*.mdc` wherever their scope globs match; Claude Code loads the skills and gets the rules through a generated `blender-rules` skill, since it does not read Cursor `.mdc` files. An agent picks a skill up when its description matches the task. Any agent that can read files in a workspace can use it the same way. There is no build step for the content — edit the Markdown and Python files directly.
 
@@ -61,7 +61,7 @@ The content is consumed by AI coding agents, installed as a plugin or read from
 
 Neither agent needs a clone of `main`: both install the slim `plugin-dist` build. Clone the full repository only to [run the examples or contribute](#run-the-examples-or-contribute).
 
-- **Cursor** — install it as a local plugin from the slim `plugin-dist` branch, then run **Developer: Reload Window**. **Customize** lists the 19 skills and 10 rules; the rules apply by glob scope and the agent loads a skill when its description matches the task.
+- **Cursor** — install it as a local plugin from the slim `plugin-dist` branch, then run **Developer: Reload Window**. **Customize** lists the 19 skills and 11 rules; the rules apply by glob scope and the agent loads a skill when its description matches the task.
 
   ```bash
   git clone --branch plugin-dist --single-branch https://github.com/TMHSDigital/Blender-Developer-Tools.git ~/.cursor/plugins/local/blender-developer-tools
@@ -129,7 +129,7 @@ Releases ship often; [CHANGELOG.md](CHANGELOG.md) lists what each one changed.
 
 ## Falsifiers
 
-Every one of the 67 examples carries a **falsifier**: a flag that changes the
+Every one of the 68 examples carries a **falsifier**: a flag that changes the
 input so a real assertion fails. It never disables the assertion, skips the
 check, or short-circuits to an error — it feeds the script something the
 contract says must not pass, and the same check that guards the happy path
@@ -157,7 +157,7 @@ per-script exit-code model, are in
 
 ## Examples and showcase
 
-**67 examples** in [`examples/`](examples/) are runnable, self-checking scripts: each asserts one API contract, carries a falsifier, and runs headless on Blender 5.2 LTS and 4.5 LTS in the `blender-smoke` workflow (5.1 on the weekly cron or by manual dispatch). Those whose contract is visible also render a still. **80 showcase pieces** in [`showcase/`](showcase/) exist to show the skills working together at production scale: each is a single headless script that models a game prop, then runs it through the same cleanup, bake, LOD, collider and export steps the skills teach, and fails if a measured budget (triangle counts, colliders, materials, real-world size) is missed. They are not API examples. Conventions: [`showcase/README.md`](showcase/README.md).
+**68 examples** in [`examples/`](examples/) are runnable, self-checking scripts: each asserts one API contract, carries a falsifier, and runs headless on Blender 5.2 LTS and 4.5 LTS in the `blender-smoke` workflow (5.1 on the weekly cron or by manual dispatch). Those whose contract is visible also render a still. **80 showcase pieces** in [`showcase/`](showcase/) exist to show the skills working together at production scale: each is a single headless script that models a game prop, then runs it through the same cleanup, bake, LOD, collider and export steps the skills teach, and fails if a measured budget (triangle counts, colliders, materials, real-world size) is missed. They are not API examples. Conventions: [`showcase/README.md`](showcase/README.md).
 
 Browse both, with filters, full-size renders and each script's README, in the **[gallery](https://tmhsdigital.github.io/Blender-Developer-Tools/gallery/)**.
 
@@ -176,10 +176,10 @@ Browse both, with filters, full-size renders and each script's README, in the **
 
 ```
 skills/<name>/SKILL.md   - 19 skill files, YAML frontmatter, one canonical pattern each
-rules/<name>.mdc         - 10 rule files, anti-pattern + correction
+rules/<name>.mdc         - 11 rule files, anti-pattern + correction
 templates/<name>/        - 3 template directories (extension-addon-template, headless-batch-script-template, ai-asset-pipeline-template)
 snippets/<name>.py       - 29 standalone Python snippets, 5 to 75 lines each
-examples/<name>/         - 67 example directories: script, README with exit codes and falsifier
+examples/<name>/         - 68 example directories: script, README with exit codes and falsifier
 showcase/<name>/         - 80 showcase pieces: budget-gated game props, script and README
 claude/                  - generated Claude Code copies of the rules (blender-rules skill + import file)
 ```
 
@@ -11,7 +11,6 @@ showcase pool further down. Each item is an open issue; nothing here is pinned t
 
 - **New skills:** `porting-to-blender-5`, one index of every 4.x to 5.x break the pack covers ([#466](https://github.com/TMHSDigital/Blender-Developer-Tools/issues/466)); teach the API contracts that shipped examples prove but no skill covers yet, such as Grease Pencil v3, the 5.x compositor, constraints and image pixels ([#456](https://github.com/TMHSDigital/Blender-Developer-Tools/issues/456))
 - **Skill corrections:** the full Principled BSDF v2 socket rename table in `procedural-materials-and-shaders` ([#382](https://github.com/TMHSDigital/Blender-Developer-Tools/issues/382))
-- **New rules:** flag the mesh-normals APIs removed in 4.1 (`use_auto_smooth`, `calc_normals_split`, `free_normals_split`) ([#379](https://github.com/TMHSDigital/Blender-Developer-Tools/issues/379))
 - **Examples for skills that have none:** check-only examples for `operators`, `ui-panels`, `addon-scaffolding` and `bl-info-migration` ([#378](https://github.com/TMHSDigital/Blender-Developer-Tools/issues/378)); a skill-to-example index and one machine-readable examples manifest with version support ([#377](https://github.com/TMHSDigital/Blender-Developer-Tools/issues/377))
 - **Verification:** run the shipped snippets and SKILL.md code blocks in CI instead of frozen copies ([#447](https://github.com/TMHSDigital/Blender-Developer-Tools/issues/447)); a weekly, non-gating smoke run against Blender daily builds to catch API breaks before a release ([#457](https://github.com/TMHSDigital/Blender-Developer-Tools/issues/457))
 - **More agents:** first-class support for Codex, Copilot, Windsurf and Gemini through `.agents/skills` and an AGENTS.md rules export ([#376](https://github.com/TMHSDigital/Blender-Developer-Tools/issues/376))
@@ -39,6 +38,7 @@ derives the actual version from conventional-commit types.
 | Extension runtime and packaging | 17 | 9 | 3 | 28 | Shipped (v0.146.0) |
 | Timers, modal operators and threading | 18 | 9 | 3 | 29 | Shipped (v0.147.0) |
 | GPU drawing without `bgl` | 19 | 10 | 3 | 29 | Shipped |
+| Removed normals API rule (pre-4.1 auto smooth) | 19 | 11 | 3 | 29 | Shipped |
 | Live-session bridge (opt-in `blender-live-session` plugin, upstream Blender Lab MCP) | - | - | - | - | Shipped |
 | Stable (1.0) | — | — | — | — | Upcoming; criteria below |
 
 
@@ -17,6 +17,12 @@ Flag `import bgl` and any `bgl.` call. The `bgl` OpenGL wrapper was deprecated i
 
 Applies to: `**/*.py`. Full rule: [`rules/no-bgl.mdc`](https://github.com/TMHSDigital/Blender-Developer-Tools/blob/main/rules/no-bgl.mdc).
 
+## no-removed-normals-api
+
+Flag the mesh normals API removed in Blender 4.1 — `use_auto_smooth`, `auto_smooth_angle`, `calc_normals_split()`, `free_normals_split()`, `create_normals_split()`. Each raises AttributeError on 4.5 LTS and 5.x. Use `Mesh.set_sharp_from_angle`, `object.shade_auto_smooth`, and `Mesh.corner_normals` (always current) instead.
+
+Applies to: `**/*.py`. Full rule: [`rules/no-removed-normals-api.mdc`](https://github.com/TMHSDigital/Blender-Developer-Tools/blob/main/rules/no-removed-normals-api.mdc).
+
 ## no-unapplied-modifiers-on-export
 
 Flag an export call on objects that still carry unapplied modifiers when the export arguments do not request evaluated geometry. The engine then receives the authored cage, not the modifier result.
 
@@ -22,6 +22,12 @@ Flag `import bgl` and any `bgl.` call. The `bgl` OpenGL wrapper was deprecated i
 
 Applies to: `**/*.py`. Full rule: [`rules/no-bgl.mdc`](https://github.com/TMHSDigital/Blender-Developer-Tools/blob/main/rules/no-bgl.mdc).
 
+## no-removed-normals-api
+
+Flag the mesh normals API removed in Blender 4.1 — `use_auto_smooth`, `auto_smooth_angle`, `calc_normals_split()`, `free_normals_split()`, `create_normals_split()`. Each raises AttributeError on 4.5 LTS and 5.x. Use `Mesh.set_sharp_from_angle`, `object.shade_auto_smooth`, and `Mesh.corner_normals` (always current) instead.
+
+Applies to: `**/*.py`. Full rule: [`rules/no-removed-normals-api.mdc`](https://github.com/TMHSDigital/Blender-Developer-Tools/blob/main/rules/no-removed-normals-api.mdc).
+
 ## no-unapplied-modifiers-on-export
 
 Flag an export call on objects that still carry unapplied modifiers when the export arguments do not request evaluated geometry. The engine then receives the authored cage, not the modifier result.
 
@@ -62,7 +62,7 @@
     <h1>Examples and Showcase</h1>
     <p>Runnable Blender Python examples, each run headless on Blender 5.2 LTS and 4.5 LTS in CI, so every render reflects code that actually runs — shown beside budget-conformance showcase props.</p>
     <details class="check-only" id="check-only">
-      <summary>56 rendered &middot; 11 check-only examples (data contracts with nothing to see)</summary>
+      <summary>56 rendered &middot; 12 check-only examples (data contracts with nothing to see)</summary>
       <div>
         A check-only example asserts a fact no render can show, such as a datablock name,
         an RNA attribute, a post-exit sidecar or a topology count. It runs in the same
@@ -75,6 +75,7 @@ <h1>Examples and Showcase</h1>
           <li><a href="https://github.com/TMHSDigital/Blender-Developer-Tools/tree/main/examples/gn-bundle-roundtrip/">gn-bundle-roundtrip</a>: Combine Bundle / Separate Bundle packing a cube plus Scale, Offset, and Mark — witnessing <code>geometry-nodes-python</code> item-name round-trip, not tree structure.</li>
           <li><a href="https://github.com/TMHSDigital/Blender-Developer-Tools/tree/main/examples/gpu-offscreen-draw/">gpu-offscreen-draw</a>: Check-only witness for drawing with the <code>gpu</code> module, the replacement for the <code>bgl</code> module that 5.x removed.</li>
           <li><a href="https://github.com/TMHSDigital/Blender-Developer-Tools/tree/main/examples/mesh-automasking-settings/">mesh-automasking-settings</a>: Pathology witness for the 5.2 move of sculpt automasking RNA off <code>Brush</code> into <code>MeshAutomaskingSettings</code>.</li>
+          <li><a href="https://github.com/TMHSDigital/Blender-Developer-Tools/tree/main/examples/mesh-normals-after-41/">mesh-normals-after-41</a>: Check-only witness for the normals API that replaced auto smooth in Blender 4.1, on 4.5 LTS and 5.x alike.</li>
           <li><a href="https://github.com/TMHSDigital/Blender-Developer-Tools/tree/main/examples/ngon-triangulate/">ngon-triangulate</a>: Synthesizes one hexagon by dissolving a cube edge, then asserts the hygiene / tangent contracts on that defective mesh.</li>
           <li><a href="https://github.com/TMHSDigital/Blender-Developer-Tools/tree/main/examples/timers-modal-threading/">timers-modal-threading</a>: Proves the event-loop contracts behind long-running add-on work.</li>
           <li><a href="https://github.com/TMHSDigital/Blender-Developer-Tools/tree/main/examples/unapplied-scale-gltf/">unapplied-scale-gltf</a>: Synthesizes unapplied non-uniform object scale on a unit cube, then asserts the glTF exporter contract.</li>
 
@@ -59,7 +59,7 @@ metadata — so the render would be identical whether the API held or broke. The
 "redesign the scene until failure would be visible" instruction above is the test:
 attempt it first, and only when it cannot succeed in principle does the example
 become check-only. The exception is for contracts that are invisible, not for
-renders that are hard. Ten of the 67 examples currently qualify, and `CLAUDE.md`
+renders that are hard. Ten of the 68 examples currently qualify, and `CLAUDE.md`
 carries the same rule. A check-only example is otherwise a full example: it still
 asserts a real contract, still exits non-zero on failure, still carries a falsifier,
 and still takes a `tests/smoke/catalog.json` row so it runs on every PR.
Original file line number	Diff line number	Diff line change
`@@ -50,6 +50,7 @@`
`50`	`50`	`"rules/validate-imported-mesh-scale.mdc",`
`51`	`51`	`"rules/no-unapplied-modifiers-on-export.mdc",`
`52`	`52`	`"rules/use-correct-axis-rna-per-exporter.mdc",`
`53`		`- "rules/no-bgl.mdc"`
	`53`	`+ "rules/no-bgl.mdc",`
	`54`	`+ "rules/no-removed-normals-api.mdc"`
`54`	`55`	`]`
`55`	`56`	`}`