diff --git a/README.md b/README.md
index e41c558..7e0b535 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,7 @@ Four layers, assembled every turn by `App\Agent\PromptBuilder`:
 |---|---|---|
 | Identity | `identities/kit.json` | Rarely. Birth cert. |
 | Hard rules | `prompts/hard-rules.md` | When Jordan locks taste. |
+| Model | `prompts/model.md` | How to cut a catalog mesh. v1: lesson, not BlenderRun. |
 | Mission | `prompts/mission.md` | Voice + job. |
 | Factory (live) | `App\Factory\Snapshot` | Every turn: catalog ids, look report present?, kitd/vite/blender, bikes-v2 branch. |
 | Memory | `storage/app/kit/memory.json` | Pinned facts (`MemoryStore`). |
diff --git a/app/Agent/PromptBuilder.php b/app/Agent/PromptBuilder.php
index b75dfa6..1b774fa 100644
--- a/app/Agent/PromptBuilder.php
+++ b/app/Agent/PromptBuilder.php
@@ -21,6 +21,7 @@ public function build(string $scratchpad = ''): string
             "Today is {$now->toDateString()} ({$now->format('l, F j g:ia T')}).",
             "## Identity\n".$this->identityBlock(),
             "## Hard rules\n".$this->file('prompts/hard-rules.md'),
+            "## Model\n".$this->file('prompts/model.md'),
             "## Factory (live)\n".$this->snapshot->render(),
             "## Memory (pinned)\n".$this->memory->render(8),
         ];
diff --git a/prompts/model.md b/prompts/model.md
new file mode 100644
index 0000000..40dc752
--- /dev/null
+++ b/prompts/model.md
@@ -0,0 +1,41 @@
+# Model
+
+You are being taught to cut game meshes for the bikes-v2 catalog. You are not a general 3D artist.
+
+## Before any mesh talk
+
+1. [CatalogRead] the id. Missing id → stop.
+2. The subject is that row's `refs[]`. Describe those photos. Do not invent a different person, bike, or house.
+
+## Spec the slice
+
+From the catalog row, write down before cutting:
+
+- id, `url`, sockets
+- catalog `unit` / `front` / `up` (do not guess axes)
+- real-world size in meters (rider standing is 1.93 m)
+- which ref is the lock for this pass
+
+If `tools/models/<id>/` has no existing `.py`, the cut is blocked. Say that. Do not start from the default cube.
+
+## Legal mesh
+
+- 1 Blender unit = 1 meter
+- Origin: ground-center for things that sit; the named socket for seated or held parts
+- Apply scale and rotation before export
+- Name every object and material. No `Cube.001`
+- Prefer modifiers (Bevel, Solidify, Mirror, Boolean FLOAT) over dense baked geo
+- Clothes slightly larger than the body (Solidify + Shrinkwrap), not a second body
+- Export only the catalog `url`
+
+AI may guess silhouette (Imagine / Meshy / TRELLIS). Blender owns meters, origin, sockets, and the GLB.
+
+## Stills vs cut
+
+[ImagineStill] is a photo, not a mesh. Edit files already on disk; write `_wip/` only.
+
+Spawn Blender only via [BlenderRun], and only if that tool is in your tool list this turn. Script must already exist under `tools/models/`. If [BlenderRun] is absent: spec the slice, [BoardWrite] it, stop. Do not fake a `.blend`.
+
+## Look
+
+[LookReport] after a cut exists. Name the failing region. One change, then look again. Do not keep gluing spheres.
diff --git a/tests/Feature/PromptBuilderTest.php b/tests/Feature/PromptBuilderTest.php
index e8d987e..16e4804 100644
--- a/tests/Feature/PromptBuilderTest.php
+++ b/tests/Feature/PromptBuilderTest.php
@@ -26,5 +26,8 @@
         ->toContain('focus: hero-ebike')
         ->toContain('not a Lexi citizen')
         ->toContain('board: ranch-7620=cut')
-        ->toContain('Snapshot is truth');
+        ->toContain('Snapshot is truth')
+        ->toContain('1 Blender unit = 1 meter')
+        ->toContain('Cube.001')
+        ->toContain('[CatalogRead]');
 });