diff --git a/AGENTS.md b/AGENTS.md
index 7df2a13b..5ed3a901 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -37,6 +37,7 @@ Formerly **DrawCraft** (renamed 2026-10-01): old `.drawcraft` files and `"format
 - **Layering** is enforced by `cargo xtask layers`. Nothing below L6 depends on egui/eframe/winit/rfd.
 - **The UI is thin**: panels read engine state and act through `app.run(id, params)`. Colours come from `theme::Tokens`.
 - **Rust only** (no handwritten JS/TS). **Never break wasm** (`cargo xtask wasm`).
+- **Shared test corpora.** Real-file test oracles (Photoshop-authored PSDs, etc.) live in [`storytold/photocraft-corpus`](https://github.com/storytold/photocraft-corpus), explained in [craftrules `standards/test-corpora.md`](https://github.com/storytold/craftrules/blob/main/standards/test-corpora.md). Never commit large binary fixtures to this repo; fetch them pinned by commit and sha256-verified, as PhotoCraft does with `cargo xtask corpus`.
 - **Quality gates** before every commit: `cargo xtask ci` (fmt, clippy -D warnings including the no-panic lints, tests, layers, wasm). One task id per commit (`M2.1: pen tool`).
 
 ## Running and looking at the app
diff --git a/CLAUDE.md b/CLAUDE.md
index 7df2a13b..5ed3a901 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -37,6 +37,7 @@ Formerly **DrawCraft** (renamed 2026-10-01): old `.drawcraft` files and `"format
 - **Layering** is enforced by `cargo xtask layers`. Nothing below L6 depends on egui/eframe/winit/rfd.
 - **The UI is thin**: panels read engine state and act through `app.run(id, params)`. Colours come from `theme::Tokens`.
 - **Rust only** (no handwritten JS/TS). **Never break wasm** (`cargo xtask wasm`).
+- **Shared test corpora.** Real-file test oracles (Photoshop-authored PSDs, etc.) live in [`storytold/photocraft-corpus`](https://github.com/storytold/photocraft-corpus), explained in [craftrules `standards/test-corpora.md`](https://github.com/storytold/craftrules/blob/main/standards/test-corpora.md). Never commit large binary fixtures to this repo; fetch them pinned by commit and sha256-verified, as PhotoCraft does with `cargo xtask corpus`.
 - **Quality gates** before every commit: `cargo xtask ci` (fmt, clippy -D warnings including the no-panic lints, tests, layers, wasm). One task id per commit (`M2.1: pen tool`).
 
 ## Running and looking at the app