diff --git a/course/harness.md b/course/harness.md
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+++ b/course/harness.md
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+# Harness contract
+
+The harness is the thin adapter between the course tests and your engine. Tests only ever call harness functions. TypeScript signatures are canonical; Rust uses the same names in snake_case on `pub struct Game` / `pub struct Baba` / `pub struct SpellGrid` in `src/harness.rs`, with `pub type Id = u32;`, `pub type Player = u8;`, and events as `pub enum GameEvent`. Rust has no default arguments, so optional parameters (`player`, `target`) are explicit there.
+
+Rust tests: `use engine::harness::*;`. TS tests: `from "../src/harness"`.
+
+Each module adds functions; `start-module` prints the line for the module you start.
+
+## Part I (`Game`): additions per module
+
+- M1: `newGame(opts?: { decks?: [string[], string[]] }): Game`; `summon(card: string, player?: 0|1): Id` (to right end of board); `addToHand(card, player?)`, `addToDeck(card, player?)`; `play(handId: Id): void` (Expansion Drop); `zoneOf(id): "deck"|"hand"|"board"|"graveyard"`; `board(player): Id[]` (left to right); `hand(player): Id[]`; `orderOfPlay(id): number`; `nameOf(id): string`.
+- M2: `hero(player): Id`; `dealDamage(target: Id, amount: number): void` (one Sequence); `cast(card: string, player?, target?: Id): void`; `health(id)`, `attack(id)`, `armor(player)`; `log(): GameEvent[]`; `clearLog()`.
+- M3: `destroy(target: Id): void` (marks pending-destroy, one Sequence).
+- M5: `registerCards(defs: CardDef[]): void`; `assemble(base: string, donor: string, half: "top"|"bottom"): string` (registers and returns new card name `"<base> (Assembled)"`; throws `AssembleError` if text unchanged).
+
+### Side by side (Part I)
+
+| Module | TypeScript | Rust (`impl Game` unless noted) |
+|---|---|---|
+| M1 | `newGame(opts?)` | `new_game(opts: GameOpts) -> Game` (free function) |
+| M1 | `summon(card, player?): Id` | `summon(&mut self, card: &str, player: Player) -> Id` |
+| M1 | `addToHand(card, player?)` | `add_to_hand(&mut self, card: &str, player: Player) -> Id` |
+| M1 | `addToDeck(card, player?)` | `add_to_deck(&mut self, card: &str, player: Player) -> Id` |
+| M1 | `play(handId)` | `play(&mut self, hand_id: Id)` |
+| M1 | `zoneOf(id)` | `zone_of(&self, id: Id) -> Zone` |
+| M1 | `board(player)` / `hand(player)` | `board(&self, player) -> Vec<Id>` / `hand(...)` |
+| M1 | `orderOfPlay(id)` | `order_of_play(&self, id: Id) -> u32` |
+| M1 | `nameOf(id)` | `name_of(&self, id: Id) -> String` |
+| M2 | `hero(player)` | `hero(&self, player) -> Id` |
+| M2 | `dealDamage(target, amount)` | `deal_damage(&mut self, target: Id, amount: i32)` |
+| M2 | `cast(card, player?, target?)` | `cast(&mut self, card: &str, player: Player, target: Option<Id>)` |
+| M2 | `health(id)`, `attack(id)`, `armor(player)` | `health`, `attack`, `armor` |
+| M2 | `log()`, `clearLog()` | `log(&self) -> Vec<GameEvent>`, `clear_log(&mut self)` |
+| M3 | `destroy(target)` | `destroy(&mut self, target: Id)` |
+| M5 | `registerCards(defs)` | `register_cards(&mut self, defs: Vec<CardDef>)` |
+| M5 | `assemble(base, donor, half)` (throws `AssembleError`) | `assemble(...) -> Result<String, AssembleError>` |
+
+### `GameEvent`
+
+Tagged by `type`: `Summoned{id}`, `Damaged{target, amount}`, `Triggered{source, trigger}` (`trigger`: `"deathrattle"|"battlecry"|"damaged"|...`), `Destroyed{id}` (removed in a Death Creation Step), `DeathPhase{round}`, `Drew{player, id}`, `Fatigue{player}`, `ArmorGained{player, amount}`, `StatsChanged{id, attack, health}`, `SpellCast{card}`.
+
+Drawing from an empty deck logs `Fatigue{player}` and does nothing else; the engine must not panic.
+
+## Part II (`Baba`): additions per module
+
+- M6: `newBaba(level: LevelDef): Baba`; `place(kind: string, x, y): Id` (kind `"baba"` or `"text:BABA"`); `rules(): string[]` (sorted, normalised `"BABA IS YOU"`, includes `"TEXT IS PUSH"`).
+- M7: `hasProperty(id, prop: string): boolean`; `activeRules(): string[]` (after NOT/identity post-pass).
+- M8: `move(dir: "up"|"down"|"left"|"right"): void` (movement only, then reparse); `posOf(id): [number, number] | null` (null once destroyed); `kindsAt(x, y): string[]` (sorted).
+- M9: `step(dir): void` (full simplified turn); `won(): boolean`; `lost(): boolean` (no YOU objects remain).
+
+Grid coordinates: `x` grows right, `y` grows down; vertical sentences read top-to-bottom.
+
+### Side by side (Part II)
+
+| Module | TypeScript | Rust (`impl Baba` unless noted) |
+|---|---|---|
+| M6 | `newBaba(level)` | `new_baba(level: LevelDef) -> Baba` (free function) |
+| M6 | `place(kind, x, y): Id` | `place(&mut self, kind: &str, x: i32, y: i32) -> Id` |
+| M6 | `rules()` | `rules(&self) -> Vec<String>` |
+| M7 | `hasProperty(id, prop)` | `has_property(&self, id: Id, prop: &str) -> bool` |
+| M7 | `activeRules()` | `active_rules(&self) -> Vec<String>` |
+| M8 | `move(dir)` | `move_dir(&mut self, dir: Dir)` (`move` is a Rust keyword) |
+| M8 | `posOf(id)` | `pos_of(&self, id: Id) -> Option<(i32, i32)>` |
+| M8 | `kindsAt(x, y)` | `kinds_at(&self, x: i32, y: i32) -> Vec<String>` |
+| M9 | `step(dir)` | `step(&mut self, dir: Dir)` |
+| M9 | `won()`, `lost()` | `won(&self) -> bool`, `lost(&self) -> bool` |
+
+## Part III (`SpellGrid`)
+
+- M10: `newSpellGrid(level: LevelDef, cards: CardDef[]): SpellGrid` exposing all of Part II plus `cast`, `health`, `log`, `hero`, `won`. Minions are grid objects whose noun is their card's `"noun"` field.
+
+Rust: `new_spell_grid(level: LevelDef, cards: Vec<CardDef>) -> SpellGrid`.
diff --git a/workspace-template/rust/.course.json b/workspace-template/rust/.course.json
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+++ b/workspace-template/rust/.course.json
@@ -0,0 +1 @@
+{ "track": "rust", "engineDirs": ["src/engine"], "contentDirs": ["src/content"], "module": "01" }
diff --git a/workspace-template/rust/Cargo.toml b/workspace-template/rust/Cargo.toml
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--- /dev/null
+++ b/workspace-template/rust/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "engine"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+# serde_json arrives at Module 5; nothing needed yet.
diff --git a/workspace-template/rust/README.md b/workspace-template/rust/README.md
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+++ b/workspace-template/rust/README.md
@@ -0,0 +1,11 @@
+# Systemic Design Course: Rust workspace
+
+Your engine lives in `src/engine/` (generic rules machinery) and `src/content/` (card definitions; only this directory may name specific cards). `src/harness.rs` is the thin adapter the course tests call; wire its `todo!()` stubs to your engine.
+
+Tests live in `tests/` and use `use engine::harness::*;`. Get a module's tests with `node tools/start-module.mjs NN <this-dir>` from the course repo.
+
+```
+cargo test
+```
+
+The crate has no dependencies yet. `serde_json` is added at Module 5.
diff --git a/workspace-template/rust/src/content/mod.rs b/workspace-template/rust/src/content/mod.rs
new file mode 100644
index 0000000..15ff0a2
--- /dev/null
+++ b/workspace-template/rust/src/content/mod.rs
@@ -0,0 +1 @@
+// Content: card definitions. Only this directory may name specific cards.
diff --git a/workspace-template/rust/src/engine/mod.rs b/workspace-template/rust/src/engine/mod.rs
new file mode 100644
index 0000000..8d7b366
--- /dev/null
+++ b/workspace-template/rust/src/engine/mod.rs
@@ -0,0 +1 @@
+// Engine code: generic rules machinery. Never name a specific card here.
diff --git a/workspace-template/rust/src/harness.rs b/workspace-template/rust/src/harness.rs
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index 0000000..2e4c432
--- /dev/null
+++ b/workspace-template/rust/src/harness.rs
@@ -0,0 +1,58 @@
+//! Test harness. Module 1 surface only; later modules add functions
+//! (see course/harness.md). Replace each `todo!()` by delegating to your engine.
+#![allow(unused_variables)]
+
+pub type Id = u32;
+pub type Player = u8;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Zone {
+    Deck,
+    Hand,
+    Board,
+    Graveyard,
+}
+
+#[derive(Debug, Default, Clone)]
+pub struct GameOpts {
+    pub decks: Option<[Vec<String>; 2]>,
+}
+
+pub struct Game {}
+
+pub fn new_game(opts: GameOpts) -> Game {
+    todo!()
+}
+
+impl Game {
+    /// Put `card` at the right end of `player`'s board.
+    pub fn summon(&mut self, card: &str, player: Player) -> Id {
+        todo!()
+    }
+    pub fn add_to_hand(&mut self, card: &str, player: Player) -> Id {
+        todo!()
+    }
+    pub fn add_to_deck(&mut self, card: &str, player: Player) -> Id {
+        todo!()
+    }
+    /// Play a card from hand (Expansion Drop).
+    pub fn play(&mut self, hand_id: Id) {
+        todo!()
+    }
+    pub fn zone_of(&self, id: Id) -> Zone {
+        todo!()
+    }
+    /// Board ids, left to right.
+    pub fn board(&self, player: Player) -> Vec<Id> {
+        todo!()
+    }
+    pub fn hand(&self, player: Player) -> Vec<Id> {
+        todo!()
+    }
+    pub fn order_of_play(&self, id: Id) -> u32 {
+        todo!()
+    }
+    pub fn name_of(&self, id: Id) -> String {
+        todo!()
+    }
+}
diff --git a/workspace-template/rust/src/lib.rs b/workspace-template/rust/src/lib.rs
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--- /dev/null
+++ b/workspace-template/rust/src/lib.rs
@@ -0,0 +1,3 @@
+pub mod content;
+pub mod engine;
+pub mod harness;
diff --git a/workspace-template/ts/.course.json b/workspace-template/ts/.course.json
new file mode 100644
index 0000000..ab4fb30
--- /dev/null
+++ b/workspace-template/ts/.course.json
@@ -0,0 +1 @@
+{ "track": "ts", "engineDirs": ["src/engine"], "contentDirs": ["src/content"], "module": "01" }
diff --git a/workspace-template/ts/README.md b/workspace-template/ts/README.md
new file mode 100644
index 0000000..3375f62
--- /dev/null
+++ b/workspace-template/ts/README.md
@@ -0,0 +1,10 @@
+# Systemic Design Course: TypeScript workspace
+
+Your engine lives in `src/engine/` (generic rules machinery) and `src/content/` (card definitions; only this directory may name specific cards). `src/harness.ts` is the thin adapter the course tests call; replace its `throw new Error("not implemented")` stubs with calls into your engine.
+
+Tests live in `tests/` and import from `"../src/harness"`. Get a module's tests with `node tools/start-module.mjs NN <this-dir>` from the course repo.
+
+```
+npm install
+npm test
+```
diff --git a/workspace-template/ts/package.json b/workspace-template/ts/package.json
new file mode 100644
index 0000000..8d2da89
--- /dev/null
+++ b/workspace-template/ts/package.json
@@ -0,0 +1,14 @@
+{
+  "name": "systemic-design-workspace",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "test": "vitest run",
+    "typecheck": "tsc --noEmit"
+  },
+  "devDependencies": {
+    "typescript": "^5.6.0",
+    "vitest": "^2.1.0"
+  }
+}
diff --git a/workspace-template/ts/src/content/index.ts b/workspace-template/ts/src/content/index.ts
new file mode 100644
index 0000000..cb0ff5c
--- /dev/null
+++ b/workspace-template/ts/src/content/index.ts
@@ -0,0 +1 @@
+export {};
diff --git a/workspace-template/ts/src/engine/index.ts b/workspace-template/ts/src/engine/index.ts
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index 0000000..cb0ff5c
--- /dev/null
+++ b/workspace-template/ts/src/engine/index.ts
@@ -0,0 +1 @@
+export {};
diff --git a/workspace-template/ts/src/harness.ts b/workspace-template/ts/src/harness.ts
new file mode 100644
index 0000000..d7f7bb3
--- /dev/null
+++ b/workspace-template/ts/src/harness.ts
@@ -0,0 +1,22 @@
+// Test harness. Module 1 surface only; later modules add functions
+// (see course/harness.md). Replace each stub by delegating to your engine.
+
+export type Id = number;
+export type Player = 0 | 1;
+export type Zone = "deck" | "hand" | "board" | "graveyard";
+
+export interface Game {
+  summon(card: string, player?: Player): Id; // to right end of board
+  addToHand(card: string, player?: Player): Id;
+  addToDeck(card: string, player?: Player): Id;
+  play(handId: Id): void; // Expansion Drop
+  zoneOf(id: Id): Zone;
+  board(player: Player): Id[]; // left to right
+  hand(player: Player): Id[];
+  orderOfPlay(id: Id): number;
+  nameOf(id: Id): string;
+}
+
+export function newGame(opts?: { decks?: [string[], string[]] }): Game {
+  throw new Error("not implemented");
+}
diff --git a/workspace-template/ts/tsconfig.json b/workspace-template/ts/tsconfig.json
new file mode 100644
index 0000000..2099df7
--- /dev/null
+++ b/workspace-template/ts/tsconfig.json
@@ -0,0 +1,12 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "Bundler",
+    "strict": true,
+    "noEmit": true,
+    "skipLibCheck": true,
+    "esModuleInterop": true
+  },
+  "include": ["src", "tests"]
+}
diff --git a/workspace-template/ts/vitest.config.ts b/workspace-template/ts/vitest.config.ts
new file mode 100644
index 0000000..00988cf
--- /dev/null
+++ b/workspace-template/ts/vitest.config.ts
@@ -0,0 +1,5 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  test: { include: ["tests/**/*.test.ts"] },
+});