diff --git a/package.json b/package.json
index 12ab14c..bad80fd 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
     "tui:legacy": "tsx tui/tui.tsx",
     "propose:apply": "node scripts/propose-apply.js",
     "stop": "bash scripts/stop.sh",
-    "test": "node --test runtime/skills/contract.test.js runtime/skills/groups.test.js runtime/skills/compat.test.js runtime/skills/recovery-tunnel-out.test.js runtime/skills/pillar-up.test.js runtime/skills/dig-in.test.js runtime/skills/_common.test.js runtime/curriculum.test.js runtime/social/social.test.js runtime/social/conversation.test.js runtime/social/chat-history.test.js runtime/social/reply-pi.test.js runtime/stuck-incident.test.js runtime/compat.test.js runtime/reflex.test.js runtime/base-site.test.js runtime/locations.test.js runtime/watch-filter.test.js runtime/world-journal.test.js runtime/scenario-memory.test.js runtime/critic.test.js runtime/skill-library.test.js runtime/skill-registry.test.js runtime/modes.test.js runtime/pathfinder-watchdog.test.js runtime/services/inventory-ledger.test.js runtime/services/motion.test.js runtime/manifesto/needs.test.js runtime/manifesto/state.test.js runtime/goal/storyline.test.js runtime/goal/goal-manager.test.js runtime/goal/village-score.test.js runtime/awareness/events.test.js runtime/awareness/wedge-detector.test.js runtime/biome-affordances.test.js runtime/knowledge/knowledge.test.js runtime/llm/provider.test.js runtime/coach/postmortem.test.js runtime/coach/advice.test.js runtime/coach/reflect.test.js runtime/coach/fast-advisor.test.js runtime/coach/advisor-trigger.test.js runtime/coach/trigger-tuner.test.js runtime/persona/chatter.test.js scripts/edit-scope.test.js scripts/lint-patch.test.js"
+    "test": "node --test runtime/skills/contract.test.js runtime/skills/groups.test.js runtime/skills/compat.test.js runtime/skills/recovery-tunnel-out.test.js runtime/skills/pillar-up.test.js runtime/skills/dig-in.test.js runtime/skills/_common.test.js runtime/skills/flee.test.js runtime/skills/worlddelta.test.js runtime/curriculum.test.js runtime/social/social.test.js runtime/social/conversation.test.js runtime/social/chat-history.test.js runtime/social/reply-pi.test.js runtime/stuck-incident.test.js runtime/compat.test.js runtime/reflex.test.js runtime/base-site.test.js runtime/locations.test.js runtime/watch-filter.test.js runtime/world-journal.test.js runtime/scenario-memory.test.js runtime/critic.test.js runtime/skill-library.test.js runtime/skill-registry.test.js runtime/modes.test.js runtime/pathfinder-watchdog.test.js runtime/anti-loop.test.js runtime/services/inventory-ledger.test.js runtime/services/motion.test.js runtime/manifesto/needs.test.js runtime/manifesto/state.test.js runtime/goal/storyline.test.js runtime/goal/goal-manager.test.js runtime/goal/village-score.test.js runtime/goal/skill-graph.test.js runtime/awareness/events.test.js runtime/awareness/wedge-detector.test.js runtime/biome-affordances.test.js runtime/knowledge/knowledge.test.js runtime/llm/provider.test.js runtime/coach/postmortem.test.js runtime/coach/advice.test.js runtime/coach/reflect.test.js runtime/coach/fast-advisor.test.js runtime/coach/advisor-trigger.test.js runtime/coach/trigger-tuner.test.js runtime/persona/chatter.test.js scripts/edit-scope.test.js scripts/lint-patch.test.js"
   },
   "dependencies": {
     "better-sqlite3": "^11.10.0",
diff --git a/runtime/actions.js b/runtime/actions.js
index 1b8aade..7ee8d1c 100644
--- a/runtime/actions.js
+++ b/runtime/actions.js
@@ -143,7 +143,30 @@ export async function attackNearest(bot, hostileType) {
 
 // ---- flee ------------------------------------------------------------------
 
-export async function fleeFrom(bot, fromEntity, distance = 16) {
+async function blindRetreat(bot, dirYaw, blindMs = 7_000) {
+	const before = bot.entity.position.clone?.() ?? { ...bot.entity.position };
+	try { bot.pathfinder?.stop?.(); } catch {}
+	try { await bot.look(dirYaw, 0, true); } catch {}
+	bot.setControlState("forward", true);
+	bot.setControlState("jump", true);
+	try {
+		await new Promise((r) => setTimeout(r, blindMs));
+	} finally {
+		bot.setControlState("forward", false);
+		bot.setControlState("jump", false);
+	}
+	const after = bot.entity.position;
+	const moved = Math.hypot(after.x - before.x, after.z - before.z);
+	return { moved, after };
+}
+
+// v0.4.0 — when a MotionService is supplied (opts.motion), retreat via
+// gotoSafe: a 12s wall-clock with a 4s progress watchdog returns a STRUCTURED
+// {stuck|timeout|nopath} fast instead of hanging the full 30s that we observed
+// live (zombie pinning the bot, every flee timing out, watchdog burning 3
+// replans). On any non-reached result we fall straight through to the blind
+// retreat. Callers without a motion service keep the legacy 30s path.
+export async function fleeFrom(bot, fromEntity, distance = 16, opts = {}) {
 	ensurePathfinder(bot);
 	const from = fromEntity?.position ?? bot.entity.position;
 	const here = bot.entity.position;
@@ -154,50 +177,62 @@ export async function fleeFrom(bot, fromEntity, distance = 16) {
 	const tx = Math.round(here.x + (dx / len) * distance);
 	const tz = Math.round(here.z + (dz / len) * distance);
 	const ty = Math.round(here.y);
+	const dirYaw = -Math.atan2(dx / len, dz / len);
+	const blindMs = opts.blindMs ?? 7_000;
 	info("action", `flee: from=${fromEntity?.name ?? "?"} → ${tx},${ty},${tz}`);
 
 	// canDig:true here is deliberate — without it the bot gets permanently
 	// stuck in dense tree canopy (observed live: bot perched at Y=85 inside
 	// dark-oak leaves, every flee timed out for hours). We accept the risk of
 	// chopping through scenery while panicking; it's how a player would react.
-	const movements = new Movements(bot);
-	movements.canDig = true;
-	movements.allow1by1towers = false;
-	bot.pathfinder.setMovements(movements);
+	try {
+		const movements = new Movements(bot);
+		movements.canDig = true;
+		movements.allow1by1towers = false;
+		bot.pathfinder.setMovements(movements);
+	} catch {
+		// fake/registry-less bot (tests) — skip movement tuning
+	}
+
+	const goal = new goals.GoalNear(tx, ty, tz, 1);
+
+	if (opts.motion?.gotoSafe) {
+		const res = await opts.motion.gotoSafe(goal, {
+			timeoutMs: opts.timeoutMs ?? 12_000,
+			stuckWindowMs: 4_000,
+			stuckDelta: 1.5,
+			label: `flee(${fromEntity?.name})`,
+		});
+		if (res.ok) return { ok: true, detail: { to: { x: tx, y: ty, z: tz }, moved: res.movedBlocks } };
+		warn("action", `flee gotoSafe → ${res.code} (moved ${res.movedBlocks}b); blind retreat`);
+		const b = await blindRetreat(bot, dirYaw, blindMs);
+		if (b.moved >= 4) {
+			return { ok: true, detail: { to: { x: Math.round(b.after.x), y: Math.round(b.after.y), z: Math.round(b.after.z) }, mode: "blind-retreat", moved: b.moved } };
+		}
+		return { ok: false, code: res.code, detail: `flee ${res.code} then blind retreat moved ${b.moved.toFixed(2)}b` };
+	}
 
 	try {
 		await withTimeout(
-			bot.pathfinder.goto(new goals.GoalNear(tx, ty, tz, 1)),
+			bot.pathfinder.goto(goal),
 			30_000,
 			`fleeFrom(${fromEntity?.name})`,
 		);
 		return { ok: true, detail: { to: { x: tx, y: ty, z: tz } } };
 	} catch (e) {
 		warn("action", `flee path failed: ${e.message}; trying blind retreat`);
-		const before = bot.entity.position.clone?.() ?? { ...bot.entity.position };
-		try { bot.pathfinder?.stop?.(); } catch {}
-		try { await bot.look(-Math.atan2(dx / len, dz / len), 0, true); } catch {}
-		bot.setControlState("forward", true);
-		bot.setControlState("jump", true);
-		try {
-			await new Promise((r) => setTimeout(r, 7_000));
-		} finally {
-			bot.setControlState("forward", false);
-			bot.setControlState("jump", false);
-		}
-		const after = bot.entity.position;
-		const moved = Math.hypot(after.x - before.x, after.z - before.z);
-		if (moved >= 4) {
+		const b = await blindRetreat(bot, dirYaw, blindMs);
+		if (b.moved >= 4) {
 			return {
 				ok: true,
 				detail: {
-					to: { x: Math.round(after.x), y: Math.round(after.y), z: Math.round(after.z) },
+					to: { x: Math.round(b.after.x), y: Math.round(b.after.y), z: Math.round(b.after.z) },
 					mode: "blind-retreat",
-					moved,
+					moved: b.moved,
 				},
 			};
 		}
-		warn("action", `flee blind retreat moved only ${moved.toFixed(2)} blocks`);
+		warn("action", `flee blind retreat moved only ${b.moved.toFixed(2)} blocks`);
 		return { ok: false, detail: e.message };
 	}
 }
diff --git a/runtime/anti-loop.js b/runtime/anti-loop.js
new file mode 100644
index 0000000..f0cfe07
--- /dev/null
+++ b/runtime/anti-loop.js
@@ -0,0 +1,70 @@
+// Anti-loop detector (QW5). The scheduler already skips a (skill, situation)
+// that has failed repeatedly (scenario-memory.shouldSkip), but that is keyed on
+// a coarse situation hash and never escalates. This detector closes the loop
+// the research describes: when the SAME skill fails N times inside a short
+// window with no success in between, it (a) blacklists that skill for a cool-off
+// and (b) emits a one-shot "fired" record the runtime turns into an
+// improvement_request — so an operator/Codex gets a ticket instead of the bot
+// silently thrashing (e.g. the live flee↔dig-in loop we observed).
+//
+// Pure + deterministic: inject `now` in tests. No disk, no bot.
+
+export function createAntiLoop({
+	windowMs = 5 * 60_000,
+	threshold = 3,
+	blacklistMs = 30 * 60_000,
+	refireCooldownMs = 30 * 60_000,
+} = {}) {
+	const state = new Map(); // key -> { fails: number[], blacklistUntil, lastFiredAt }
+	const firedQueue = [];
+
+	function keyOf(skillId, targetKey) {
+		return targetKey ? `${skillId}@${targetKey}` : skillId;
+	}
+	function get(key) {
+		let s = state.get(key);
+		// lastFiredAt = -Infinity so the FIRST loop always fires (a real epoch
+		// `now` minus 0 would otherwise be < refireCooldownMs early in uptime).
+		if (!s) { s = { fails: [], blacklistUntil: 0, lastFiredAt: Number.NEGATIVE_INFINITY }; state.set(key, s); }
+		return s;
+	}
+
+	function record({ skillId, ok, code = null, targetKey = null, detail = null, now = Date.now() }) {
+		if (!skillId) return { fired: false };
+		const key = keyOf(skillId, targetKey);
+		const s = get(key);
+		if (ok) { s.fails = []; return { fired: false }; }
+
+		s.fails.push(now);
+		s.fails = s.fails.filter((t) => now - t <= windowMs);
+
+		if (s.fails.length >= threshold) {
+			s.blacklistUntil = now + blacklistMs;
+			const count = s.fails.length;
+			s.fails = []; // reset streak so we don't blacklist-spam every further fail
+			if (now - s.lastFiredAt >= refireCooldownMs) {
+				s.lastFiredAt = now;
+				const fired = { key, skillId, targetKey, count, code, detail, ts: now, until: s.blacklistUntil };
+				firedQueue.push(fired);
+				return { fired: true, ...fired };
+			}
+		}
+		return { fired: false };
+	}
+
+	function shouldSkip(skillId, targetKey = null, now = Date.now()) {
+		const s = state.get(keyOf(skillId, targetKey));
+		return !!s && now < s.blacklistUntil;
+	}
+
+	// Returns and clears the queue of newly-fired loops (for improvement_requests).
+	function drainFired() {
+		return firedQueue.splice(0);
+	}
+
+	function snapshot() {
+		return { tracked: state.size, pendingFired: firedQueue.length };
+	}
+
+	return { record, shouldSkip, drainFired, snapshot, _state: () => state };
+}
diff --git a/runtime/anti-loop.test.js b/runtime/anti-loop.test.js
new file mode 100644
index 0000000..f4b93b0
--- /dev/null
+++ b/runtime/anti-loop.test.js
@@ -0,0 +1,58 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+
+import { createAntiLoop } from "./anti-loop.js";
+
+test("fires after N failures in the window and blacklists the skill", () => {
+	const al = createAntiLoop({ windowMs: 60_000, threshold: 3, blacklistMs: 30_000 });
+	assert.equal(al.record({ skillId: "survive.flee", ok: false, now: 1000 }).fired, false);
+	assert.equal(al.record({ skillId: "survive.flee", ok: false, now: 2000 }).fired, false);
+	const third = al.record({ skillId: "survive.flee", ok: false, now: 3000 });
+	assert.equal(third.fired, true);
+	assert.equal(third.count, 3);
+	assert.equal(al.shouldSkip("survive.flee", null, 4000), true);
+	assert.equal(al.shouldSkip("survive.flee", null, 40_000), false); // blacklist expired
+});
+
+test("a success resets the fail streak", () => {
+	const al = createAntiLoop({ threshold: 3 });
+	al.record({ skillId: "gather.logs", ok: false, now: 1 });
+	al.record({ skillId: "gather.logs", ok: false, now: 2 });
+	al.record({ skillId: "gather.logs", ok: true, now: 3 });
+	const r = al.record({ skillId: "gather.logs", ok: false, now: 4 });
+	assert.equal(r.fired, false);
+});
+
+test("failures outside the window do not accumulate", () => {
+	const al = createAntiLoop({ windowMs: 1000, threshold: 3 });
+	al.record({ skillId: "s", ok: false, now: 0 });
+	al.record({ skillId: "s", ok: false, now: 500 });
+	const r = al.record({ skillId: "s", ok: false, now: 5000 }); // first two pruned
+	assert.equal(r.fired, false);
+});
+
+test("targetKey separates loops on different targets", () => {
+	const al = createAntiLoop({ threshold: 2 });
+	al.record({ skillId: "mine", ok: false, targetKey: "A", now: 1 });
+	const a2 = al.record({ skillId: "mine", ok: false, targetKey: "A", now: 2 });
+	assert.equal(a2.fired, true);
+	const b1 = al.record({ skillId: "mine", ok: false, targetKey: "B", now: 3 });
+	assert.equal(b1.fired, false); // different target, own streak
+});
+
+test("drainFired returns and clears the queue", () => {
+	const al = createAntiLoop({ threshold: 2 });
+	al.record({ skillId: "x", ok: false, now: 1 });
+	al.record({ skillId: "x", ok: false, now: 2 });
+	assert.equal(al.drainFired().length, 1);
+	assert.equal(al.drainFired().length, 0);
+});
+
+test("refire cooldown prevents immediate re-fire", () => {
+	const al = createAntiLoop({ threshold: 2, blacklistMs: 1000, refireCooldownMs: 100_000 });
+	al.record({ skillId: "x", ok: false, now: 1 });
+	assert.equal(al.record({ skillId: "x", ok: false, now: 2 }).fired, true);
+	// after blacklist expires, two more fails — within refire cooldown → no fire
+	al.record({ skillId: "x", ok: false, now: 2000 });
+	assert.equal(al.record({ skillId: "x", ok: false, now: 2100 }).fired, false);
+});
diff --git a/runtime/bot.js b/runtime/bot.js
index ad3e15b..d4b80e9 100644
--- a/runtime/bot.js
+++ b/runtime/bot.js
@@ -59,6 +59,7 @@ import { createScenarioMemory, situationHash } from "./scenario-memory.js";
 import { createOwnedBlocksLedger } from "./owned-blocks.js";
 import { createInventoryLedger } from "./services/inventory-ledger.js";
 import { createMotionService } from "./services/motion.js";
+import { createAntiLoop } from "./anti-loop.js";
 import { initKnowledge } from "./knowledge/index.js";
 import { attach as attachCoach } from "./coach/postmortem.js";
 import { attach as attachReflect } from "./coach/reflect.js";
@@ -109,6 +110,7 @@ const worldJournal = createWorldJournal();
 const scenarioMemory = createScenarioMemory();
 const ownedBlocks = createOwnedBlocksLedger();
 const inventoryLedger = createInventoryLedger();
+const antiLoop = createAntiLoop();
 const goalManager = createGoalManager();
 let motionService = null; // armed on spawn (needs a live bot for pathfinder)
 let lastResult = null; // { label, ok, code, detail, ts }
@@ -138,6 +140,7 @@ const reflexCtx = {
 	metrics: skillMetrics,
 	owned: ownedBlocks,
 	ledger: inventoryLedger,
+	antiLoop,
 	motion: null, // set on spawn alongside the pathfinder watchdog
 };
 
@@ -971,6 +974,40 @@ function tick() {
 			void filePostCritique(wedged, "wedged");
 		}
 
+		// QW5 — anti-loop: a skill that failed ≥3× in 5 min is blacklisted by
+		// the detector; here we turn each fired loop into an improvement_request
+		// so the operator/Codex gets a concrete ticket instead of silent thrash.
+		for (const loop of antiLoop.drainFired()) {
+			try {
+				writeProposal({
+					kind: `anti-loop-${loop.skillId}`,
+					summary: `${loop.skillId} looped ${loop.count}× in 5min (last code=${loop.code ?? "?"})`,
+					body: [
+						`# Anti-loop: ${loop.skillId}`,
+						``,
+						`The same skill failed ${loop.count} times within 5 minutes with no success`,
+						`in between, so it has been blacklisted until ${new Date(loop.until).toISOString()}.`,
+						``,
+						`- skill: ${loop.skillId}`,
+						loop.targetKey ? `- target: ${loop.targetKey}` : `- target: (none)`,
+						`- last failure code: ${loop.code ?? "?"}`,
+						`- runtime state: ${lastSnapshot.runtimeState ?? "?"}`,
+						`- no-progress reason: ${lastSnapshot.noProgressReason ?? "?"}`,
+						`- position: ${JSON.stringify(lastSnapshot.position ?? null)}`,
+						`- milestone: ${lastSnapshot.contract?.milestone?.id ?? lastSnapshot.currentMilestone ?? "?"}`,
+						``,
+						`## Suggested fix`,
+						`Either the skill's preconditions are too loose (it keeps being chosen`,
+						`when it cannot succeed here) or it needs a real recovery branch. Inspect`,
+						`runtime/skills/${loop.skillId.split(".").pop()}*.js and the scheduler path.`,
+					].join("\n"),
+					editScope: ["runtime/skills/", "runtime/reflex.js", "runtime/modes.js"],
+				});
+			} catch (e) {
+				warn("anti-loop", `writeProposal failed: ${e?.message ?? e}`);
+			}
+		}
+
 		ipc?.broadcast(EVENT_TYPES.STATUS, lastSnapshot);
 	} else {
 		lastSnapshot = { connected: false };
diff --git a/runtime/goal/goal-manager.js b/runtime/goal/goal-manager.js
index 635fbd2..3a4440a 100644
--- a/runtime/goal/goal-manager.js
+++ b/runtime/goal/goal-manager.js
@@ -17,6 +17,7 @@
 
 import { SETTLEMENT_CONTRACT } from "./contract.js";
 import { checkInvariants, worldFromSnapshot } from "./invariants.js";
+import { prerequisitesMet } from "./skill-graph.js";
 
 export function createGoalManager({ contract = SETTLEMENT_CONTRACT } = {}) {
 	// Evaluate every milestone; returns the per-milestone invariant status plus
@@ -57,6 +58,14 @@ export function createGoalManager({ contract = SETTLEMENT_CONTRACT } = {}) {
 			suggestedSkill = null;
 		}
 
+		// Annotate the suggestion with skill-graph prerequisite status (Plan4MC).
+		// Observability + a guard surface: if prereqs are unmet the curriculum
+		// chain should already be steering toward them, but we expose the gap.
+		if (suggestedSkill?.skillId) {
+			const pre = prerequisitesMet(suggestedSkill.skillId, world);
+			if (!pre.ok) suggestedSkill = { ...suggestedSkill, blockedBy: pre.missing };
+		}
+
 		const reason = current.urgency > 0 && current.index > unmet[0].index
 			? `urgent:${current.id}(${current.urgency}) preempts ${unmet[0].id}`
 			: `lowest unmet: ${current.id}`;
diff --git a/runtime/goal/skill-graph.js b/runtime/goal/skill-graph.js
new file mode 100644
index 0000000..b98df0f
--- /dev/null
+++ b/runtime/goal/skill-graph.js
@@ -0,0 +1,89 @@
+// Skill dependency graph (Plan4MC-style, research §C). A static, declarative
+// model of "what does this skill need, what does it produce". The contract
+// already SEQUENCES the early game via the curriculum, so this graph is the
+// queryable prerequisite layer on top: the GoalManager annotates each suggested
+// skill with whether its prerequisites currently hold (surfaced for the TUI and
+// as a guard against suggesting a skill that physically cannot succeed here).
+//
+// Requirement kinds:
+//   { item: <semantic-group|exact>, min }   — need N of an item / group
+//   { tool: "pickaxe" | "axe" | "sword" }     — need any tier of that tool
+// Semantic groups: logs (*_log/_stem), planks (*_planks), sticks, cobblestone,
+// wool (*_wool), coal, bed (*_bed). Anything else is matched as an exact name.
+
+import { totalMatching, has } from "./invariants.js";
+
+const GROUP = {
+	logs: (k) => k.endsWith("_log") || k.endsWith("_stem"),
+	planks: (k) => k.endsWith("_planks"),
+	wool: (k) => k.endsWith("_wool"),
+	cobblestone: (k) => k === "cobblestone" || k === "cobbled_deepslate",
+	coal: (k) => k === "coal" || k === "charcoal",
+};
+
+const TOOL = {
+	pickaxe: (k) => k.endsWith("_pickaxe"),
+	axe: (k) => k.endsWith("_axe") && !k.endsWith("_pickaxe"),
+	sword: (k) => k.endsWith("_sword"),
+};
+
+export const SKILL_GRAPH = Object.freeze({
+	"gather.logs": { requires: [], produces: ["logs"] },
+	"gather.wool": { requires: [], produces: ["wool"] },
+	"gather.stone": { requires: [{ tool: "pickaxe" }], produces: ["cobblestone"] },
+	"craft.planks": { requires: [{ item: "logs", min: 1 }], produces: ["planks"] },
+	"craft.sticks": { requires: [{ item: "planks", min: 2 }], produces: ["stick"] },
+	"craft.wooden-axe": { requires: [{ item: "planks", min: 3 }, { item: "stick", min: 2 }], produces: ["wooden_axe"] },
+	"craft.wooden-pickaxe": { requires: [{ item: "planks", min: 3 }, { item: "stick", min: 2 }], produces: ["wooden_pickaxe"] },
+	"craft.wooden-sword": { requires: [{ item: "planks", min: 2 }, { item: "stick", min: 1 }], produces: ["wooden_sword"] },
+	"craft.stone-axe": { requires: [{ item: "cobblestone", min: 3 }, { item: "stick", min: 2 }], produces: ["stone_axe"] },
+	"craft.stone-pickaxe": { requires: [{ item: "cobblestone", min: 3 }, { item: "stick", min: 2 }], produces: ["stone_pickaxe"] },
+	"craft.stone-sword": { requires: [{ item: "cobblestone", min: 2 }, { item: "stick", min: 1 }], produces: ["stone_sword"] },
+	"craft.furnace": { requires: [{ item: "cobblestone", min: 8 }], produces: ["furnace"] },
+	"craft.chest": { requires: [{ item: "planks", min: 8 }], produces: ["chest"] },
+	"craft.torch": { requires: [{ item: "coal", min: 1 }, { item: "stick", min: 1 }], produces: ["torch"] },
+	"craft.bed": { requires: [{ item: "wool", min: 3 }, { item: "planks", min: 3 }], produces: ["bed"] },
+	"village.choose-base": { requires: [], produces: ["loc:base"] },
+	"village.build-shelter": { requires: [{ item: "planks", min: 1 }], produces: ["loc:shelter"] },
+	"village.place-chest": { requires: [{ item: "chest", min: 1 }], produces: ["loc:chest"] },
+	"farm.wheat": { requires: [], produces: [] },
+});
+
+function itemCount(inv, name) {
+	const g = GROUP[name];
+	return g ? totalMatching(inv, g) : (inv?.[name] ?? 0);
+}
+
+function hasTool(inv, kind) {
+	const t = TOOL[kind];
+	if (!t) return false;
+	return Object.keys(inv ?? {}).some((k) => t(k) && (inv[k] ?? 0) > 0);
+}
+
+// { ok, missing: [{ item|tool, min, have }] } for a skill given the world.
+export function prerequisitesMet(skillId, world) {
+	const node = SKILL_GRAPH[skillId];
+	if (!node) return { ok: true, missing: [], known: false };
+	const inv = world?.inventory ?? {};
+	const missing = [];
+	for (const req of node.requires) {
+		if (req.tool) {
+			if (!hasTool(inv, req.tool)) missing.push({ tool: req.tool });
+		} else if (req.item) {
+			const have = itemCount(inv, req.item);
+			if (have < (req.min ?? 1)) missing.push({ item: req.item, min: req.min ?? 1, have });
+		}
+	}
+	return { ok: missing.length === 0, missing, known: true };
+}
+
+export function canRun(skillId, world) {
+	return prerequisitesMet(skillId, world).ok;
+}
+
+// All skills whose prerequisites currently hold (Plan4MC "frontier").
+export function runnableFrontier(world) {
+	return Object.keys(SKILL_GRAPH).filter((id) => canRun(id, world));
+}
+
+export const _internal = { GROUP, TOOL, itemCount, hasTool, has };
diff --git a/runtime/goal/skill-graph.test.js b/runtime/goal/skill-graph.test.js
new file mode 100644
index 0000000..0359f49
--- /dev/null
+++ b/runtime/goal/skill-graph.test.js
@@ -0,0 +1,56 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+
+import { prerequisitesMet, canRun, runnableFrontier, _internal } from "./skill-graph.js";
+
+function world(inv = {}) {
+	return { inventory: inv };
+}
+
+test("gather.logs needs nothing", () => {
+	assert.equal(canRun("gather.logs", world()), true);
+});
+
+test("gather.stone needs a pickaxe (any tier)", () => {
+	assert.equal(canRun("gather.stone", world({})), false);
+	assert.equal(canRun("gather.stone", world({ wooden_pickaxe: 1 })), true);
+	assert.equal(canRun("gather.stone", world({ stone_pickaxe: 1 })), true);
+});
+
+test("craft.planks needs a log (semantic group)", () => {
+	assert.equal(canRun("craft.planks", world({})), false);
+	assert.equal(canRun("craft.planks", world({ birch_log: 1 })), true);
+	assert.equal(canRun("craft.planks", world({ mangrove_stem: 2 })), true);
+});
+
+test("craft.furnace needs 8 cobblestone", () => {
+	assert.equal(canRun("craft.furnace", world({ cobblestone: 7 })), false);
+	assert.equal(canRun("craft.furnace", world({ cobblestone: 8 })), true);
+	assert.equal(canRun("craft.furnace", world({ cobbled_deepslate: 8 })), true);
+});
+
+test("prerequisitesMet reports the missing requirement detail", () => {
+	const r = prerequisitesMet("craft.wooden-pickaxe", world({ stick: 2 }));
+	assert.equal(r.ok, false);
+	assert.deepEqual(r.missing, [{ item: "planks", min: 3, have: 0 }]);
+});
+
+test("unknown skill is treated as runnable (known:false)", () => {
+	const r = prerequisitesMet("explore.far", world());
+	assert.equal(r.ok, true);
+	assert.equal(r.known, false);
+});
+
+test("axe matcher excludes pickaxe", () => {
+	assert.equal(_internal.TOOL.axe("wooden_axe"), true);
+	assert.equal(_internal.TOOL.axe("wooden_pickaxe"), false);
+	assert.equal(_internal.TOOL.pickaxe("stone_pickaxe"), true);
+});
+
+test("runnableFrontier grows as inventory fills", () => {
+	const empty = runnableFrontier(world());
+	const stocked = runnableFrontier(world({ oak_planks: 8, stick: 4, cobblestone: 8, wooden_pickaxe: 1 }));
+	assert.ok(stocked.length > empty.length);
+	assert.ok(stocked.includes("gather.stone"));
+	assert.ok(stocked.includes("craft.furnace"));
+});
diff --git a/runtime/reflex.js b/runtime/reflex.js
index fe42858..38fc3d2 100644
--- a/runtime/reflex.js
+++ b/runtime/reflex.js
@@ -712,6 +712,14 @@ function curriculumReflex(ctx) {
 		}
 	}
 
+	// QW5 anti-loop: this skill failed ≥3× in 5 min → it's blacklisted. Skip
+	// and nudge toward exploration so we leave the situation that loops it.
+	if (ctx.antiLoop?.shouldSkip(skillId)) {
+		ctx.skillBackoff = ctx.skillBackoff ?? {};
+		ctx.skillBackoff["__wander_hint__"] = Date.now() + SKILL_BACKOFF_MS;
+		return { action: "noop", kind: "anti-loop-blacklisted", label: skillId };
+	}
+
 	// v0.2.0 — consult learned lessons. If a high-confidence lesson says
 	// "avoid <skillId> in this situation", swap to its preferred
 	// alternative (or back off entirely if no safe alternative is named).
@@ -734,6 +742,9 @@ function curriculumReflex(ctx) {
 	ctx.dispatch(() => runSkill(dispatchSkillId, ctx, dispatchArgs), dispatchSkillId, {
 		onComplete: (res) => {
 			ctx.skillBackoff = ctx.skillBackoff ?? {};
+			// QW5 anti-loop bookkeeping: feed every outcome so repeated failures
+			// of the same skill get detected, blacklisted and ticketed.
+			ctx.antiLoop?.record({ skillId: dispatchSkillId, ok: !!res?.ok, code: res?.code ?? null });
 			if (advice.lessonId) reportAdviceOutcome({ lessonId: advice.lessonId, succeeded: !!res?.ok });
 			if (appliedRecommendationId) {
 				markRecommendationOutcome(appliedRecommendationId, {
diff --git a/runtime/skills/flee.js b/runtime/skills/flee.js
index 90a33f3..6655af5 100644
--- a/runtime/skills/flee.js
+++ b/runtime/skills/flee.js
@@ -39,7 +39,7 @@ export const skill = Object.freeze({
 	async execute(ctx, args = {}) {
 		const hit = nearestHostile(ctx.bot, args);
 		if (!hit) return { ok: false, code: "no_hostile", detail: "no matching hostile after precondition", worldDelta: null };
-		const res = await fleeFrom(ctx.bot, hit.entity, args.distance ?? 16);
+		const res = await fleeFrom(ctx.bot, hit.entity, args.distance ?? 16, { motion: ctx.motion, blindMs: args.blindMs });
 		if (res.ok) {
 			return {
 				ok: true,
@@ -48,8 +48,10 @@ export const skill = Object.freeze({
 				worldDelta: { fledTo: res.detail?.to ?? null },
 			};
 		}
+		// Prefer the structured code from MotionService (stuck/timeout/nopath);
+		// fall back to string-sniffing the legacy path's message.
 		const msg = String(res.detail ?? "");
-		const code = msg.includes("timed out") ? "timeout" : "failed";
+		const code = res.code ?? (msg.includes("timed out") ? "timeout" : "failed");
 		return { ok: false, code, detail: res.detail, worldDelta: null };
 	},
 	recover(ctx, result) {
diff --git a/runtime/skills/flee.test.js b/runtime/skills/flee.test.js
new file mode 100644
index 0000000..f5cfa80
--- /dev/null
+++ b/runtime/skills/flee.test.js
@@ -0,0 +1,62 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+
+import { skill } from "./flee.js";
+
+function vec(x, y, z) {
+	return {
+		x, y, z,
+		clone() { return vec(x, y, z); },
+		distanceTo(o) { return Math.hypot(x - o.x, y - o.y, z - o.z); },
+		offset(dx, dy, dz) { return vec(x + dx, y + dy, z + dz); },
+	};
+}
+
+function fakeBot({ moveOnForward = 0 } = {}) {
+	const bot = {
+		entity: { position: vec(0, 64, 0), yaw: 0 },
+		entities: { z1: { name: "zombie", position: vec(2, 64, 0) } },
+		loadPlugin() {},
+		pathfinder: { goto: () => new Promise(() => {}), stop() {}, setMovements() {} },
+		setControlState(name, on) {
+			if (name === "forward" && on && moveOnForward) {
+				bot.entity.position = vec(moveOnForward, 64, 0);
+			}
+		},
+		async look() {},
+	};
+	return bot;
+}
+
+test("flee returns done when motion reaches the retreat point", async () => {
+	const bot = fakeBot();
+	const ctx = { bot, motion: { gotoSafe: async () => ({ ok: true, code: "reached", movedBlocks: 16 }) } };
+	const res = await skill.execute(ctx, {});
+	assert.equal(res.ok, true);
+	assert.equal(res.code, "done");
+	assert.ok(res.worldDelta.fledTo);
+});
+
+test("flee falls back to blind retreat and succeeds when it moves far enough", async () => {
+	const bot = fakeBot({ moveOnForward: 8 });
+	const ctx = { bot, motion: { gotoSafe: async () => ({ ok: false, code: "stuck", movedBlocks: 0 }) } };
+	const res = await skill.execute(ctx, { blindMs: 20 });
+	assert.equal(res.ok, true);
+	assert.equal(res.detail.mode, "blind-retreat");
+});
+
+test("flee surfaces the structured motion code when stuck and blind retreat fails", async () => {
+	const bot = fakeBot({ moveOnForward: 0 }); // never moves
+	const ctx = { bot, motion: { gotoSafe: async () => ({ ok: false, code: "stuck", movedBlocks: 0 }) } };
+	const res = await skill.execute(ctx, { blindMs: 20 });
+	assert.equal(res.ok, false);
+	assert.equal(res.code, "stuck");
+});
+
+test("flee precondition fails with no hostile", () => {
+	const bot = fakeBot();
+	bot.entities = {};
+	const pre = skill.preconditions({ bot }, {});
+	assert.equal(pre.ok, false);
+	assert.equal(pre.code, "no_hostile");
+});
diff --git a/runtime/skills/index.js b/runtime/skills/index.js
index 87296ca..ce28944 100644
--- a/runtime/skills/index.js
+++ b/runtime/skills/index.js
@@ -130,6 +130,18 @@ export const RUNNER_CODES = Object.freeze({
 	DONE: "done",
 });
 
+// Signed inventory diff between two count Maps (from InventoryLedger.mark/
+// snapshot). Used to attach the real world change to a skill result.
+function invDiff(before, after) {
+	const out = {};
+	const names = new Set([...(before?.keys?.() ?? []), ...(after?.keys?.() ?? [])]);
+	for (const n of names) {
+		const d = (after?.get?.(n) ?? 0) - (before?.get?.(n) ?? 0);
+		if (d !== 0) out[n] = d;
+	}
+	return out;
+}
+
 function normaliseResult(res, fallbackCode) {
 	const ok = !!res?.ok;
 	return {
@@ -222,6 +234,12 @@ export async function runSkill(id, ctx, args = {}) {
 		return result;
 	}
 
+	// WorldDelta diff layer (research §TL;DR): snapshot the inventory before
+	// execute so we can attach the REAL inventory change to the result and,
+	// for skills that opt in via `expectGain`, assert the claimed gain actually
+	// happened instead of trusting the skill's own bookkeeping.
+	const ledgerBefore = ctx?.ledger?.mark?.() ?? null;
+
 	const timeoutMs = skill.timeoutMs ?? 30_000;
 	let raw;
 	try {
@@ -277,6 +295,31 @@ export async function runSkill(id, ctx, args = {}) {
 			return failed;
 		}
 	}
+	// Closed loop: compare the inventory now vs the pre-execute baseline.
+	if (result.ok && ledgerBefore && ctx?.ledger) {
+		try { if (ctx.bot) ctx.ledger.update(ctx.bot); } catch {}
+		const observed = invDiff(ledgerBefore, ctx.ledger.snapshot());
+		if (Object.keys(observed).length > 0) {
+			result.worldDelta = { ...(result.worldDelta ?? {}), _invObserved: observed };
+		}
+		// Opt-in strict check: the world must show the claimed gain.
+		if (skill.expectGain) {
+			const gain = ctx.ledger.gainedSince(ledgerBefore, skill.expectGain.matcher);
+			if (gain < (skill.expectGain.min ?? 1)) {
+				const failed = {
+					ok: false,
+					code: "world_unchanged",
+					detail: `${id} reported ok but ${skill.expectGain.label ?? "expected items"} did not increase (gain ${gain})`,
+					worldDelta: result.worldDelta,
+				};
+				if (typeof skill.recover === "function") {
+					try { failed.recovery = skill.recover(ctx, failed) ?? null; } catch {}
+				}
+				return failed;
+			}
+		}
+	}
+
 	if (!result.ok && typeof skill.recover === "function") {
 		try {
 			result.recovery = skill.recover(ctx, result) ?? null;
diff --git a/runtime/skills/worlddelta.test.js b/runtime/skills/worlddelta.test.js
new file mode 100644
index 0000000..09ee675
--- /dev/null
+++ b/runtime/skills/worlddelta.test.js
@@ -0,0 +1,77 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+
+import { runSkill, _registerForTest } from "./index.js";
+import { createInventoryLedger } from "../services/inventory-ledger.js";
+
+function botWithMutableInv(initial) {
+	let inv = initial;
+	return {
+		bot: { inventory: { items: () => inv } },
+		set(next) { inv = next; },
+	};
+}
+
+test("expectGain passes and attaches the observed inventory delta", async () => {
+	const m = botWithMutableInv([{ name: "cobblestone", count: 0 }]);
+	const ledger = createInventoryLedger();
+	ledger.update(m.bot);
+	const teardown = _registerForTest({
+		id: "test.mine-ok",
+		title: "t", timeoutMs: 1000,
+		preconditions: () => ({ ok: true }),
+		execute: async () => { m.set([{ name: "cobblestone", count: 5 }]); return { ok: true, code: "done", worldDelta: {} }; },
+		expectGain: { matcher: "cobblestone", min: 1, label: "cobblestone" },
+	});
+	const res = await runSkill("test.mine-ok", { bot: m.bot, ledger });
+	teardown();
+	assert.equal(res.ok, true);
+	assert.equal(res.worldDelta._invObserved.cobblestone, 5);
+});
+
+test("expectGain fails with world_unchanged when the world did not move", async () => {
+	const m = botWithMutableInv([{ name: "cobblestone", count: 0 }]);
+	const ledger = createInventoryLedger();
+	ledger.update(m.bot);
+	const teardown = _registerForTest({
+		id: "test.mine-liar",
+		title: "t", timeoutMs: 1000,
+		preconditions: () => ({ ok: true }),
+		execute: async () => ({ ok: true, code: "done", worldDelta: {} }), // claims ok, gains nothing
+		expectGain: { matcher: "cobblestone", min: 1, label: "cobblestone" },
+	});
+	const res = await runSkill("test.mine-liar", { bot: m.bot, ledger });
+	teardown();
+	assert.equal(res.ok, false);
+	assert.equal(res.code, "world_unchanged");
+});
+
+test("no ledger in ctx → no validation, skill passes untouched", async () => {
+	const teardown = _registerForTest({
+		id: "test.no-ledger",
+		title: "t", timeoutMs: 1000,
+		preconditions: () => ({ ok: true }),
+		execute: async () => ({ ok: true, code: "done", worldDelta: { foo: 1 } }),
+		expectGain: { matcher: "diamond", min: 1 },
+	});
+	const res = await runSkill("test.no-ledger", { bot: { inventory: { items: () => [] } } });
+	teardown();
+	assert.equal(res.ok, true);
+	assert.equal(res.worldDelta.foo, 1);
+});
+
+test("observed delta is attached even without expectGain", async () => {
+	const m = botWithMutableInv([{ name: "oak_log", count: 2 }]);
+	const ledger = createInventoryLedger();
+	ledger.update(m.bot);
+	const teardown = _registerForTest({
+		id: "test.observe-only",
+		title: "t", timeoutMs: 1000,
+		preconditions: () => ({ ok: true }),
+		execute: async () => { m.set([{ name: "oak_log", count: 6 }]); return { ok: true, code: "done", worldDelta: null }; },
+	});
+	const res = await runSkill("test.observe-only", { bot: m.bot, ledger });
+	teardown();
+	assert.equal(res.ok, true);
+	assert.equal(res.worldDelta._invObserved.oak_log, 4);
+});