diff --git a/src/resources/extensions/sf/memory-store.js b/src/resources/extensions/sf/memory-store.js
index d41b297a2..c4c81d423 100644
--- a/src/resources/extensions/sf/memory-store.js
+++ b/src/resources/extensions/sf/memory-store.js
@@ -18,6 +18,7 @@ import {
 	updateMemoryContentRow,
 } from "./sf-db.js";
 import { queueMemorySync } from "./sync-scheduler.js";
+import { querySmMemories } from "./sm-client.js";
 
 export { isDbAvailable };
 
@@ -118,6 +119,37 @@ export async function getRelevantMemoriesRanked(query, limit = 10) {
 	if (pool.length === 0 || !query.trim()) {
 		return pool.slice(0, limit);
 	}
+
+	// Phase 3: Query cross-project memories from Singularity Memory (fail-open)
+	let crossProjectMemories = [];
+	try {
+		const smResults = await querySmMemories(query, {
+			limit: Math.max(3, Math.ceil(limit * 0.3)), // Cross-project recall is 30% of local limit
+			smConnected: process.env.SM_ENABLED !== "false",
+		});
+		// Convert SM results to local format (all cross-project memories tagged as such)
+		crossProjectMemories = (smResults || []).map((m) => ({
+			id: `sm-${m.id || "unknown"}`,
+			category: m.category || "pattern",
+			content: m.content || m.text || "",
+			confidence: Math.min(0.8, (m.confidence || 0.5) * 0.9), // Cap and reduce cross-project confidence
+			source_unit_type: "cross-project",
+			source_unit_id: m.source_tool || "sm",
+			created_at: m.created_at || Date.now(),
+			updated_at: m.updated_at || Date.now(),
+			superseded_by: null,
+			hit_count: m.hit_count || 0,
+			tags: ["cross-project"],
+		}));
+	} catch {
+		// SM unavailable or query failed — gracefully degrade to local-only
+	}
+
+	// Merge local and cross-project memories
+	const mergedPool = [...pool, ...crossProjectMemories];
+	if (mergedPool.length === 0 || !query.trim()) {
+		return mergedPool.slice(0, limit);
+	}
 	try {
 		const { embedQueryViaGateway, loadEmbeddingMap, rankMemoriesByEmbedding } =
 			await import("./memory-embeddings.js");
@@ -126,10 +158,10 @@ export async function getRelevantMemoriesRanked(query, limit = 10) {
 			Promise.resolve(loadEmbeddingMap()),
 		]);
 		if (!queryVec || embeddingMap.size === 0) {
-			return pool.slice(0, limit);
+			return mergedPool.slice(0, limit);
 		}
 		let ranked = rankMemoriesByEmbedding(
-			pool.map((m) => ({
+			mergedPool.map((m) => ({
 				id: m.id,
 				staticScore: m.confidence * (1 + m.hit_count * 0.1),
 			})),
@@ -165,7 +197,7 @@ export async function getRelevantMemoriesRanked(query, limit = 10) {
 		} catch {
 			// Relation boost is additive; failure preserves cosine ranking.
 		}
-		const byId = new Map(pool.map((m) => [m.id, m]));
+		const byId = new Map(mergedPool.map((m) => [m.id, m]));
 		// Top-K from cosine+relation rank — feed this into the optional rerank pass.
 		const topK = [];
 		for (const r of ranked) {
@@ -201,7 +233,7 @@ export async function getRelevantMemoriesRanked(query, limit = 10) {
 		}
 		return topK;
 	} catch {
-		return pool.slice(0, limit);
+		return mergedPool.slice(0, limit);
 	}
 }
 /**