From ce33ed436a140b01640543e19eba5cf57f94c8fe Mon Sep 17 00:00:00 2001
From: Levalicious <24482560+Levalicious@users.noreply.github.com>
Date: Sun, 23 Aug 2026 22:47:33 -0400
Subject: [PATCH] fix(get_neighbors): omitted depth now honors the schema
 default (0 = immediate)
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Bug_DepthDefaultMismatch_2026_08_23: three depth numberings coexist —
C hop-count (1 = immediate), MCP schema 0-indexed (default 0), op_bench d0.
The TS boundary bridges with depth+1, but the handler defaulted omitted
depth to 1 (and getNeighbors' signature to 1), so schema-default calls
silently returned TWO-hop neighborhoods.

Canonical semantics: the 0-indexed schema numbering. C hop-count is
internal; the single +1 translation lives at the TS boundary. New test pins
the OMITTED-depth path specifically — explicit-depth tests cannot catch a
default divergence.

Behavioral change: default get_neighbors walks shrink from 2-hop to the
schema-promised 1-hop set.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017GGvxNSpbpc5TVyMYYYzBr
---
 server.ts                   |  4 ++--
 tests/memory-server.test.ts | 16 ++++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/server.ts b/server.ts
index 0603987..963cde2 100644
--- a/server.ts
+++ b/server.ts
@@ -822,7 +822,7 @@ export class KnowledgeGraphManager {
 
   async getNeighbors(
     entityName: string,
-    depth: number = 1,
+    depth: number = 0,
     sortBy?: EntitySortField,
     sortDir?: SortDirection,
     direction: 'forward' | 'backward' | 'any' = 'forward'
@@ -1690,7 +1690,7 @@ The file MUST be plaintext (.txt, .tex, .md, source code, etc.). For PDFs, use p
         return { content: [{ type: "text", text: JSON.stringify(paginateGraph(graph, args.entityCursor as number ?? 0, args.relationCursor as number ?? 0)) }] };
       }
       case "get_neighbors": {
-        const neighbors = await knowledgeGraphManager.getNeighbors(args.entityName as string, args.depth as number ?? 1, args.sortBy as EntitySortField | undefined, args.sortDir as SortDirection | undefined, (args.direction as 'forward' | 'backward' | 'any') ?? 'forward');
+        const neighbors = await knowledgeGraphManager.getNeighbors(args.entityName as string, args.depth as number ?? 0, args.sortBy as EntitySortField | undefined, args.sortDir as SortDirection | undefined, (args.direction as 'forward' | 'backward' | 'any') ?? 'forward');
         // Record walker visits for returned neighbors
         knowledgeGraphManager.recordWalkerVisits(neighbors.map(n => n.name));
         return { content: [{ type: "text", text: JSON.stringify(paginateItems(neighbors, args.cursor as number ?? 0)) }] };
diff --git a/tests/memory-server.test.ts b/tests/memory-server.test.ts
index 52a2e76..00e9259 100644
--- a/tests/memory-server.test.ts
+++ b/tests/memory-server.test.ts
@@ -613,6 +613,22 @@ describe('MCP Memory Server E2E Tests', () => {
       expect(names).toContain('Child2');
     });
 
+    it('omitted depth must equal the schema default (0 = immediate only)', async () => {
+      // Bug_DepthDefaultMismatch_2026_08_23: the handler defaulted to 1 while
+      // the tool schema advertises 0, so omitted-depth calls silently returned
+      // TWO-hop neighborhoods. This pins the default path itself — the
+      // explicit-depth tests above cannot catch a default divergence.
+      const result = await callTool(client, 'get_neighbors', {
+        entityName: 'Root'
+      }) as PaginatedResult<Neighbor>;
+
+      expect(result.items).toHaveLength(2);
+      const names = result.items.map(n => n.name);
+      expect(names).toContain('Child1');
+      expect(names).toContain('Child2');
+      expect(names).not.toContain('Grandchild');
+    });
+
     it('should get neighbors at depth 1 (includes neighbors of neighbors)', async () => {
       const result = await callTool(client, 'get_neighbors', {
         entityName: 'Root',