diff --git a/.changeset/resolve-tool-results.md b/.changeset/resolve-tool-results.md
new file mode 100644
index 00000000..33cde60c
--- /dev/null
+++ b/.changeset/resolve-tool-results.md
@@ -0,0 +1,5 @@
+---
+"@perstack/tui-components": patch
+---
+
+Handle resolveToolResults event type in delegation tree builder
diff --git a/packages/tui-components/src/log-viewer/build-run-tree.test.ts b/packages/tui-components/src/log-viewer/build-run-tree.test.ts
index 4bdad4a5..eb5525c7 100644
--- a/packages/tui-components/src/log-viewer/build-run-tree.test.ts
+++ b/packages/tui-components/src/log-viewer/build-run-tree.test.ts
@@ -503,6 +503,43 @@ describe("buildRunTreeFromEvents", () => {
     expect(gd1Flat.depth).toBe(4) // root > build > te1 > bg1 > gd1
   })
 
+  it("handles resolveToolResults events without affecting tree structure", () => {
+    // resolveToolResults fires after MCP tool execution and after resumeFromStop.
+    // It should be handled gracefully without creating spurious nodes or breaking merges.
+    const events = [
+      startRun("root", "coordinator"),
+      makeEvent("callTools", "root", "coordinator", {
+        newMessage: {},
+        toolCalls: [],
+        usage: baseUsage,
+      }),
+      // resolveToolResults after MCP tool execution
+      makeEvent("resolveToolResults", "root", "coordinator", {
+        toolResults: [{ id: "tr-1", skillName: "read_file", toolName: "read_file", result: [] }],
+      }),
+      stopByDelegate("root", "coordinator"),
+      startRun("child", "@coordinator/worker", "root"),
+      completeRun("child", "@coordinator/worker"),
+      // Resume and immediately resolveToolResults (same timestamp pattern from real data)
+      resumeFromStop("root-resume", "coordinator"),
+      makeEvent("resolveToolResults", "root-resume", "coordinator", {
+        toolResults: [{ id: "tr-2", skillName: "delegate/worker", toolName: "worker", result: [] }],
+      }),
+      completeRun("root-resume", "coordinator"),
+    ]
+
+    const { treeState, runStats } = buildRunTreeFromEvents(events)
+
+    // Resume merged correctly
+    expect(treeState.nodes.size).toBe(2) // root, child
+    expect(treeState.nodes.get("root")?.status).toBe("completed")
+    expect(treeState.nodes.get("child")?.parentRunId).toBe("root")
+
+    // resolveToolResults events counted in stats
+    const rootStats = runStats.get("root")!
+    expect(rootStats.eventCount).toBeGreaterThanOrEqual(6) // start, callTools, resolve, stop, resume, resolve, complete
+  })
+
   it("shows failed delegates as error nodes (startRun + stopRunByError)", () => {
     // With the runtime fix, failed delegates now emit startRun + stopRunByError events.
     // design-roles delegates to 4x find-skill, all fail immediately.
diff --git a/packages/tui-components/src/log-viewer/build-run-tree.ts b/packages/tui-components/src/log-viewer/build-run-tree.ts
index 0fab8f5d..1f582058 100644
--- a/packages/tui-components/src/log-viewer/build-run-tree.ts
+++ b/packages/tui-components/src/log-viewer/build-run-tree.ts
@@ -296,6 +296,12 @@ export function buildRunTreeFromEvents(events: RunEvent[]): RunTreeResult {
         }
         break
       }
+
+      case "resolveToolResults": {
+        // Tool results resolved — no node state change needed.
+        // Stats are already recorded at the top of the loop.
+        break
+      }
     }
   }