diff --git a/src/main/agent-runtime/artifact-projector.ts b/src/main/agent-runtime/artifact-projector.ts
index ab282007..7cb574bc 100644
--- a/src/main/agent-runtime/artifact-projector.ts
+++ b/src/main/agent-runtime/artifact-projector.ts
@@ -110,17 +110,24 @@ const BASELINE_SKIP_DIR_NAMES: ReadonlySet<string> = new Set([
 ]);
 
 /**
- * Walk `workspacePath` and record the mtime of every non-directory
- * entry. Directories matching `BASELINE_SKIP_DIR_NAMES` are pruned at
- * walk time — the same categories the registrability filter rejects —
- * so the baseline stays bounded on real project trees. Stops early at
+ * Capture a run-start mtime baseline only for workspaces that need
+ * one. Git workspaces return null here because `git status` already
+ * provides the authoritative diff — paying for an O(tree) walk on
+ * every run just to throw the result away is a hot-path tax the
+ * scheduler should not be paying.
+ *
+ * For non-git workspaces, walk the workspace and record the mtime of
+ * every non-directory entry. Directories matching
+ * `BASELINE_SKIP_DIR_NAMES` are pruned at walk time — the same
+ * categories the registrability filter rejects — so the baseline
+ * stays bounded on real project trees. The walker stops early at
  * `MAX_BASELINE_ENTRIES` and flags `truncated`; the partial baseline
- * still lets the diff detect every file it saw, while the operator is
- * told via the skip reason that an oversize workspace fell off the
- * tail.
+ * still covers every path that was captured while the operator sees
+ * the cap signal.
  */
-export function captureWorkspaceBaseline(workspacePath: string): WorkspaceBaseline | null {
+export function captureBaselineIfRequired(workspacePath: string | null): WorkspaceBaseline | null {
   if (!workspacePath) return null;
+  if (isGitRepo(workspacePath)) return null;
   try {
     if (!statSync(workspacePath).isDirectory()) return null;
   } catch {
diff --git a/src/main/agent-runtime/runtime-bridge.ts b/src/main/agent-runtime/runtime-bridge.ts
index b64ea94c..08ec78f3 100644
--- a/src/main/agent-runtime/runtime-bridge.ts
+++ b/src/main/agent-runtime/runtime-bridge.ts
@@ -11,7 +11,7 @@ import type { CredentialResolver } from "@main/credentials";
 import { getConnectorDefinition } from "@main/connectors";
 import { projectInboxMessageToPi } from "./inbox-projection";
 import { projectAgentEventToLogChunk, extractTextBody } from "./agent-event-projection";
-import { captureWorkspaceBaseline, reconcileWorkspaceArtifacts } from "./artifact-projector";
+import { captureBaselineIfRequired, reconcileWorkspaceArtifacts } from "./artifact-projector";
 import {
   handleBeforeToolCall,
   handleAfterToolCall,
@@ -501,13 +501,13 @@ export class RuntimeBridge {
       workspaceId: string | null;
       workspacePath: string | null;
     };
-    // Capture an mtime baseline for non-git workspaces so `bash` and
-    // the end-of-run reconciliation can still diff changed files
-    // against a known-start reference. Git workspaces leave the
-    // baseline as null — `git status` is the source of truth there.
-    const baseline = payload.workspacePath
-      ? captureWorkspaceBaseline(payload.workspacePath)
-      : null;
+    // Capture an mtime baseline only for non-git workspaces so `bash`
+    // and the end-of-run reconciliation can still diff changed files
+    // against a known-start reference. Git workspaces skip the walk —
+    // `git status` is the source of truth there, and paying for an
+    // O(tree) scan on every run just to throw the result away is a
+    // hot-path tax the scheduler should not be paying.
+    const baseline = captureBaselineIfRequired(payload.workspacePath);
     this.registerActiveRun({
       runId,
       agentId: payload.agentId,