diff --git a/src/main/ai-vault/session-scanner-discovery-first-match.test.ts b/src/main/ai-vault/session-scanner-discovery-first-match.test.ts
new file mode 100644
index 00000000000..9cde6d8083b
--- /dev/null
+++ b/src/main/ai-vault/session-scanner-discovery-first-match.test.ts
@@ -0,0 +1,49 @@
+import type { Dirent } from 'node:fs'
+import { describe, expect, it, vi } from 'vitest'
+import { walkSessionFiles } from './session-scanner-discovery'
+
+function dirent(name: string, directory: boolean): Dirent {
+  return { name, isDirectory: () => directory, isFile: () => !directory } as Dirent
+}
+
+/** Two project directories, each holding the transcript the caller asked for. */
+function tree(): Record<string, Dirent[]> {
+  return {
+    '/projects': [dirent('a', true), dirent('b', true)],
+    '/projects/a': [dirent('other.jsonl', false), dirent('target.jsonl', false)],
+    '/projects/b': [dirent('target.jsonl', false)]
+  }
+}
+
+describe('walkSessionFiles stopAfterFirstMatch', () => {
+  const options = (readDirectory: (path: string) => Promise<Dirent[]>) => ({
+    extensions: new Set(['.jsonl']),
+    filePredicate: (path: string) => path.endsWith('target.jsonl'),
+    readDirectory
+  })
+
+  it('stops walking once one file matches', async () => {
+    const entries = tree()
+    const readDirectory = vi.fn(async (path: string) => entries[path] ?? [])
+
+    const files = await walkSessionFiles('/projects', 'claude', [], {
+      ...options(readDirectory),
+      stopAfterFirstMatch: true
+    })
+
+    expect(files).toEqual(['/projects/a/target.jsonl'])
+    // The whole point: the rest of the tree is never read. On a home with
+    // thousands of transcripts that traversal is most of the call.
+    expect(readDirectory.mock.calls.map((call) => call[0])).toEqual(['/projects', '/projects/a'])
+  })
+
+  it('returns the same file the exhaustive walk would have returned first', async () => {
+    const entries = tree()
+    const readDirectory = vi.fn(async (path: string) => entries[path] ?? [])
+
+    const all = await walkSessionFiles('/projects', 'claude', [], options(readDirectory))
+
+    expect(all[0]).toBe('/projects/a/target.jsonl')
+    expect(all).toHaveLength(2)
+  })
+})
diff --git a/src/main/ai-vault/session-scanner-discovery.ts b/src/main/ai-vault/session-scanner-discovery.ts
index a5cf386043e..b941e2265f9 100644
--- a/src/main/ai-vault/session-scanner-discovery.ts
+++ b/src/main/ai-vault/session-scanner-discovery.ts
@@ -96,6 +96,11 @@ export async function walkSessionFiles(
     // rootDir, so pruned subtrees are never stat'd or parsed.
     directoryPredicate?: (name: string, depth: number) => boolean
     readDirectory?: (dirPath: string) => Promise<Dirent[]>
+    /** Return as soon as one file matches. For a caller that only wants
+     *  `files[0]`, walking the rest of the tree is pure cost — on a home with
+     *  thousands of transcripts it is most of the call. Traversal order is
+     *  unchanged, so the file returned is the same one. */
+    stopAfterFirstMatch?: boolean
     signal?: AbortSignal
   },
   depth = 0
@@ -125,6 +130,9 @@ export async function walkSessionFiles(
       // avoiding the readdir cost of descending into them.
       if (options.directoryPredicate?.(entry.name, depth) ?? true) {
         files.push(...(await walkSessionFiles(fullPath, agent, issues, options, depth + 1)))
+        if (options.stopAfterFirstMatch && files.length > 0) {
+          return files
+        }
       }
       continue
     }
@@ -134,6 +142,9 @@ export async function walkSessionFiles(
       (options.filePredicate?.(fullPath) ?? true)
     ) {
       files.push(fullPath)
+      if (options.stopAfterFirstMatch) {
+        return files
+      }
     }
   }
   return files
diff --git a/src/main/native-chat/session-file-resolver.ts b/src/main/native-chat/session-file-resolver.ts
index 55746b12b2a..c4aa79b3ad3 100644
--- a/src/main/native-chat/session-file-resolver.ts
+++ b/src/main/native-chat/session-file-resolver.ts
@@ -234,6 +234,8 @@ async function resolveClaudeSessionFile(
     const files = await walkSessionFiles(projectsDir, 'claude', [], {
       extensions: new Set(['.jsonl']),
       filePredicate: (path) => basename(path) === targetName,
+      // Only `files[0]` is ever used, and this runs on every acquisition.
+      stopAfterFirstMatch: true,
       signal
     })
     if (files[0]) {
@@ -291,6 +293,7 @@ async function findCodexRolloutInDirs(
         : (
             await walkSessionFiles(sessionsDir, 'codex', [], {
               ...scanOptions,
+              stopAfterFirstMatch: true,
               signal
             })
           )[0]