diff --git a/sessions/0017/SESSION-0017.0-TRANSCRIPT-2026-06-10T23-52--INPROGRESS.md b/sessions/0017/SESSION-0017.0-TRANSCRIPT-2026-06-10T23-52--INPROGRESS.md
new file mode 100644
index 0000000..6a5ce3d
--- /dev/null
+++ b/sessions/0017/SESSION-0017.0-TRANSCRIPT-2026-06-10T23-52--INPROGRESS.md
@@ -0,0 +1,23 @@
+# Session 0017.0 — Transcript
+
+> App: vscode-cowriting-plugin
+> Start: 2026-06-10T23-52 (PST)
+> Type: brainstorming
+> Status: **PLACEHOLDER — claimed at session start; finalized at session end.**
+>
+> This file reserves session ID 0017 for vscode-cowriting-plugin. The driver replaces this
+> body with the full transcript and renames the file to its final
+> SESSION-0017.0-TRANSCRIPT-2026-06-10T23-52--<end>.md form at session end.
+
+## Launch prompt
+
+```
+/goal Brainstorm Feature #17 (diff-view toggle) into its Solution Design — the baseline fork (turn start / last accept / save / pinned) is the load-bearing decision; constraints and non-goals are in the issue body
+
+```
+
+## Deferred decisions
+
+_Autonomous-mode low-confidence calls the driver made and would have
+liked operator input on. Appended as the session runs; surfaced at
+finalize. Empty if none._
diff --git a/sessions/sessions.json b/sessions/sessions.json
index c6b7179..0c06207 100644
--- a/sessions/sessions.json
+++ b/sessions/sessions.json
@@ -46,5 +46,8 @@
   },
   "0016": {
     "title": ""
+  },
+  "0017": {
+    "title": ""
   }
 }