diff --git a/TASKS.md b/TASKS.md
index 5854ec5..bdb96e5 100644
--- a/TASKS.md
+++ b/TASKS.md
@@ -70,6 +70,7 @@
 | 52 | **Zoom box (anchored 2× magnifier)** | ✅ Done — shipped 2026-10-08 (3 creator corrections during the build: loupe → anchored capture over the full composite, drawn last → never shows the dim shading) | [`TASKS/task-52-zoom-box.md`](TASKS/task-52-zoom-box.md) |
 | 53 | **Output-format verification: Shorts/TikTok geometry (9:16)** | ☐ Queued (2026-10-08) — output formats never tested end-to-end; pin + prove the vertical geometry | [`TASKS/task-53-output-formats.md`](TASKS/task-53-output-formats.md) |
 | 54 | **Marcom round: free-forever positioning + merch storefront** | 🔶 In progress — llamacasty.com copy live 2026-10-08 (pricing stripped); merch POD + app About links queued | [`TASKS/task-54-marcom-free-merch.md`](TASKS/task-54-marcom-free-merch.md) |
+| 55 | **Disk hygiene: log rotation + low-disk guard** | ☐ Queued (2026-10-09) — `startup.log` appears uncapped; also temp alert-clip cleanup + free-space check before recording | [`TASKS/task-55-disk-hygiene.md`](TASKS/task-55-disk-hygiene.md) |
 
 ---
 
diff --git a/TASKS/task-55-disk-hygiene.md b/TASKS/task-55-disk-hygiene.md
new file mode 100644
index 0000000..d7446a7
--- /dev/null
+++ b/TASKS/task-55-disk-hygiene.md
@@ -0,0 +1,29 @@
+# TASK 55 — Disk hygiene: log rotation + low-disk guard (queued 2026-10-09)
+
+> Catalog: [`TASKS.md`](../TASKS.md) — status and requirements live here.
+
+**Why (creator ask, 2026-10-09):** "we need some sort of log-rotation so that we don't
+inadvertently fill up a user's drive." A free app that quietly eats disk space is a support
+ticket and a trust breach.
+
+**What's known (from the 2026-10-09 privacy-policy code research — re-verify before building):**
+- `Helpers/AppLog.cs` appends to `%APPDATA%\ytLlive\startup.log`, a timestamped line per entry,
+  with **no size cap or rotation found** (not specifically searched — confirm first).
+- `Services/Encoder/FfmpegEncoder.cs` (~:371) logs **every non-progress ffmpeg stderr line**
+  (≤400 chars each) — the main growth source over long streams.
+- Default alert clip is written to `%TEMP%\ytLive-alert-<id>.mp4`
+  (`ViewModels/MainViewModel.Chat.cs` ~:106) — confirm whether it's ever deleted.
+- Recordings (`.mp4`, default `Downloads`) are user-directed, but nothing checks free space.
+
+**Slices (one integration test each, in order):**
+
+1. ☐ **Size-capped log rotation** — when `startup.log` passes a cap (~5 MB), roll it to
+   `startup.1.log` (keep 1–2 old files), start fresh. Test: write past the cap, assert the roll
+   and the bounded total. Standard pattern (NLog/Serilog `fileSizeLimitBytes` +
+   `retainedFileCountLimit`) — cite in the commit.
+2. ☐ **Temp alert clip cleanup** — delete the `%TEMP%` alert clip on app close (and sweep
+   stale ones at startup). Test: create, close, assert gone.
+3. ☐ **Low-disk guard for recordings** — check free space on the record folder's drive before
+   Record starts, and warn (toast) when it runs low mid-recording. Thresholds TBD with the creator.
+
+**Design decisions:** keep `AppLog`'s call surface unchanged — rotation lives inside it.