diff --git a/devlog/2026-08-05_debug-nudge-phantom-loop/REQ.md b/devlog/2026-08-05_debug-nudge-phantom-loop/REQ.md
new file mode 100644
index 00000000..616e05a7
--- /dev/null
+++ b/devlog/2026-08-05_debug-nudge-phantom-loop/REQ.md
@@ -0,0 +1,20 @@
+# REQ — Debug Nudge Phantom Turn Loop
+
+## Problem
+
+When `config.debug: true`, ACP's debug notifications used `sendIgnoredMessage()` to persist nudge text and compress notifications to the conversation DB as `ignored: true` user messages. opencode's runtime loop detects the last user message by `role == "user"` WITHOUT checking the `ignored` flag, so the phantom user message triggers a new turn → model keeps working → calls compress → another notification → infinite loop.
+
+## Evidence
+
+From issue #20 floor 1734 (awork investigation):
+- 867 messages in session, 10 compress calls, 10 `ignored: true` user messages
+- Each phantom user message made the runtime loop continue
+- Session eventually stopped but was stuck in a loop for extended period
+
+## Fix
+
+Remove ALL `sendIgnoredMessage` calls from debug-mode notification paths:
+1. `hooks.ts:205-232` — Debug nudge callback: removed `sendIgnoredMessage`, kept `logger.debug` + `showToast`
+2. `notification.ts:281-285` — Debug compress notification: removed `sendIgnoredMessage`, kept `showToast` + added `logger.debug`
+
+Both sites now use `logger.debug` (file log at `~/.config/opencode/logs/acp/`) + `showToast` (5-second popup) for debug visibility, without writing to the conversation DB.
diff --git a/devlog/2026-08-05_debug-nudge-phantom-loop/WORKLOG.md b/devlog/2026-08-05_debug-nudge-phantom-loop/WORKLOG.md
new file mode 100644
index 00000000..b3844387
--- /dev/null
+++ b/devlog/2026-08-05_debug-nudge-phantom-loop/WORKLOG.md
@@ -0,0 +1,13 @@
+# WORKLOG — Debug Nudge Phantom Turn Loop
+
+## Changes
+
+1. `lib/hooks.ts`: Removed `sendIgnoredMessage` from debug nudge callback (lines 205-220). Removed unused import (line 40). Kept `logger.debug` + `showToast`.
+2. `lib/ui/notification.ts`: Replaced `sendIgnoredMessage` call with `logger.debug` in debug compress notification block (lines 281-285).
+
+## Verification
+
+- TypeScript: 0 errors
+- Tests: 954 pass, 0 fail
+- Build: 386.21 KB
+- Deployed to `~/.cache/opencode/packages/opencode-acp@latest/`
diff --git a/lib/hooks.ts b/lib/hooks.ts
index 12b4b481..f576d455 100644
--- a/lib/hooks.ts
+++ b/lib/hooks.ts
@@ -37,7 +37,6 @@ import { applyMessageFilters } from "./messages/filter/apply"
 import { ensureBuiltinFiltersRegistered } from "./messages/filter/builtin"
 import { createSessionState, saveSessionState, syncToolCache, updatePerTurnState, type SessionStateRegistry } from "./state"
 import { cacheSystemPromptTokens } from "./ui/utils"
-import { sendIgnoredMessage } from "./ui/notification"
 import { runBatchCleanup } from "./gc/merge"
 import { getCurrentTokenUsage } from "./token-utils"
 
@@ -203,22 +202,11 @@ export function createChatMessageTransformHandler(
             compressionPriorities,
             config.debug
                 ? (text: string) => {
+                      // sendIgnoredMessage writes an ignored:true user msg to DB.
+                      // opencode's runtime loop detects it as "last user" (role-only,
+                      // ignores the flag) → phantom turn → compress → notification →
+                      // infinite loop. Use logger.debug + toast instead.
                       logger.debug(`[ACP Debug] Nudge injected:\n${text}`)
-                      if (state.sessionId && lastUserMessage) {
-                          const userInfo = lastUserMessage.info as any
-                          sendIgnoredMessage(
-                              client,
-                              state.sessionId,
-                              `[ACP Debug Nudge]\n${text}`,
-                              {
-                                  providerId: userInfo.model?.providerID,
-                                  modelId: userInfo.model?.modelID,
-                                  agent: userInfo.agent,
-                                  variant: userInfo.variant,
-                              },
-                              logger,
-                          ).catch(() => {})
-                      }
                       client.tui
                           .showToast({
                               body: {
diff --git a/lib/ui/notification.ts b/lib/ui/notification.ts
index b1651c89..2676b970 100644
--- a/lib/ui/notification.ts
+++ b/lib/ui/notification.ts
@@ -278,10 +278,11 @@ export async function sendCompressNotification(
     toastMessage =
         config.pruneNotification === "minimal" ? toastMessage : truncateToastBody(toastMessage)
 
+    // [DEBUG] Use toast + logger only. Do NOT use sendIgnoredMessage — it writes
+    // an ignored:true user msg to DB that opencode's runtime loop detects as
+    // "last user" (role-only) → phantom turn → infinite loop (issue #20 floor 1734).
     if (config.debug) {
-        const chatMessage =
-            config.pruneNotification === "minimal" ? message : truncateToastBody(message)
-        await sendIgnoredMessage(client, sessionId, chatMessage, params, logger)
+        logger.debug(`[ACP Debug] Compress notification:\n${message}`)
     }
 
     await client.tui.showToast({