From b3d5d472edf594b6a0c90fe69a6a4b1d62cc0548 Mon Sep 17 00:00:00 2001
From: Daniel Smolsky <dannysmo@gmail.com>
Date: Mon, 5 Jan 2026 01:13:30 -0500
Subject: [PATCH] fix: skip DCP injection for internal agents (title, summary,
 compaction)

Detect internal agent sessions by their system prompt signatures and skip
injecting context management prompts. This prevents wasting tokens and
confusing small models used for title generation and conversation summaries.

Fixes #218
---
 index.ts           | 15 +++++++++++++++
 lib/hooks.ts       |  2 +-
 lib/state/state.ts |  2 ++
 lib/state/types.ts |  5 +++--
 4 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/index.ts b/index.ts
index d7a7a145..13df1b08 100644
--- a/index.ts
+++ b/index.ts
@@ -30,6 +30,21 @@ const plugin: Plugin = (async (ctx) => {
             _input: unknown,
             output: { system: string[] },
         ) => {
+            const systemText = output.system.join("\n")
+            const internalAgentSignatures = [
+                "You are a title generator",
+                "You are a helpful AI assistant tasked with summarizing conversations",
+                "Summarize what was done in this conversation",
+            ]
+            if (internalAgentSignatures.some((sig) => systemText.includes(sig))) {
+                logger.info("Skipping DCP injection for internal agent")
+                state.isInternalAgent = true
+                return
+            }
+
+            // Reset flag for normal sessions
+            state.isInternalAgent = false
+
             const discardEnabled = config.tools.discard.enabled
             const extractEnabled = config.tools.extract.enabled
 
diff --git a/lib/hooks.ts b/lib/hooks.ts
index e70c892a..231357df 100644
--- a/lib/hooks.ts
+++ b/lib/hooks.ts
@@ -15,7 +15,7 @@ export function createChatMessageTransformHandler(
     return async (input: {}, output: { messages: WithParts[] }) => {
         await checkSession(client, state, logger, output.messages)
 
-        if (state.isSubAgent) {
+        if (state.isSubAgent || state.isInternalAgent) {
             return
         }
 
diff --git a/lib/state/state.ts b/lib/state/state.ts
index 956ac9dd..05ebc0cb 100644
--- a/lib/state/state.ts
+++ b/lib/state/state.ts
@@ -43,6 +43,7 @@ export function createSessionState(): SessionState {
     return {
         sessionId: null,
         isSubAgent: false,
+        isInternalAgent: false,
         prune: {
             toolIds: [],
         },
@@ -61,6 +62,7 @@ export function createSessionState(): SessionState {
 export function resetSessionState(state: SessionState): void {
     state.sessionId = null
     state.isSubAgent = false
+    state.isInternalAgent = false
     state.prune = {
         toolIds: [],
     }
diff --git a/lib/state/types.ts b/lib/state/types.ts
index 9a6de02d..f9dfd7af 100644
--- a/lib/state/types.ts
+++ b/lib/state/types.ts
@@ -12,7 +12,7 @@ export interface ToolParameterEntry {
     parameters: any
     status?: ToolStatus
     error?: string
-    turn: number // Which turn (step-start count) this tool was called on
+    turn: number
 }
 
 export interface SessionStats {
@@ -27,11 +27,12 @@ export interface Prune {
 export interface SessionState {
     sessionId: string | null
     isSubAgent: boolean
+    isInternalAgent: boolean
     prune: Prune
     stats: SessionStats
     toolParameters: Map<string, ToolParameterEntry>
     nudgeCounter: number
     lastToolPrune: boolean
     lastCompaction: number
-    currentTurn: number // Current turn count derived from step-start parts
+    currentTurn: number
 }