From f9c8a5107ce6830b16481234971aa93e1e806153 Mon Sep 17 00:00:00 2001
From: Ayaan Zaidi <hi@obviy.us>
Date: Sun, 26 Apr 2026 09:14:53 +0530
Subject: [PATCH] fix(cli): cap fresh session reseed size

---
 src/agents/cli-runner/session-history.test.ts | 12 ++++++++++++
 src/agents/cli-runner/session-history.ts      |  9 ++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/agents/cli-runner/session-history.test.ts b/src/agents/cli-runner/session-history.test.ts
index effe9756b3a..e166946f447 100644
--- a/src/agents/cli-runner/session-history.test.ts
+++ b/src/agents/cli-runner/session-history.test.ts
@@ -329,4 +329,16 @@ describe("buildCliSessionHistoryPrompt", () => {
       }),
     ).toBeUndefined();
   });
+
+  it("caps rendered reseed history before adding the next user message", () => {
+    const prompt = buildCliSessionHistoryPrompt({
+      messages: [{ role: "compactionSummary", summary: "x".repeat(100) }],
+      prompt: "current ask must survive",
+      maxHistoryChars: 20,
+    });
+
+    expect(prompt).toContain("[OpenClaw reseed history truncated]");
+    expect(prompt).toContain("<next_user_message>\ncurrent ask must survive\n</next_user_message>");
+    expect(prompt).not.toContain("x".repeat(80));
+  });
 });
diff --git a/src/agents/cli-runner/session-history.ts b/src/agents/cli-runner/session-history.ts
index 0fbd5b102e1..1f5d2a51568 100644
--- a/src/agents/cli-runner/session-history.ts
+++ b/src/agents/cli-runner/session-history.ts
@@ -14,6 +14,7 @@ import {
 
 export const MAX_CLI_SESSION_HISTORY_FILE_BYTES = 5 * 1024 * 1024;
 export const MAX_CLI_SESSION_HISTORY_MESSAGES = MAX_AGENT_HOOK_HISTORY_MESSAGES;
+export const MAX_CLI_SESSION_RESEED_HISTORY_CHARS = 12 * 1024;
 
 type HistoryMessage = {
   role?: unknown;
@@ -48,8 +49,10 @@ function coerceHistoryText(content: unknown): string {
 export function buildCliSessionHistoryPrompt(params: {
   messages: unknown[];
   prompt: string;
+  maxHistoryChars?: number;
 }): string | undefined {
-  const renderedHistory = params.messages
+  const maxHistoryChars = params.maxHistoryChars ?? MAX_CLI_SESSION_RESEED_HISTORY_CHARS;
+  const renderedHistoryRaw = params.messages
     .flatMap((message) => {
       if (!message || typeof message !== "object") {
         return [];
@@ -74,6 +77,10 @@ export function buildCliSessionHistoryPrompt(params: {
     })
     .join("\n\n")
     .trim();
+  const renderedHistory =
+    renderedHistoryRaw.length > maxHistoryChars
+      ? `${renderedHistoryRaw.slice(0, maxHistoryChars).trimEnd()}\n[OpenClaw reseed history truncated]`
+      : renderedHistoryRaw;
 
   if (!renderedHistory) {
     return undefined;