feat(core): layered tool-output truncation, per-message budget, per-t…

…ool limits Bound tool output before it enters conversation history, mirroring Claude Code's three-layer model: - Single-result: a per-tool/global char threshold spills oversized output to a temp file with a recoverable preview + read_file pointer; media parts are kept, with a token-aware fallback, 0600 owner-only perms on the spilled file, and a sentinel re-entrancy guard. - Per-message: when one batch of tool results exceeds toolOutputBatchBudget (default 200k chars), the largest results are offloaded to disk; a warning is logged if it still can't get under budget. - Per-tool: DeclarativeTool.maxOutputChars/truncateKeep getters (shell 30k, grep 20k, read-file self-managed, mcp 500k, agent 32k/tail). Truncation runs in CoreToolScheduler, deferring PostToolUse/skill metadata injection until after truncation so reminders are never bisected. Per-tool budgets are char-only so the global line cap can't undercut a self-managed tool (read-file) or a declared char budget (grep). The re-entrancy guard matches the truncation prefix at the start of the output so an injected copy of the phrase can't bypass the budget. Adds the toolOutputBatchBudget setting (core + CLI schema) and supporting tests.
wenshao · Jun 11, 2026 · Jun 9, 2026 · Jun 10, 2026 · cdfef5190e5b5be24b23a36def36b7ea3122fff3
commit cdfef5190e5b5be24b23a36def36b7ea3122fff3
diff --git a/packages/cli/src/acp-integration/acpAgent.worktree.test.ts b/packages/cli/src/acp-integration/acpAgent.worktree.test.ts
@@ -118,6 +118,7 @@ vi.mock('@qwen-code/qwen-code-core', () => ({
   })),
   SessionService: vi.fn(),
   SESSION_TITLE_MAX_LENGTH: 200,
+  DEFAULT_TOOL_OUTPUT_BATCH_BUDGET: 200_000,
   tokenLimit: vi.fn(),
   SessionStartSource: { Startup: 'startup', Resume: 'resume' },
   SessionEndReason: { PromptInputExit: 'prompt_input_exit', Other: 'other' },

diff --git a/packages/cli/src/config/config.ts b/packages/cli/src/config/config.ts
@@ -1909,6 +1909,7 @@ export async function loadCliConfig(
     skipStartupContext: settings.model?.skipStartupContext ?? false,
     truncateToolOutputThreshold: settings.tools?.truncateToolOutputThreshold,
     truncateToolOutputLines: settings.tools?.truncateToolOutputLines,
+    toolOutputBatchBudget: settings.tools?.toolOutputBatchBudget,
     eventEmitter: appEvents,
     gitCoAuthor: settings.general?.gitCoAuthor,
     output: {

diff --git a/packages/cli/src/config/settingsSchema.ts b/packages/cli/src/config/settingsSchema.ts
@@ -16,6 +16,7 @@ import type {
 import {
   ApprovalMode,
   DEFAULT_STOP_HOOK_BLOCK_CAP,
+  DEFAULT_TOOL_OUTPUT_BATCH_BUDGET,
   DEFAULT_TRUNCATE_TOOL_OUTPUT_LINES,
   DEFAULT_TRUNCATE_TOOL_OUTPUT_THRESHOLD,
 } from '@qwen-code/qwen-code-core';
@@ -1962,6 +1963,16 @@ const SETTINGS_SCHEMA = {
         description: 'The number of lines to keep when truncating tool output.',
         showInDialog: false,
       },
+      toolOutputBatchBudget: {
+        type: 'number',
+        label: 'Tool Output Batch Budget',
+        category: 'General',
+        requiresRestart: true,
+        default: DEFAULT_TOOL_OUTPUT_BATCH_BUDGET,
+        description:
+          'Per-message budget (characters) for the combined output of one batch of tool calls; the largest results are offloaded to disk when exceeded. Set to -1 to disable.',
+        showInDialog: false,
+      },
       computerUse: {
         type: 'object',
         label: 'Computer Use',

@@ -536,6 +536,12 @@ export interface ExtensionInstallMetadata {
 
 export const DEFAULT_TRUNCATE_TOOL_OUTPUT_THRESHOLD = 25_000;
 export const DEFAULT_TRUNCATE_TOOL_OUTPUT_LINES = 1000;
+/**
+ * Per-message budget (chars) for the combined model-facing output of one
+ * batch of tool calls. When a batch's total output exceeds this, the largest
+ * results are offloaded to disk (with a recoverable pointer). `<= 0` disables.
+ */
+export const DEFAULT_TOOL_OUTPUT_BATCH_BUDGET = 200_000;
 
 export class MCPServerConfig {
   constructor(
@@ -795,6 +801,7 @@ export interface ConfigParameters {
   skipLoopDetection?: boolean;
   truncateToolOutputThreshold?: number;
   truncateToolOutputLines?: number;
+  toolOutputBatchBudget?: number;
   eventEmitter?: EventEmitter;
   output?: OutputSettings;
   inputFormat?: InputFormat;
@@ -1182,6 +1189,7 @@ export class Config {
   private readonly fileExclusions: FileExclusions;
   private readonly truncateToolOutputThreshold: number;
   private readonly truncateToolOutputLines: number;
+  private readonly toolOutputBatchBudget: number;
   private readonly eventEmitter?: EventEmitter;
   private readonly channel: string | undefined;
   private readonly jsonFd: number | undefined;
@@ -1376,6 +1384,8 @@ export class Config {
       DEFAULT_TRUNCATE_TOOL_OUTPUT_THRESHOLD;
     this.truncateToolOutputLines =
       params.truncateToolOutputLines ?? DEFAULT_TRUNCATE_TOOL_OUTPUT_LINES;
+    this.toolOutputBatchBudget =
+      params.toolOutputBatchBudget ?? DEFAULT_TOOL_OUTPUT_BATCH_BUDGET;
     this.channel = params.channel;
     this.jsonFd = params.jsonFd;
     this.jsonFile = params.jsonFile;
@@ -3806,6 +3816,14 @@ export class Config {
     return this.truncateToolOutputLines;
   }
 
+  getToolOutputBatchBudget(): number {
+    if (this.toolOutputBatchBudget <= 0) {
+      return Number.POSITIVE_INFINITY;
+    }
+
+    return this.toolOutputBatchBudget;
+  }
+
   getOutputFormat(): OutputFormat {
     return this.outputFormat;
   }