fix(coding-agent): configure HTTP idle timeout (#4759)

packages/coding-agent/src/core/http-dispatcher.ts

@@ -0,0 +1,55 @@
+import * as undici from "undici";
+
+export const DEFAULT_HTTP_IDLE_TIMEOUT_MS = 300_000;
+
+export const HTTP_IDLE_TIMEOUT_CHOICES = [
+	{ label: "30 sec", timeoutMs: 30_000 },
+	{ label: "1 min", timeoutMs: 60_000 },
+	{ label: "2 min", timeoutMs: 120_000 },
+	{ label: "5 min", timeoutMs: 300_000 },
+	{ label: "disabled", timeoutMs: 0 },
+] as const;
+
+export function parseHttpIdleTimeoutMs(value: unknown): number | undefined {
+	if (typeof value === "string") {
+		const trimmed = value.trim();
+		if (trimmed.toLowerCase() === "disabled") {
+			return 0;
+		}
+		if (trimmed.length === 0) {
+			return undefined;
+		}
+		return parseHttpIdleTimeoutMs(Number(trimmed));
+	}
+
+	if (typeof value !== "number" || !Number.isFinite(value) || value < 0) {
+		return undefined;
+	}
+	return Math.floor(value);
+}
+
+export function formatHttpIdleTimeoutMs(timeoutMs: number): string {
+	const choice = HTTP_IDLE_TIMEOUT_CHOICES.find((item) => item.timeoutMs === timeoutMs);
+	if (choice) {
+		return choice.label;
+	}
+	return `${timeoutMs / 1000} sec`;
+}
+
+export function configureHttpDispatcher(timeoutMs: number = DEFAULT_HTTP_IDLE_TIMEOUT_MS): void {
+	const normalizedTimeoutMs = parseHttpIdleTimeoutMs(timeoutMs);
+	if (normalizedTimeoutMs === undefined) {
+		throw new Error(`Invalid HTTP idle timeout: ${String(timeoutMs)}`);
+	}
+	undici.setGlobalDispatcher(
+		new undici.EnvHttpProxyAgent({
+			allowH2: false,
+			bodyTimeout: normalizedTimeoutMs,
+			headersTimeout: normalizedTimeoutMs,
+		}),
+	);
+	// Keep fetch and the dispatcher on the same undici implementation. Node 26.0's
+	// bundled fetch can otherwise consume compressed responses through npm undici's
+	// dispatcher without decompressing them, causing response.json() failures.
+	undici.install?.();
+}

packages/coding-agent/src/core/settings-manager.ts

@@ -4,6 +4,7 @@ import { homedir } from "os";
 import { dirname, join } from "path";
 import lockfile from "proper-lockfile";
 import { CONFIG_DIR_NAME, getAgentDir } from "../config.ts";
+import { DEFAULT_HTTP_IDLE_TIMEOUT_MS, parseHttpIdleTimeoutMs } from "./http-dispatcher.ts";
 
 export interface CompactionSettings {
 	enabled?: boolean; // default: true
@@ -110,6 +111,7 @@ export interface Settings {
 	markdown?: MarkdownSettings;
 	warnings?: WarningSettings;
 	sessionDir?: string; // Custom session storage directory (same format as --session-dir CLI flag)
+	httpIdleTimeoutMs?: number; // HTTP header/body idle timeout in milliseconds; 0 disables it
 }
 
 /** Deep merge settings: project/overrides take precedence, nested objects merge recursively */
@@ -726,6 +728,27 @@ export class SettingsManager {
 		};
 	}
 
+	getHttpIdleTimeoutMs(): number {
+		const value = this.settings.httpIdleTimeoutMs;
+		const timeoutMs = parseHttpIdleTimeoutMs(value);
+		if (timeoutMs !== undefined) {
+			return timeoutMs;
+		}
+		if (value !== undefined) {
+			throw new Error(`Invalid httpIdleTimeoutMs setting: ${String(value)}`);
+		}
+		return DEFAULT_HTTP_IDLE_TIMEOUT_MS;
+	}
+
+	setHttpIdleTimeoutMs(timeoutMs: number): void {
+		if (!Number.isFinite(timeoutMs) || timeoutMs < 0) {
+			throw new Error(`Invalid httpIdleTimeoutMs setting: ${String(timeoutMs)}`);
+		}
+		this.globalSettings.httpIdleTimeoutMs = Math.floor(timeoutMs);
+		this.markModified("httpIdleTimeoutMs");
+		this.save();
+	}
+
 	getProviderRetrySettings(): { timeoutMs?: number; maxRetries?: number; maxRetryDelayMs: number } {
 		return {
 			timeoutMs: this.settings.retry?.provider?.timeoutMs,