code-yeongyu · grim-susemi · Aug 17, 2026 · Aug 18, 2026 · Aug 18, 2026 · Aug 18, 2026
diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
@@ -317,6 +317,8 @@
 
 ### Fixed
 
+- Windows spawns no longer flash a console: every `spawn`/`spawnSync`/`execFile` site now passes `windowsHide:true`, with `utils/child-process.ts` forcing it on win32 for all current and future `spawnProcess` callers ([#927](https://github.com/code-yeongyu/senpi/pull/927)).
+
 - Goals no longer stall after a settings hot-reload: a reload `session_start` now re-engages an active goal (re-arming the monitor backstop while wake sources are live, or queueing a continuation through the existing sessionStart admission) instead of parking it until the next user message; stopped goals still never auto-start on reload ([#936](https://github.com/code-yeongyu/senpi/pull/936)).
 - Cursor CLI OAuth is now available by default when its real prerequisites exist: with `cursor-agent` installed and no managed CLI account, a native `cursor` OAuth credential is copied automatically into one canonical `native` slot without modifying the primary credential; explicit `enabled: false` remains a hard opt-out, repeated/concurrent startup is idempotent, and `/login cursor` refreshes the CLI fallback in the same session ([#931](https://github.com/code-yeongyu/senpi/pull/931)).
 
@@ -7614,4 +7616,4 @@ Initial public release.
 - Git branch display in footer
 - Message queueing during streaming responses
 - OAuth integration for Gmail and Google Calendar access
-- HTML export with syntax highlighting and collapsible sections
+- HTML export with syntax highlighting and collapsible sections
diff --git a/packages/coding-agent/src/beta/omo-local-update-worker.ts b/packages/coding-agent/src/beta/omo-local-update-worker.ts
@@ -48,6 +48,7 @@ export const defaultSpawnWorker: OmoLocalSpawnWorker = (request) => {
 		try {
 			const child = spawn(process.execPath, workerCommandArgs(request.force), {
 				detached: true,
+				windowsHide: true,
 				env: process.env,
 				stdio: ["ignore", logFd, logFd],
 			});

diff --git a/packages/coding-agent/src/changes.md b/packages/coding-agent/src/changes.md
@@ -240,6 +240,29 @@
 
 - `main.ts` model/thinking option resolution block.
 
+## Windows console hide for top-level entry and config helpers (2026-08-18)
+
+### What changed
+
+- `packages/coding-agent/src/cli.ts`: main entry re-spawn now passes `windowsHide:true`.
+- `packages/coding-agent/src/config.ts`: `readCommandOutput` via `spawnProcessSync` now passes `windowsHide:true`.
+- `packages/coding-agent/src/package-manager-cli.ts`: self-update step via `spawnProcess` now passes `windowsHide:true`.
+- `packages/coding-agent/src/self-update-bootstrap.ts`: npm update step via `spawn` now passes `windowsHide:true`.
+- `packages/coding-agent/src/beta/omo-local-update-worker.ts`: detached worker spawn now passes `windowsHide:true` alongside `detached:true`.
+
+### Why
+
+- Windows console less parents briefly show a conhost window for every spawn without `windowsHide:true`. Detached/background helpers run periodically, so flashes recur until all sites are hidden.
+
+### Why an extension could not handle it
+
+- Spawn options live inside the caller (helper, daemon, runner). Extensions cannot inject `windowsHide` from outside; the spawn site itself must set it.
+
+### Expected merge conflict zones
+
+- LOW: the spawn options literal in the patched file(s).
+
+
 ## Repository audit baseline for the src tracker (2026-08-17)
 
 ### What changed

diff --git a/packages/coding-agent/src/cli.ts b/packages/coding-agent/src/cli.ts
@@ -64,6 +64,7 @@ async function spawnFullCli(): Promise<number> {
 		const child = spawn(process.execPath, [...process.execArgv, fullCliPath, ...args], {
 			env: process.env,
 			stdio: "inherit",
+			windowsHide: true,
 		});
 		child.on("error", (error) => {
 			reject(error);

diff --git a/packages/coding-agent/src/config.ts b/packages/coding-agent/src/config.ts
@@ -209,6 +209,7 @@ function readCommandOutput(
 	const result = spawnProcessSync(command, args, {
 		encoding: "utf-8",
 		stdio: ["ignore", "pipe", "pipe"],
+		windowsHide: true,
 	});
 	if (result.status === 0) return result.stdout.trim() || undefined;
 	if (options.requireSuccess) {

diff --git a/packages/coding-agent/src/core/changes.md b/packages/coding-agent/src/core/changes.md
@@ -551,6 +551,27 @@ Conflict zone: `cursor-exec-bridge.ts` `executeTool`, `cursor-exec-bridge-sessio
 - `model-resolver.ts` pattern matching and partial-match ordering, `agent-session.ts` thinking-level setters,
   `session-manager.ts` entry schema.
 
+## Windows console hide for core exec and package helpers (2026-08-18)
+
+### What changed
+
+- `packages/coding-agent/src/core/exec.ts`: `execCommand` via `spawn` now passes `windowsHide:true`.
+- `packages/coding-agent/src/core/footer-data-provider.ts`: git `spawnSync`/`execFile` probes now pass `windowsHide:true`.
+- `packages/coding-agent/src/core/package-manager.ts`: `spawnCommand`/`spawnCaptureCommand`/`runCommandSync` now pass `windowsHide:true` (central wrapper also forces it).
+
+### Why
+
+- Windows console less parents briefly show a conhost window for every spawn without `windowsHide:true`. Detached/background helpers run periodically, so flashes recur until all sites are hidden.
+
+### Why an extension could not handle it
+
+- Spawn options live inside the caller (helper, daemon, runner). Extensions cannot inject `windowsHide` from outside; the spawn site itself must set it.
+
+### Expected merge conflict zones
+
+- LOW: the spawn options literal in the patched file(s).
+
+
 ## Cursor bridge lifecycle events retain run ownership (2026-08-18)
 
 ### What changed

diff --git a/packages/coding-agent/src/core/exec.ts b/packages/coding-agent/src/core/exec.ts
@@ -42,6 +42,7 @@ export async function execCommand(
 			cwd,
 			shell: false,
 			stdio: ["ignore", "pipe", "pipe"],
+			windowsHide: true,
 		});
 
 		let stdout = "";

diff --git a/packages/coding-agent/src/core/extensions/builtin/cursor-cli-oauth/changes.md b/packages/coding-agent/src/core/extensions/builtin/cursor-cli-oauth/changes.md
@@ -1,3 +1,23 @@
+
+## Windows console hide for Cursor CLI probes (2026-08-18)
+
+### What changed
+
+- `packages/coding-agent/src/core/extensions/builtin/cursor-cli-oauth/executable.ts`: `VersionProbeOptions` now allows `windowsHide` and probe `execFile` passes `windowsHide:true`.
+- `packages/coding-agent/src/core/extensions/builtin/cursor-cli-oauth/models.ts`: model probe `spawn` now passes `windowsHide:true`.
+
+### Why
+
+- Windows console less parents briefly show a conhost window for every spawn without `windowsHide:true`. Detached/background helpers run periodically, so flashes recur until all sites are hidden.
+
+### Why an extension could not handle it
+
+- Spawn options live inside the caller (helper, daemon, runner). Extensions cannot inject `windowsHide` from outside; the spawn site itself must set it.
+
+### Expected merge conflict zones
+
+- LOW: the spawn options literal in the patched file(s).
+
 # cursor-cli-oauth extension changes
 
 ## 2026-08-21 - Cache provider settings loads by mtime+size to cut lock convoy

diff --git a/packages/coding-agent/src/core/extensions/builtin/cursor-cli-oauth/executable.ts b/packages/coding-agent/src/core/extensions/builtin/cursor-cli-oauth/executable.ts
@@ -20,6 +20,7 @@ export type CursorAgentExecutableDeps = {
 export type VersionProbeOptions = {
 	encoding: "utf8";
 	timeout: number;
+	windowsHide?: boolean;
 };
 
 export type VersionProbeCallback = (error: Error | null, stdout: string, stderr: string) => void;
@@ -116,7 +117,7 @@ export function probeCursorAgentVersion(
 	deps: VersionProbeDeps = defaultVersionProbeDeps,
 ): Promise<string> {
 	return new Promise((resolve, reject) => {
-		deps.execFile(executable, ["--version"], { encoding: "utf8", timeout: 10_000 }, (error, stdout) => {
+		deps.execFile(executable, ["--version"], { encoding: "utf8", timeout: 10_000, windowsHide: true }, (error, stdout) => {
 			if (error) {
 				reject(error);
 				return;

diff --git a/packages/coding-agent/src/core/extensions/builtin/cursor-cli-oauth/models.ts b/packages/coding-agent/src/core/extensions/builtin/cursor-cli-oauth/models.ts
@@ -125,6 +125,7 @@ async function runModelsProbe(executable: string, stdoutPath: string, timeoutMs:
 		await new Promise<void>((resolve, reject) => {
 			const child = spawn(executable, ["models"], {
 				stdio: ["ignore", output.fd, "ignore"],
+				windowsHide: true,
 			});
 			let timedOut = false;
 			let settled = false;

diff --git a/packages/coding-agent/src/core/extensions/builtin/mcp/changes.md b/packages/coding-agent/src/core/extensions/builtin/mcp/changes.md
@@ -1,3 +1,22 @@
+
+## Windows console hide for MCP diagnostics (2026-08-18)
+
+### What changed
+
+- `packages/coding-agent/src/core/extensions/builtin/mcp/diagnose.ts`: `execFile` diagnostics now pass `windowsHide:true`.
+
+### Why
+
+- Windows console less parents briefly show a conhost window for every spawn without `windowsHide:true`. Detached/background helpers run periodically, so flashes recur until all sites are hidden.
+
+### Why an extension could not handle it
+
+- Spawn options live inside the caller (helper, daemon, runner). Extensions cannot inject `windowsHide` from outside; the spawn site itself must set it.
+
+### Expected merge conflict zones
+
+- LOW: the spawn options literal in the patched file(s).
+
 # mcp Extension Changes
 
 ## Explicit pgrep match-all pattern for process-tree collection (2026-08-12)

diff --git a/packages/coding-agent/src/core/extensions/builtin/mcp/diagnose.ts b/packages/coding-agent/src/core/extensions/builtin/mcp/diagnose.ts
@@ -121,6 +121,7 @@ function execFileForDiagnostics(
 				cwd: options.cwd,
 				env: options.env,
 				killSignal: "SIGKILL",
+				windowsHide: true,
 				maxBuffer: MCP_STDIO_DIAGNOSTIC_MAX_BYTES * 4,
 				timeout: MCP_STDIO_DIAGNOSTIC_TIMEOUT_MS,
 			},

diff --git a/packages/coding-agent/src/core/footer-data-provider.ts b/packages/coding-agent/src/core/footer-data-provider.ts
@@ -53,6 +53,7 @@ function resolveBranchWithGitSync(repoDir: string): string | null {
 		cwd: repoDir,
 		encoding: "utf8",
 		stdio: ["ignore", "pipe", "ignore"],
+		windowsHide: true,
 	});
 	const branch = result.status === 0 ? result.stdout.trim() : "";
 	return branch || null;
@@ -67,6 +68,7 @@ function resolveBranchWithGitAsync(repoDir: string): Promise<string | null> {
 			{
 				cwd: repoDir,
 				encoding: "utf8",
+				windowsHide: true,
 			},
 			(error: ExecFileException | null, stdout: string) => {
 				if (error) {

diff --git a/packages/coding-agent/src/core/package-manager.ts b/packages/coding-agent/src/core/package-manager.ts
@@ -2668,6 +2668,7 @@ export class DefaultPackageManager implements PackageManager {
 			cwd: options?.cwd,
 			stdio: isStdoutTakenOver() ? ["ignore", 2, 2] : "inherit",
 			env,
+			windowsHide: true,
 		});
 	}
 
@@ -2682,6 +2683,7 @@ export class DefaultPackageManager implements PackageManager {
 			cwd: options?.cwd,
 			stdio: ["ignore", "pipe", "pipe"],
 			env,
+			windowsHide: true,
 		});
 	}
 
@@ -2749,6 +2751,7 @@ export class DefaultPackageManager implements PackageManager {
 			stdio: ["ignore", "pipe", "pipe"],
 			encoding: "utf-8",
 			env,
+			windowsHide: true,
 		});
 		if (result.error || result.status !== 0) {
 			throw new Error(

diff --git a/packages/coding-agent/src/core/tools/changes.md b/packages/coding-agent/src/core/tools/changes.md
@@ -1,3 +1,23 @@
+
+## Windows console hide for fd/rg helpers (2026-08-18)
+
+### What changed
+
+- `packages/coding-agent/src/core/tools/find.ts`: fd helper `spawn` now passes `windowsHide:true`.
+- `packages/coding-agent/src/core/tools/grep.ts`: rg helper `spawn` now passes `windowsHide:true`.
+
+### Why
+
+- Windows console less parents briefly show a conhost window for every spawn without `windowsHide:true`. Detached/background helpers run periodically, so flashes recur until all sites are hidden.
+
+### Why an extension could not handle it
+
+- Spawn options live inside the caller (helper, daemon, runner). Extensions cannot inject `windowsHide` from outside; the spawn site itself must set it.
+
+### Expected merge conflict zones
+
+- LOW: the spawn options literal in the patched file(s).
+
 # core/tools changes
 
 ## Edit tool keeps filesystem policy and themed diff rendering after the 59a71b23 pin (2026-08-19)

diff --git a/packages/coding-agent/src/core/tools/find.ts b/packages/coding-agent/src/core/tools/find.ts
@@ -282,7 +282,7 @@ export function createFindToolDefinition(
 						}
 						args.push("--", effectivePattern, searchPath);
 
-						const child = spawn(fdPath, args, { stdio: ["ignore", "pipe", "pipe"] });
+						const child = spawn(fdPath, args, { stdio: ["ignore", "pipe", "pipe"], windowsHide: true });
 						const rl = createInterface({ input: child.stdout });
 						let stderr = "";
 						const lines: string[] = [];

diff --git a/packages/coding-agent/src/core/tools/grep.ts b/packages/coding-agent/src/core/tools/grep.ts
@@ -240,7 +240,7 @@ export function createGrepToolDefinition(
 						if (glob) args.push("--glob", glob);
 						args.push("--", pattern, searchPath);
 
-						const child = spawn(rgPath, args, { stdio: ["ignore", "pipe", "pipe"] });
+						const child = spawn(rgPath, args, { stdio: ["ignore", "pipe", "pipe"], windowsHide: true });
 						const rl = createInterface({ input: child.stdout });
 						let stderr = "";
 						let matchCount = 0;

diff --git a/packages/coding-agent/src/modes/app-server/changes.md b/packages/coding-agent/src/modes/app-server/changes.md
@@ -1,5 +1,24 @@
 # changes
 
+## Windows console hide for app-server daemon (2026-08-18)
+
+### What changed
+
+- `packages/coding-agent/src/modes/app-server/daemon.ts`: daemon `spawn` with `detached:true` now also passes `windowsHide:true`.
+
+### Why
+
+- Windows console less parents briefly show a conhost window for every spawn without `windowsHide:true`. Detached/background helpers run periodically, so flashes recur until all sites are hidden.
+
+### Why an extension could not handle it
+
+- Spawn options live inside the caller (helper, daemon, runner). Extensions cannot inject `windowsHide` from outside; the spawn site itself must set it.
+
+### Expected merge conflict zones
+
+- LOW: the daemon spawn options literal.
+
+
 ## Registry-owned thread teardown (2026-08-13)
 
 ### What changed

diff --git a/packages/coding-agent/src/modes/app-server/daemon.ts b/packages/coding-agent/src/modes/app-server/daemon.ts
@@ -176,6 +176,7 @@ async function spawnDaemon(paths: DaemonPaths, listen: AppServerListen): Promise
 			[...process.execArgv, resolveCliMainPath(), "app-server", "--listen", listen.url],
 			{
 				detached: true,
+				windowsHide: true,
 				env: process.env,
 				stdio: ["ignore", "ignore", stderr.fd],
 			},

diff --git a/packages/coding-agent/src/modes/interactive/changes.md b/packages/coding-agent/src/modes/interactive/changes.md
@@ -276,6 +276,27 @@ Conflict zone: `interactive-mode.ts` `message_update` / `message_end`.
   `interactive-mode.ts` (adjacent to the paste handler wiring), and
   `queueCompactionSubmission()` next to `queueCompactionMessage()`.
 
+## Windows console hide for interactive helpers (2026-08-18)
+
+### What changed
+
+- `packages/coding-agent/src/modes/interactive/external-editor.ts`: both editor `spawn` calls now pass `windowsHide:true`.
+- `packages/coding-agent/src/modes/interactive/interactive-mode.ts`: tmux `spawn` and `gh` `spawnSync`/`spawn` helpers now pass `windowsHide:true`.
+- `packages/coding-agent/src/modes/interactive/components/session-selector.ts`: `trash` `spawnSync` now passes `windowsHide:true`.
+
+### Why
+
+- Windows console less parents briefly show a conhost window for every spawn without `windowsHide:true`. Detached/background helpers run periodically, so flashes recur until all sites are hidden.
+
+### Why an extension could not handle it
+
+- Spawn options live inside the caller (helper, daemon, runner). Extensions cannot inject `windowsHide` from outside; the spawn site itself must set it.
+
+### Expected merge conflict zones
+
+- LOW: the spawn options literal in the patched file(s).
+
+
 ## Native Cursor login refreshes the CLI fallback lane in the same session (2026-08-18)
 
 ### What changed

diff --git a/packages/coding-agent/src/modes/interactive/components/session-selector.ts b/packages/coding-agent/src/modes/interactive/components/session-selector.ts
@@ -647,7 +647,7 @@ async function deleteSessionFile(
 ): Promise<{ ok: boolean; method: "trash" | "unlink"; error?: string }> {
 	// Try `trash` first (if installed)
 	const trashArgs = sessionPath.startsWith("-") ? ["--", sessionPath] : [sessionPath];
-	const trashResult = spawnSync("trash", trashArgs, { encoding: "utf-8" });
+	const trashResult = spawnSync("trash", trashArgs, { encoding: "utf-8", windowsHide: true });
 
 	const getTrashErrorHint = (): string | null => {
 		const parts: string[] = [];

diff --git a/packages/coding-agent/src/modes/interactive/external-editor.ts b/packages/coding-agent/src/modes/interactive/external-editor.ts
@@ -31,6 +31,7 @@ export async function editInExternalEditor(options: ExternalEditorOptions): Prom
 			const child = spawn(editor, [...editorArgs, filePath], {
 				stdio: "inherit",
 				shell: process.platform === "win32",
+				windowsHide: true,
 			});
 			child.on("error", () => resolve({ launched: false }));
 			child.on("close", (code) => resolve({ launched: true, code }));
@@ -64,6 +65,7 @@ export async function editFileInExternalEditor(options: { command: string; path:
 		const child = spawn(editor, [...editorArgs, options.path], {
 			stdio: "inherit",
 			shell: process.platform === "win32",
+			windowsHide: true,
 		});
 		child.on("error", () => resolve({ launched: false }));
 		child.on("close", (code) => resolve({ launched: true, code }));

diff --git a/packages/coding-agent/src/modes/interactive/interactive-mode.ts b/packages/coding-agent/src/modes/interactive/interactive-mode.ts
@@ -1660,6 +1660,7 @@ export class InteractiveMode {
 			return new Promise((resolve) => {
 				const proc = spawn("tmux", args, {
 					stdio: ["ignore", "pipe", "ignore"],
+					windowsHide: true,
 				});
 				let stdout = "";
 				const timer = setTimeout(() => {
@@ -7895,9 +7896,7 @@ export class InteractiveMode {
 	private async handleShareCommand(): Promise<void> {
 		// Check if gh is available and logged in
 		try {
-			const authResult = spawnSync("gh", ["auth", "status"], {
-				encoding: "utf-8",
-			});
+			const authResult = spawnSync("gh", ["auth", "status"], { encoding: "utf-8", windowsHide: true });
 			if (authResult.status !== 0) {
 				this.showError("GitHub CLI is not logged in. Run 'gh auth login' first.");
 				return;
@@ -7945,12 +7944,8 @@ export class InteractiveMode {
 		};
 
 		try {
-			const result = await new Promise<{
-				stdout: string;
-				stderr: string;
-				code: number | null;
-			}>((resolve) => {
-				proc = spawn("gh", ["gist", "create", "--public=false", tmpFile]);
+			const result = await new Promise<{ stdout: string; stderr: string; code: number | null }>((resolve) => {
+				proc = spawn("gh", ["gist", "create", "--public=false", tmpFile], { windowsHide: true });
 				let stdout = "";
 				let stderr = "";
 				proc.stdout?.on("data", (data) => {