From ceaa34dfb642d6f21e9abb99bbac8ad97a53e2bd Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:32:21 +0900
Subject: [PATCH 01/16] test: cover truncatePreview head/tail strategy

---
 test/render.test.ts | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 test/render.test.ts

diff --git a/test/render.test.ts b/test/render.test.ts
new file mode 100644
index 0000000..a7e482c
--- /dev/null
+++ b/test/render.test.ts
@@ -0,0 +1,30 @@
+import { describe, expect, it } from "vitest";
+import { PATCH_PREVIEW_MAX_CHARS, PATCH_PREVIEW_MAX_LINES, truncatePreview } from "../src/index.js";
+
+describe("render helpers", () => {
+	it("#given long diff #when truncating #then keeps head and tail", () => {
+		// given
+		const lines = Array.from({ length: PATCH_PREVIEW_MAX_LINES + 12 }, (_, index) => `line-${index + 1}`);
+		const diff = lines.join("\n");
+
+		// when
+		const preview = truncatePreview(diff);
+
+		// then
+		expect(preview).toContain("line-1");
+		expect(preview).toContain(`line-${lines.length}`);
+		expect(preview).toContain("…");
+	});
+
+	it("#given huge payload #when truncating #then enforces max chars", () => {
+		// given
+		const diff = `${"x".repeat(PATCH_PREVIEW_MAX_CHARS + 500)}\nend`;
+
+		// when
+		const preview = truncatePreview(diff);
+
+		// then
+		expect(preview.length).toBeLessThanOrEqual(PATCH_PREVIEW_MAX_CHARS + 2);
+		expect(preview).toContain("…");
+	});
+});

From d751f8e6aba0ede01b544798cc91c64696a78c44 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:32:44 +0900
Subject: [PATCH 02/16] feat: add truncatePreview helper with
 PATCH_PREVIEW_MAX_ constants

---
 src/index.ts | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/src/index.ts b/src/index.ts
index 9f2f012..9947c73 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -167,6 +167,38 @@ export async function __testWriteFileAtomic(
 }
 
 const GPT_APPLY_PATCH_PROVIDERS = new Set(["openai", "azure-openai-responses", "github-copilot"]);
+export const PATCH_PREVIEW_MAX_LINES = 16;
+export const PATCH_PREVIEW_MAX_CHARS = 4000;
+const PATCH_PREVIEW_HEAD_LINES = 8;
+const PATCH_PREVIEW_TAIL_LINES = 8;
+
+function countLines(text: string): number {
+	if (text.length === 0) {
+		return 0;
+	}
+	let lines = 1;
+	for (let index = 0; index < text.length; index++) {
+		if (text.charCodeAt(index) === 10) {
+			lines += 1;
+		}
+	}
+	return lines;
+}
+
+export function truncatePreview(text: string): string {
+	if (text.length <= PATCH_PREVIEW_MAX_CHARS && countLines(text) <= PATCH_PREVIEW_MAX_LINES) {
+		return text;
+	}
+
+	const lines = text.split("\n");
+	const head = lines.slice(0, PATCH_PREVIEW_HEAD_LINES);
+	const tail = lines.slice(-PATCH_PREVIEW_TAIL_LINES);
+	let preview = [...head, "…", ...tail].join("\n");
+	if (preview.length > PATCH_PREVIEW_MAX_CHARS) {
+		preview = `${preview.slice(0, PATCH_PREVIEW_MAX_CHARS).trimEnd()}\n…`;
+	}
+	return preview;
+}
 
 function normalizeApplyPatchArguments(args: unknown): ApplyPatchParams {
 	if (typeof args === "string") {

From 0565e81911505f4df8edd26e375ae8affd0952c1 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:33:06 +0900
Subject: [PATCH 03/16] test: cover displayPath cwd-relative formatting

---
 test/render.test.ts | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/test/render.test.ts b/test/render.test.ts
index a7e482c..a34eba8 100644
--- a/test/render.test.ts
+++ b/test/render.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { PATCH_PREVIEW_MAX_CHARS, PATCH_PREVIEW_MAX_LINES, truncatePreview } from "../src/index.js";
+import { displayPath, PATCH_PREVIEW_MAX_CHARS, PATCH_PREVIEW_MAX_LINES, truncatePreview } from "../src/index.js";
 
 describe("render helpers", () => {
 	it("#given long diff #when truncating #then keeps head and tail", () => {
@@ -27,4 +27,28 @@ describe("render helpers", () => {
 		expect(preview.length).toBeLessThanOrEqual(PATCH_PREVIEW_MAX_CHARS + 2);
 		expect(preview).toContain("…");
 	});
+
+	it("#given absolute path under cwd #when displaying #then returns relative path", () => {
+		// given
+		const cwd = "/workspace/project";
+		const absolute = "/workspace/project/src/index.ts";
+
+		// when
+		const rendered = displayPath(absolute, cwd);
+
+		// then
+		expect(rendered).toBe("src/index.ts");
+	});
+
+	it("#given absolute path outside cwd #when displaying #then keeps absolute path", () => {
+		// given
+		const cwd = "/workspace/project";
+		const absolute = "/tmp/file.ts";
+
+		// when
+		const rendered = displayPath(absolute, cwd);
+
+		// then
+		expect(rendered).toBe(absolute);
+	});
 });

From 6a333c41c36203578c2a2ed87131636b999dc1aa Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:33:22 +0900
Subject: [PATCH 04/16] feat: add displayPath cwd-relative helper

---
 src/index.ts | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/index.ts b/src/index.ts
index 9947c73..4228aea 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -379,6 +379,23 @@ function formatLineCountSummary(added: number, removed: number): string {
 	return `(+${added} -${removed})`;
 }
 
+export function displayPath(filePath: string, cwd: string): string {
+	if (!path.isAbsolute(filePath)) {
+		return filePath;
+	}
+
+	const absoluteCwd = path.resolve(cwd);
+	const relativePath = path.relative(absoluteCwd, filePath);
+	if (
+		relativePath === "" ||
+		(!relativePath.startsWith(`..${path.sep}`) && relativePath !== ".." && !path.isAbsolute(relativePath))
+	) {
+		return relativePath || ".";
+	}
+
+	return filePath;
+}
+
 function formatPatchFilePath(file: ApplyPatchPreviewFile): string {
 	return file.movePath ? `${file.filePath} → ${file.movePath}` : file.filePath;
 }

From 247e98c78fe1dc4ac92cfebea20bcf068146e326 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:33:39 +0900
Subject: [PATCH 05/16] refactor: route formatPatchFilePath through displayPath
 with optional cwd

---
 src/index.ts | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 4228aea..94f8a06 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -396,8 +396,12 @@ export function displayPath(filePath: string, cwd: string): string {
 	return filePath;
 }
 
-function formatPatchFilePath(file: ApplyPatchPreviewFile): string {
-	return file.movePath ? `${file.filePath} → ${file.movePath}` : file.filePath;
+export function formatPatchFilePath(file: ApplyPatchPreviewFile, cwd: string = process.cwd()): string {
+	const filePath = displayPath(file.filePath, cwd);
+	if (!file.movePath) {
+		return filePath;
+	}
+	return `${filePath} → ${displayPath(file.movePath, cwd)}`;
 }
 
 function formatPatchOperation(operation: ApplyPatchOperation): string {

From b827ff87572c0806cbf0a0ac6128e2239d2c17ca Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:34:49 +0900
Subject: [PATCH 06/16] test: cover formatPatchPreview collapsed expanded modes
 and backward compat

---
 test/render.test.ts | 58 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 57 insertions(+), 1 deletion(-)

diff --git a/test/render.test.ts b/test/render.test.ts
index a34eba8..79941b1 100644
--- a/test/render.test.ts
+++ b/test/render.test.ts
@@ -1,5 +1,11 @@
 import { describe, expect, it } from "vitest";
-import { displayPath, PATCH_PREVIEW_MAX_CHARS, PATCH_PREVIEW_MAX_LINES, truncatePreview } from "../src/index.js";
+import {
+	displayPath,
+	formatPatchPreview,
+	PATCH_PREVIEW_MAX_CHARS,
+	PATCH_PREVIEW_MAX_LINES,
+	truncatePreview,
+} from "../src/index.js";
 
 describe("render helpers", () => {
 	it("#given long diff #when truncating #then keeps head and tail", () => {
@@ -51,4 +57,54 @@ describe("render helpers", () => {
 		// then
 		expect(rendered).toBe(absolute);
 	});
+
+	it("#given expanded false #when formatting preview #then renders headers only", () => {
+		// given
+		const preview = {
+			files: [
+				{
+					filePath: "/workspace/project/src/foo.ts",
+					operation: "update" as const,
+					diff: "-1 old\n+1 new",
+					added: 1,
+					removed: 1,
+				},
+			],
+			added: 1,
+			removed: 1,
+		};
+
+		// when
+		const collapsed = formatPatchPreview(preview, "/workspace/project", false);
+		const expanded = formatPatchPreview(preview, "/workspace/project", true);
+
+		// then
+		expect(collapsed).toContain("• Edited src/foo.ts (+1 -1)");
+		expect(collapsed).not.toContain("+1 new");
+		expect(expanded).toContain("+1 new");
+	});
+
+	it("#given omitted optional args #when formatting preview #then keeps backward compatible defaults", () => {
+		// given
+		const preview = {
+			files: [
+				{
+					filePath: "src/foo.ts",
+					operation: "update" as const,
+					diff: "-1 old\n+1 new",
+					added: 1,
+					removed: 1,
+				},
+			],
+			added: 1,
+			removed: 1,
+		};
+
+		// when
+		const rendered = formatPatchPreview(preview);
+
+		// then
+		expect(rendered).toContain("• Edited src/foo.ts (+1 -1)");
+		expect(rendered).toContain("+1 new");
+	});
 });

From ffbe0f6bfe0d11c0b4903153752074c13a874f87 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:35:42 +0900
Subject: [PATCH 07/16] feat: add expanded flag and truncation to
 formatPatchPreview

---
 src/index.ts | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 94f8a06..4baea3f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -414,16 +414,24 @@ function formatPatchOperation(operation: ApplyPatchOperation): string {
 	return "Edited";
 }
 
-function formatPatchPreview(preview: ApplyPatchPreview): string {
+export function formatPatchPreview(
+	preview: ApplyPatchPreview,
+	cwd: string = process.cwd(),
+	expanded: boolean = true,
+): string {
 	const lines: string[] = [];
 	if (preview.files.length === 1) {
 		const file = preview.files[0];
 		if (file) {
 			lines.push(
-				`• ${formatPatchOperation(file.operation)} ${formatPatchFilePath(file)} ${formatLineCountSummary(file.added, file.removed)}`,
+				`• ${formatPatchOperation(file.operation)} ${formatPatchFilePath(file, cwd)} ${formatLineCountSummary(file.added, file.removed)}`,
 			);
-			if (file.diff) {
-				lines.push(...file.diff.split("\n").map((line) => `  ${line}`));
+			if (expanded && file.diff) {
+				lines.push(
+					...truncatePreview(file.diff)
+						.split("\n")
+						.map((line) => `  ${line}`),
+				);
 			}
 		}
 		return lines.join("\n");
@@ -432,9 +440,13 @@ function formatPatchPreview(preview: ApplyPatchPreview): string {
 	const noun = preview.files.length === 1 ? "file" : "files";
 	lines.push(`• Edited ${preview.files.length} ${noun} ${formatLineCountSummary(preview.added, preview.removed)}`);
 	for (const file of preview.files) {
-		lines.push(`  └ ${formatPatchFilePath(file)} ${formatLineCountSummary(file.added, file.removed)}`);
-		if (file.diff) {
-			lines.push(...file.diff.split("\n").map((line) => `    ${line}`));
+		lines.push(`  └ ${formatPatchFilePath(file, cwd)} ${formatLineCountSummary(file.added, file.removed)}`);
+		if (expanded && file.diff) {
+			lines.push(
+				...truncatePreview(file.diff)
+					.split("\n")
+					.map((line) => `    ${line}`),
+			);
 		}
 	}
 	return lines.join("\n");

From 9cde6af4f4fda5e99bf9c3247fe43e64dbba530d Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:36:08 +0900
Subject: [PATCH 08/16] test: cover formatInFlightCallText path extraction

---
 test/render.test.ts | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/test/render.test.ts b/test/render.test.ts
index 79941b1..692132c 100644
--- a/test/render.test.ts
+++ b/test/render.test.ts
@@ -1,6 +1,7 @@
 import { describe, expect, it } from "vitest";
 import {
 	displayPath,
+	formatInFlightCallText,
 	formatPatchPreview,
 	PATCH_PREVIEW_MAX_CHARS,
 	PATCH_PREVIEW_MAX_LINES,
@@ -107,4 +108,20 @@ describe("render helpers", () => {
 		expect(rendered).toContain("• Edited src/foo.ts (+1 -1)");
 		expect(rendered).toContain("+1 new");
 	});
+
+	it("#given parseable call text #when formatting in-flight label #then includes count and paths", () => {
+		// given
+		const patch = `*** Begin Patch
+*** Update File: src/a.ts
+*** Add File: src/b.ts
+*** End Patch`;
+
+		// when
+		const callText = formatInFlightCallText(patch);
+
+		// then
+		expect(callText).toContain("(2 files)");
+		expect(callText).toContain("src/a.ts");
+		expect(callText).toContain("src/b.ts");
+	});
 });

From 2b5e8ccdae89b490a5f4951339c98e0a3654d7d1 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:36:26 +0900
Subject: [PATCH 09/16] feat: add formatInFlightCallText for in-flight
 renderCall labels

---
 src/index.ts | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/index.ts b/src/index.ts
index 4baea3f..7b9061f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -452,6 +452,16 @@ export function formatPatchPreview(
 	return lines.join("\n");
 }
 
+export function formatInFlightCallText(patchText: string): string {
+	const paths = extractPatchedPaths(patchText);
+	if (paths.length === 0) {
+		return "Patching";
+	}
+	const noun = paths.length === 1 ? "file" : "files";
+	const count = paths.length > 1 ? ` (${paths.length} ${noun})` : "";
+	return `Patching${count}: ${paths.join(", ")}`;
+}
+
 function renderPatchPreview(preview: ApplyPatchPreview, theme: ApplyPatchTheme): string {
 	return formatPatchPreview(preview)
 		.split("\n")

From 5841e467aa603a71b2d7f78fa9a38bc9e3b51c9c Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:36:51 +0900
Subject: [PATCH 10/16] test: cover clearApplyPatchRenderState helper exists

---
 test/render.test.ts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test/render.test.ts b/test/render.test.ts
index 692132c..6647dd9 100644
--- a/test/render.test.ts
+++ b/test/render.test.ts
@@ -1,5 +1,6 @@
 import { describe, expect, it } from "vitest";
 import {
+	clearApplyPatchRenderState,
 	displayPath,
 	formatInFlightCallText,
 	formatPatchPreview,
@@ -109,6 +110,11 @@ describe("render helpers", () => {
 		expect(rendered).toContain("+1 new");
 	});
 
+	it("#given cached state #when clearing #then reset helper is callable", () => {
+		// given/when/then
+		expect(() => clearApplyPatchRenderState()).not.toThrow();
+	});
+
 	it("#given parseable call text #when formatting in-flight label #then includes count and paths", () => {
 		// given
 		const patch = `*** Begin Patch

From 4752e4261609279172eaf4a35f87ed9a84f94a3e Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:39:01 +0900
Subject: [PATCH 11/16] feat: add applyPatchRenderStates map and
 clearApplyPatchRenderState

---
 src/index.ts | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/index.ts b/src/index.ts
index 7b9061f..e8a4fe3 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -107,6 +107,14 @@ export class ApplyPatchError extends Error {
 	}
 }
 
+type ApplyPatchRenderState = {
+	cwd: string;
+	patchText: string;
+	callText: string;
+	collapsed: string;
+	expanded: string;
+};
+
 type ApplyPatchThemeColor =
 	| "accent"
 	| "error"
@@ -171,6 +179,7 @@ export const PATCH_PREVIEW_MAX_LINES = 16;
 export const PATCH_PREVIEW_MAX_CHARS = 4000;
 const PATCH_PREVIEW_HEAD_LINES = 8;
 const PATCH_PREVIEW_TAIL_LINES = 8;
+const applyPatchRenderStates = new Map<string, ApplyPatchRenderState>();
 
 function countLines(text: string): number {
 	if (text.length === 0) {
@@ -452,6 +461,10 @@ export function formatPatchPreview(
 	return lines.join("\n");
 }
 
+export function clearApplyPatchRenderState(): void {
+	applyPatchRenderStates.clear();
+}
+
 export function formatInFlightCallText(patchText: string): string {
 	const paths = extractPatchedPaths(patchText);
 	if (paths.length === 0) {

From 87f048f98c202c0a674e682d451dafa5973e3d12 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:39:28 +0900
Subject: [PATCH 12/16] test: cover renderCall argsComplete and paths
 integration

---
 test/render.test.ts | 54 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/test/render.test.ts b/test/render.test.ts
index 6647dd9..5c78290 100644
--- a/test/render.test.ts
+++ b/test/render.test.ts
@@ -1,6 +1,7 @@
 import { describe, expect, it } from "vitest";
 import {
 	clearApplyPatchRenderState,
+	createApplyPatchTool,
 	displayPath,
 	formatInFlightCallText,
 	formatPatchPreview,
@@ -9,6 +10,13 @@ import {
 	truncatePreview,
 } from "../src/index.js";
 
+const identityTheme = {
+	fg: (_name: string, text: string) => text,
+	bg: (_name: string, text: string) => text,
+	bold: (text: string) => text,
+	inverse: (text: string) => text,
+};
+
 describe("render helpers", () => {
 	it("#given long diff #when truncating #then keeps head and tail", () => {
 		// given
@@ -130,4 +138,50 @@ describe("render helpers", () => {
 		expect(callText).toContain("src/a.ts");
 		expect(callText).toContain("src/b.ts");
 	});
+
+	it("#given partial args #when rendering call #then shows patching placeholder", () => {
+		// given
+		const tool = createApplyPatchTool();
+
+		// when
+		const component = tool.renderCall?.(
+			{ input: "{" },
+			identityTheme as never,
+			{
+				argsComplete: false,
+				cwd: "/workspace/project",
+				toolCallId: "call-1",
+			} as never,
+		);
+		const rendered = component?.render(120).join("\n") ?? "";
+
+		// then
+		expect(rendered).toContain("apply_patch: Patching");
+	});
+
+	it("#given patch args #when rendering call #then shows paths and count", () => {
+		// given
+		const tool = createApplyPatchTool();
+		const args = {
+			input: `*** Begin Patch
+*** Update File: src/a.ts
+*** Add File: src/b.ts
+*** End Patch`,
+		};
+
+		// when
+		const component = tool.renderCall?.(
+			args,
+			identityTheme as never,
+			{
+				argsComplete: true,
+				cwd: "/workspace/project",
+				toolCallId: "call-2",
+			} as never,
+		);
+		const rendered = component?.render(200).join("\n") ?? "";
+
+		// then
+		expect(rendered).toContain("apply_patch: Patching (2 files): src/a.ts, src/b.ts");
+	});
 });

From 9f2d2b4ae4db5ec6fbfe221ac1872e46bebe8091 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:40:04 +0900
Subject: [PATCH 13/16] feat: integrate render state cache and argsComplete in
 renderCall

---
 src/index.ts | 44 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 42 insertions(+), 2 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index e8a4fe3..60bf760 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -461,6 +461,39 @@ export function formatPatchPreview(
 	return lines.join("\n");
 }
 
+function getApplyPatchRenderState(toolCallId: string, cwd: string, patchText: string): ApplyPatchRenderState {
+	const existing = applyPatchRenderStates.get(toolCallId);
+	if (existing && existing.cwd === cwd && existing.patchText === patchText) {
+		return existing;
+	}
+
+	const callText = formatInFlightCallText(patchText);
+	let collapsed = "";
+	let expanded = "";
+	try {
+		const hunks = parsePatch(patchText);
+		if (hunks.length > 0) {
+			const files = hunks.map((hunk) => ({
+				filePath: hunk.filePath,
+				movePath: hunk.type === "update" ? hunk.movePath : undefined,
+				operation: hunk.type,
+				diff: "",
+				added: 0,
+				removed: 0,
+			})) satisfies ApplyPatchPreviewFile[];
+			const preview: ApplyPatchPreview = { files, added: 0, removed: 0 };
+			collapsed = formatPatchPreview(preview, cwd, false);
+			expanded = formatPatchPreview(preview, cwd, true);
+		}
+	} catch {
+		// leave summaries empty for partial/incomplete patch text
+	}
+
+	const nextState: ApplyPatchRenderState = { cwd, patchText, callText, collapsed, expanded };
+	applyPatchRenderStates.set(toolCallId, nextState);
+	return nextState;
+}
+
 export function clearApplyPatchRenderState(): void {
 	applyPatchRenderStates.clear();
 }
@@ -1054,8 +1087,15 @@ export function createApplyPatchTool(): ApplyPatchToolDefinition {
 				details: { result },
 			};
 		},
-		renderCall(_args, theme) {
-			return new Text(theme.fg("toolTitle", theme.bold("apply_patch")), 0, 0);
+		renderCall(args, theme, context) {
+			if (!context.argsComplete) {
+				return new Text(theme.fg("toolTitle", theme.bold("apply_patch: Patching")), 0, 0);
+			}
+
+			const normalizedArgs = normalizeApplyPatchArguments(args);
+			const renderState = getApplyPatchRenderState(context.toolCallId, context.cwd, normalizedArgs.input);
+			const text = renderState.callText.length > 0 ? `apply_patch: ${renderState.callText}` : "apply_patch";
+			return new Text(theme.fg("toolTitle", theme.bold(text)), 0, 0);
 		},
 		renderResult(result, options, theme) {
 			const component = new Container();

From a246cd7046bab76163c129a040b1e9cef32a6dc9 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:40:34 +0900
Subject: [PATCH 14/16] test: cover renderResult collapsed multi-file and large
 diff truncation

---
 test/render.test.ts | 98 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)

diff --git a/test/render.test.ts b/test/render.test.ts
index 5c78290..6ac79a4 100644
--- a/test/render.test.ts
+++ b/test/render.test.ts
@@ -184,4 +184,102 @@ describe("render helpers", () => {
 		// then
 		expect(rendered).toContain("apply_patch: Patching (2 files): src/a.ts, src/b.ts");
 	});
+
+	it("#given preview #when rendering result collapsed #then shows headers without diff lines", () => {
+		// given
+		const tool = createApplyPatchTool();
+		const result = {
+			content: [{ type: "text" as const, text: "Applying patch" }],
+			details: {
+				preview: {
+					files: [
+						{
+							filePath: "src/foo.ts",
+							operation: "update" as const,
+							diff: "-1 old\n+1 new",
+							added: 1,
+							removed: 1,
+						},
+					],
+					added: 1,
+					removed: 1,
+				},
+			},
+		};
+
+		// when
+		const component = tool.renderResult?.(
+			result,
+			{ expanded: false, isPartial: false },
+			identityTheme as never,
+			{ cwd: "/workspace/project", toolCallId: "result-1", args: { input: "" } } as never,
+		);
+		const rendered = component?.render(200).join("\n") ?? "";
+
+		// then
+		expect(rendered).toContain("• Edited src/foo.ts (+1 -1)");
+		expect(rendered).not.toContain("+1 new");
+	});
+
+	it("#given multi-file preview #when rendering result collapsed #then shows grouped summary", () => {
+		// given
+		const tool = createApplyPatchTool();
+		const result = {
+			content: [{ type: "text" as const, text: "Applying patch" }],
+			details: {
+				preview: {
+					files: [
+						{ filePath: "src/a.ts", operation: "update" as const, diff: "+1 one", added: 1, removed: 0 },
+						{ filePath: "src/b.ts", operation: "update" as const, diff: "+1 two", added: 1, removed: 0 },
+					],
+					added: 2,
+					removed: 0,
+				},
+			},
+		};
+
+		// when
+		const component = tool.renderResult?.(
+			result,
+			{ expanded: false, isPartial: false },
+			identityTheme as never,
+			{ cwd: "/workspace/project", toolCallId: "result-3", args: { input: "" } } as never,
+		);
+		const rendered = component?.render(400).join("\n") ?? "";
+
+		// then
+		expect(rendered).toContain("• Edited 2 files (+2 -0)");
+		expect(rendered).toContain("└ src/a.ts (+1 -0)");
+		expect(rendered).toContain("└ src/b.ts (+1 -0)");
+		expect(rendered).not.toContain("+1 one");
+	});
+
+	it("#given large preview #when rendering result expanded #then shows truncation marker", () => {
+		// given
+		const tool = createApplyPatchTool();
+		const diff = Array.from({ length: 50 }, (_, index) => `+${index + 1} line`).join("\n");
+		const result = {
+			content: [{ type: "text" as const, text: "Applying patch" }],
+			details: {
+				preview: {
+					files: [{ filePath: "src/large.ts", operation: "update" as const, diff, added: 50, removed: 0 }],
+					added: 50,
+					removed: 0,
+				},
+			},
+		};
+
+		// when
+		const component = tool.renderResult?.(
+			result,
+			{ expanded: true, isPartial: false },
+			identityTheme as never,
+			{ cwd: "/workspace/project", toolCallId: "result-large", args: { input: "" } } as never,
+		);
+		const rendered = component?.render(400).join("\n") ?? "";
+
+		// then
+		expect(rendered).toContain("• Edited src/large.ts (+50 -0)");
+		expect(rendered).toContain("…");
+	});
 });

From f4b3e5d37a33e735b17002454bd48b7de4123f07 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:45:31 +0900
Subject: [PATCH 15/16] feat: route renderResult through cwd-aware expanded
 mode

---
 src/index.ts | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 60bf760..3c38372 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -508,8 +508,13 @@ export function formatInFlightCallText(patchText: string): string {
 	return `Patching${count}: ${paths.join(", ")}`;
 }
 
-function renderPatchPreview(preview: ApplyPatchPreview, theme: ApplyPatchTheme): string {
-	return formatPatchPreview(preview)
+function renderPatchPreview(
+	preview: ApplyPatchPreview,
+	cwd: string,
+	theme: ApplyPatchTheme,
+	expanded: boolean,
+): string {
+	return formatPatchPreview(preview, cwd, expanded)
 		.split("\n")
 		.map((line) => {
 			const trimmed = line.trimStart();
@@ -1097,7 +1102,7 @@ export function createApplyPatchTool(): ApplyPatchToolDefinition {
 			const text = renderState.callText.length > 0 ? `apply_patch: ${renderState.callText}` : "apply_patch";
 			return new Text(theme.fg("toolTitle", theme.bold(text)), 0, 0);
 		},
-		renderResult(result, options, theme) {
+		renderResult(result, options, theme, context) {
 			const component = new Container();
 			const preview = result.details?.preview;
 			if (preview) {
@@ -1105,7 +1110,8 @@ export function createApplyPatchTool(): ApplyPatchToolDefinition {
 				const box = new Box(1, 1, (text: string) => theme.bg(bgName, text));
 				box.addChild(new Text(theme.fg("toolTitle", theme.bold("Applying patch")), 0, 0));
 				box.addChild(new Spacer(1));
-				box.addChild(new Text(renderPatchPreview(preview, theme), 0, 0));
+				const expanded = options.isPartial ? true : (options.expanded ?? true);
+				box.addChild(new Text(renderPatchPreview(preview, context.cwd, theme, expanded), 0, 0));
 				component.addChild(box);
 				return component;
 			}

From 99e48e27f8cd06c5fbbfa7d0c7edbd00ce2956f8 Mon Sep 17 00:00:00 2001
From: YeonGyu-Kim <code.yeon.gyu@gmail.com>
Date: Sun, 10 May 2026 14:46:08 +0900
Subject: [PATCH 16/16] feat: integrate Pi renderDiff with safe fallback to
 themed rendering

---
 src/index.ts | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/index.ts b/src/index.ts
index 3c38372..83d5924 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -2,7 +2,7 @@ import { mkdir, readFile, realpath, rename, rm, stat, unlink, writeFile } from "
 import path from "node:path";
 import type { AgentToolResult } from "@mariozechner/pi-agent-core";
 import type { Model } from "@mariozechner/pi-ai";
-import { defineTool, type ExtensionAPI, type ToolDefinition } from "@mariozechner/pi-coding-agent";
+import { defineTool, type ExtensionAPI, renderDiff, type ToolDefinition } from "@mariozechner/pi-coding-agent";
 import { Box, Container, Spacer, Text } from "@mariozechner/pi-tui";
 import * as Diff from "diff";
 import { Type } from "typebox";
@@ -514,6 +514,26 @@ function renderPatchPreview(
 	theme: ApplyPatchTheme,
 	expanded: boolean,
 ): string {
+	if (expanded) {
+		try {
+			const renderedFiles = preview.files
+				.map((file) => {
+					const header = `• ${formatPatchOperation(file.operation)} ${formatPatchFilePath(file, cwd)} ${formatLineCountSummary(file.added, file.removed)}`;
+					if (!file.diff) {
+						return header;
+					}
+					const previewDiff = truncatePreview(file.diff);
+					return `${header}\n${renderDiff(previewDiff)}`;
+				})
+				.join("\n");
+			if (renderedFiles.length > 0) {
+				return renderedFiles;
+			}
+		} catch {
+			// fall back to manual themed line rendering
+		}
+	}
+
 	return formatPatchPreview(preview, cwd, expanded)
 		.split("\n")
 		.map((line) => {