Finish async tool cleanup

packages/coding-agent/CHANGELOG.md

@@ -24,6 +24,7 @@
 - Fixed bash tool truncation line counts to ignore the trailing newline as an extra output line ([#4818](https://github.com/earendil-works/pi/issues/4818)).
 - Fixed footer home-directory abbreviation to avoid shortening sibling paths that only share the same prefix ([#4878](https://github.com/earendil-works/pi/issues/4878)).
 - Fixed macOS Bun release binaries to resolve the native clipboard sidecar so Ctrl+V image paste can load `@mariozechner/clipboard` ([#4307](https://github.com/earendil-works/pi/issues/4307)).
+- Fixed coding-agent tools to avoid synchronous filesystem operations during streaming and moved image resizing off the main TUI thread ([#4756](https://github.com/earendil-works/pi-mono/pull/4756) by [@mitsuhiko](https://github.com/mitsuhiko)).
 
 ## [0.75.4] - 2026-05-20
 

packages/coding-agent/package.json

@@ -31,7 +31,7 @@
 	"scripts": {
 		"clean": "shx rm -rf dist",
 		"build": "tsgo -p tsconfig.build.json && shx chmod +x dist/cli.js && npm run copy-assets",
-		"build:binary": "npm --prefix ../tui run build && npm --prefix ../ai run build && npm --prefix ../agent run build && npm run build && bun build --compile ./dist/bun/cli.js ./dist/utils/image-resize-worker.js --outfile dist/pi && npm run copy-binary-assets",
+		"build:binary": "npm --prefix ../tui run build && npm --prefix ../ai run build && npm --prefix ../agent run build && npm run build && bun build --compile ./dist/bun/cli.js ./src/utils/image-resize-worker.ts --outfile dist/pi && npm run copy-binary-assets",
 		"copy-assets": "shx mkdir -p dist/modes/interactive/theme && shx cp src/modes/interactive/theme/*.json dist/modes/interactive/theme/ && shx mkdir -p dist/modes/interactive/assets && shx cp src/modes/interactive/assets/*.png dist/modes/interactive/assets/ && shx mkdir -p dist/core/export-html/vendor && shx cp src/core/export-html/template.html src/core/export-html/template.css src/core/export-html/template.js dist/core/export-html/ && shx cp src/core/export-html/vendor/*.js dist/core/export-html/vendor/",
 		"copy-binary-assets": "shx cp package.json dist/ && shx cp README.md dist/ && shx cp CHANGELOG.md dist/ && shx mkdir -p dist/theme && shx cp src/modes/interactive/theme/*.json dist/theme/ && shx mkdir -p dist/assets && shx cp src/modes/interactive/assets/*.png dist/assets/ && shx mkdir -p dist/export-html/vendor && shx cp src/core/export-html/template.html dist/export-html/ && shx cp src/core/export-html/vendor/*.js dist/export-html/vendor/ && shx cp -r docs dist/ && shx cp -r examples dist/ && shx cp ../../node_modules/@silvia-odwyer/photon-node/photon_rs_bg.wasm dist/",
 		"test": "vitest --run",

packages/coding-agent/src/core/tools/find.ts

@@ -1,5 +1,3 @@
-import { constants } from "node:fs";
-import { access as fsAccess } from "node:fs/promises";
 import { createInterface } from "node:readline";
 import type { AgentTool } from "@earendil-works/pi-agent-core";
 import { Text } from "@earendil-works/pi-tui";
@@ -9,7 +7,7 @@ import { type Static, Type } from "typebox";
 import { keyHint } from "../../modes/interactive/components/keybinding-hints.ts";
 import { ensureTool } from "../../utils/tools-manager.ts";
 import type { ToolDefinition, ToolRenderResultOptions } from "../extensions/types.ts";
-import { resolveToCwd } from "./path-utils.ts";
+import { pathExists, resolveToCwd } from "./path-utils.ts";
 import { getTextOutput, invalidArgText, shortenPath, str } from "./render-utils.ts";
 import { wrapToolDefinition } from "./tool-definition-wrapper.ts";
 import { DEFAULT_MAX_BYTES, formatSize, type TruncationResult, truncateHead } from "./truncate.ts";
@@ -47,14 +45,7 @@ export interface FindOperations {
 }
 
 const defaultFindOperations: FindOperations = {
-	exists: async (absolutePath) => {
+	exists: pathExists,
-		try {
-			await fsAccess(absolutePath, constants.F_OK);
-			return true;
-		} catch {
-			return false;
-		}
-	},
 	// This is a placeholder. Actual fd execution happens in execute() when no custom glob is provided.
 	glob: () => [],
 };

packages/coding-agent/src/core/tools/ls.ts

@@ -1,12 +1,11 @@
-import { constants } from "node:fs";
+import { readdir as fsReaddir, stat as fsStat } from "node:fs/promises";
-import { access as fsAccess, readdir as fsReaddir, stat as fsStat } from "node:fs/promises";
 import type { AgentTool } from "@earendil-works/pi-agent-core";
 import { Text } from "@earendil-works/pi-tui";
 import nodePath from "path";
 import { type Static, Type } from "typebox";
 import { keyHint } from "../../modes/interactive/components/keybinding-hints.ts";
 import type { ToolDefinition, ToolRenderResultOptions } from "../extensions/types.ts";
-import { resolveToCwd } from "./path-utils.ts";
+import { pathExists, resolveToCwd } from "./path-utils.ts";
 import { getTextOutput, invalidArgText, shortenPath, str } from "./render-utils.ts";
 import { wrapToolDefinition } from "./tool-definition-wrapper.ts";
 import { DEFAULT_MAX_BYTES, formatSize, type TruncationResult, truncateHead } from "./truncate.ts";
@@ -39,14 +38,7 @@ export interface LsOperations {
 }
 
 const defaultLsOperations: LsOperations = {
-	exists: async (absolutePath) => {
+	exists: pathExists,
-		try {
-			await fsAccess(absolutePath, constants.F_OK);
-			return true;
-		} catch {
-			return false;
-		}
-	},
 	stat: fsStat,
 	readdir: fsReaddir,
 };

packages/coding-agent/src/core/tools/path-utils.ts

@@ -28,7 +28,7 @@ function fileExists(filePath: string): boolean {
 	}
 }
 
-async function fileExistsAsync(filePath: string): Promise<boolean> {
+export async function pathExists(filePath: string): Promise<boolean> {
 	try {
 		await access(filePath, constants.F_OK);
 		return true;
@@ -86,31 +86,31 @@ export function resolveReadPath(filePath: string, cwd: string): string {
 export async function resolveReadPathAsync(filePath: string, cwd: string): Promise<string> {
 	const resolved = resolveToCwd(filePath, cwd);
 
-	if (await fileExistsAsync(resolved)) {
+	if (await pathExists(resolved)) {
 		return resolved;
 	}
 
 	// Try macOS AM/PM variant (narrow no-break space before AM/PM)
 	const amPmVariant = tryMacOSScreenshotPath(resolved);
-	if (amPmVariant !== resolved && (await fileExistsAsync(amPmVariant))) {
+	if (amPmVariant !== resolved && (await pathExists(amPmVariant))) {
 		return amPmVariant;
 	}
 
 	// Try NFD variant (macOS stores filenames in NFD form)
 	const nfdVariant = tryNFDVariant(resolved);
-	if (nfdVariant !== resolved && (await fileExistsAsync(nfdVariant))) {
+	if (nfdVariant !== resolved && (await pathExists(nfdVariant))) {
 		return nfdVariant;
 	}
 
 	// Try curly quote variant (macOS uses U+2019 in screenshot names)
 	const curlyVariant = tryCurlyQuoteVariant(resolved);
-	if (curlyVariant !== resolved && (await fileExistsAsync(curlyVariant))) {
+	if (curlyVariant !== resolved && (await pathExists(curlyVariant))) {
 		return curlyVariant;
 	}
 
 	// Try combined NFD + curly quote (for French macOS screenshots like "Capture d'écran")
 	const nfdCurlyVariant = tryCurlyQuoteVariant(nfdVariant);
-	if (nfdCurlyVariant !== resolved && (await fileExistsAsync(nfdCurlyVariant))) {
+	if (nfdCurlyVariant !== resolved && (await pathExists(nfdCurlyVariant))) {
 		return nfdCurlyVariant;
 	}
 

packages/coding-agent/src/core/tools/write.ts

@@ -201,18 +201,14 @@ export function createWriteToolDefinition(
 			const absolutePath = resolveToCwd(path, cwd);
 			const dir = dirname(absolutePath);
 			return withFileMutationQueue(absolutePath, async () => {
-				let aborted = signal?.aborted ?? false;
+				// Do not reject from an abort event listener here: that would release the
-				const onAbort = () => {
+				// mutation queue while an in-flight filesystem operation may still finish.
-					aborted = true;
+				// Checking signal.aborted after each await observes the same aborts while
-				};
+				// keeping the queue locked until the current operation has settled.
 				const throwIfAborted = (): void => {
-					if (aborted || signal?.aborted) {
+					if (signal?.aborted) throw new Error("Operation aborted");
-						throw new Error("Operation aborted");
-					}
 				};
 
-				signal?.addEventListener("abort", onAbort, { once: true });
-				try {
 				throwIfAborted();
 				// Create parent directories if needed.
 				await ops.mkdir(dir);
@@ -226,9 +222,6 @@ export function createWriteToolDefinition(
 					content: [{ type: "text", text: `Successfully wrote ${content.length} bytes to ${path}` }],
 					details: undefined,
 				};
-				} finally {
-					signal?.removeEventListener("abort", onAbort);
-				}
 			});
 		},
 		renderCall(args, theme, context) {

packages/coding-agent/src/utils/image-resize.ts

@@ -1,5 +1,5 @@
 import { Worker } from "node:worker_threads";
-import type { ImageResizeOptions, ResizedImage } from "./image-resize-core.ts";
+import { type ImageResizeOptions, type ResizedImage, resizeImageInProcess } from "./image-resize-core.ts";
 
 export type { ImageResizeOptions, ResizedImage } from "./image-resize-core.ts";
 
@@ -18,21 +18,17 @@ function isResizeImageWorkerResponse(value: unknown): value is ResizeImageWorker
 	return value !== null && typeof value === "object";
 }
 
-function createResizeWorker(): Worker {
+function createResizeWorker(workerSpecifier: string | URL): Worker {
-	const isTypeScriptRuntime = import.meta.url.endsWith(".ts");
+	return new Worker(workerSpecifier);
-	const workerUrl = new URL(
-		isTypeScriptRuntime ? "./image-resize-worker.ts" : "./image-resize-worker.js",
-		import.meta.url,
-	);
-	return new Worker(workerUrl);
 }
 
 async function resizeImageInWorker(
+	workerSpecifier: string | URL,
 	inputBytes: Uint8Array,
 	mimeType: string,
 	options?: ImageResizeOptions,
 ): Promise<ResizedImage | null> {
-	const worker = createResizeWorker();
+	const worker = createResizeWorker(workerSpecifier);
 	try {
 		const inputBytesForWorker = toTransferableBytes(inputBytes);
 		return await new Promise<ResizedImage | null>((resolve, reject) => {
@@ -82,15 +78,35 @@ async function resizeImageInWorker(
 /**
  * Resize an image to fit within the specified max dimensions and encoded file size.
  * Runs Photon in a worker thread so WASM decoding, resizing, and encoding do not
- * block the TUI event loop. Worker failures are propagated instead of retried on
+ * block the TUI event loop. If the worker cannot be loaded (for example in some
- * the main thread.
+ * Bun compiled executable layouts), fall back to in-process resizing so image
+ * reads still work.
  */
 export async function resizeImage(
 	inputBytes: Uint8Array,
 	mimeType: string,
 	options?: ImageResizeOptions,
 ): Promise<ResizedImage | null> {
-	return resizeImageInWorker(inputBytes, mimeType, options);
+	const isTypeScriptRuntime = import.meta.url.endsWith(".ts");
+	const workerUrl = new URL(
+		isTypeScriptRuntime ? "./image-resize-worker.ts" : "./image-resize-worker.js",
+		import.meta.url,
+	);
+
+	// Bun compiled executables resolve worker entrypoints by string path, not via
+	// new URL(..., import.meta.url). Try the string path first under Bun so the
+	// release binary uses the embedded worker instead of falling back in-process.
+	if (typeof process.versions.bun === "string") {
+		try {
+			return await resizeImageInWorker("./src/utils/image-resize-worker.ts", inputBytes, mimeType, options);
+		} catch {}
+	}
+
+	try {
+		return await resizeImageInWorker(workerUrl, inputBytes, mimeType, options);
+	} catch {
+		return resizeImageInProcess(inputBytes, mimeType, options);
+	}
 }
 
 /**

scripts/build-binaries.sh

@@ -132,9 +132,9 @@ for platform in "${PLATFORMS[@]}"; do
     # explicit build entrypoints. The runtime can still use new URL(...), but the
     # worker must be present in the compiled executable.
     if [[ "$platform" == windows-* ]]; then
-        bun build --compile --target=bun-$platform ./dist/bun/cli.js ./dist/utils/image-resize-worker.js --outfile "$OUTPUT_DIR/$platform/pi.exe"
+        bun build --compile --target=bun-$platform ./dist/bun/cli.js ./src/utils/image-resize-worker.ts --outfile "$OUTPUT_DIR/$platform/pi.exe"
     else
-        bun build --compile --target=bun-$platform ./dist/bun/cli.js ./dist/utils/image-resize-worker.js --outfile "$OUTPUT_DIR/$platform/pi"
+        bun build --compile --target=bun-$platform ./dist/bun/cli.js ./src/utils/image-resize-worker.ts --outfile "$OUTPUT_DIR/$platform/pi"
     fi
 done