add a docker attach terminal mode

server.js

@@ -267,6 +267,13 @@ function buildDockerStreamRequest(path, target, body = '') {
 	);
 }
 
+// Mirrors translateAttachInput in docker-stream-core.ts: for non-TTY attach map a lone
+// \r (xterm Enter) to \n (no pty to do it); exec / TTY attach pass through. Keep in sync.
+function translateAttachInput(data, nonTtyAttach) {
+	if (!nonTtyAttach) return data;
+	return data.replace(/\r(?!\n)/g, '\n');
+}
+
 function createDockerStreamState(multiplexed = false) {
 	return {
 		headersStripped: false,
@@ -538,7 +545,8 @@ async function handleTerminalConnection(ws, url, connId) {
 			try {
 				const msg = JSON.parse(data.toString());
 				if (msg.type === 'input' && msg.data) {
-					dockerStream.write(msg.data);
+					// Non-TTY attach has no pty to convert Enter (\r) to a newline.
+					dockerStream.write(translateAttachInput(msg.data, multiplexed));
 				} else if (msg.type === 'resize' && msg.cols && msg.rows) {
 					if (mode === 'attach') {
 						if (typeof globalThis.__terminalResizeContainer === 'function') {
@@ -644,10 +652,12 @@ function handleEdgeExec(ws, connId, containerId, shell, user, environmentId, mod
 		try {
 			const msg = JSON.parse(data.toString());
 			if (msg.type === 'input' && msg.data) {
+				// Non-TTY attach has no pty to convert Enter (\r) to a newline.
+				const inputData = translateAttachInput(msg.data, attach && multiplexed);
 				const inputMsg = JSON.stringify({
 					type: 'exec_input',
 					execId,
-					data: Buffer.from(msg.data).toString('base64')
+					data: Buffer.from(inputData).toString('base64')
 				});
 				globalThis.__hawserSendMessage(environmentId, inputMsg);
 			} else if (msg.type === 'resize' && msg.cols && msg.rows) {

src/lib/server/docker-stream-core.ts

@@ -136,3 +136,18 @@ export function processDockerStreamChunk(data: Buffer | Uint8Array | string, sta
 
 	return output;
 }
+
+/**
+ * Translate terminal input before writing it to the container's stdin. xterm sends a
+ * carriage return (\r) when Enter is pressed; with a TTY the pty converts that to a
+ * newline, but attach to a container started without a tty has no pty, so a shell
+ * `read` never sees an end-of-line and the session looks unresponsive. When
+ * `nonTtyAttach` is set, map a lone \r to \n (leaving an existing \r\n alone) so Enter
+ * ends a line. For exec and TTY attach (nonTtyAttach false) the input passes through
+ * verbatim. The gate lives here so it is unit-tested alongside the transform, rather
+ * than only in the inline call-site ternaries.
+ */
+export function translateAttachInput(data: string, nonTtyAttach: boolean): string {
+	if (!nonTtyAttach) return data;
+	return data.replace(/\r(?!\n)/g, '\n');
+}

tests/docker-stream-core.test.ts

@@ -3,7 +3,8 @@ import { describe, expect, test } from 'bun:test';
 import {
 	createDockerStreamState,
 	decodeChunkedDockerBody,
-	processDockerStreamChunk
+	processDockerStreamChunk,
+	translateAttachInput
 } from '../src/lib/server/docker-stream-core';
 
 const HTTP_HEAD = 'HTTP/1.1 200 OK\r\nContent-Type: application/vnd.docker.raw-stream\r\n\r\n';
@@ -157,3 +158,32 @@ describe('processDockerStreamChunk - edge attach seeding (headersStripped, no HT
 		expect(processDockerStreamChunk(f.subarray(4), st).join('')).toBe('split');
 	});
 });
+
+describe('translateAttachInput - CR to LF gated on non-TTY attach', () => {
+	// nonTtyAttach=true: attach to a container with no pty (the CR->LF case).
+	test('maps a lone carriage return (xterm Enter) to a newline', () => {
+		expect(translateAttachInput('ls\r', true)).toBe('ls\n');
+	});
+
+	test('leaves an existing CRLF alone (no doubled newline)', () => {
+		expect(translateAttachInput('a\r\nb', true)).toBe('a\r\nb');
+	});
+
+	test('translates multiple lone CRs', () => {
+		expect(translateAttachInput('one\rtwo\rthree\r', true)).toBe('one\ntwo\nthree\n');
+	});
+
+	test('passes plain text and bare LF through unchanged', () => {
+		expect(translateAttachInput('hello\n', true)).toBe('hello\n');
+		expect(translateAttachInput('no-eol', true)).toBe('no-eol');
+	});
+
+	// nonTtyAttach=false: exec or TTY attach - input MUST pass through verbatim,
+	// including a lone \r (the pty/exec handles line-ending itself). This guards the
+	// gate: a flipped call site would corrupt exec keystrokes and this would fail.
+	test('passes a lone CR through UNCHANGED for exec / TTY attach', () => {
+		expect(translateAttachInput('ls\r', false)).toBe('ls\r');
+		expect(translateAttachInput('\r', false)).toBe('\r');
+		expect(translateAttachInput('a\rb\rc', false)).toBe('a\rb\rc');
+	});
+});

vite.config.ts

@@ -184,7 +184,7 @@ function buildDockerStreamHttpRequest(path: string, target: DockerTarget, body =
 
 // ============ Stream Processing ============
 
-import { createDockerStreamState, processDockerStreamChunk, type DockerStreamState } from './src/lib/server/docker-stream-core';
+import { createDockerStreamState, processDockerStreamChunk, translateAttachInput, type DockerStreamState } from './src/lib/server/docker-stream-core';
 
 // ============ Hawser Edge Exec Messages ============
 
@@ -764,7 +764,9 @@ function webSocketPlugin(): Plugin {
 								try {
 									const msg = JSON.parse(message.toString());
 									if (msg.type === 'input') {
-										conn.ws.send(JSON.stringify(createExecInputMessage(edgeExecId, msg.data)));
+										// Non-TTY attach has no pty to convert Enter (\r) to a newline.
+										const inputData = translateAttachInput(msg.data, !!session.streamState?.multiplexed);
+										conn.ws.send(JSON.stringify(createExecInputMessage(edgeExecId, inputData)));
 									} else if (msg.type === 'resize') {
 										conn.ws.send(JSON.stringify(createExecResizeMessage(edgeExecId, msg.cols, msg.rows)));
 									}
@@ -785,7 +787,8 @@ function webSocketPlugin(): Plugin {
 					try {
 						const msg = JSON.parse(message.toString());
 						if (msg.type === 'input' && d.stream) {
-							d.stream.write(msg.data);
+							// Non-TTY attach has no pty to convert Enter (\r) to a newline.
+							d.stream.write(translateAttachInput(msg.data, d.mode === 'attach' && d.state.multiplexed));
 						} else if (msg.type === 'resize') {
 							if (d.mode === 'attach') {
 								resizeContainerForWs(d.containerId, msg.cols, msg.rows, d.target);