attach: stop nudging a child that is already the right size; remove --no-resize

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## 0.12.0
 
+### Attach no longer nudges a child that is already at the right size
+
+- The attach-time redraw nudge (resize to `cols - 1` and back, to paper over serialize-replay artifacts) now fires only when the attaching client's geometry differs from the session's. Attaching at the size the session already has leaves the child alone, so connecting a viewer no longer delivers `SIGWINCH` to an idle process.
+
 ### Package renamed: `@myobie/pty` → `@compoundingtech/pty`
 
 - The npm scope + GitHub org moved from `@myobie`/`myobie` to `@compoundingtech`/`compoundingtech`. The package is now **`@compoundingtech/pty`**; all subpaths (`/tui`, `/client`, `/server`, `/testing`, `/protocol`, `/keys`) and the CLI command (`pty`) are unchanged in shape. Update imports and any `@myobie/pty*` dependency specifiers.
@@ -45,10 +49,6 @@
 
 - New `badge(label, opts)` widget renders a small SRCL-style chip: an uppercase, padded label on a muted fill (mirroring SRCL's `Badge` — `text-transform: uppercase`, `padding: 0 1ch`, filled background). Status `variant`s (`neutral | ok | warn | error | accent | info`) color the label, or fill the chip when `solid: true`. `uppercase` and `bold` are configurable. Returns a `TextNode` styled with semantic color tokens only (no terminal-only escapes), so the same call can render under a non-terminal backend.
 
-### Geometry-neutral interactive attach
-
-- `pty attach --no-resize <ref>` receives the live screen and forwards input without contributing its terminal dimensions to the shared PTY's min-wins size negotiation. It also suppresses the attach-time redraw `SIGWINCH` nudge. This supports embedded interactive viewers whose stdio is piped (and would otherwise report the 80x24 fallback) while leaving ordinary multi-viewer behavior unchanged. The CLI refuses the flag against a daemon that does not advertise `capabilities.geometryNeutralAttach`, rather than silently degrading.
-
 ### `pty.toml` — per-session `cwd` field
 
 - Sessions in a `pty.toml` accept an optional `cwd = "..."` setting the working directory. An absolute path is used as-is; a relative path resolves against the manifest's directory. Omitted → the session runs in the manifest's directory (the unchanged default).

README.md

@@ -70,7 +70,6 @@ pty list --filter-tag role=web            # show only sessions with matching tag
 
 pty attach myserver                       # reconnect to a session
 pty attach -r myserver                    # reconnect, auto-restart if exited
-pty attach --no-resize myserver           # interactive viewer; preserve shared PTY geometry
 pty exec -- codex                         # replace this session's process (inside a session)
 pty peek myserver                         # print current screen and exit
 pty peek --plain myserver                 # print as plain text (no ANSI)

completions/pty.bash

@@ -28,7 +28,7 @@ _pty() {
       ;;
     attach|a)
       if [[ "${cur}" == -* ]]; then
-        COMPREPLY=($(compgen -W "-r --auto-restart --no-resize --force --remote" -- "${cur}"))
+        COMPREPLY=($(compgen -W "-r --auto-restart --force --remote" -- "${cur}"))
       else
         COMPREPLY=($(compgen -W "${names}" -- "${cur}"))
       fi

completions/pty.fish

@@ -75,7 +75,6 @@ complete -c pty -n '__pty_using_command run' -l cwd -d 'Working directory'
 complete -c pty -n '__pty_using_command run' -l isolate-env -d 'Scrub env to a safe allow-list'
 complete -c pty -n '__pty_using_command run' -l force -d 'Create even from inside another pty'
 complete -c pty -n '__pty_using_command attach a' -l auto-restart -s r -d 'Auto-restart if the session is exited'
-complete -c pty -n '__pty_using_command attach a' -l no-resize -d 'Preserve shared PTY geometry'
 complete -c pty -n '__pty_using_command attach a' -l force -d 'Attach even from inside another pty'
 complete -c pty -n '__pty_using_command attach a' -l remote -d 'Attach a session on a fabric peer'
 complete -c pty -n '__pty_using_command attach a' -a '(__pty_sessions)' -d 'Session'

completions/pty.zsh

@@ -68,7 +68,6 @@ _pty() {
         attach|a)
           _arguments \
             '(r --auto-restart){r,--auto-restart}[Auto-restart if the session is exited]' \
-            '--no-resize[Preserve shared PTY geometry]' \
             '--force[Attach even from inside another pty]' \
             '--remote[Attach a session on a fabric peer]' \
             '1:session:_pty_sessions'

src/cli.ts

@@ -99,13 +99,12 @@ Examples:
   pty run -- node server.js
   pty run -d --name "API" --tag role=web -- node server.js`,
 
-  attach: `Usage: pty attach [-r] [--no-resize] [--force] [--remote <peer>] <ref>
+  attach: `Usage: pty attach [-r] [--force] [--remote <peer>] <ref>
 
 Reconnect to a session (alias: pty a). Detach again with Ctrl+\\.
 
 Flags:
   -r, --auto-restart   Auto-restart the session if it has exited
-  --no-resize          Send input and receive output without changing PTY geometry
   --force              Attach even from inside another pty session (nested)
   --remote <peer>      Attach a session on a fabric peer (over fabric); <ref> is
                        the session's name/id ON THE REMOTE
@@ -401,7 +400,6 @@ Create sessions:
 
 Attach & interact:
   pty attach <ref>                        Attach to an existing session (alias: pty a)
-  pty attach --no-resize <ref>            Attach without changing shared PTY geometry
   pty attach --force <ref>                Attach even from inside another pty session (nested)
   pty attach -r <ref>                     Attach, auto-restart if the session is exited
   pty attach --remote <peer> <ref>        Attach a session on a fabric peer (over fabric)
@@ -855,13 +853,11 @@ async function main(): Promise<void> {
     case "a": {
       let autoRestart = false;
       let force = false;
-      let geometryNeutral = false;
       let attachName: string | null = null;
       let attachRemotePeer: string | null = null;
       for (let ai = 1; ai < args.length; ai++) {
         const a = args[ai];
         if (a === "--auto-restart" || a === "-r") autoRestart = true;
-        else if (a === "--no-resize") geometryNeutral = true;
         else if (a === "--force") force = true;
         else if (a === "--remote" && ai + 1 < args.length) { attachRemotePeer = args[++ai]; }
         else if (!attachName) attachName = a;
@@ -871,7 +867,7 @@ async function main(): Promise<void> {
         }
       }
       if (!attachName) {
-        console.error("Usage: pty attach [-r|--auto-restart] [--no-resize] [--force] [--remote <peer>] <name>");
+        console.error("Usage: pty attach [-r|--auto-restart] [--force] [--remote <peer>] <name>");
         process.exit(1);
       }
       // Nesting guard runs BEFORE name validation / ref resolution. A nested
@@ -887,15 +883,11 @@ async function main(): Promise<void> {
           "  Pass --force to attach anyway (nested clients are usually a mistake).",
       });
       if (attachRemotePeer) {
-        if (geometryNeutral) {
-          console.error("pty attach: --no-resize is not yet supported with --remote");
-          process.exit(1);
-        }
         // The name is the session's id ON THE REMOTE — don't resolve locally.
         await cmdAttachRemote(attachRemotePeer, attachName);
       } else {
         const resolvedAttachName = await resolveRef(attachName);
-        await cmdAttach(resolvedAttachName, autoRestart, force, geometryNeutral);
+        await cmdAttach(resolvedAttachName, autoRestart, force);
       }
       break;
     }
@@ -1553,7 +1545,6 @@ async function cmdAttach(
   name: string,
   autoRestart = false,
   _force = false,
-  geometryNeutral = false,
 ): Promise<void> {
   // Nesting guard runs in the dispatcher (before name resolution) so the
   // user gets the nesting hint even for typo'd refs. cmdAttach itself is
@@ -1568,33 +1559,17 @@ async function cmdAttach(
   }
 
   if (session.status === "running") {
-    if (geometryNeutral) await requireGeometryNeutralAttach(name);
-    doAttach(name, geometryNeutral);
+    doAttach(name);
     return;
   }
 
   // Dead session — show last lines and offer to restart
-  await handleDeadSession(session, autoRestart, geometryNeutral);
-}
-
-async function requireGeometryNeutralAttach(name: string): Promise<void> {
-  let supported = false;
-  try {
-    const stats = await queryStats(name);
-    supported = stats.capabilities?.geometryNeutralAttach === true;
-  } catch {}
-  if (!supported) {
-    console.error(
-      `Session "${name}" does not support --no-resize. Upgrade its pty daemon or attach without the flag.`,
-    );
-    process.exit(1);
-  }
+  await handleDeadSession(session, autoRestart);
 }
 
 async function handleDeadSession(
   session: SessionInfo,
   autoRestart = false,
-  geometryNeutral = false,
 ): Promise<void> {
   const meta = session.metadata;
   if (!meta) {
@@ -1636,14 +1611,12 @@ async function handleDeadSession(
     scrubEnv: RESTART_SCRUBBED_ENV,
   });
   console.log(`Session "${session.name}" restarted.`);
-  if (geometryNeutral) await requireGeometryNeutralAttach(session.name);
-  doAttach(session.name, geometryNeutral);
+  doAttach(session.name);
 }
 
-function doAttach(name: string, geometryNeutral = false): void {
+function doAttach(name: string): void {
   attach({
     name,
-    geometryNeutral,
     onDetach: () => process.exit(0),
     onExit: (code) => process.exit(code),
   });

src/client.ts

@@ -314,9 +314,7 @@ export interface StatsResult {
     total: number;
     attached: number;
     readOnly: number;
-    geometryNeutral?: number;
   };
-  capabilities?: { geometryNeutralAttach?: boolean };
   modes: {
     sgrMouse: boolean;
     cursorHidden: boolean;
@@ -377,10 +375,6 @@ export function queryStats(name: string, timeoutMs = 2000): Promise<StatsResult>
 
 export interface AttachOptions {
   name: string;
-  /** Receive output and send input without participating in PTY geometry or
-   * attach-time redraw nudges. Callers must first verify the daemon advertises
-   * `capabilities.geometryNeutralAttach` in stats. */
-  geometryNeutral?: boolean;
   onExit?: (code: number) => void;
   onDetach?: () => void;
   /** Attach over this ALREADY-CONNECTED socket instead of dialing the local
@@ -497,7 +491,7 @@ export function attach(options: AttachOptions): void {
     stdin.on("data", stdinDataHandler);
     // Explicitly resume stdin — see the note on readline leaving flowing=false.
     stdin.resume();
-    if (stdout instanceof tty.WriteStream && !options.geometryNeutral) {
+    if (stdout instanceof tty.WriteStream) {
       resizeHandler = () => { try { socket.write(encodeResize(stdout.rows, stdout.columns)); } catch {} };
       stdout.on("resize", resizeHandler);
     }
@@ -507,7 +501,7 @@ export function attach(options: AttachOptions): void {
     enterRawMode();
     const rows = (stdout as tty.WriteStream).rows ?? 24;
     const cols = (stdout as tty.WriteStream).columns ?? 80;
-    try { socket.write(encodeAttach(rows, cols, options.geometryNeutral === true)); } catch {}
+    try { socket.write(encodeAttach(rows, cols)); } catch {}
     wireInput();
   }
 

src/completions.ts

@@ -84,7 +84,6 @@ const COMMANDS: readonly CommandSpec[] = [
     dynamic: "sessions",
     flags: [
       { name: "auto-restart", short: "r", desc: "Auto-restart if the session is exited" },
-      { name: "no-resize", desc: "Preserve shared PTY geometry" },
       { name: "force", desc: "Attach even from inside another pty" },
       { name: "remote", desc: "Attach a session on a fabric peer" },
     ],

src/protocol.ts

@@ -51,29 +51,13 @@ export function encodeData(data: string): Buffer {
   return encodePacket(MessageType.DATA, Buffer.from(data));
 }
 
-/** Optional ATTACH flag: this interactive client receives output and may send
- * input, but does not participate in PTY size negotiation or redraw nudges. */
-export const ATTACH_FLAG_GEOMETRY_NEUTRAL = 0x01;
-
-export function encodeAttach(
-  rows: number,
-  cols: number,
-  geometryNeutral = false,
-): Buffer {
-  // Keep the legacy frame byte-for-byte identical. The optional flag byte is
-  // appended only when needed; older servers already ignore bytes after the
-  // first four size bytes.
-  const payload = Buffer.alloc(geometryNeutral ? 5 : 4);
+export function encodeAttach(rows: number, cols: number): Buffer {
+  const payload = Buffer.alloc(4);
   payload.writeUInt16BE(rows, 0);
   payload.writeUInt16BE(cols, 2);
-  if (geometryNeutral) payload.writeUInt8(ATTACH_FLAG_GEOMETRY_NEUTRAL, 4);
   return encodePacket(MessageType.ATTACH, payload);
 }
 
-export function decodeAttachFlags(payload: Buffer): number {
-  return payload.length >= 5 ? payload.readUInt8(4) : 0;
-}
-
 export function encodeDetach(): Buffer {
   return encodePacket(MessageType.DETACH, Buffer.alloc(0));
 }

src/server.ts

@@ -16,8 +16,6 @@ import {
   encodeScreen,
   encodeStatusResponse,
   decodeSize,
-  decodeAttachFlags,
-  ATTACH_FLAG_GEOMETRY_NEUTRAL,
 } from "./protocol.ts";
 import {
   getSocketPath,
@@ -39,7 +37,6 @@ interface Client {
   cols: number;
   readonly: boolean;
   attachSeq: number;
-  geometryNeutral: boolean;
 }
 
 export interface ServerOptions {
@@ -586,7 +583,6 @@ export class PtyServer {
       cols: this.terminal.cols,
       readonly: false,
       attachSeq: 0,
-      geometryNeutral: false,
     };
     this.clients.set(socket, client);
 
@@ -606,8 +602,10 @@ export class PtyServer {
           case MessageType.ATTACH: {
             if (packet.payload.length < 4) break;
             const size = decodeSize(packet.payload);
-            client.geometryNeutral =
-              (decodeAttachFlags(packet.payload) & ATTACH_FLAG_GEOMETRY_NEUTRAL) !== 0;
+            // Read before negotiateSize(): a smaller client shrinks the session
+            // to its own size, which would then look like it had matched.
+            const sizeMatched =
+              size.rows === this.terminal.rows && size.cols === this.terminal.cols;
             client.rows = size.rows;
             client.cols = size.cols;
             client.attachSeq = ++this.attachCounter;
@@ -640,9 +638,12 @@ export class PtyServer {
                 // drew (e.g., background fills in ratatui). Nudge the child
                 // with a SIGWINCH so it does a fresh full redraw, whose DATA
                 // overwrites any serialize artifacts on the client.
-                // A geometry-neutral viewer accepts the serialized snapshot as
-                // is: nudging would perturb the shared child it came to observe.
-                if (!client.geometryNeutral) this.nudgeRedraw();
+                //
+                // Skipped when the client attached at the size the session
+                // already has: the child is drawn for that geometry, so the
+                // nudge buys nothing and wakes an otherwise idle process every
+                // time someone connects.
+                if (!sizeMatched) this.nudgeRedraw();
               }
             };
 
@@ -754,13 +755,9 @@ export class PtyServer {
 
     let attached = 0;
     let readOnly = 0;
-    let geometryNeutral = 0;
     for (const c of this.clients.values()) {
       if (c.readonly) readOnly++;
-      else if (c.attachSeq > 0) {
-        attached++;
-        if (c.geometryNeutral) geometryNeutral++;
-      }
+      else if (c.attachSeq > 0) attached++;
     }
 
     const createdAt = meta?.createdAt ?? null;
@@ -795,10 +792,6 @@ export class PtyServer {
         total: attached + readOnly,
         attached,
         readOnly,
-        geometryNeutral,
-      },
-      capabilities: {
-        geometryNeutralAttach: true,
       },
       modes: {
         sgrMouse: this.sgrMouseMode,
@@ -818,7 +811,7 @@ export class PtyServer {
     let cols = 0;
 
     for (const client of this.clients.values()) {
-      if (!client.readonly && client.attachSeq > 0 && !client.geometryNeutral) {
+      if (!client.readonly && client.attachSeq > 0) {
         rows = rows === 0 ? client.rows : Math.min(rows, client.rows);
         cols = cols === 0 ? client.cols : Math.min(cols, client.cols);
       }