AGENTS.md

@@ -214,8 +214,8 @@ Each file answers one question, and a fact belongs to the file whose question it
 - **README.md — what you can rely on, and where this is heading.** Observable behaviour, for
   someone using the package, plus the goals and the audience. It carries a reason only where the
   reason changes how you would call the thing.
-- **CHANGELOG.md — what changed for a consumer, per release.** Written for whoever takes the package
+- **CHANGELOG.md — what changed for a consumer, per release.** Written for the public, never for the
-  off npm, never for the next agent, and a line lands there as the work ships rather than at release.
+  next agent, and a line lands there as the work ships rather than at release.
 - **MIGRATION.md — what a 0.4.0 consumer has to change.** Renamed and removed surface, and the
   behaviour that changed on the wire.
 - **AGENTS.md — what may not change, and why.** Hard rules, architecture, conventions, and an index

docs/decisions.md

@@ -534,8 +534,9 @@ rule and an index of the titles below.
   `secureConnect` for a TLS socket, so a peer that accepts and then says nothing is bounded the same
   way a black-holed SYN is. Rejected: `socket.setTimeout()`, an idle timeout that goes on arming
   once the link is up. Rejected: bounding it with `responseTimeout`, which names the wait for an
-  answer on a link that already exists and would retune both at once. Open while it has no default:
+  answer on a link that already exists and would retune both at once. `server()` shares the checker
-  whether a later major gives it one.
+  and ignores the option, as it already ignores `reconnect` — nothing at that end connects out. Open
+  while it has no default: whether a later major gives it one.
 
 - **A stream this library cannot frame is a dead link; one PDU it cannot parse is not.**
   Maintainer's call, 2026-08-31, narrowed 2026-09-05 via the interop plan: a `command_length` below

src/client.ts

@@ -94,8 +94,7 @@ function openSocket(options: ClientOptions): Promise<Result<{ sock: Socket }>> {
 		}
 
 		const settle = (result: Result<{ sock: Socket }>): void => {
-			if (timer) clearTimeout(timer);
+			clearTimeout(timer);
-
 			sock.removeListener('error', onError);
 			signal?.removeEventListener('abort', onAbort);
 			resolve(result);

src/session-options.ts

@@ -168,15 +168,23 @@ function limitsOf(options: CheckableOptions): [string, number, number][] {
 	];
 }
 
-/** Leaving it out is how the wait stays the OS's, so 0 would be a second spelling for that. */
+/** Node's timers are 32-bit, and a delay above this one fires after 1 ms instead of never. */
+const maxTimerDelay = 2_147_483_647;
+
 function checkConnectTimeout(connectTimeout: number | undefined): VoidResult {
 	if (connectTimeout === undefined) return {};
 
-	if (Number.isInteger(connectTimeout) && connectTimeout >= 1) return {};
-
 	const got = String(connectTimeout);
 
-	return { err: new Error(`connectTimeout must be 1 or more, got ${got}; omit it to wait the OS out`) };
+	if (!Number.isInteger(connectTimeout) || connectTimeout < 1) {
+		return { err: new Error(`connectTimeout must be a whole number of milliseconds, 1 or more, got ${got}; omit it to wait the OS out`) };
+	}
+
+	if (connectTimeout > maxTimerDelay) {
+		return { err: new Error(`connectTimeout must be ${String(maxTimerDelay)} or less, got ${got}`) };
+	}
+
+	return {};
 }
 
 function checkLimits(limits: [string, number, number][]): VoidResult {

test/session-extras.test.ts

@@ -1022,7 +1022,10 @@ describe('connectTimeout', () => {
 	/** Accepts and then says nothing, so a TLS handshake started on it never completes. */
 	async function stalledListener(t: TestContext): Promise<{ accepted: net.Socket[]; port: number }> {
 		const accepted: net.Socket[] = [];
-		const listener = net.createServer(sock => { accepted.push(sock); });
+		const listener = net.createServer(sock => {
+			accepted.push(sock);
+			sock.resume();
+		});
 
 		closeListenerAfter(t, listener, accepted);
 		await new Promise<void>(resolve => { listener.listen(0, '127.0.0.1', resolve); });
@@ -1034,7 +1037,6 @@ describe('connectTimeout', () => {
 
 	test('gives up on a connect the peer never completes', async t => {
 		const { port } = await stalledListener(t);
-		const started = Date.now();
 		const settled = await within(2000, client({
 			connectTimeout: 150,
 			host: '127.0.0.1',
@@ -1047,7 +1049,6 @@ describe('connectTimeout', () => {
 		assert.ok(settled.err instanceof Error);
 		assert.match(settled.err.message, /Timed out connecting/);
 		assert.equal(settled.session, undefined);
-		assert.ok(Date.now() - started >= 150, 'the timeout is what settles it, not a socket error');
 	});
 
 	test('retries a connect it timed out on, like any other failed attempt', async t => {
@@ -1070,10 +1071,10 @@ describe('connectTimeout', () => {
 
 	test('disarms on the connect that completed, rather than on the socket that follows it', async t => {
 		const smpp = await startServer(t);
-		const { session } = await connect(t, smpp, { connectTimeout: 50 });
+		const { session } = await connect(t, smpp, { connectTimeout: 200 });
 
 		assert.ok(session);
-		await delay(150);
+		await delay(300);
 
 		const probe = await session.send({ cmdName: 'enquire_link' });
 
@@ -1088,12 +1089,19 @@ describe('connectTimeout', () => {
 			'off is spelled by leaving it out, so 0 may not stand in for it',
 		);
 		assert.match(checkSessionOptions({ connectTimeout: -1 }).err?.message ?? '', /connectTimeout/);
-		assert.match(checkSessionOptions({ connectTimeout: 1.5 }).err?.message ?? '', /connectTimeout/);
+		assert.match(checkSessionOptions({ connectTimeout: 1.5 }).err?.message ?? '', /whole number/);
+		assert.match(
+			checkSessionOptions({ connectTimeout: 2_147_483_648 }).err?.message ?? '',
+			/2147483647 or less/,
+			'a delay Node cannot hold in 32 bits fires after 1 ms, the inverse of what it asked for',
+		);
+		assert.equal(checkSessionOptions({ connectTimeout: 2_147_483_647 }).err, undefined);
 		assert.equal(checkSessionOptions({ connectTimeout: 1000 }).err, undefined);
 
 		const refused = await client({ connectTimeout: 0, port: 1 });
 
 		assert.ok(refused.err instanceof Error);
+		assert.match(refused.err.message, /omit it/, 'the socket may not be opened before the option is refused');
 		assert.equal(refused.session, undefined);
 	});
 });

todo.md

@@ -185,6 +185,12 @@ the rewrite, for a dependency added later. Maintainer's call, 2026-09-14.
       unit until 1.0.0. Needs a number an operator would recognise, where SwiftHero's fork picked
       10 s.
 
+- [ ] **Refuse a delay Node's timers cannot hold, in `checkLimits`.** `idleTimeout`,
+      `reassemblyTimeout`, `responseTimeout` and `shutdownTimeout` take any integer, and `setTimeout`
+      fires after 1 ms for anything above 2147483647 — so a value in the wrong unit gets the inverse
+      of what it asked for, explained only by a warning on stderr. `connectTimeout` refuses one
+      already, which is the asymmetry to close. Raised by review, 2026-09-20.
+
 - [ ] **A send the codec will refuse waits for a link and a window slot first.** `refuse()` in
       `outgoing-requests.ts` runs `misuse()` and the abort check before the wait, precisely so a call
       that can never go out does not queue for what it will never use; a body `objToPdu()` refuses on