@@ -0,0 +1,10 @@
+---
+'@objectstack/plugin-hono-server': patch
+---
+
+fix(plugin-hono-server): a graceful `close()` now finishes when the last in-flight request ends, not a keep-alive window later
+
+Clause-②: no
+Metadata-protocol: none
+
+`HonoHttpServer.close()` released idle keep-alive sockets only once, at the start of the drain. A connection whose request was still running at that moment became an idle keep-alive socket after its response ended, and `close()` then waited for the client to drop it: about 3 s with `fetch` and 4 s with the `node:http` / `node:https` agent, or the server's own keep-alive timeout. During a drain, a response that has not written its headers yet now goes out with `Connection: close`, and a response that had already sent keep-alive headers closes its own connection once every byte of it has been flushed. Other connections are not touched when one response ends. The drain window still force-closes whatever outlasts it.
@@ -338,6 +338,22 @@ describe('#24295 / #24342: no file that spawns the CLI draws a released port', (
     }
   });
 
+  /**
+   * An explicit budget, sized to the measured work. The case reads and parses
+   * every `.ts` file under `test/` (`liveTree()`). Reaching the whole live
+   * tree is what the case claims, so the walk is not cut. The case is
+   * synchronous, so vitest judges it after the body returns.
+   *
+   * Readings: the slowest `Test Core` reading is 2629 ms (`main` push and merge
+   * group runs, 2026-11-03..06, n=6); local idle, 1102-1291 ms.
+   *
+   * The rule is 3x the slowest reading, rounded up to the next second (the rule
+   * and why 3x: plugin-sharing's `share-link-password-webcontainer.test.ts`):
+   * 3 x 2629 = 7887, so the budget is 8000. If `test/` grows much, re-measure
+   * and re-size.
+   */
+  const LIVE_TREE_BUDGET_MS = 8_000;
+
   it('the census reaches the live tree: every way of spawning the CLI, and the draw, are found', () => {
     const tree = liveTree();
     const population = cliSpawners(tree);
@@ -359,7 +375,7 @@ describe('#24295 / #24342: no file that spawns the CLI draws a released port', (
     const instrument = tree.get('serve-port-bind-probe.test.ts');
     expect(instrument?.drawLines.length ?? 0, 'the draw census finds no draw in the bind-probe instrument').toBeGreaterThan(0);
     expect(instrument?.spawnsCli).toBe(false);
-  });
+  }, LIVE_TREE_BUDGET_MS);
 
   it('every file that spawns the CLI draws exactly what its ledger entry allows — zero without one', () => {
     const offenders: string[] = [];
 
@@ -214,8 +214,10 @@ const arrangeServer = async () => {
 };
 
 /**
- * [#23181] The file's ONE server, built by the first case that signs in and
- * shared by every later one. Each case still signs a user of its own up on it,
+ * [#23181] The file's ONE server, shared by every case. It is built at module
+ * scope right after the warm-up (below), so no case's clock carries its
+ * engine, schema sync and better-auth instance: before, the first case to
+ * sign in built it inside its own window. Each case still signs a user of its own up on it,
  * through a client of its own, and every assertion here is about that user's
  * credential: a rotation revokes only the rotating user's sessions, and a
  * case reads its own user by address. So no case reads another case's writes,
@@ -357,6 +359,10 @@ const closeEngines = async (): Promise<void> => {
 // and `④` below pins that.
 await signedIn();
 await closeEngines();
+// The cases' shared server, built here for the same reason: it is
+// arrangement, not behaviour, and the first case used to pay it. Its
+// better-auth instance is built on first use, so that is asked for here too.
+await (await fileServer()).manager.getAuthInstance();
 
 beforeEach(() => {
   vi.spyOn(console, 'warn').mockImplementation(() => {});
 
@@ -512,12 +512,32 @@ describe('[#12792] ③ no detach-then-call shape survives in sql-driver.ts', ()
     expect(SCANNED.length).toBeGreaterThan(1);
   });
 
+  /**
+   * An explicit budget, sized to the measured work. The case parses every
+   * module in SCANNED with the TypeScript compiler and walks each tree twice
+   * (37 files, about 1.5 MB of source, at this commit). That work is the claim,
+   * so it is not cut. The case is synchronous, so vitest judges it after the
+   * body returns.
+   *
+   * Readings: the slowest `Test Core` reading is 2499 ms (`main` push and merge
+   * group runs, 2026-11-03..06, n=2); local idle, 442 and 469 ms.
+   *
+   * The rule (plugin-sharing's `share-link-password-webcontainer.test.ts`):
+   * a case whose slowest reading is over half the default gets 3x that
+   * reading, rounded up to the next second. 2499 ms is 1 ms under that line,
+   * and it takes the budget anyway: the default leaves it 2.0x, barely above
+   * the 1.88x spread between two CI runs that the rule's 3x was sized on, from
+   * only two readings. 3 x 2499 = 7497, so the budget is 8000. If the split
+   * adds modules, re-measure and re-size.
+   */
+  const SCAN_BUDGET_MS = 8_000;
+
   it('sql-driver.ts and the modules split out of it contain none of them', () => {
     const found = SCANNED.flatMap((name) =>
       scan(readFileSync(new URL(`./${name}`, import.meta.url), 'utf8'), name).map(
         (f) => `${name} ${f.shape} @${f.line}: ${f.text.trim()}`,
       ),
     );
     expect(found, 'every log call must go through a property access so the receiver stays bound').toEqual([]);
-  });
+  }, SCAN_BUDGET_MS);
 });
@@ -226,13 +226,17 @@ describe('[#9190] derived reference sites — derivation is a pure function of t
         // The module-load singleton must not be doing anything a caller cannot
         // reproduce; a derived registry that depends on WHEN it ran is a
         // curated one wearing a function.
+        //
+        // The two derivations are the module-load singleton and one call made
+        // now, at a different time and in a different state of the process.
+        // A third call would only repeat the second at the cost of another
+        // full schema walk, so the case derives once.
         const a = deriveReferenceSites();
-        const b = deriveReferenceSites();
+        expect(a).not.toBe(REFERENCE_SITES); // a second derivation, not the singleton handed back
         const flatten = (index: ReturnType<typeof deriveReferenceSites>) =>
             [...index.byTarget.entries()]
                 .map(([target, sites]) => `${target}=${sites.map((s) => `${s.fromType}.${s.property}`).join(',')}`)
                 .sort();
-        expect(flatten(a)).toEqual(flatten(b));
         expect(flatten(a)).toEqual(flatten(REFERENCE_SITES));
         expect([...a.compositeKeyByTarget]).toEqual([...REFERENCE_SITES.compositeKeyByTarget]);
     });
 
@@ -1,10 +1,55 @@
 // Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
 
+import { connect, type Socket } from 'node:net';
+import type { ServerResponse } from 'node:http';
 import { describe, it, expect } from 'vitest';
 import { HonoHttpServer } from './adapter';
 
 const sleep = (ms: number) => new Promise((r) => setTimeout(r, ms));
 
+/**
+ * A raw HTTP/1.1 connection: what it writes is exactly what the server parses,
+ * so a test can split one request's headers across a `close()`, pipeline
+ * several requests in one write, or stop reading a response part-way.
+ */
+async function rawConnection(port: number) {
+  const socket: Socket = connect(port, '127.0.0.1');
+  await new Promise<void>((resolve, reject) => {
+    socket.once('connect', resolve);
+    socket.once('error', reject);
+  });
+  const chunks: Buffer[] = [];
+  socket.on('data', (chunk: Buffer) => chunks.push(chunk));
+  socket.on('error', () => { /* a destroyed connection is part of some cases */ });
+  const ended = new Promise<void>((resolve) => socket.once('close', () => resolve()));
+  return {
+    socket,
+    ended,
+    received: () => Buffer.concat(chunks),
+  };
+}
+
+/** The head of the first response in `bytes`, its header map, and the body bytes after it. */
+function splitResponse(bytes: Buffer) {
+  const at = bytes.indexOf('\r\n\r\n');
+  if (at < 0) return { head: '', headers: {} as Record<string, string>, body: Buffer.alloc(0) };
+  const head = bytes.subarray(0, at).toString('latin1');
+  const headers: Record<string, string> = {};
+  for (const line of head.split('\r\n').slice(1)) {
+    const colon = line.indexOf(':');
+    headers[line.slice(0, colon).trim().toLowerCase()] = line.slice(colon + 1).trim();
+  }
+  return { head, headers, body: bytes.subarray(at + 4) };
+}
+
+/** Every response the adapter is still holding for its drain bookkeeping. */
+function retainedResponses(server: HonoHttpServer): number {
+  const tracked = (server as unknown as { inFlightResponses: Map<unknown, Set<unknown>> }).inFlightResponses;
+  let n = 0;
+  for (const pending of tracked.values()) n += pending.size;
+  return n;
+}
+
 /**
  * P1-3 regression: `close()` must DRAIN in-flight requests (let them finish)
  * rather than force-killing them, and must force-close only after the drain
@@ -27,9 +72,144 @@ describe('HonoHttpServer — graceful close drains in-flight requests (P1-3)', (
     const res = await reqP;
     expect(res.status).toBe(200);
     expect(await res.text()).toBe('drained-ok'); // completed, not reset
+    // Written after the drain began, so it closes its connection rather than
+    // leaving an idle keep-alive socket for `close()` to wait out.
+    expect(res.headers.get('connection')).toBe('close');
+    await closeP;
+  });
+
+  it('a response whose keep-alive headers went out before close() releases its connection when it ends', async () => {
+    // The arm `Connection: close` cannot reach: the headers are already on the
+    // wire. Before the fix `close()` resolved only when the client dropped the
+    // idle socket — about 3 s later for `fetch`, its keep-alive margin under
+    // the server's `timeout=5` hint.
+    const server = new HonoHttpServer(0, undefined, 5000);
+    server.getRawApp().get('/stream', (c) => c.body(new ReadableStream({
+      async start(controller) {
+        controller.enqueue(new TextEncoder().encode('head-'));
+        await sleep(200); // still streaming when close() is called
+        controller.enqueue(new TextEncoder().encode('tail'));
+        controller.close();
+      },
+    })));
+    await server.listen(0);
+    const port = server.getPort();
+
+    const res = await fetch(`http://127.0.0.1:${port}/stream`);
+    expect(res.headers.get('connection')).toBe('keep-alive'); // sent before the drain
+    const closeP = server.close();
+
+    expect(await res.text()).toBe('head-tail'); // completed, not reset
+    const bodyEnded = Date.now();
+    await closeP;
+    // 1000 ms is a third of the defect's 3 s wait and far above the few
+    // milliseconds the release takes, so neither load nor a slow box decides it.
+    expect(Date.now() - bodyEnded).toBeLessThan(1000);
+  });
+
+  it('a request whose headers finish arriving after close() began is answered Connection: close', async () => {
+    // A connection mid-headers when the drain starts is active, so
+    // `closeIdleConnections()` leaves it alone, and its response is created
+    // only after `close()` has run its loop over the in-flight ones. The
+    // request-time branch is what keeps that response from going out
+    // keep-alive.
+    const server = new HonoHttpServer(0, undefined, 5000);
+    server.getRawApp().get('/probe', (c) => c.text('late-arrival'));
+    await server.listen(0);
+    const conn = await rawConnection(server.getPort());
+
+    conn.socket.write('GET /probe HTTP/1.1\r\nHost: 127.0.0.1\r\n');
+    await sleep(50); // the first half has been read: the connection is active
+    const closeP = server.close();
+    await sleep(20);
+    conn.socket.write('Accept: */*\r\n\r\n');
+
+    await conn.ended; // the server ended the connection after the response
+    const { head, headers, body } = splitResponse(conn.received());
+    expect(head).toMatch(/^HTTP\/1\.1 200/);
+    expect(body.toString('utf8')).toBe('late-arrival');
+    expect(headers.connection).toBe('close');
     await closeP;
   });
 
+  it('a stream ending during the drain does not cut short another connection\'s response that is still flushing', async () => {
+    // Connection B's response calls `end()` during the drain with a body larger
+    // than the socket buffers, to a client that is not reading, so it is ended
+    // but still flushing. Connection A's stream, whose keep-alive headers went
+    // out before `close()`, then ends. Releasing A's connection must not touch
+    // B's: Node counts a response as done once it has called `end()`, before
+    // its bytes are flushed, so a server-wide `closeIdleConnections()` at that
+    // moment destroys B mid-body.
+    const BIG = new Uint8Array(32 * 1024 * 1024).fill(0x61);
+    let bigResponse: ServerResponse | undefined;
+    let releaseBig: () => void = () => {};
+    const bigReleased = new Promise<void>((resolve) => { releaseBig = resolve; });
+    const server = new HonoHttpServer(0, undefined, 10_000);
+    server.getRawApp().get('/big', async (c) => {
+      bigResponse = (c.env as { outgoing: ServerResponse }).outgoing;
+      await bigReleased; // in flight, not ended, when the drain starts
+      return c.body(BIG);
+    });
+    server.getRawApp().get('/stream', (c) => c.body(new ReadableStream({
+      async start(controller) {
+        controller.enqueue(new TextEncoder().encode('head-'));
+        await sleep(200);
+        controller.enqueue(new TextEncoder().encode('tail'));
+        controller.close();
+      },
+    })));
+    await server.listen(0);
+    const port = server.getPort();
+
+    const slowReader = await rawConnection(port);
+    slowReader.socket.pause(); // reads nothing until resumed below
+    slowReader.socket.write('GET /big HTTP/1.1\r\nHost: 127.0.0.1\r\n\r\n');
+    const stream = await fetch(`http://127.0.0.1:${port}/stream`);
+    expect(stream.headers.get('connection')).toBe('keep-alive'); // sent before the drain
+
+    const closeP = server.close();
+    releaseBig();
+    await sleep(50);
+    // The premise: B's response has called end() and is still flushing.
+    expect(bigResponse?.writableEnded, 'the big response has called end()').toBe(true);
+    expect(bigResponse?.writableFinished, 'the big response is still flushing').toBe(false);
+
+    expect(await stream.text()).toBe('head-tail'); // A ends during the drain
+    await sleep(50);
+    slowReader.socket.resume();
+    await slowReader.ended;
+    const { head, headers, body } = splitResponse(slowReader.received());
+    expect(head).toMatch(/^HTTP\/1\.1 200/);
+    expect(Number(headers['content-length'])).toBe(BIG.length);
+    expect(body.length, 'every byte of the body arrived').toBe(BIG.length);
+    await closeP;
+  });
+
+  it('forgets a pipelined response whose connection died before it was written', async () => {
+    // Pipelined requests queue behind the first one's response; the queued
+    // responses have no socket of their own, so if the connection dies they
+    // never emit 'close'. The drain bookkeeping must still let them go, or
+    // any client can grow the server's memory by pipelining and hanging up.
+    const server = new HonoHttpServer(0, undefined, 5000);
+    server.getRawApp().get('/slow', async (c) => {
+      await sleep(150);
+      return c.text('first');
+    });
+    server.getRawApp().get('/probe', (c) => c.text('queued'));
+    await server.listen(0);
+    const conn = await rawConnection(server.getPort());
+
+    const get = (path: string) => `GET ${path} HTTP/1.1\r\nHost: 127.0.0.1\r\n\r\n`;
+    conn.socket.write(get('/slow') + get('/probe') + get('/probe') + get('/probe'));
+    await sleep(60);
+    expect(retainedResponses(server), 'all four responses are tracked while their connection lives').toBe(4);
+
+    conn.socket.destroy();
+    await sleep(300); // past the first response's 150 ms, and the server has seen the connection close
+    expect(retainedResponses(server)).toBe(0);
+    await server.close();
+  });
+
   it('force-closes after the drain window so shutdown cannot hang', async () => {
     const server = new HonoHttpServer(0, undefined, 100); // tiny drain window
     server.getRawApp().get('/hang', async (c) => {