@@ -0,0 +1,30 @@
+---
+'@objectstack/hono': minor
+---
+
+fix(hono)!: `createHonoApp` reads a dispatched body by `@objectstack/plugin-hono-server`'s rule, so a JSON body sent as `text/plain`, or any other body that declares neither JSON nor a form, is refused `400 INVALID_REQUEST` when the dispatched domain reads it, instead of being parsed or dispatched as `{}`
+
+Clause-②: no (narrowing)
+
+<!-- adr-0087: not-required (no-migration-prescription) No metadata moves: no spec key, authorable spelling, object definition or stored shape is added, removed, renamed or re-shaped, no stored row is rewritten or deleted, and no exported declaration is added, removed or narrowed, so there is nothing for `objectstack migrate meta` to rewrite. What narrows is the accept set of the `createHonoApp` catch-all and its `/auth/*` fallback for bodies that declare neither JSON nor a form, which used to be parsed as JSON whatever they declared or dispatched as `{}`, and are now refused when a domain reads them. The remedy is in the requests a client sends, never a rewrite of a package source or a stored row. The other categories are closed on facts: the package publishes (not unpublished); no ADR-0087 id is named or touched (not registered or already-registered); and nothing exported is removed or narrowed (not runtime-interface-only, type-surface-only or runtime-export-retired). -->
+
+**BREAKING** (an accept-set narrowing), shipped as `minor` under the launch-window convention for breaking changes.
+
+The `${prefix}/*` catch-all and the `/auth/*` legacy fallback parsed every body as JSON whatever its `Content-Type`, and handed `dispatch()` `{}` for any body that did not parse. So the two Hono doors answered one request two ways: `@objectstack/plugin-hono-server` (`objectstack dev`, `os serve`) refused a valid query body sent as `text/plain`, and this door honoured it; a garbled body that did not declare JSON reached the data domain here as `{}`, the empty query, and read every row the caller could read.
+
+What changes for an integrator, on a host that serves `createHonoApp`, for a `POST`, `PUT` or `PATCH` body read by a domain that reads the parsed body (the data, metadata and every other domain that takes `body`), and on the `/auth/*` legacy fallback for every method it hands a body (all but `GET` and `HEAD`):
+
+- A JSON body sent as `text/plain`, or as any media type other than JSON or a form: FROM parsed and honoured, TO `400` with `{ "success": false, "error": { "code": "INVALID_REQUEST", "message": "The request body was sent as text/plain, which this server does not read into a request body. It was refused rather than read as an empty body: send it as application/json." } }`, the message naming the media type that was sent.
+- Any other body that declares neither JSON nor a form (`text/plain`, `application/octet-stream`, a `+json` suffix type such as `application/merge-patch+json`, or no `Content-Type` at all), when the request declares a body (`Content-Length` other than `0`, or `Transfer-Encoding`): FROM `{}`, TO the same refusal ("sent with no Content-Type" when there is none).
+- A `multipart/form-data` or `application/x-www-form-urlencoded` body: FROM `{}`, TO its parsed fields, as `plugin-hono-server` hands them (Hono's `parseBody`: the last value of a repeated name). A form that does not parse: TO the refusal "The request body could not be parsed as form data (it was sent as multipart/form-data). It was refused rather than read as an empty body."
+
+The domain acts on nothing past its read of the body, and the dispatcher's own gates still answer first. Each answer is the status and body `@objectstack/plugin-hono-server` gives the same request. This replaces the earlier `createHonoApp` entry's statement that a body that does not declare JSON is read as before.
+
+**Remedy, in one line.** Send a JSON body with `Content-Type: application/json`, or send no body.
+
+**Unchanged.**
+
+- A body sent as `application/json` (matched case-insensitively) is parsed when well-formed, `{}` when blank or whitespace-only, and refused when it does not parse, as before.
+- A request that declares no body is dispatched as `{}`, whatever its media type.
+- The request handed on beside the body still arrives unread, in every case. A domain that forwards it and reads its own bytes answers exactly as before, whatever the body declares: `/webhooks/redeliver` and the inbound automation hooks give their own refusal after their own sign-in or signature check, and the `/approvals/act` form `POST` reads its form.
+- The catch-all dispatches `GET`, `HEAD` and `DELETE` with no body, and the `/auth/*` fallback hands `GET` and `HEAD` `{}`, as before.
@@ -1,14 +1,18 @@
 // Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
 
 /**
- * [#23914] `createHonoApp` refuses a declared JSON body that does not parse
- * with `400 INVALID_REQUEST` when a dispatched domain READS the body, and only
- * then — the rule `@objectstack/plugin-hono-server` applies to `req.body` — and
- * answers it with the same status and body as that package.
+ * [#23914, #24042] `createHonoApp` reads a dispatched body by
+ * `@objectstack/plugin-hono-server`'s rule, media type by media type, and
+ * refuses what it cannot read with `400 INVALID_REQUEST` when a dispatched
+ * domain READS the body, and only then — the rule `plugin-hono-server` applies
+ * to `req.body` — answering it with the same status and body as that package.
  *
- * The catch-all used to hand `dispatch()` `{}` for such a body, which the data
- * domain read as an empty query (every row) or an empty update (a `200` for a
- * write that changed nothing).
+ * The catch-all used to hand `dispatch()` `{}` for a declared JSON body that
+ * did not parse (#23914), and, until #24042, it parsed every other body as
+ * JSON whatever it declared: a JSON body sent as `text/plain` was honoured,
+ * and any other body that did not declare JSON, a form included, was `{}`.
+ * The data domain read `{}` as an empty query (every row) or an empty update
+ * (a `200` for a write that changed nothing).
  *
  * The dispatcher is a fixture (this package's config aliases
  * `@objectstack/runtime` to a stub), standing in for the two kinds of domain:
@@ -22,6 +26,11 @@
  * `@objectstack/plugin-hono-server` resolves to its source here
  * (`vitest.config.ts`), so the parity case drives that package's real request
  * path, not a copy of it.
+ *
+ * In-process `Request`s carry no `Content-Length` of their own, and both doors
+ * judge whether a body is present by its framing headers (RFC 9112 §6.3), so
+ * a case that stands for a client's body sends `Content-Length` the way a
+ * client does.
  */
 
 import { describe, it, expect, vi, beforeEach } from 'vitest';
@@ -74,29 +83,53 @@ vi.mock('@objectstack/runtime', () => ({
 import { createHonoApp } from './index';
 
 const PREFIX = '/api/v1';
+const QUERY = '/data/showcase_account/query';
 const kernel = { name: 'test-kernel' } as any;
 
-const send = (path: string, method: string, contentType: string | undefined, body: string) =>
-  createHonoApp({ kernel, prefix: PREFIX, cors: false }).request(`http://hosted.test${PREFIX}${path}`, {
-    method,
-    headers: contentType ? { 'Content-Type': contentType } : {},
-    body,
-  });
+/**
+ * How a case frames its body. `length` sends `Content-Length` as a client
+ * does; `chunked` sends `Transfer-Encoding` instead. `bytes` sends the body as
+ * a `Uint8Array`: undici stamps `text/plain;charset=UTF-8` on any STRING body
+ * that declares no type, so a request with no `Content-Type` at all can only
+ * be built from bytes.
+ */
+interface Framing { length?: boolean; chunked?: boolean; bytes?: boolean }
+
+function requestInit(method: string, contentType: string | undefined, body: string | undefined, framing: Framing = {}): RequestInit {
+  const headers: Record<string, string> = {};
+  if (contentType) headers['content-type'] = contentType;
+  if (framing.length && body !== undefined) headers['content-length'] = String(Buffer.byteLength(body));
+  if (framing.chunked) headers['transfer-encoding'] = 'chunked';
+  const payload = framing.bytes && body !== undefined ? new TextEncoder().encode(body) : body;
+  return { method, headers, body: payload };
+}
+
+/** The hosted door: `createHonoApp`'s catch-all, in front of the fixture dispatcher. */
+const send = (path: string, method: string, contentType: string | undefined, body: string | undefined, framing?: Framing) =>
+  createHonoApp({ kernel, prefix: PREFIX, cors: false })
+    .request(`http://hosted.test${PREFIX}${path}`, requestInit(method, contentType, body, framing));
+
+/** The self-hosted door: a `plugin-hono-server` route that reads `req.body` and answers what it read. */
+function sendDirect(method: string, contentType: string | undefined, body: string | undefined, framing?: Framing) {
+  const server = new HonoHttpServer(0);
+  server.post(`${PREFIX}/data/:object/query`, (req, res) => { res.json({ success: true, data: req.body }); });
+  return server.getRawApp().fetch(new Request(`http://direct.test${PREFIX}${QUERY}`, requestInit(method, contentType, body, framing)));
+}
 
 /**
  * The declared refusal, read whole. Structural rather than `ApiErrorSchema`
  * (this package does not depend on `@objectstack/spec`): the parity case below
  * holds this body equal to `@objectstack/plugin-hono-server`'s, whose own suite
  * (`request-body-refusal.test.ts`) parses it against the declared envelope.
  */
-async function expectRefused(res: Response, body: string) {
+async function expectRefused(res: Response, body: string, names: RegExp = /parsed as JSON/) {
   const json = await res.json() as any;
   expect(res.status, JSON.stringify(json)).toBe(400);
   expect(json).toEqual({
     success: false,
-    error: { code: 'INVALID_REQUEST', message: expect.stringMatching(/parsed as JSON/) },
+    error: { code: 'INVALID_REQUEST', message: expect.stringMatching(names) },
   });
-  expect(json.error.message).not.toContain(body.trim());
+  if (body.trim() !== '') expect(json.error.message).not.toContain(body.trim());
   return json;
 }
 
@@ -108,8 +141,8 @@ beforeEach(() => {
 
 describe('[#23914] a domain that READS the body refuses the card\'s bodies, with this adapter\'s answer', () => {
   it.each([
-    ['step 2 — a truncated query', 'POST', '/data/showcase_account/query', '{"where": {"status": "churned"}'],
-    ['step 3 — `{ not json`', 'POST', '/data/showcase_account/query', '{ not json'],
+    ['step 2 — a truncated query', 'POST', QUERY, '{"where": {"status": "churned"}'],
+    ['step 3 — `{ not json`', 'POST', QUERY, '{ not json'],
     ['step 5 — a truncated PATCH', 'PATCH', '/data/showcase_account/rec_1', '{"name": "HACKED"'],
     ['step 6 — a truncated create', 'POST', '/data/showcase_account', '{"name": "Door Truncated Create"'],
     ['a truncated PUT', 'PUT', '/meta/object/account', '{"name": "account"'],
@@ -134,6 +167,38 @@ describe('[#23914] a domain that READS the body refuses the card\'s bodies, with
   });
 });
 
+describe('[#24042] a body that declares neither JSON nor a form is refused by the domain that reads it', () => {
+  it.each([
+    ['step 4 — a valid query body sent as text/plain', 'text/plain', '{"where": {"status": "churned"}}', /sent as text\/plain/],
+    ['text that does not declare JSON', 'text/plain', 'hello', /sent as text\/plain/],
+    ['bytes sent as application/octet-stream', 'application/octet-stream', 'raw bytes', /sent as application\/octet-stream/],
+  ])('%s: refused 400, though the domain answered its own 500', async (_label, contentType, body, names) => {
+    await expectRefused(await send(QUERY, 'POST', contentType, body, { length: true }), body, names);
+    expect(mockDispatcher.dispatch).toHaveBeenCalledTimes(1);
+    expect(seen).toEqual([]);
+  });
+
+  it('a body with no Content-Type at all is refused, not read as empty', async () => {
+    const body = '{"where": {"status": "churned"}}';
+    await expectRefused(await send(QUERY, 'POST', undefined, body, { length: true, bytes: true }), body, /with no Content-Type/);
+  });
+
+  it('the /auth/* legacy fallback refuses it the same way', async () => {
+    await expectRefused(
+      await send('/auth/sign-in/email', 'POST', 'text/plain', '{"email": "a@b.c"}', { length: true }),
+      '{"email": "a@b.c"}',
+      /sent as text\/plain/,
+    );
+    expect(mockDispatcher.handleAuth).toHaveBeenCalledTimes(1);
+  });
+
+  it('a form that does not parse is refused by its reader', async () => {
+    const body = '--nope\r\nnot a part';
+    await expectRefused(await send(QUERY, 'POST', 'multipart/form-data; boundary=elsewhere', body), body, /form data/);
+    expect(seen).toEqual([]);
+  });
+});
+
 describe('[#23914] a domain that FORWARDS the request answers it itself, exactly as before', () => {
   it('the forwarder reads every byte the client sent and answers its own refusal; this adapter adds nothing', async () => {
     const body = '{deliveryId:';
@@ -143,44 +208,87 @@ describe('[#23914] a domain that FORWARDS the request answers it itself, exactly
     expect(seen).toEqual([{ path: '/webhooks/redeliver', forwarded: body }]);
   });
 
+  it('[#24042] so does a body that does not declare JSON: the forwarder\'s own answer, every byte read', async () => {
+    const body = '{deliveryId:';
+    const res = await send('/webhooks/redeliver', 'POST', 'text/plain', body, { length: true });
+    expect(res.status).toBe(400);
+    expect(await res.json()).toEqual({ success: false, error: { code: 'INVALID_REQUEST', message: 'Request body must be JSON.' } });
+    expect(seen).toEqual([{ path: '/webhooks/redeliver', forwarded: body }]);
+  });
+
   it('a well-formed body reaches the forwarder untouched', async () => {
     const body = '{ "deliveryId" : "d_1" }';
     expect((await send('/webhooks/redeliver', 'POST', 'application/json', body)).status).toBe(200);
     expect(seen).toEqual([{ path: '/webhooks/redeliver', forwarded: body }]);
   });
 });
 
-describe('[#23914] CONTROL — what was readable is handed on as before', () => {
+describe('[#23914, #24042] CONTROL — what is readable is handed on', () => {
   it.each([
     ['a valid JSON body', 'application/json', '{"where": {"status": "churned"}}', { where: { status: 'churned' } }],
     ['an empty JSON body (an empty query)', 'application/json', '', {}],
     ['a whitespace-only JSON body', 'application/json', '  \n', {}],
-    ['a form body', 'application/x-www-form-urlencoded', 'token=abc', {}],
-    ['a JSON body sent as text/plain (the content-type-blind read, unchanged)', 'text/plain', '{"a":1}', { a: 1 }],
-    ['text that does not declare JSON (unchanged)', 'text/plain', 'hello', {}],
+    ['[#24042] a form body, parsed as plugin-hono-server parses it', 'application/x-www-form-urlencoded', 'token=abc', { token: 'abc' }],
+    ['[#24042] a request that declares no body, whatever its media type', 'text/plain', undefined, {}],
   ])('%s', async (_label, contentType, body, expected) => {
     const res = await send('/data/task/query', 'POST', contentType, body);
     expect(res.status).toBe(200);
     expect(seen).toEqual([{ path: '/data/task/query', read: expected }]);
   });
 });
 
-describe('[#23914] both Hono doors answer one unparseable body alike', () => {
-  it.each([
-    ['a truncated query', '{"where": {"status": "churned"}'],
-    ['`{ not json`', '{ not json'],
-  ])('%s: the same status and the same body', async (_label, body) => {
-    const hosted = await send('/data/showcase_account/query', 'POST', 'application/json', body);
-
-    const server = new HonoHttpServer(0);
-    server.post(`${PREFIX}/data/:object/query`, (req, res) => { res.json({ query: req.body }); });
-    const direct = await server.getRawApp().fetch(new Request(`http://direct.test${PREFIX}/data/showcase_account/query`, {
-      method: 'POST',
-      headers: { 'content-type': 'application/json' },
-      body,
-    }));
-
-    expect(direct.status).toBe(hosted.status);
-    expect(await direct.json()).toEqual(await expectRefused(hosted, body));
+/**
+ * [#24042] One table, both doors. Each row is sent to the hosted door (the
+ * catch-all, in front of the reading domain) and to the self-hosted door (a
+ * `plugin-hono-server` route that reads `req.body`), and the two answers must
+ * be equal: the same status, and the same body — for a refusal, the same
+ * `code` and the same `message`; for a body that is read, the same value.
+ *
+ * [label, Content-Type, body, framing, the expected status]
+ */
+const PARITY: Array<[string, string | undefined, string | undefined, Framing, number]> = [
+  // Declared JSON.
+  ['a valid JSON body', 'application/json', '{"where": {"status": "churned"}}', { length: true }, 200],
+  ['a truncated query (step 2)', 'application/json', '{"where": {"status": "churned"}', { length: true }, 400],
+  ['`{ not json` (step 3)', 'application/json', '{ not json', {}, 400],
+  ['declared JSON in another spelling', 'Application/JSON; charset=utf-8', '{ not json', { length: true }, 400],
+  ['a blank JSON body', 'application/json', '', { length: true }, 200],
+  ['a whitespace-only JSON body', 'application/json', '  \n', { length: true }, 200],
+  // A form.
+  ['a urlencoded form', 'application/x-www-form-urlencoded', 'token=abc&token=def&x=1', { length: true }, 200],
+  ['a malformed urlencoded form (read leniently by the parser on both doors)', 'application/x-www-form-urlencoded', 'a=%zz&b=%&=&&{"a":1}', { length: true }, 200],
+  ['a multipart form', 'multipart/form-data; boundary=b', '--b\r\nContent-Disposition: form-data; name="a"\r\n\r\n1\r\n--b--\r\n', { length: true }, 200],
+  ['a multipart form that does not parse', 'multipart/form-data; boundary=elsewhere', '--nope\r\nnot a part', { length: true }, 400],
+  // Any other media type, or none, with a body.
+  ['step 4 — `{"a":1}` sent as text/plain', 'text/plain', '{"a":1}', { length: true }, 400],
+  ['step 4 — the query body sent as text/plain;charset=UTF-8', 'text/plain;charset=UTF-8', '{"where": {"status": "churned"}}', { length: true }, 400],
+  ['plain text', 'text/plain', 'hello', { length: true }, 400],
+  ['a body with no Content-Type', undefined, '{"a":1}', { length: true, bytes: true }, 400],
+  ['application/octet-stream', 'application/octet-stream', 'raw bytes', { length: true }, 400],
+  ['a +json suffix type', 'application/merge-patch+json', '{"a":1}', { length: true }, 400],
+  ['a media type that is not a token pair (named as unrecognised)', 'text/plain extra', 'hello', { length: true }, 400],
+  ['a body framed by Transfer-Encoding', 'text/plain', '{"a":1}', { chunked: true }, 400],
+  // No body declared.
+  ['a text/plain request with no body', 'text/plain', undefined, {}, 200],
+  ['a text/plain body framed as zero-length', 'text/plain', '', { length: true }, 200],
+  ['an in-process text/plain body with no framing headers (read as no body on both doors)', 'text/plain', 'hello', {}, 200],
+];
+
+describe('[#23914, #24042] both Hono doors answer one body alike, media type by media type', () => {
+  it.each(PARITY)('%s: the same status and the same body', async (_label, contentType, body, framing, status) => {
+    const hosted = await send(QUERY, 'POST', contentType, body, framing);
+    const direct = await sendDirect('POST', contentType, body, framing);
+
+    const hostedJson = await hosted.json() as any;
+    const directJson = await direct.json() as any;
+    expect(hosted.status, JSON.stringify(hostedJson)).toBe(status);
+    expect(direct.status, JSON.stringify(directJson)).toBe(status);
+    expect(hostedJson).toEqual(directJson);
+    if (status === 400) {
+      expect(hostedJson).toEqual({ success: false, error: { code: 'INVALID_REQUEST', message: expect.any(String) } });
+      if (body && body.trim() !== '') expect(hostedJson.error.message).not.toContain(body.trim());
+    } else {
+      expect(hostedJson.success).toBe(true);
+    }
   });
 });