diff --git a/changelog.d/1759-project-assistant-owner.fixed.md b/changelog.d/1759-project-assistant-owner.fixed.md
new file mode 100644
index 000000000..d799bbfcb
--- /dev/null
+++ b/changelog.d/1759-project-assistant-owner.fixed.md
@@ -0,0 +1 @@
+The Project Assistant settings — the digest opt-out, the quiet window and the zone — can now be written by the Project's owner from the product: `project-assistant-owner` is dispatched by the host channel and authorization-checked like the other Project writes, so a non-owner gets `bot/forbidden` instead of `Unknown endpoint` ([#1759](https://github.com/ThinkFlowLab/FlyBot/issues/1759)).
diff --git a/core/src/host/authz.js b/core/src/host/authz.js
index 5884e93ad..c0458de89 100644
--- a/core/src/host/authz.js
+++ b/core/src/host/authz.js
@@ -69,8 +69,11 @@ const TASK_ENDPOINTS = new Set([
   // other wiring point was present, and a signed-in host answered `bot/not-found: Unknown
   // endpoint project-board` while `project-read` and `project-of` answered ALLOW.
   'projects', 'project-create', 'project-read', 'project-bind', 'project-of', 'project-board',
-  // The assistant (#1712): its memory is per Project, and deleting a Project takes it along.
-  'project-memory', 'project-memory-write', 'project-delete',
+  // The assistant (#1712): its memory is per Project, and deleting a Project takes it along. The
+  // owner controls (#1759) are a Project-wide write — the digest opt-out silences every member's
+  // 09:00 digest — so `project-assistant-owner` belongs here with them: dispatched but missing
+  // from this list would reach `store.js` with no owner check in front of it.
+  'project-memory', 'project-memory-write', 'project-delete', 'project-assistant-owner',
 ])
 
 const deny = (code, message) => ({ ok: false, code, message })
diff --git a/core/src/host/channel.js b/core/src/host/channel.js
index eee23cf1e..dd4a826e1 100644
--- a/core/src/host/channel.js
+++ b/core/src/host/channel.js
@@ -675,6 +675,7 @@ export function install(rt) {
         case 'project-delete':
         case 'project-memory':
         case 'project-memory-write':
+        case 'project-assistant-owner':
           await rt.load()
           return ok(await rt.projectEndpoint(endpoint, body, actor))
         case 'share-brief':
diff --git a/core/test/projects.test.js b/core/test/projects.test.js
index 2a78a8ccc..ba2ad0d18 100644
--- a/core/test/projects.test.js
+++ b/core/test/projects.test.js
@@ -290,3 +290,35 @@ test('a Project carries an optional working folder and refuses a relative one',
     }
   } finally { await stop() }
 })
+
+// #1759: `project-assistant-owner` had a store case and an owner gate (#1740) but no channel case
+// and no `TASK_ENDPOINTS` entry, so every call failed `bot/not-found` and the digest opt-out, the
+// quiet window and the zone were writable only in-process. There is no read endpoint: the second
+// write's answer echoes the record the first one stored, so it proves the write went through the
+// Project's own assistant rather than being accepted and dropped.
+test('the Project owner writes the assistant settings through the host channel (#1759)', async () => {
+  const { call, stop } = await start()
+  try {
+    const project = created(await call('project-create', { name: 'Assistant', repository: 'acme/assistant' }, 'tok-a'))
+    assert.equal(typeof project.assistant?.botId, 'string', `the Project got an assistant: ${JSON.stringify(project.assistant)}`)
+
+    // Before #1759 this answered `Unknown endpoint project-assistant-owner` / `bot/not-found` for
+    // both callers: the endpoint was not dispatched at all.
+    const refused = await call('project-assistant-owner', { id: project.id, settings: { off: true } }, 'tok-b')
+    assert.equal(refused.ok, false, JSON.stringify(refused))
+    assert.equal(refused.error.code, 'bot/forbidden', JSON.stringify(refused))
+
+    const written = value(await call('project-assistant-owner', {
+      id: project.id,
+      settings: { off: true, quiet: { on: true, from: '09:00', to: '11:00' }, zone: 'Asia/Shanghai' },
+    }, 'tok-a'))
+    assert.equal(written.owner, 'owner-1')
+    assert.equal(written.off, true)
+    assert.deepEqual(written.quiet, { on: true, from: '09:00', to: '11:00', zone: 'Asia/Shanghai' })
+    assert.equal(written.changed, true)
+
+    const reread = value(await call('project-assistant-owner', { id: project.id, settings: { off: false } }, 'tok-a'))
+    assert.equal(reread.off, false)
+    assert.deepEqual(reread.quiet, { on: true, from: '09:00', to: '11:00', zone: 'Asia/Shanghai' }, 'the window and the zone are still stored')
+  } finally { await stop() }
+})
diff --git a/docs/subsystems/core-host.md b/docs/subsystems/core-host.md
index 0245eae90..39dd9df8b 100644
--- a/docs/subsystems/core-host.md
+++ b/docs/subsystems/core-host.md
@@ -589,8 +589,11 @@ gate. The same check covers the record itself since #1740: `project-delete`, `pr
 non-owner gets `bot/forbidden` and the Project, its memory and the other owner's digest settings
 are unchanged afterwards — a refusal, never a silent no-op. `project-assistant-owner` also refuses
 a body whose `ownerId` is not the caller's own record, so even a Project's owner cannot rewrite
-another owner's quiet window or opt-out before that endpoint is wired; an omitted `ownerId` means
-the caller's own. The gate returns early on a missing id, so `project-memory` keeps the not-found
+another owner's quiet window or opt-out; an omitted `ownerId` means the caller's own. Since #1759
+`project-assistant-owner` is dispatched by `channel.js` alongside the other `project-*` endpoints
+and listed in `authz.js`'s `TASK_ENDPOINTS`, so the owner reaches the store case through the host
+channel instead of only in-process; the two landed together because a dispatch without the
+allow-list entry would reach `store.js` with the owner check bypassed. The gate returns early on a missing id, so `project-memory` keeps the not-found
 refusal it answered before rather than turning an unknown id into a 403. Tests:
 `core/test/project-owner-gate.test.js`.
 Reading the board (`project-board`) stays open to a non-owner: the same rows, read-only.
@@ -706,4 +709,6 @@ the host side only, so the tier stays T2 and `core/src/shared/` is untouched.
   delivered to each owner's own Session through `deliver()` with no connector signed in, and the
   refusal is recorded on that digest's note (`GitHub write refused: …`) instead of suppressing the
   message. `Written-by:`/`Posted-for:` appear only when an identity was resolved.
-- Endpoint `project-assistant-owner` (`{ id, ownerId, settings }`) exposes the controls.
+- Endpoint `project-assistant-owner` (`{ id, ownerId, settings }`) exposes the controls: dispatched
+  by `channel.js` and in `authz.js`'s `TASK_ENDPOINTS` since #1759, with `requireProjectOwner`
+  refusing a non-owner with `bot/forbidden` before any record is written.
diff --git a/patches/ds-bot/0005-social-seams.patch b/patches/ds-bot/0005-social-seams.patch
index aab3e019d..cf491f0ed 100644
--- a/patches/ds-bot/0005-social-seams.patch
+++ b/patches/ds-bot/0005-social-seams.patch
@@ -832,7 +832,7 @@ diff --git a/src/host/channel.js b/src/host/channel.js
            await rt.ensureCapabilities(sessionId)
            await ctx.sessionController.prompt({
              requestId: randomUUID(),
-@@ -319,32 +319,132 @@ export function install(rt) {
+@@ -319,32 +319,133 @@ export function install(rt) {
          case 'diagnostics-clear':
            await rt.diagnostics.clear()
            return ok(true)
@@ -865,6 +865,7 @@ diff --git a/src/host/channel.js b/src/host/channel.js
 +        case 'project-delete':
 +        case 'project-memory':
 +        case 'project-memory-write':
++        case 'project-assistant-owner':
 +          await rt.load()
 +          return ok(await rt.projectEndpoint(endpoint, body, actor))
 +        case 'share-brief':
diff --git a/patches/ds-bot/files/src/host/authz.js b/patches/ds-bot/files/src/host/authz.js
index 5884e93ad..c0458de89 100644
--- a/patches/ds-bot/files/src/host/authz.js
+++ b/patches/ds-bot/files/src/host/authz.js
@@ -69,8 +69,11 @@ const TASK_ENDPOINTS = new Set([
   // other wiring point was present, and a signed-in host answered `bot/not-found: Unknown
   // endpoint project-board` while `project-read` and `project-of` answered ALLOW.
   'projects', 'project-create', 'project-read', 'project-bind', 'project-of', 'project-board',
-  // The assistant (#1712): its memory is per Project, and deleting a Project takes it along.
-  'project-memory', 'project-memory-write', 'project-delete',
+  // The assistant (#1712): its memory is per Project, and deleting a Project takes it along. The
+  // owner controls (#1759) are a Project-wide write — the digest opt-out silences every member's
+  // 09:00 digest — so `project-assistant-owner` belongs here with them: dispatched but missing
+  // from this list would reach `store.js` with no owner check in front of it.
+  'project-memory', 'project-memory-write', 'project-delete', 'project-assistant-owner',
 ])
 
 const deny = (code, message) => ({ ok: false, code, message })
diff --git a/patches/ds-bot/files/test/projects.test.js b/patches/ds-bot/files/test/projects.test.js
index 2a78a8ccc..ba2ad0d18 100644
--- a/patches/ds-bot/files/test/projects.test.js
+++ b/patches/ds-bot/files/test/projects.test.js
@@ -290,3 +290,35 @@ test('a Project carries an optional working folder and refuses a relative one',
     }
   } finally { await stop() }
 })
+
+// #1759: `project-assistant-owner` had a store case and an owner gate (#1740) but no channel case
+// and no `TASK_ENDPOINTS` entry, so every call failed `bot/not-found` and the digest opt-out, the
+// quiet window and the zone were writable only in-process. There is no read endpoint: the second
+// write's answer echoes the record the first one stored, so it proves the write went through the
+// Project's own assistant rather than being accepted and dropped.
+test('the Project owner writes the assistant settings through the host channel (#1759)', async () => {
+  const { call, stop } = await start()
+  try {
+    const project = created(await call('project-create', { name: 'Assistant', repository: 'acme/assistant' }, 'tok-a'))
+    assert.equal(typeof project.assistant?.botId, 'string', `the Project got an assistant: ${JSON.stringify(project.assistant)}`)
+
+    // Before #1759 this answered `Unknown endpoint project-assistant-owner` / `bot/not-found` for
+    // both callers: the endpoint was not dispatched at all.
+    const refused = await call('project-assistant-owner', { id: project.id, settings: { off: true } }, 'tok-b')
+    assert.equal(refused.ok, false, JSON.stringify(refused))
+    assert.equal(refused.error.code, 'bot/forbidden', JSON.stringify(refused))
+
+    const written = value(await call('project-assistant-owner', {
+      id: project.id,
+      settings: { off: true, quiet: { on: true, from: '09:00', to: '11:00' }, zone: 'Asia/Shanghai' },
+    }, 'tok-a'))
+    assert.equal(written.owner, 'owner-1')
+    assert.equal(written.off, true)
+    assert.deepEqual(written.quiet, { on: true, from: '09:00', to: '11:00', zone: 'Asia/Shanghai' })
+    assert.equal(written.changed, true)
+
+    const reread = value(await call('project-assistant-owner', { id: project.id, settings: { off: false } }, 'tok-a'))
+    assert.equal(reread.off, false)
+    assert.deepEqual(reread.quiet, { on: true, from: '09:00', to: '11:00', zone: 'Asia/Shanghai' }, 'the window and the zone are still stored')
+  } finally { await stop() }
+})