diff --git a/docs/prd/mosaic-stack.md b/docs/prd/mosaic-stack.md
index 717c66fce..a6db9b4a1 100644
--- a/docs/prd/mosaic-stack.md
+++ b/docs/prd/mosaic-stack.md
@@ -1,6 +1,6 @@
 # PRD: Mosaic Stack
 
-- Status: approved, version 1.15. Jason approved draft 0.4 unchanged as
+- Status: approved, version 1.16. Jason approved draft 0.4 unchanged as
   1.0 on 2026-10-05 (lead decision 61). They approved version 1.1, the
   Organization requirements, in decision 03130d08-ddce-480d-a601-e59f64744fc3
   on 2026-10-14. They approved version 1.2, the chief of staff, the
@@ -44,7 +44,17 @@
   as 1.11 (mos-1233, mos-1238, mos-1241, vikunja:19/464). Version 1.15
   rewrites REQ-LIB-6 to Jason's Q223 and Q226 rulings and adds supporting
   folders to REQ-LIB-1 and REQ-LIB-2. Mos ordered it in mos-1320 item 8,
-  and Jason gets a report.
+  and Jason gets a report. Version 1.16 routes the new action
+  `library.write` under REQ-LIB-6 (REQ-WAIT-3). A change to the hard waits
+  needs Jason's approval under REQ-WAIT-2, so Mos puts the text to him as
+  written, and it lands only after his yes (mos-1328, mos-1329).
+- Version 1.16 source: Webby's review webby-0164 B2, from Scrooge's row
+  285. Version 1.15 lets creative agents write in supporting folders, but
+  the write action stayed a hard wait under REQ-WAIT-3, and REQ-WAIT-2
+  refuses every role file that grants one. Mos ruled in mos-1328 and
+  mos-1329 that the routing is its own version. The bounds come from
+  REQ-LIB-6 and the Case 2 design's ruling after r11, f6e3e7f20 on
+  `gosalyn/case2-design`.
 - Version 1.15 source: Jason's Q223, answering Q29: "The agents are not
   allowed to write the prose into the writing projects. Agents are
   allowed to CRUD character sheets, info summaries, cross-link info, and
@@ -706,6 +716,14 @@ Added in version 1.5 (Q167).
   `host.sudo` was added as a hard wait and routes under REQ-CRED-4 since
   version 1.8.
 
+  `library.write` was added as a hard wait and routes under REQ-LIB-6
+  since version 1.16. It is granted within-role to the six creative roles
+  only, and only for Markdown files under the supporting folders a human
+  marks. It never writes a story file. A write also needs the writing
+  agent's own live Gitea grant on the library project. Each write is one
+  commit by that agent's own Gitea account with a trailer naming the
+  agent, and the user sees a notice for it and can revert it.
+
 ### Messages
 
 - **REQ-MSG-1.** Messages are addressed to a role. They are append-only
@@ -1259,8 +1277,10 @@ library is the user's own writing repository.
   write is one commit by that agent's own Gitea account, with a trailer
   naming the agent. The user sees a notice for it and can revert it. Its
   tools are the lookups, a message to the human and the two write tools,
-  and research and companion also fetch web pages through the broker.
-  Agents talk with the user in free text. A reply may cite lines of the
+  and research and companion also fetch web pages through the broker. The
+  write tools need the action `library.write`, which routes under this
+  requirement within the bounds REQ-WAIT-3 names (version 1.16). Agents
+  talk with the user in free text. A reply may cite lines of the
   repository at a commit or pages the agent fetched, and the broker
   checks every citation before it stores the message. A setting,
   `requireCitation`, makes every reply carry a citation, except the
@@ -1750,6 +1770,15 @@ latest-by date and a hard target (Q176).
     ruling after r11 and in the Q226 briefs of
     `docs/plans/2026-10-20_case2-rows.md`. Sage files the rows under
     Vikunja 416. This amendment adds the requirements only.
+- Version 1.16:
+  - REQ-WAIT-3 gains one paragraph, the `library.write` routing and its
+    bounds. REQ-LIB-6 gains one sentence naming the action. No other
+    requirement text changes.
+  - `packages/tasks/requirements.json` changes its version to 1.16 and
+    nothing else. The titles stay and the id count stays 85.
+  - The commit that adds `library.write` to `ROUTED` in the business
+    vocabulary and the broker is C2-08b, row 285. It lands only after this
+    version.
 
 ## Risks and open questions
 
diff --git a/packages/tasks/requirements.json b/packages/tasks/requirements.json
index a079888e0..15b01311e 100644
--- a/packages/tasks/requirements.json
+++ b/packages/tasks/requirements.json
@@ -1,6 +1,6 @@
 {
   "prd": "docs/prd/mosaic-stack.md",
-  "version": "1.15",
+  "version": "1.16",
   "requirements": [
     { "id": "REQ-ROLE-1", "title": "Each role is a reviewed roles/<name>.json: contract, authority map, credentials" },
     { "id": "REQ-ROLE-2", "title": "One holder per role instance, one per assistant session; the chief of staff may end a run, others need a decision" },
diff --git a/packages/tasks/tests/requirements.test.mjs b/packages/tasks/tests/requirements.test.mjs
index 759b011fc..0629e9cd5 100644
--- a/packages/tasks/tests/requirements.test.mjs
+++ b/packages/tasks/tests/requirements.test.mjs
@@ -21,7 +21,7 @@ test("the list holds the PRD's requirement ids, in its order, at its version", (
   assert.equal(ids.length, 85);
   assert.deepEqual(list.requirements.map((r) => r.id), ids);
   assert.match(prd, new RegExp(`^- Status: approved, version ${list.version.replace('.', '\\.')}\\.`, 'm'));
-  assert.deepEqual([list.prd, list.version], ['docs/prd/mosaic-stack.md', '1.15']);
+  assert.deepEqual([list.prd, list.version], ['docs/prd/mosaic-stack.md', '1.16']);
 });
 
 test('the committed list loads frozen', () => {