diff --git a/extensions/processes-dock/components/log-dock-component.test.ts b/extensions/processes-dock/components/log-dock-component.test.ts
index 85ff9ff..eb78727 100644
--- a/extensions/processes-dock/components/log-dock-component.test.ts
+++ b/extensions/processes-dock/components/log-dock-component.test.ts
@@ -151,6 +151,33 @@ describe("renderLogDock", () => {
     expect(lines.join("\n")).toContain("warn once");
   });
 
+  it("treats expanded height as log rows, not total widget rows", () => {
+    const lines = renderLogDock(
+      snapshot({
+        pinnedLines: [
+          { type: "stdout", text: "line one" },
+          { type: "stdout", text: "line two" },
+          { type: "stdout", text: "line three" },
+        ],
+        state: {
+          visibility: "expanded",
+          followEnabled: true,
+          focusedProcessId: "proc_1",
+        },
+      }),
+      makeTheme(),
+      100,
+      2,
+    );
+
+    // Chrome is added on top of the configured log rows:
+    // top border + process strip + rule + 2 log rows + bottom border.
+    expect(lines).toHaveLength(6);
+    expect(lines.join("\n")).toContain("line two");
+    expect(lines.join("\n")).toContain("line three");
+    expect(lines.join("\n")).not.toContain("line one");
+  });
+
   it("shows notification badges and highlights matching lines", () => {
     const lines = renderLogDock(
       snapshot({
diff --git a/extensions/processes-dock/components/log-dock-component.ts b/extensions/processes-dock/components/log-dock-component.ts
index b95633d..001f6b2 100644
--- a/extensions/processes-dock/components/log-dock-component.ts
+++ b/extensions/processes-dock/components/log-dock-component.ts
@@ -42,14 +42,14 @@ export function renderLogDock(
   snapshot: LogDockSnapshot,
   theme: Theme,
   width: number,
-  height: number,
+  logRows: number,
 ): string[] {
   if (snapshot.state.visibility === "closed") return [];
   if (snapshot.processes.length === 0) return [];
 
   const body =
     snapshot.state.visibility === "expanded"
-      ? buildExpandedBody(snapshot, theme, Math.max(1, height - 4))
+      ? buildExpandedBody(snapshot, theme, Math.max(1, logRows))
       : buildCollapsedBody(snapshot, theme);
 
   return new Panel({
@@ -59,9 +59,7 @@ export function renderLogDock(
     padding: 0,
     borderStyle: (text) => theme.fg("dim", text),
     titleStyle: (text) => theme.fg("accent", theme.bold(text)),
-  })
-    .render(width)
-    .slice(0, height);
+  }).render(width);
 }
 
 function buildCollapsedBody(
diff --git a/extensions/processes-dock/widget/setup.ts b/extensions/processes-dock/widget/setup.ts
index 9aa395f..836a429 100644
--- a/extensions/processes-dock/widget/setup.ts
+++ b/extensions/processes-dock/widget/setup.ts
@@ -5,6 +5,7 @@ import type {
 } from "@earendil-works/pi-coding-agent";
 import {
   CHANNELS,
+  type CommandPinPayload,
   type ProcessesOutputChangedPayload,
   type ProcessProtocolNotificationPayload,
 } from "../../../src/protocol";
@@ -14,6 +15,7 @@ import {
   type ProcessLogLine,
   requestCombinedOutput,
   requestConfig,
+  requestProcess,
   requestProcessList,
 } from "../client";
 import { renderLogDock } from "../components/log-dock-component";
@@ -124,11 +126,6 @@ export function setupDockWidgets(
       const pinned = selectPinnedProcess(processes, current);
       if (!pinned) {
         state.actions.setFocus(null);
-      } else if (!LIVE_STATUSES.has(pinned.status)) {
-        const latestRunning = processes.find((process) =>
-          LIVE_STATUSES.has(process.status),
-        );
-        if (latestRunning) state.actions.setFocus(latestRunning.id);
       }
     }
 
@@ -142,7 +139,8 @@ export function setupDockWidgets(
 
     if (
       processes.length === 0 ||
-      (hasSeenRunningProcess &&
+      (!state.getState().focusedProcessId &&
+        hasSeenRunningProcess &&
         processes.every((process) => !LIVE_STATUSES.has(process.status)))
     ) {
       state.actions.close();
@@ -287,10 +285,51 @@ export function setupDockWidgets(
     render();
   };
 
+  const handlePin = (payload: unknown) => {
+    const command = payload as CommandPinPayload;
+    if (!isCommandPinPayload(command)) return;
+    // COMMAND_PIN can arrive before the dock's throttled CHANGED refresh has
+    // run. Refresh the local snapshot first so expand/pin renders immediately
+    // against the current process list.
+    processes = sortProcesses(requestProcessList(events));
+    // id: null unpins the dock (mirrors `/ps:pin clear`).
+    if (command.id === null) {
+      actions.setFocus(null);
+      actions.expand();
+      render();
+      safeReply(command.reply, { ok: true });
+      return;
+    }
+    const process = requestProcess(events, command.id);
+    if (!process) {
+      safeReply(command.reply, { ok: false, error: "Process not found" });
+      return;
+    }
+    if (
+      !LIVE_STATUSES.has(process.status) &&
+      actions.getFocusedProcessId() !== process.id
+    ) {
+      safeReply(command.reply, {
+        ok: false,
+        error: "Only running processes can be pinned",
+      });
+      return;
+    }
+    actions.setFocus(process.id);
+    actions.expand();
+    render();
+    safeReply(command.reply, { ok: true });
+  };
+
   disposers.push(events.on(CHANNELS.STARTED, handleStarted));
   disposers.push(events.on(CHANNELS.ENDED, scheduleRefresh));
   disposers.push(events.on(CHANNELS.CHANGED, scheduleRefresh));
   disposers.push(events.on(CHANNELS.OUTPUT_CHANGED, handleOutputChanged));
+  disposers.push(
+    events.on(CHANNELS.COMMAND_PIN, (payload) => {
+      handlePin(payload);
+    }),
+  );
   disposers.push(
     events.on(CHANNELS.NOTIFICATION, (payload) => {
       if (!isLogMatchNotification(payload)) return;
@@ -372,3 +411,20 @@ function isLogMatchNotification(
     typeof payload.logMatch.line === "string"
   );
 }
+
+function isCommandPinPayload(payload: unknown): payload is CommandPinPayload {
+  return (
+    isRecord(payload) &&
+    (typeof payload.id === "string" || payload.id === null) &&
+    typeof payload.reply === "function"
+  );
+}
+
+function safeReply<T>(reply: (result: T) => void, result: T): void {
+  try {
+    reply(result);
+  } catch {
+    // Reply callbacks are owned by the requester.
+    return;
+  }
+}
diff --git a/extensions/processes/settings/build-sections.ts b/extensions/processes/settings/build-sections.ts
index 340c93e..7e2c49a 100644
--- a/extensions/processes/settings/build-sections.ts
+++ b/extensions/processes/settings/build-sections.ts
@@ -235,7 +235,7 @@ function buildDockDetailItem(
   return {
     id: "dock.details",
     label: "Dock",
-    currentValue: `${dockDefaultState} · ${dockHeight} lines`,
+    currentValue: `${dockDefaultState} · ${dockHeight} log lines`,
     description:
       "Open focused settings for the /ps:dock widget above the editor.",
     submenu: (_current, done) => {
@@ -276,8 +276,9 @@ function buildDockDetailItem(
           {
             id: "dock.height",
             type: "text",
-            label: "Number of lines displayed",
-            description: "Maximum rows rendered by the dock.",
+            label: "Log lines displayed",
+            description:
+              "Maximum log/content rows shown inside the dock. Border, title, process strip, and separator are added on top.",
             getValue: () => nextDockHeight,
             setValue: (value) => {
               nextDockHeight = value;
@@ -287,7 +288,7 @@ function buildDockDetailItem(
           },
         ],
         getDoneSummary: () =>
-          `${nextDockDefaultState} · ${parsePositiveInt(nextDockHeight)} lines`,
+          `${nextDockDefaultState} · ${parsePositiveInt(nextDockHeight)} log lines`,
         onDone: (summary) => done(summary),
       });
     },
diff --git a/src/protocol/channels.ts b/src/protocol/channels.ts
index bf3e804..7520a7b 100644
--- a/src/protocol/channels.ts
+++ b/src/protocol/channels.ts
@@ -17,6 +17,8 @@ export const CHANNELS = {
   // Command channels (UI -> core, callback)
   COMMAND_KILL: "processes:command:kill",
   COMMAND_CLEAR: "processes:command:clear",
+  // Pin handled by the dock extension, if loaded.
+  COMMAND_PIN: "processes:command:pin",
 
   // Log subscription channels
   LOGS_SUBSCRIBE: "processes:logs:subscribe",
diff --git a/src/protocol/commands.ts b/src/protocol/commands.ts
index e75c940..8c754bb 100644
--- a/src/protocol/commands.ts
+++ b/src/protocol/commands.ts
@@ -12,3 +12,13 @@ export interface CommandKillPayload {
 export interface CommandClearPayload {
   reply: (cleared: number) => void;
 }
+
+// UI emits; the dock extension (if loaded) handles it by pinning the process
+// to the dock. Pass `id: null` to unpin. If the dock extension is not
+// registered, no listener replies.
+export interface CommandPinPayload {
+  id: string | null;
+  reply: (result: CommandPinResult) => void;
+}
+
+export type CommandPinResult = { ok: true } | { ok: false; error: string };
diff --git a/src/protocol/index.ts b/src/protocol/index.ts
index 7847db4..e330b22 100644
--- a/src/protocol/index.ts
+++ b/src/protocol/index.ts
@@ -5,7 +5,12 @@ export type {
   ProcessesStartedPayload,
 } from "./broadcasts";
 export { CHANNELS } from "./channels";
-export type { CommandClearPayload, CommandKillPayload } from "./commands";
+export type {
+  CommandClearPayload,
+  CommandKillPayload,
+  CommandPinPayload,
+  CommandPinResult,
+} from "./commands";
 export type {
   LogsChunkPayload,
   LogsSubscribePayload,