diff --git a/crates/application/src/slash_command.rs b/crates/application/src/slash_command.rs
index 25a1380..c221bd8 100644
--- a/crates/application/src/slash_command.rs
+++ b/crates/application/src/slash_command.rs
@@ -244,13 +244,17 @@ mod tests {
     }
 
     #[test]
-    fn profile_is_known_but_not_executable_yet() {
-        let err = ExecuteSlashCommand::new(SlashCommandRegistry::new())
+    fn profile_returns_profile_switch_effect() {
+        let sid = session();
+        let out = ExecuteSlashCommand::new(SlashCommandRegistry::new())
             .execute(ExecuteSlashCommandInput {
                 name: "/profile".to_owned(),
-                session_id: Some(session()),
+                session_id: Some(sid),
             })
-            .unwrap_err();
-        assert!(matches!(err, AppError::Invalid(message) if message.contains("unavailable")));
+            .unwrap();
+        assert_eq!(
+            out.effect,
+            SlashCommandEffect::ProfileSwitch { session_id: sid }
+        );
     }
 }
diff --git a/crates/domain/src/slash_command.rs b/crates/domain/src/slash_command.rs
index 7af9d21..dba1911 100644
--- a/crates/domain/src/slash_command.rs
+++ b/crates/domain/src/slash_command.rs
@@ -133,9 +133,7 @@ pub fn native_slash_commands() -> Vec<SlashCommand> {
             "/profile",
             "Changer le profil de l'agent",
             true,
-            SlashCommandAvailability::Unavailable {
-                reason: "La selection de profil est livree par le ticket #164".to_owned(),
-            },
+            SlashCommandAvailability::Available,
             SlashCommandSource::Native,
             Some(NativeSlashCommand::Profile),
         )
@@ -180,7 +178,7 @@ mod tests {
         assert_eq!(names, vec!["/help", "/clean", "/profile"]);
         assert!(commands[0].availability.is_available());
         assert!(commands[1].availability.is_available());
-        assert!(!commands[2].availability.is_available());
+        assert!(commands[2].availability.is_available());
         assert!(commands[2].requires_confirmation);
     }
 
diff --git a/frontend/src/adapters/mock/index.ts b/frontend/src/adapters/mock/index.ts
index b26bc99..100065f 100644
--- a/frontend/src/adapters/mock/index.ts
+++ b/frontend/src/adapters/mock/index.ts
@@ -422,10 +422,7 @@ export class MockAgentGateway implements AgentGateway {
       name: "/profile",
       shortDescription: "Changer le profil de l'agent",
       requiresConfirmation: true,
-      availability: {
-        status: "unavailable",
-        reason: "La selection de profil est livree par le ticket #164",
-      },
+      availability: { status: "available" },
       source: "native",
       native: "profile",
     },
@@ -939,6 +936,21 @@ export class MockAgentGateway implements AgentGateway {
         },
       };
     }
+    if (command.native === "profile") {
+      if (!options.sessionId) {
+        throw {
+          code: "INVALID",
+          message: "/profile requires a current session id",
+        } as GatewayError;
+      }
+      return {
+        command: structuredClone(command),
+        effect: {
+          kind: "profileSwitch",
+          sessionId: options.sessionId,
+        },
+      };
+    }
     return {
       command: structuredClone(command),
       effect: {
diff --git a/frontend/src/features/agents/CustomAgentChatView.test.tsx b/frontend/src/features/agents/CustomAgentChatView.test.tsx
index 5df7c9d..dc61888 100644
--- a/frontend/src/features/agents/CustomAgentChatView.test.tsx
+++ b/frontend/src/features/agents/CustomAgentChatView.test.tsx
@@ -522,6 +522,129 @@ describe("CustomAgentChatView", () => {
     expect(screen.queryByRole("listbox", { name: "suggestions commandes slash" })).toBeNull();
   });
 
+  it("executes /profile as a confirmed profile-switch flow that resets the current session", async () => {
+    const agent = {
+      launchAgentChat: vi.fn(async () => ({
+        sessionId: "chat-session-2",
+        cellKind: "chat" as const,
+        assignedConversationId: "conversation-2",
+      })),
+      reattachAgentChat: vi.fn(async (sessionId: string) => ({
+        sessionId,
+        scrollback: [],
+      })),
+      sendAgentChat: vi.fn(async () => {}),
+      executeSlashCommand: vi.fn(async () => ({
+        command: {
+          name: "/profile",
+          shortDescription: "Changer le profil de l'agent",
+          requiresConfirmation: true,
+          availability: { status: "available" as const },
+          source: "native" as const,
+          native: "profile" as const,
+        },
+        effect: {
+          kind: "profileSwitch" as const,
+          sessionId: "chat-session-1",
+        },
+      })),
+      changeAgentProfile: vi.fn(async () => ({ agent: { id: "agent-1" } })),
+      cancelAgentChat: vi.fn(async () => {}),
+      closeAgentChat: vi.fn(async () => {}),
+    };
+    const profileGateway = {
+      listProfiles: vi.fn(async () => [
+        profile,
+        {
+          ...profile,
+          id: "codex-high",
+          name: "Codex High",
+        },
+      ]),
+    };
+    const onSessionId = vi.fn();
+    const onConversationId = vi.fn();
+
+    render(
+      <DIProvider
+        gateways={{
+          agent,
+          profile: profileGateway,
+          system: { pickFile: vi.fn(async () => null) },
+        } as unknown as Gateways}
+      >
+        <CustomAgentChatView
+          projectId="project-1"
+          agentId="agent-1"
+          agentName="Worker"
+          profile={profile}
+          cwd="/repo"
+          nodeId="node-1"
+          sessionId="chat-session-1"
+          conversationId="conversation-1"
+          onSessionId={onSessionId}
+          onConversationId={onConversationId}
+        />
+      </DIProvider>,
+    );
+
+    await waitFor(() =>
+      expect(agent.reattachAgentChat).toHaveBeenCalledWith(
+        "chat-session-1",
+        expect.any(Function),
+      ),
+    );
+
+    const composer = screen.getByLabelText(/message CLI custom/) as HTMLTextAreaElement;
+    fireEvent.change(composer, { target: { value: "/profile" } });
+    fireEvent.keyDown(composer, { key: "Enter" });
+
+    const dialog = await screen.findByRole("dialog", { name: "Changer de profil" });
+    expect(dialog.textContent).toContain("réinitialiser la session courante");
+    expect(dialog.textContent).toContain("L'historique de cette CLI custom sera perdu");
+    expect(agent.executeSlashCommand).toHaveBeenCalledWith("/profile", {
+      sessionId: "chat-session-1",
+    });
+    expect(agent.sendAgentChat).not.toHaveBeenCalled();
+
+    const confirmButton = screen.getByRole("button", {
+      name: "Reset et changer le profil",
+    }) as HTMLButtonElement;
+    expect(confirmButton.disabled).toBe(true);
+
+    fireEvent.change(screen.getByLabelText("profil cible"), {
+      target: { value: "codex-high" },
+    });
+    fireEvent.click(screen.getByLabelText("Je confirme que la session courante sera reset."));
+    expect(confirmButton.disabled).toBe(false);
+    fireEvent.click(confirmButton);
+
+    await waitFor(() =>
+      expect(agent.changeAgentProfile).toHaveBeenCalledWith(
+        "project-1",
+        "agent-1",
+        "codex-high",
+        24,
+        80,
+      ),
+    );
+    await waitFor(() =>
+      expect(agent.launchAgentChat).toHaveBeenCalledWith("project-1", "agent-1", {
+        cwd: "/repo",
+        rows: 24,
+        cols: 80,
+        conversationId: undefined,
+        nodeId: "node-1",
+      }),
+    );
+    expect(onSessionId).toHaveBeenCalledWith(null);
+    expect(onConversationId).toHaveBeenCalledWith(null);
+    expect(onSessionId).toHaveBeenCalledWith("chat-session-2");
+    expect(onConversationId).toHaveBeenCalledWith("conversation-2");
+    expect(screen.getByText("Profil changé vers Codex High.")).toBeTruthy();
+    expect(screen.queryByRole("dialog", { name: "Changer de profil" })).toBeNull();
+  });
+
   it("pastes a clipboard image as a removable preview chip", async () => {
     const agent = {
       launchAgentChat: vi.fn(),
diff --git a/frontend/src/features/agents/CustomAgentChatView.tsx b/frontend/src/features/agents/CustomAgentChatView.tsx
index c938aef..9406eb7 100644
--- a/frontend/src/features/agents/CustomAgentChatView.tsx
+++ b/frontend/src/features/agents/CustomAgentChatView.tsx
@@ -58,6 +58,14 @@ interface AttachmentDraft {
   previewUrl?: string;
 }
 
+interface ProfileCommandDialogState {
+  profiles: AgentProfile[];
+  selectedProfileId: string;
+  confirmedReset: boolean;
+  busy: boolean;
+  error: string | null;
+}
+
 function describe(e: unknown): string {
   if (e && typeof e === "object" && "message" in e) {
     return String((e as GatewayError).message);
@@ -319,7 +327,7 @@ export function CustomAgentChatView({
   onSessionId,
   onConversationId,
 }: CustomAgentChatViewProps) {
-  const { agent, system } = useGateways();
+  const { agent, profile: profileGateway, system } = useGateways();
   const [turns, setTurns] = useState<ChatTurn[]>([]);
   const [currentSession, setCurrentSession] = useState(sessionId);
   const [externalSessionId, setExternalSessionId] = useState(sessionId);
@@ -328,6 +336,8 @@ export function CustomAgentChatView({
   const [slashCommands, setSlashCommands] = useState<SlashCommand[]>([]);
   const [slashMenuOpen, setSlashMenuOpen] = useState(false);
   const [slashActiveIndex, setSlashActiveIndex] = useState(0);
+  const [profileDialog, setProfileDialog] =
+    useState<ProfileCommandDialogState | null>(null);
   const [opening, setOpening] = useState(false);
   const [busy, setBusy] = useState(false);
   const [error, setError] = useState<string | null>(null);
@@ -448,7 +458,13 @@ export function CustomAgentChatView({
   );
 
   const recoverStructuredSession = useCallback(
-    async (options: { applyScrollback?: boolean; retryAttachNotFound?: boolean } = {}) => {
+    async (
+      options: {
+        applyScrollback?: boolean;
+        retryAttachNotFound?: boolean;
+        conversationId?: string | null;
+      } = {},
+    ) => {
       if (!agent.launchAgentChat) throw new Error("Structured launch unavailable");
       console.debug("[ticket149] recoverStructuredSession:start", {
         timestamp: new Date().toISOString(),
@@ -462,7 +478,10 @@ export function CustomAgentChatView({
           cwd,
           rows: 24,
           cols: 80,
-          conversationId: conversationId ?? undefined,
+          conversationId:
+            options.conversationId === undefined
+              ? conversationId ?? undefined
+              : options.conversationId ?? undefined,
           nodeId,
         };
         console.debug("[ticket149] recoverStructuredSession:launchAgentChat:start", {
@@ -641,6 +660,102 @@ export function CustomAgentChatView({
     [supported, draft, attachments.length, busy, opening],
   );
 
+  async function openProfileCommandFlow() {
+    if (!agent.executeSlashCommand) {
+      setError("Commande /profile indisponible dans ce runtime.");
+      return;
+    }
+    setError(null);
+    try {
+      const sid =
+        currentSession ??
+        (await recoverStructuredSession({
+          applyScrollback: false,
+          retryAttachNotFound: true,
+        }));
+      const result = await agent.executeSlashCommand("/profile", { sessionId: sid });
+      if (result.effect.kind !== "profileSwitch") {
+        throw new Error("La commande /profile n'a pas renvoyé le flow profil.");
+      }
+      const availableProfiles = (await profileGateway.listProfiles()).filter(
+        (candidate) => Boolean(candidate.structuredAdapter),
+      );
+      if (availableProfiles.length === 0) {
+        throw new Error("Aucun profil compatible avec la CLI custom n'est configuré.");
+      }
+      setDraft("");
+      setProfileDialog({
+        profiles: availableProfiles,
+        selectedProfileId:
+          availableProfiles.find((candidate) => candidate.id !== profile.id)?.id ??
+          availableProfiles[0].id,
+        confirmedReset: false,
+        busy: false,
+        error: null,
+      });
+    } catch (e) {
+      setError(describe(e));
+    }
+  }
+
+  async function confirmProfileCommandChange() {
+    if (!profileDialog) return;
+    if (!agent.changeAgentProfile) {
+      setProfileDialog((prev) =>
+        prev ? { ...prev, error: "Changement de profil indisponible." } : prev,
+      );
+      return;
+    }
+    const selected = profileDialog.profiles.find(
+      (candidate) => candidate.id === profileDialog.selectedProfileId,
+    );
+    if (!selected) return;
+
+    setProfileDialog((prev) => (prev ? { ...prev, busy: true, error: null } : prev));
+    try {
+      const { relaunchedSession } = await agent.changeAgentProfile(
+        projectId,
+        agentId,
+        selected.id,
+        24,
+        80,
+      );
+      setTurns([]);
+      setCurrentSession(null);
+      publishSessionId(null);
+      onConversationIdRef.current(null);
+
+      if (relaunchedSession?.sessionId) {
+        try {
+          setCurrentSession(relaunchedSession.sessionId);
+          publishSessionId(relaunchedSession.sessionId);
+          await reattachStructuredSession(relaunchedSession.sessionId, {
+            applyScrollback: false,
+          });
+        } catch {
+          await recoverStructuredSession({
+            applyScrollback: false,
+            retryAttachNotFound: true,
+            conversationId: null,
+          });
+        }
+      } else {
+        await recoverStructuredSession({
+          applyScrollback: false,
+          retryAttachNotFound: true,
+          conversationId: null,
+        });
+      }
+
+      setTurns([{ role: "tool", label: `Profil changé vers ${selected.name}.` }]);
+      setProfileDialog(null);
+    } catch (e) {
+      setProfileDialog((prev) =>
+        prev ? { ...prev, busy: false, error: describe(e) } : prev,
+      );
+    }
+  }
+
   async function pickAttachment() {
     const path = await system.pickFile();
     if (path) {
@@ -685,6 +800,10 @@ export function CustomAgentChatView({
   async function send() {
     const text = draft.trim();
     if (!canSend || !agent.sendAgentChat) return;
+    if (text === "/profile") {
+      await openProfileCommandFlow();
+      return;
+    }
     const outgoingAttachments = attachments;
     const attachmentInputs = outgoingAttachments.map((item) => item.input);
     const attachmentLabels = outgoingAttachments.map((item) => item.label);
@@ -797,6 +916,101 @@ export function CustomAgentChatView({
           {error}
         </p>
       )}
+      {profileDialog && (
+        <div
+          role="dialog"
+          aria-modal="true"
+          aria-labelledby={`profile-command-title-${nodeId}`}
+          className="m-3 rounded-md border border-border bg-surface p-3 shadow-lg"
+        >
+          <div className="flex min-w-0 items-start justify-between gap-3">
+            <div className="min-w-0">
+              <h2
+                id={`profile-command-title-${nodeId}`}
+                className="text-sm font-semibold text-content"
+              >
+                Changer de profil
+              </h2>
+              <p className="mt-1 text-xs text-muted">
+                Valider ce changement va réinitialiser la session courante. L'historique de cette CLI custom sera perdu.
+              </p>
+            </div>
+            <Button
+              size="sm"
+              variant="ghost"
+              disabled={profileDialog.busy}
+              onClick={() => setProfileDialog(null)}
+            >
+              Fermer
+            </Button>
+          </div>
+          <div className="mt-3 flex min-w-0 flex-col gap-2">
+            <label className="flex min-w-0 flex-col gap-1 text-xs text-muted">
+              Profil
+              <select
+                aria-label="profil cible"
+                value={profileDialog.selectedProfileId}
+                disabled={profileDialog.busy}
+                className="rounded-md border border-border bg-raised px-2 py-1 text-sm text-content"
+                onChange={(event) =>
+                  setProfileDialog((prev) =>
+                    prev
+                      ? {
+                          ...prev,
+                          selectedProfileId: event.target.value,
+                          confirmedReset: false,
+                        }
+                      : prev,
+                  )
+                }
+              >
+                {profileDialog.profiles.map((candidate) => (
+                  <option key={candidate.id} value={candidate.id}>
+                    {candidate.name}
+                  </option>
+                ))}
+              </select>
+            </label>
+            <label className="flex items-start gap-2 text-xs text-content">
+              <input
+                type="checkbox"
+                checked={profileDialog.confirmedReset}
+                disabled={profileDialog.busy}
+                onChange={(event) =>
+                  setProfileDialog((prev) =>
+                    prev ? { ...prev, confirmedReset: event.target.checked } : prev,
+                  )
+                }
+              />
+              <span>Je confirme que la session courante sera reset.</span>
+            </label>
+            {profileDialog.error && (
+              <p role="alert" className="text-xs text-danger">
+                {profileDialog.error}
+              </p>
+            )}
+            <div className="flex justify-end gap-2">
+              <Button
+                size="sm"
+                variant="ghost"
+                disabled={profileDialog.busy}
+                onClick={() => setProfileDialog(null)}
+              >
+                Annuler
+              </Button>
+              <Button
+                size="sm"
+                variant="danger"
+                disabled={!profileDialog.confirmedReset || profileDialog.busy}
+                loading={profileDialog.busy}
+                onClick={() => void confirmProfileCommandChange()}
+              >
+                Reset et changer le profil
+              </Button>
+            </div>
+          </div>
+        </div>
+      )}
 
       <div
         ref={scrollRef}