diff --git a/server/encryptid-sdk.d.ts b/server/encryptid-sdk.d.ts
index e28fa40..d176c95 100644
--- a/server/encryptid-sdk.d.ts
+++ b/server/encryptid-sdk.d.ts
@@ -18,7 +18,7 @@ declare module '@encryptid/sdk/server' {
 		options: { getSpaceConfig: (slug: string) => Promise<SpaceAuthConfig | null> },
 	): Promise<{ allowed: boolean; readOnly: boolean; reason?: string; claims?: EncryptIDClaims }>;
 	export function extractToken(headers: Headers): string | null;
-	export function authenticateWSUpgrade(req: Request): Promise<EncryptIDClaims | null>;
+	export function authenticateWSUpgrade(req: Request, options?: VerifyOptions): Promise<EncryptIDClaims | null>;
 
 	export interface EncryptIDClaims {
 		sub: string;
diff --git a/server/index.ts b/server/index.ts
index d794380..62dcc99 100644
--- a/server/index.ts
+++ b/server/index.ts
@@ -1743,7 +1743,7 @@ app.post("/api/prompt", async (c) => {
 				// Record tool calls and build function responses
 				const fnResponseParts: any[] = [];
 				for (const part of fnCalls) {
-					const fc = part.functionCall;
+					const fc = part.functionCall!;
 					const tool = findTool(fc.name);
 					const label = tool?.actionLabel(fc.args) || fc.name;
 					toolCalls.push({ name: fc.name, args: fc.args, label });
diff --git a/shared/components/rstack-identity.ts b/shared/components/rstack-identity.ts
index 3619c93..73b2616 100644
--- a/shared/components/rstack-identity.ts
+++ b/shared/components/rstack-identity.ts
@@ -223,6 +223,38 @@ function storeSession(token: string, username: string, did: string): void {
 	localStorage.setItem(SESSION_KEY, JSON.stringify(session));
 	if (username) localStorage.setItem("rspace-username", username);
 	_setSessionCookie(token);
+	if (username && did) addKnownPersona(username, did);
+}
+
+// ── Persona helpers (client-side multi-account) ──
+
+const PERSONAS_KEY = "rspace-known-personas";
+
+interface KnownPersona {
+	username: string;
+	did: string;
+}
+
+function getKnownPersonas(): KnownPersona[] {
+	try {
+		return JSON.parse(localStorage.getItem(PERSONAS_KEY) || "[]");
+	} catch { return []; }
+}
+
+function addKnownPersona(username: string, did: string): void {
+	const personas = getKnownPersonas();
+	const idx = personas.findIndex(p => p.did === did);
+	if (idx >= 0) {
+		personas[idx] = { username, did };
+	} else {
+		personas.push({ username, did });
+	}
+	localStorage.setItem(PERSONAS_KEY, JSON.stringify(personas));
+}
+
+function removeKnownPersona(did: string): void {
+	const personas = getKnownPersonas().filter(p => p.did !== did);
+	localStorage.setItem(PERSONAS_KEY, JSON.stringify(personas));
 }
 
 // ── Auto-space resolution after auth ──
@@ -311,11 +343,24 @@ export class RStackIdentity extends HTMLElement {
 		if (session?.accessToken && session.claims.username) {
 			autoProvisionSpace(session.accessToken);
 		}
+
+		// Propagate login/logout across tabs via storage events
+		window.addEventListener("storage", this.#onStorageChange);
 	}
 
 	disconnectedCallback() {
+		window.removeEventListener("storage", this.#onStorageChange);
 	}
 
+	#onStorageChange = (e: StorageEvent) => {
+		if (e.key === "encryptid_session" || e.key === PERSONAS_KEY) {
+			this.#render();
+			if (e.key === "encryptid_session") {
+				this.dispatchEvent(new CustomEvent("auth-change", { bubbles: true, composed: true }));
+			}
+		}
+	};
+
 	async #refreshIfNeeded() {
 		let session = getSession();
 		let token = session?.accessToken ?? null;
@@ -369,6 +414,8 @@ export class RStackIdentity extends HTMLElement {
 			const did = session.claims.did || session.claims.sub;
 			const displayName = username || (did.length > 24 ? did.slice(0, 16) + "..." + did.slice(-6) : did);
 			const initial = username ? username[0].toUpperCase() : did.slice(8, 10).toUpperCase();
+			const currentDid = session.claims.did || "";
+			const otherPersonas = getKnownPersonas().filter(p => p.did !== currentDid);
 
 			this.#shadow.innerHTML = `
 				<style>${STYLES}</style>
@@ -379,6 +426,21 @@ export class RStackIdentity extends HTMLElement {
 					<span class="name">${displayName}</span>
 					<div class="dropdown" id="dropdown">
 						<div class="dropdown-header">${displayName}</div>
+						${otherPersonas.length > 0 ? `
+						<div class="dropdown-divider"></div>
+						<div class="dropdown-label">Switch Persona</div>
+						${otherPersonas.map(p => `
+						<div class="persona-row">
+							<button class="dropdown-item persona-item" data-action="switch-persona" data-did="${p.did}">
+								<div class="persona-avatar">${p.username[0].toUpperCase()}</div>
+								<span>${p.username}</span>
+							</button>
+							<button class="persona-remove" data-action="remove-persona" data-did="${p.did}">&times;</button>
+						</div>
+						`).join("")}
+						` : ""}
+						<div class="dropdown-divider"></div>
+						<button class="dropdown-item" data-action="add-persona">＋ Add Persona</button>
 						<div class="dropdown-divider"></div>
 						<button class="dropdown-item" data-action="my-account">👤 My Account</button>
 						<button class="dropdown-item" data-action="my-spaces">🌐 My Spaces</button>
@@ -446,6 +508,23 @@ export class RStackIdentity extends HTMLElement {
 						}
 					} else if (action === "settings") {
 						(document.getElementById("settings-btn") as HTMLElement)?.click();
+					} else if (action === "switch-persona") {
+						const targetDid = (el as HTMLElement).dataset.did || "";
+						const persona = getKnownPersonas().find(p => p.did === targetDid);
+						if (!persona) return;
+						clearSession();
+						resetDocBridge();
+						this.showAuthModal({ onSuccess: () => {}, onCancel: () => { this.#render(); } }, persona.username);
+					} else if (action === "add-persona") {
+						clearSession();
+						resetDocBridge();
+						this.#render();
+						this.dispatchEvent(new CustomEvent("auth-change", { bubbles: true, composed: true }));
+						this.showAuthModal();
+					} else if (action === "remove-persona") {
+						const targetDid = (el as HTMLElement).dataset.did || "";
+						removeKnownPersona(targetDid);
+						this.#render();
 					}
 				});
 			});
@@ -493,8 +572,9 @@ export class RStackIdentity extends HTMLElement {
 		return getSession() !== null;
 	}
 
-	/** Public method: show the auth modal programmatically */
-	showAuthModal(callbacks?: { onSuccess?: () => void; onCancel?: () => void }): void {
+	/** Public method: show the auth modal programmatically.
+	 *  Pass usernameHint to auto-trigger passkey sign-in for a specific persona. */
+	showAuthModal(callbacks?: { onSuccess?: () => void; onCancel?: () => void }, usernameHint?: string): void {
 		if (document.querySelector(".rstack-auth-overlay")) return;
 
 		const overlay = document.createElement("div");
@@ -542,17 +622,16 @@ export class RStackIdentity extends HTMLElement {
 		};
 
 		const handleSignIn = async () => {
-			const errEl = overlay.querySelector("#auth-error") as HTMLElement;
-			const btn = overlay.querySelector('[data-action="signin"]') as HTMLButtonElement;
-			errEl.textContent = "";
-			btn.disabled = true;
-			btn.innerHTML = '<span class="spinner"></span> Authenticating...';
+			const errEl = overlay.querySelector("#auth-error") as HTMLElement | null;
+			const btn = overlay.querySelector('[data-action="signin"]') as HTMLButtonElement | null;
+			if (errEl) errEl.textContent = "";
+			if (btn) { btn.disabled = true; btn.innerHTML = '<span class="spinner"></span> Authenticating...'; }
 
 			try {
 				const startRes = await fetch(`${ENCRYPTID_URL}/api/auth/start`, {
 					method: "POST",
 					headers: { "Content-Type": "application/json" },
-					body: JSON.stringify({}),
+					body: JSON.stringify(usernameHint ? { username: usernameHint } : {}),
 				});
 				if (!startRes.ok) throw new Error("Failed to start authentication");
 				const { options: serverOptions } = await startRes.json();
@@ -586,9 +665,11 @@ export class RStackIdentity extends HTMLElement {
 				// Auto-redirect to personal space
 				autoResolveSpace(data.token, data.username || "");
 			} catch (err: any) {
-				btn.disabled = false;
-				btn.innerHTML = "🔑 Sign In with Passkey";
-				errEl.textContent = err.name === "NotAllowedError" ? "Authentication was cancelled." : err.message || "Authentication failed.";
+				if (btn) { btn.disabled = false; btn.innerHTML = "🔑 Sign In with Passkey"; }
+				const msg = err.name === "NotAllowedError" ? "Authentication was cancelled." : err.message || "Authentication failed.";
+				if (errEl) errEl.textContent = msg;
+				// If auto-triggered persona switch was cancelled, close modal and restore previous state
+				if (usernameHint) { close(); this.#render(); callbacks?.onCancel?.(); }
 			}
 		};
 
@@ -696,6 +777,11 @@ export class RStackIdentity extends HTMLElement {
 
 		document.body.appendChild(overlay);
 		render();
+
+		// If switching persona, auto-trigger sign-in immediately
+		if (usernameHint) {
+			handleSignIn();
+		}
 	}
 
 	// ── Account modal (consolidated) ──
@@ -1668,6 +1754,28 @@ const STYLES = `
   padding: 0 4px; border: 2px solid var(--rs-bg-surface); line-height: 1;
 }
 
+/* Persona switcher in dropdown */
+.dropdown-label {
+  padding: 6px 16px; font-size: 0.7rem; text-transform: uppercase;
+  letter-spacing: 0.05em; color: var(--rs-text-secondary); font-weight: 600;
+}
+.persona-row {
+  display: flex; align-items: center; padding-right: 8px;
+}
+.persona-row .persona-item { flex: 1; }
+.persona-avatar {
+  width: 24px; height: 24px; border-radius: 50%;
+  background: linear-gradient(135deg, #06b6d4, #7c3aed);
+  display: flex; align-items: center; justify-content: center;
+  font-weight: 700; font-size: 0.65rem; color: white; flex-shrink: 0;
+}
+.persona-remove {
+  opacity: 0.4; cursor: pointer; font-size: 0.75rem;
+  padding: 2px 6px; border-radius: 4px; border: none;
+  background: none; color: var(--rs-text-secondary); flex-shrink: 0;
+}
+.persona-remove:hover { opacity: 1; background: var(--rs-bg-hover); }
+
 /* Notification items in dropdown */
 .dropdown-section-label {
   padding: 8px 16px 4px; font-size: 0.65rem; font-weight: 600;