diff --git a/package-lock.json b/package-lock.json
index d4cbc7e..8a92c54 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12,7 +12,7 @@
         "@noble/hashes": "^1.7.2",
         "@scure/base": "^1.2.4",
         "@tanstack/react-query": "^5.90.0",
-        "@unicitylabs/sphere-sdk": "^0.5.4",
+        "@unicitylabs/sphere-sdk": "^0.5.6",
         "lucide-react": "^0.552.0",
         "react": "^18.3.1",
         "react-dom": "^18.3.1"
@@ -68,7 +68,6 @@
       "integrity": "sha512-CGOfOJqWjg2qW/Mb6zNsDm+u5vFQ8DxXfbM09z69p5Z6+mE1ikP2jUXw+j42Pf1XTYED2Rni5f95npYeuwMDQA==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@babel/code-frame": "^7.29.0",
         "@babel/generator": "^7.29.0",
@@ -2358,7 +2357,6 @@
       "integrity": "sha512-RpV6r/ij22zRRdyBPcxDeKAzH43phWVKEjL2iksqo1Vz3CuBUrgmPpPhALKiRfU7OMCmeeO9vECBMsV0hMTG8Q==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "undici-types": "~7.18.0"
       }
@@ -2376,7 +2374,6 @@
       "integrity": "sha512-z9VXpC7MWrhfWipitjNdgCauoMLRdIILQsAEV+ZesIzBq/oUlxk0m3ApZuMFCXdnS4U7KrI+l3WRUEGQ8K1QKw==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@types/prop-types": "*",
         "csstype": "^3.2.2"
@@ -2437,7 +2434,6 @@
       "integrity": "sha512-klQbnPAAiGYFyI02+znpBRLyjL4/BrBd0nyWkdC0s/6xFLkXYQ8OoRrSkqacS1ddVxf/LDyODIKbQ5TgKAf/Fg==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@typescript-eslint/scope-manager": "8.56.1",
         "@typescript-eslint/types": "8.56.1",
@@ -2705,9 +2701,9 @@
       }
     },
     "node_modules/@unicitylabs/sphere-sdk": {
-      "version": "0.5.4",
-      "resolved": "https://registry.npmjs.org/@unicitylabs/sphere-sdk/-/sphere-sdk-0.5.4.tgz",
-      "integrity": "sha512-MdkVAEdU9lWD8WGLerwaMxZZJBv1/BQpwd8cnhowRUY4IRCC6EZVIYJP8soshyWPLUQ1f0E0KFfez9arQc88Sg==",
+      "version": "0.5.6",
+      "resolved": "https://registry.npmjs.org/@unicitylabs/sphere-sdk/-/sphere-sdk-0.5.6.tgz",
+      "integrity": "sha512-CmOz3cDxamE25E/W8MRNV8h2cY/Bmn7zmyHpeGZWqQSPL0AYxCeyYUCdnhiTD4082wId0UCXNBiJyQoPRAxS+w==",
       "license": "MIT",
       "dependencies": {
         "@noble/curves": "^2.0.1",
@@ -2858,7 +2854,6 @@
       "integrity": "sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "bin": {
         "acorn": "bin/acorn"
       },
@@ -3273,7 +3268,6 @@
         }
       ],
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "baseline-browser-mapping": "^2.9.0",
         "caniuse-lite": "^1.0.30001759",
@@ -3964,7 +3958,6 @@
       "integrity": "sha512-VmQ+sifHUbI/IcSopBCF/HO3YiHQx/AVd3UVyYL6weuwW+HvON9VYn5l6Zl1WZzPWXPNZrSQpxwkkZ/VuvJZzg==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@eslint-community/eslint-utils": "^4.8.0",
         "@eslint-community/regexpp": "^4.12.1",
@@ -5069,9 +5062,9 @@
       }
     },
     "node_modules/libphonenumber-js": {
-      "version": "1.12.36",
-      "resolved": "https://registry.npmjs.org/libphonenumber-js/-/libphonenumber-js-1.12.36.tgz",
-      "integrity": "sha512-woWhKMAVx1fzzUnMCyOzglgSgf6/AFHLASdOBcchYCyvWSGWt12imw3iu2hdI5d4dGZRsNWAmWiz37sDKUPaRQ==",
+      "version": "1.12.38",
+      "resolved": "https://registry.npmjs.org/libphonenumber-js/-/libphonenumber-js-1.12.38.tgz",
+      "integrity": "sha512-vwzxmasAy9hZigxtqTbFEwp8ZdZ975TiqVDwj5bKx5sR+zi5ucUQy9mbVTkKM9GzqdLdxux/hTw2nmN5J7POMA==",
       "license": "MIT"
     },
     "node_modules/locate-path": {
@@ -5624,7 +5617,6 @@
       "integrity": "sha512-5gTmgEY/sqK6gFXLIsQNH19lWb4ebPDLA4SdLP7dsWkIXHWlG66oPuVvXSGFPppYZz8ZDZq0dYYrbHfBCVUb1Q==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "engines": {
         "node": ">=12"
       },
@@ -5822,7 +5814,6 @@
       "resolved": "https://registry.npmjs.org/react/-/react-18.3.1.tgz",
       "integrity": "sha512-wS+hAgJShR0KhEvPJArfuPVN1+Hz1t0Y6n5jLrGQbkb4urgPE/0Rve+1kMB1v/oWgHgm4WIcV+i7F2pTVj+2iQ==",
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "loose-envify": "^1.1.0"
       },
@@ -6681,7 +6672,6 @@
       "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
       "dev": true,
       "license": "Apache-2.0",
-      "peer": true,
       "bin": {
         "tsc": "bin/tsc",
         "tsserver": "bin/tsserver"
@@ -6864,7 +6854,6 @@
       "integrity": "sha512-+Oxm7q9hDoLMyJOYfUYBuHQo+dkAloi33apOPP56pzj+vsdJDzr+j1NISE5pyaAuKL4A3UD34qd0lx5+kfKp2g==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "esbuild": "^0.25.0",
         "fdir": "^6.4.4",
diff --git a/package.json b/package.json
index e3d1549..7404897 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,7 @@
     "@noble/hashes": "^1.7.2",
     "@scure/base": "^1.2.4",
     "@tanstack/react-query": "^5.90.0",
-    "@unicitylabs/sphere-sdk": "^0.5.4",
+    "@unicitylabs/sphere-sdk": "^0.5.6",
     "lucide-react": "^0.552.0",
     "react": "^18.3.1",
     "react-dom": "^18.3.1"
diff --git a/src/components/ui/BaseModal.tsx b/src/components/ui/BaseModal.tsx
index 1e9129b..175b392 100644
--- a/src/components/ui/BaseModal.tsx
+++ b/src/components/ui/BaseModal.tsx
@@ -61,7 +61,7 @@ export function BaseModal({
         <div
           ref={panelRef}
           onClick={(e) => e.stopPropagation()}
-          className={`relative w-full ${sizeClasses[size]} max-h-[70dvh] sm:max-h-[600px] bg-white dark:bg-[#111] border border-neutral-200 dark:border-white/10 rounded-3xl shadow-2xl pointer-events-auto flex flex-col overflow-hidden opacity-0 scale-95 translate-y-4 transition-all duration-300 ease-out ${className}`}
+          className={`relative w-full ${sizeClasses[size]} max-h-[70dvh] sm:max-h-150 bg-white dark:bg-[#111] border border-neutral-200 dark:border-white/10 rounded-3xl shadow-2xl pointer-events-auto flex flex-col overflow-hidden opacity-0 scale-95 translate-y-4 transition-all duration-300 ease-out ${className}`}
         >
           {/* Background Orbs */}
           {showOrbs && (
diff --git a/src/components/wallet/UnlockWallet.tsx b/src/components/wallet/UnlockWallet.tsx
index b14fcd1..bbe20c9 100644
--- a/src/components/wallet/UnlockWallet.tsx
+++ b/src/components/wallet/UnlockWallet.tsx
@@ -1,5 +1,6 @@
 import { useState } from 'react';
 import { Loader2, Lock, AlertCircle } from 'lucide-react';
+import { getErrorMessage } from '@/sdk/errors';
 
 interface UnlockWalletProps {
   onUnlock: (password: string) => Promise<void>;
@@ -20,7 +21,7 @@ export function UnlockWallet({ onUnlock }: UnlockWalletProps) {
     try {
       await onUnlock(password);
     } catch (err) {
-      setError((err as Error).message || 'Failed to unlock wallet');
+      setError(getErrorMessage(err));
     } finally {
       setIsLoading(false);
     }
@@ -36,7 +37,7 @@ export function UnlockWallet({ onUnlock }: UnlockWalletProps) {
         {/* Lock Icon */}
         <div className="relative">
           <div className="absolute inset-0 rounded-2xl blur-lg opacity-50 bg-orange-500" />
-          <div className="relative w-16 h-16 rounded-2xl bg-gradient-to-br from-orange-500 to-orange-600 flex items-center justify-center shadow-xl shadow-orange-500/25">
+          <div className="relative w-16 h-16 rounded-2xl bg-linear-to-br from-orange-500 to-orange-600 flex items-center justify-center shadow-xl shadow-orange-500/25">
             <Lock className="w-8 h-8 text-white" />
           </div>
         </div>
@@ -78,7 +79,7 @@ export function UnlockWallet({ onUnlock }: UnlockWalletProps) {
           <button
             type="submit"
             disabled={isLoading || !password.trim()}
-            className="w-full py-3 px-4 bg-gradient-to-r from-orange-500 to-orange-600 text-white text-sm font-medium rounded-xl shadow-lg shadow-orange-500/25 disabled:opacity-50 disabled:cursor-not-allowed hover:scale-[1.02] active:scale-[0.98] transition-transform"
+            className="w-full py-3 px-4 bg-linear-to-r from-orange-500 to-orange-600 text-white text-sm font-medium rounded-xl shadow-lg shadow-orange-500/25 disabled:opacity-50 disabled:cursor-not-allowed hover:scale-[1.02] active:scale-[0.98] transition-transform"
           >
             {isLoading ? (
               <span className="flex items-center justify-center gap-2">
diff --git a/src/components/wallet/modals/ConnectIntentModal.tsx b/src/components/wallet/modals/ConnectIntentModal.tsx
index e08dbcc..80276ac 100644
--- a/src/components/wallet/modals/ConnectIntentModal.tsx
+++ b/src/components/wallet/modals/ConnectIntentModal.tsx
@@ -15,6 +15,7 @@
 import { useEffect, useState, useRef, useCallback } from 'react';
 import { MessageSquare, Key, Zap, Loader2 } from 'lucide-react';
 import { ERROR_CODES } from '@unicitylabs/sphere-sdk/connect';
+import { getErrorMessage } from '@/sdk/errors';
 import { BaseModal } from '@/components/ui/BaseModal';
 import { ModalHeader } from '@/components/ui/ModalHeader';
 import { Button } from '@/components/ui/Button';
@@ -264,7 +265,7 @@ function L1SendIntentModal({
       await resolveIntent(id, { result: { success: true, txHash: result.txHash } });
       onClose();
     } catch (e) {
-      setError(e instanceof Error ? e.message : 'Send failed');
+      setError(getErrorMessage(e));
     } finally {
       setLoading(false);
     }
@@ -402,7 +403,7 @@ function DmIntentModal({
       });
       onClose();
     } catch (e) {
-      setError(e instanceof Error ? e.message : 'Failed to send DM');
+      setError(getErrorMessage(e));
     } finally {
       setLoading(false);
     }
@@ -488,7 +489,7 @@ function SignMessageIntentModal({
       await resolveIntent(id, { result: { signature: signResult.signature } });
       onClose();
     } catch (e) {
-      setError(e instanceof Error ? e.message : 'Signing failed');
+      setError(getErrorMessage(e));
     } finally {
       setLoading(false);
     }
diff --git a/src/components/wallet/modals/LookupModal.tsx b/src/components/wallet/modals/LookupModal.tsx
index 281aacf..cc25040 100644
--- a/src/components/wallet/modals/LookupModal.tsx
+++ b/src/components/wallet/modals/LookupModal.tsx
@@ -2,6 +2,7 @@ import { useState, useCallback, useEffect } from 'react';
 import { Key, Search, Loader2, Copy, Check } from 'lucide-react';
 import { BaseModal, ModalHeader } from '@/components/ui';
 import { useSphereContext, useIdentity } from '@/sdk';
+import { getErrorMessage } from '@/sdk/errors';
 
 interface ResolvedInfo {
   nametag?: string;
@@ -77,7 +78,7 @@ export function LookupModal({ isOpen, onClose }: LookupModalProps) {
         setResult(info as ResolvedInfo);
       }
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Lookup failed');
+      setError(getErrorMessage(err));
     } finally {
       setIsLoading(false);
     }
diff --git a/src/components/wallet/modals/PaymentRequestModal.tsx b/src/components/wallet/modals/PaymentRequestModal.tsx
index 5c08643..be5684c 100644
--- a/src/components/wallet/modals/PaymentRequestModal.tsx
+++ b/src/components/wallet/modals/PaymentRequestModal.tsx
@@ -2,6 +2,7 @@ import { Check, Sparkles, Trash2, Loader2, XIcon, ArrowRight, Clock, Receipt, Al
 import { useTransfer } from '@/sdk';
 import { useState } from 'react';
 import { BaseModal, ModalHeader, EmptyState } from '@/components/ui';
+import { getErrorMessage } from '@/sdk/errors';
 
 export enum PaymentRequestStatus {
   PENDING = 'pending',
@@ -56,11 +57,7 @@ export function PaymentRequestsModal({ isOpen, onClose, requests, pendingCount,
       await transfer({ recipient, amount: req.amount.toString(), coinId: req.coinId });
       paid(req);
     } catch (error: unknown) {
-      let errorMessage = 'Transaction failed';
-      if (error instanceof Error) {
-        errorMessage = error.message.includes('Insufficient') ? 'Insufficient funds' : error.message;
-      }
-      setErrors(prev => ({ ...prev, [req.id]: errorMessage }));
+      setErrors(prev => ({ ...prev, [req.id]: getErrorMessage(error) }));
     } finally {
       setProcessingId(null);
     }
diff --git a/src/components/wallet/modals/SendModal.tsx b/src/components/wallet/modals/SendModal.tsx
index 7d290a0..030eb8e 100644
--- a/src/components/wallet/modals/SendModal.tsx
+++ b/src/components/wallet/modals/SendModal.tsx
@@ -2,6 +2,7 @@ import { useState, useEffect, useRef, useCallback } from 'react';
 import { ArrowRight, Loader2, User, CheckCircle, Coins, Hash, Copy, Check } from 'lucide-react';
 import type { Asset } from '@unicitylabs/sphere-sdk';
 import { useAssets, useTransfer, useSphereContext, CurrencyUtils } from '@/sdk';
+import { getErrorMessage } from '@/sdk/errors';
 import { BaseModal, ModalHeader, Button } from '@/components/ui';
 
 type Step = 'recipient' | 'asset' | 'amount' | 'confirm' | 'processing' | 'success';
@@ -169,7 +170,7 @@ export function SendModal({ isOpen, onClose, prefill }: SendModalProps) {
       setStep('success');
     } catch (e: unknown) {
       console.error(e);
-      setRecipientError(e instanceof Error ? e.message : "Transfer failed");
+      setRecipientError(getErrorMessage(e));
       setStep('confirm');
     }
   };
diff --git a/src/components/wallet/modals/SendPaymentRequestModal.tsx b/src/components/wallet/modals/SendPaymentRequestModal.tsx
index 111970f..c9d35a6 100644
--- a/src/components/wallet/modals/SendPaymentRequestModal.tsx
+++ b/src/components/wallet/modals/SendPaymentRequestModal.tsx
@@ -10,6 +10,7 @@ import { ArrowRight, Loader2, User, CheckCircle, Hash, Receipt } from 'lucide-re
 import { TokenRegistry, toSmallestUnit } from '@unicitylabs/sphere-sdk';
 import { BaseModal, ModalHeader, Button } from '@/components/ui';
 import { POPUP_MESSAGES } from '@/shared/messages';
+import { getErrorMessage } from '@/sdk/errors';
 
 type Step = 'recipient' | 'coin' | 'amount' | 'confirm' | 'processing' | 'success';
 
@@ -154,7 +155,7 @@ export function SendPaymentRequestModal({ isOpen, onClose, prefill }: SendPaymen
       setRequestId(result.requestId || null);
       setStep('success');
     } catch (e: unknown) {
-      setError(e instanceof Error ? e.message : 'Failed to send payment request');
+      setError(getErrorMessage(e));
       setStep('confirm');
     }
   };
diff --git a/src/components/wallet/modals/SwapModal.tsx b/src/components/wallet/modals/SwapModal.tsx
index 8c4e0f3..cf2690a 100644
--- a/src/components/wallet/modals/SwapModal.tsx
+++ b/src/components/wallet/modals/SwapModal.tsx
@@ -3,6 +3,7 @@ import { ArrowDownUp, Loader2, TrendingUp, CheckCircle, ArrowDown } from 'lucide
 import type { Asset } from '@unicitylabs/sphere-sdk';
 import { useIdentity, useAssets, useTransfer } from '@/sdk';
 import { CurrencyUtils } from '@/sdk';
+import { getErrorMessage } from '@/sdk/errors';
 import { BaseModal, ModalHeader, Button } from '@/components/ui';
 
 type Step = 'swap' | 'processing' | 'success';
@@ -85,7 +86,7 @@ export function SwapModal({ isOpen, onClose }: SwapModalProps) {
       setStep('success');
     } catch (e: unknown) {
       console.error('Swap failed:', e);
-      setError(e instanceof Error ? e.message : 'Swap failed');
+      setError(getErrorMessage(e));
       setStep('swap');
     }
   };
diff --git a/src/components/wallet/modals/TopUpModal.tsx b/src/components/wallet/modals/TopUpModal.tsx
index 5fb6913..9b9e4a3 100644
--- a/src/components/wallet/modals/TopUpModal.tsx
+++ b/src/components/wallet/modals/TopUpModal.tsx
@@ -2,6 +2,7 @@ import { useState } from 'react';
 import { Plus, Sparkles, CheckCircle, XCircle } from 'lucide-react';
 import { useIdentity } from '@/sdk';
 import { BaseModal, ModalHeader, Button } from '@/components/ui';
+import { getErrorMessage } from '@/sdk/errors';
 
 const FAUCET_API_URL = 'https://faucet.unicity.network/api/v1/faucet/request';
 
@@ -54,7 +55,7 @@ export function TopUpModal({ isOpen, onClose }: TopUpModalProps) {
             success: false,
             coin,
             amount,
-            message: error instanceof Error ? error.message : 'Unknown error',
+            message: getErrorMessage(error),
           }))
         )
       );
@@ -68,7 +69,7 @@ export function TopUpModal({ isOpen, onClose }: TopUpModalProps) {
         setTimeout(() => setFaucetSuccess(false), 3000);
       }
     } catch (error) {
-      setFaucetError(error instanceof Error ? error.message : 'Failed to request tokens');
+      setFaucetError(getErrorMessage(error));
     } finally {
       setIsFaucetLoading(false);
     }
diff --git a/src/components/wallet/onboarding/StartScreen.tsx b/src/components/wallet/onboarding/StartScreen.tsx
index 01887e8..c84a975 100644
--- a/src/components/wallet/onboarding/StartScreen.tsx
+++ b/src/components/wallet/onboarding/StartScreen.tsx
@@ -23,11 +23,9 @@ export function StartScreen({
   return (
     <div className="relative z-10 w-full max-w-90">
       {/* Icon with glow effect */}
-      <div className="relative w-18 h-18 mx-auto mb-6">
-        <div className="absolute inset-0 bg-linear-to-br from-orange-500 to-orange-600 rounded-2xl blur-xl opacity-45" />
-        <div className="relative w-full h-full rounded-2xl bg-linear-to-br from-orange-500 to-orange-600 flex items-center justify-center shadow-xl shadow-orange-500/25">
-          <UnionIcon size={36} />
-        </div>
+      <div className="relative w-20 h-20 mx-auto mb-6 flex items-center justify-center">
+        <div className="absolute inset-0 bg-orange-500 rounded-full blur-2xl opacity-30" />
+        <UnionIcon size={56} className="relative" />
       </div>
 
       <h2 className="text-2xl font-bold text-neutral-900 dark:text-white mb-2 tracking-tight">
diff --git a/src/components/wallet/onboarding/useOnboardingFlow.ts b/src/components/wallet/onboarding/useOnboardingFlow.ts
index 2a78b3f..08d95a5 100644
--- a/src/components/wallet/onboarding/useOnboardingFlow.ts
+++ b/src/components/wallet/onboarding/useOnboardingFlow.ts
@@ -9,6 +9,7 @@
  */
 import { useState, useCallback, useEffect } from "react";
 import { useSphereContext } from "@/sdk/context";
+import { getErrorMessage } from "@/sdk/errors";
 
 export type NametagAvailability = "idle" | "checking" | "available" | "taken";
 
@@ -202,7 +203,7 @@ export function useOnboardingFlow() {
         setProcessingStatus("Setup complete!");
         setIsProcessingComplete(true);
       } catch (e) {
-        const message = e instanceof Error ? e.message : "Invalid recovery phrase";
+        const message = getErrorMessage(e);
         setError(message);
         setStep("restore");
       } finally {
@@ -233,7 +234,7 @@ export function useOnboardingFlow() {
             setProcessingStep(2);
           } catch (e) {
             // Nametag registration failed but wallet was created
-            console.error("Nametag registration failed:", e);
+            console.error("Unicity ID registration failed:", e);
             setProcessingStep(2);
           }
         } else {
@@ -243,7 +244,7 @@ export function useOnboardingFlow() {
         setProcessingStatus("Setup complete!");
         setIsProcessingComplete(true);
       } catch (e) {
-        const message = e instanceof Error ? e.message : "Failed to create wallet";
+        const message = getErrorMessage(e);
         setError(message);
         setStep("passwordSetup");
       } finally {
diff --git a/src/components/wallet/shared/AddressSelector.tsx b/src/components/wallet/shared/AddressSelector.tsx
index be031e3..e2cca6a 100644
--- a/src/components/wallet/shared/AddressSelector.tsx
+++ b/src/components/wallet/shared/AddressSelector.tsx
@@ -24,7 +24,7 @@ export function AddressSelector({ compact = true }: AddressSelectorProps) {
       setCopied('nametag');
       setTimeout(() => setCopied(false), 2000);
     } catch (err) {
-      console.error('Failed to copy nametag:', err);
+      console.error('Failed to copy Unicity ID:', err);
     }
   }, [nametag]);
 
diff --git a/src/components/wallet/shared/RegisterNametagModal.tsx b/src/components/wallet/shared/RegisterNametagModal.tsx
index 90f02db..5432433 100644
--- a/src/components/wallet/shared/RegisterNametagModal.tsx
+++ b/src/components/wallet/shared/RegisterNametagModal.tsx
@@ -3,6 +3,7 @@ import { X, Loader2, ArrowRight, Tag, CheckCircle2, AlertCircle } from 'lucide-r
 import { useQueryClient } from '@tanstack/react-query';
 import { useSphereContext } from '@/sdk/context';
 import { SPHERE_KEYS } from '@/sdk/queryKeys';
+import { getErrorMessage } from '@/sdk/errors';
 
 type NametagAvailability = 'idle' | 'checking' | 'available' | 'taken';
 
@@ -93,7 +94,7 @@ export function RegisterNametagModal({ isOpen, onClose }: RegisterNametagModalPr
         setNametagInput('');
       }, 1500);
     } catch (e) {
-      setError(e instanceof Error ? e.message : 'Registration failed');
+      setError(getErrorMessage(e));
     } finally {
       setIsBusy(false);
     }
diff --git a/src/platform/extension/SphereProvider.tsx b/src/platform/extension/SphereProvider.tsx
index b7aecdc..334358c 100644
--- a/src/platform/extension/SphereProvider.tsx
+++ b/src/platform/extension/SphereProvider.tsx
@@ -3,6 +3,7 @@ import { useQueryClient } from '@tanstack/react-query';
 import { TokenRegistry, NETWORKS } from '@unicitylabs/sphere-sdk';
 import { SphereContext, type SphereContextValue } from '@/sdk/context';
 import { SPHERE_KEYS } from '@/sdk/queryKeys';
+import { getErrorMessage } from '@/sdk/errors';
 import type { WalletIdentity } from '@/sdk/types';
 import type { Asset, Token, TransactionHistoryEntry } from '@unicitylabs/sphere-sdk';
 import type { AggregatorConfig, NametagInfo, NametagResolution, PendingTransaction } from '@/shared/types';
@@ -76,7 +77,7 @@ export function ExtensionSphereProvider({ children }: { children: React.ReactNod
           } catch { /* non-fatal — identity loaded without nametag */ }
         }
       } catch (err) {
-        setError((err as Error).message);
+        setError(getErrorMessage(err));
       } finally {
         setIsLoading(false);
       }
diff --git a/src/platform/extension/background/index.ts b/src/platform/extension/background/index.ts
index ba217a5..d44fea8 100644
--- a/src/platform/extension/background/index.ts
+++ b/src/platform/extension/background/index.ts
@@ -8,6 +8,7 @@
  */
 
 import { handleContentMessage, handlePopupMessage } from './message-handler';
+import { getErrorMessage } from '@/sdk/errors';
 import { initConnectHost, destroyConnectHost, isConnectHostActive, openPopupForConnect } from './connect-host';
 import { isExtensionConnectEnvelope, EXT_MSG_TO_HOST } from '@unicitylabs/sphere-sdk/connect/browser';
 
@@ -48,7 +49,7 @@ chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
       console.error('Message handler error:', error);
       sendResponse({
         success: false,
-        error: error.message || 'Unknown error',
+        error: getErrorMessage(error),
       });
     });
 
diff --git a/src/platform/extension/background/message-handler.ts b/src/platform/extension/background/message-handler.ts
index 6375c3a..1322eb0 100644
--- a/src/platform/extension/background/message-handler.ts
+++ b/src/platform/extension/background/message-handler.ts
@@ -9,6 +9,7 @@
  */
 
 import { walletManager } from './wallet-manager';
+import { getErrorMessage } from '@/sdk/errors';
 import {
   initConnectHost,
   destroyConnectHost,
@@ -154,7 +155,7 @@ export async function handleContentMessage(
     return {
       type: `${type}_RESPONSE`,
       success: false,
-      error: (error as Error).message || 'Unknown error',
+      error: getErrorMessage(error),
     };
   }
 }
@@ -449,7 +450,7 @@ export async function handlePopupMessage(
     console.error('Background popup handler error:', error);
     return {
       success: false,
-      error: (error as Error).message || 'Unknown error',
+      error: getErrorMessage(error),
     };
   }
 }
@@ -725,7 +726,7 @@ async function handleSignNostrEventRequest(
     return {
       type: 'SPHERE_SIGN_NOSTR_EVENT_RESPONSE',
       success: false,
-      error: (error as Error).message || 'Failed to sign event',
+      error: getErrorMessage(error),
     };
   }
 }
@@ -766,7 +767,7 @@ async function handleResolveNametag(
     return {
       type: 'SPHERE_RESOLVE_NAMETAG_RESPONSE',
       success: false,
-      error: (error as Error).message,
+      error: getErrorMessage(error),
     };
   }
 }
@@ -807,7 +808,7 @@ async function handleCheckNametagAvailable(
     return {
       type: 'SPHERE_CHECK_NAMETAG_AVAILABLE_RESPONSE',
       success: false,
-      error: (error as Error).message,
+      error: getErrorMessage(error),
     };
   }
 }
@@ -825,7 +826,7 @@ async function handlePopupCheckNametagAvailable(
   } catch (error) {
     return {
       success: false,
-      error: (error as Error).message || 'Failed to check nametag availability',
+      error: getErrorMessage(error),
     };
   }
 }
@@ -839,7 +840,7 @@ async function handlePopupRegisterNametag(
 
   try {
     const cleanTag = nametag.replace('@', '').trim().toLowerCase();
-    console.log(`[NametagHandler] Registering nametag: @${cleanTag}`);
+    console.log(`[NametagHandler] Registering Unicity ID: @${cleanTag}`);
 
     const result = await nametagMintService.register(cleanTag);
 
@@ -854,13 +855,13 @@ async function handlePopupRegisterNametag(
       status: 'active',
     };
 
-    console.log(`[NametagHandler] Nametag registered: @${cleanTag}`);
+    console.log(`[NametagHandler] Unicity ID registered: @${cleanTag}`);
     return { success: true, nametag: nametagInfo };
   } catch (error) {
     console.error('[NametagHandler] Registration error:', error);
     return {
       success: false,
-      error: (error as Error).message || 'Failed to register nametag',
+      error: getErrorMessage(error),
     };
   }
 }
@@ -880,7 +881,7 @@ async function handlePopupGetMyNametag(): Promise<{
   } catch (error) {
     return {
       success: false,
-      error: (error as Error).message || 'Failed to get nametag',
+      error: getErrorMessage(error),
     };
   }
 }
@@ -920,7 +921,7 @@ async function handleGetMyNametag(
     return {
       type: 'SPHERE_GET_MY_NAMETAG_RESPONSE',
       success: false,
-      error: (error as Error).message || 'Failed to get nametag',
+      error: getErrorMessage(error),
     };
   }
 }
@@ -936,7 +937,7 @@ async function handlePopupGetAggregatorConfig(): Promise<{
   } catch (error) {
     return {
       success: false,
-      error: (error as Error).message || 'Failed to get aggregator config',
+      error: getErrorMessage(error),
     };
   }
 }
@@ -951,7 +952,7 @@ async function handlePopupSetAggregatorConfig(config: {
   } catch (error) {
     return {
       success: false,
-      error: (error as Error).message || 'Failed to set aggregator config',
+      error: getErrorMessage(error),
     };
   }
 }
@@ -970,7 +971,7 @@ async function handlePopupSendTokens(
   } catch (error) {
     return {
       success: false,
-      error: (error as Error).message || 'Failed to send tokens',
+      error: getErrorMessage(error),
     };
   }
 }
@@ -987,7 +988,7 @@ async function handlePopupResolveNametag(
   } catch (error) {
     return {
       success: false,
-      error: (error as Error).message || 'Failed to resolve nametag',
+      error: getErrorMessage(error),
     };
   }
 }
@@ -1043,10 +1044,10 @@ async function handleApproveTransaction(requestId: string): Promise<{ success: b
       type: 'SPHERE_TRANSACTION_RESULT',
       requestId,
       success: false,
-      error: (error as Error).message,
+      error: getErrorMessage(error),
     });
 
-    return { success: false, error: (error as Error).message };
+    return { success: false, error: getErrorMessage(error) };
   }
 }
 
diff --git a/src/platform/extension/background/wallet-manager.ts b/src/platform/extension/background/wallet-manager.ts
index 17420a4..3b94d77 100644
--- a/src/platform/extension/background/wallet-manager.ts
+++ b/src/platform/extension/background/wallet-manager.ts
@@ -11,10 +11,14 @@
  * - Nametag operations
  */
 
-import { Sphere } from '@unicitylabs/sphere-sdk';
+import { Sphere, logger } from '@unicitylabs/sphere-sdk';
 import type { Asset, Token, TransactionHistoryEntry } from '@unicitylabs/sphere-sdk';
 import { createBrowserProviders } from '@unicitylabs/sphere-sdk/impl/browser';
 
+// Expose SDK logger on globalThis for runtime debugging in service worker console.
+// Usage: logger.configure({ debug: true }) or logger.setTagDebug("Nostr", true)
+(globalThis as unknown as Record<string, unknown>).logger = logger;
+
 type BrowserProviders = ReturnType<typeof createBrowserProviders>;
 import type {
   IdentityInfo,
@@ -183,12 +187,12 @@ export class WalletManager {
       const hasNametag = (this.sphere as any)._payments?.hasNametag?.() ?? false;
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
       const nametagData = (this.sphere as any)._payments?.getNametag?.();
-      console.log('[WalletManager] Nametag loaded:', hasNametag, nametagData ? `name=${nametagData.name}` : '(none)');
+      console.log('[WalletManager] Unicity ID loaded:', hasNametag, nametagData ? `name=${nametagData.name}` : '(none)');
       if (!hasNametag) {
         console.warn('[WalletManager] WARNING: No nametag token loaded — PROXY transfers will be rejected');
       }
     } catch (e) {
-      console.log('[WalletManager] Could not check nametag state:', e);
+      console.log('[WalletManager] Could not check Unicity ID state:', e);
     }
 
     // Verify nametag binding points to our current transport pubkey
@@ -597,7 +601,7 @@ export class WalletManager {
     try {
       const transport = sphere.getTransport();
       if (!transport.resolveNametag) {
-        console.warn('[WalletManager] Transport does not support nametag resolution');
+        console.warn('[WalletManager] Transport does not support Unicity ID resolution');
         return null;
       }
 
@@ -612,7 +616,7 @@ export class WalletManager {
         proxyAddress: pubkey, // The SDK transport handles routing
       };
     } catch (error) {
-      console.error('[WalletManager] Nametag resolution error:', error);
+      console.error('[WalletManager] Unicity ID resolution error:', error);
       return null;
     }
   }
@@ -634,7 +638,7 @@ export class WalletManager {
         console.log('[WalletManager] isNametagAvailable result for', cleanTag, ':', result);
         return result;
       } catch (error) {
-        console.error('[WalletManager] Nametag availability check error:', error);
+        console.error('[WalletManager] Unicity ID availability check error:', error);
         return false;
       }
     }
@@ -663,10 +667,10 @@ export class WalletManager {
 
       const resolved = await transport.resolveNametag?.(cleanTag);
       const available = !resolved;
-      console.log(`[WalletManager] Standalone nametag check for @${cleanTag}: ${available ? 'available' : 'taken'}`);
+      console.log(`[WalletManager] Standalone Unicity ID check for @${cleanTag}: ${available ? 'available' : 'taken'}`);
       return available;
     } catch (error) {
-      console.error('[WalletManager] Standalone nametag check error:', error);
+      console.error('[WalletManager] Standalone Unicity ID check error:', error);
       return false;
     } finally {
       try { await tempProviders?.transport?.disconnect?.(); } catch { /* ignore */ }
@@ -681,7 +685,7 @@ export class WalletManager {
     // failed on a previous attempt), skip re-registration and just retry the mint.
     const existingNametag = sphere.identity?.nametag;
     if (existingNametag) {
-      console.log(`[WalletManager] Identity already has nametag @${existingNametag}, skipping NOSTR binding`);
+      console.log(`[WalletManager] Identity already has Unicity ID @${existingNametag}, skipping NOSTR binding`);
       if (existingNametag !== cleanTag) {
         throw new Error(`Cannot register @${cleanTag}: address already bound to @${existingNametag}`);
       }
@@ -778,12 +782,12 @@ export class WalletManager {
 
       const resolved: string | null = await transport.resolveNametag(stored.name);
       if (!resolved) {
-        console.warn(`[WalletManager] Nametag @${stored.name} not found on relay`);
+        console.warn(`[WalletManager] Unicity ID @${stored.name} not found on relay`);
         return;
       }
 
       if (resolved === myTransportPubkey) {
-        console.log(`[WalletManager] Nametag @${stored.name} binding OK — matches transport pubkey`);
+        console.log(`[WalletManager] Unicity ID @${stored.name} binding OK — matches transport pubkey`);
         // Binding is fine, but still check if the on-chain token needs re-minting
         await this.ensureNametagTokenMigrated(stored.name);
         return;
@@ -829,7 +833,7 @@ export class WalletManager {
         console.error(`[WalletManager] PROXY transfers will fail until nametag is re-minted`);
       }
     } catch (e) {
-      console.warn('[WalletManager] Nametag binding verification failed:', e);
+      console.warn('[WalletManager] Unicity ID binding verification failed:', e);
     }
   }
 
diff --git a/src/platform/extension/popup/main.tsx b/src/platform/extension/popup/main.tsx
index 228f2fd..5402e67 100644
--- a/src/platform/extension/popup/main.tsx
+++ b/src/platform/extension/popup/main.tsx
@@ -3,6 +3,7 @@ import ReactDOM from 'react-dom/client';
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
 import { ExtensionSphereProvider } from '../SphereProvider';
 import { PopupApp } from './PopupApp';
+import { getErrorMessage } from '@/sdk/errors';
 import './styles.css';
 
 const queryClient = new QueryClient({
@@ -11,6 +12,11 @@ const queryClient = new QueryClient({
       staleTime: 30_000,
       retry: 1,
     },
+    mutations: {
+      onError: (err) => {
+        console.error('[Mutation error]', getErrorMessage(err));
+      },
+    },
   },
 });
 
diff --git a/src/sdk/errors.ts b/src/sdk/errors.ts
new file mode 100644
index 0000000..8ff7ce8
--- /dev/null
+++ b/src/sdk/errors.ts
@@ -0,0 +1,27 @@
+import { isSphereError, type SphereErrorCode } from '@unicitylabs/sphere-sdk';
+
+// Friendly overrides for codes where SDK message is too technical.
+// For codes NOT listed here, we use the SDK's own err.message (which is
+// already user-readable, e.g. "Unicity ID @bob is already taken").
+const FRIENDLY_OVERRIDES: Partial<Record<SphereErrorCode, string>> = {
+  TRANSPORT_ERROR: 'Connection issue. Check your network',
+  TIMEOUT: 'Request timed out. Try again',
+  NETWORK_ERROR: 'Network error. Check your connection',
+  AGGREGATOR_ERROR: 'Network unavailable. Try again',
+  DECRYPTION_ERROR: 'Wrong password',
+  STORAGE_ERROR: 'Storage error',
+  MODULE_NOT_AVAILABLE: 'Feature not available',
+};
+
+export function getErrorMessage(err: unknown): string {
+  if (isSphereError(err)) {
+    return FRIENDLY_OVERRIDES[err.code] ?? err.message;
+  }
+  return err instanceof Error ? err.message : 'Something went wrong';
+}
+
+export function getErrorCode(err: unknown): SphereErrorCode | null {
+  return isSphereError(err) ? err.code : null;
+}
+
+export { isSphereError };