fix: make debug mode toggle work at runtime

The debug/insecure warning banner was only controlled by the compile-time
DEBUG constant. The settings easter egg checkbox toggled state.debugMode
and the runtime log flag, but neither index.js nor helpers.js checked
these runtime values — the banner was created/updated based solely on
the compile-time constant.

Changes:
- Extract banner logic into updateDebugBanner() in helpers.js that
  checks isDebug() (combines compile-time DEBUG and runtime debugMode)
- Banner is dynamically created/removed: appears when debug is enabled,
  removed when disabled (no stale banners)
- index.js init() syncs runtime debug flag from persisted state before
  first render, then delegates to updateDebugBanner()
- settings.js calls updateDebugBanner() after the checkbox change so
  the banner immediately reflects the new state
- Debug mode persists across popup close/reopen via state.debugMode

Fixes the bug where the settings debug toggle had no visible effect.

.dockerignore

@@ -1,4 +1,3 @@
-.git
 node_modules
 .DS_Store
 dist

Dockerfile

@@ -1,7 +1,7 @@
 # node:22-slim (22.x LTS), 2026-02-24
 FROM node@sha256:5373f1906319b3a1f291da5d102f4ce5c77ccbe29eb637f072b6c7b70443fc36
 
-RUN apt-get update && apt-get install -y --no-install-recommends make && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && apt-get install -y --no-install-recommends make git && rm -rf /var/lib/apt/lists/*
 RUN corepack enable && corepack prepare yarn@1.22.22 --activate
 
 WORKDIR /app

build.js

@@ -11,9 +11,51 @@ function ensureDir(dir) {
     fs.mkdirSync(dir, { recursive: true });
 }
 
+function getBuildInfo() {
+    const pkg = JSON.parse(
+        fs.readFileSync(path.join(__dirname, "package.json"), "utf8"),
+    );
+    let commitHash = "unknown";
+    try {
+        commitHash = execSync("git rev-parse --short HEAD", {
+            encoding: "utf8",
+        }).trim();
+    } catch (_) {
+        // not a git repo or git not available
+    }
+    let commitHashFull = "unknown";
+    try {
+        commitHashFull = execSync("git rev-parse HEAD", {
+            encoding: "utf8",
+        }).trim();
+    } catch (_) {
+        // not a git repo or git not available
+    }
+    return {
+        version: pkg.version,
+        license: pkg.license,
+        author: pkg.author,
+        commitHash,
+        commitHashFull,
+        buildDate: new Date().toISOString().slice(0, 10),
+    };
+}
+
 async function build() {
     console.log("Building AutistMask extension...");
 
+    const buildInfo = getBuildInfo();
+    console.log("Build info:", buildInfo);
+
+    const define = {
+        __BUILD_VERSION__: JSON.stringify(buildInfo.version),
+        __BUILD_LICENSE__: JSON.stringify(buildInfo.license),
+        __BUILD_AUTHOR__: JSON.stringify(buildInfo.author),
+        __BUILD_COMMIT__: JSON.stringify(buildInfo.commitHash),
+        __BUILD_COMMIT_FULL__: JSON.stringify(buildInfo.commitHashFull),
+        __BUILD_DATE__: JSON.stringify(buildInfo.buildDate),
+    };
+
     // compile tailwind CSS
     console.log("Compiling Tailwind CSS...");
     const tailwindInput = path.join(SRC, "popup", "styles", "main.css");
@@ -38,6 +80,7 @@ async function build() {
             platform: "browser",
             target: ["chrome110", "firefox110"],
             minify: true,
+            define,
         });
 
         // bundle background script
@@ -49,6 +92,7 @@ async function build() {
             platform: "browser",
             target: ["chrome110", "firefox110"],
             minify: true,
+            define,
         });
 
         // bundle content script
@@ -60,6 +104,7 @@ async function build() {
             platform: "browser",
             target: ["chrome110", "firefox110"],
             minify: true,
+            define,
         });
 
         // bundle inpage script (injected into page context, separate file)
@@ -71,6 +116,7 @@ async function build() {
             platform: "browser",
             target: ["chrome110", "firefox110"],
             minify: true,
+            define,
         });
 
         // copy popup HTML

src/background/index.js

@@ -2,12 +2,16 @@
 // Handles EIP-1193 RPC requests from content scripts and proxies
 // non-sensitive calls to the configured Ethereum JSON-RPC endpoint.
 
-const {
-    ETHEREUM_MAINNET_CHAIN_ID,
-    DEFAULT_RPC_URL,
-} = require("../shared/constants");
+const { DEFAULT_RPC_URL } = require("../shared/constants");
+const { SUPPORTED_CHAIN_IDS, networkByChainId } = require("../shared/networks");
+const { onChainSwitch } = require("../shared/chainSwitch");
 const { getBytes } = require("ethers");
-const { state, loadState, saveState } = require("../shared/state");
+const {
+    state,
+    loadState,
+    saveState,
+    currentNetwork,
+} = require("../shared/state");
 const { refreshBalances, getProvider } = require("../shared/balances");
 const { debugFetch } = require("../shared/log");
 const { decryptWithPassword } = require("../shared/vault");
@@ -329,31 +333,43 @@ async function handleRpc(method, params, origin) {
     }
 
     if (method === "eth_chainId") {
-        return { result: ETHEREUM_MAINNET_CHAIN_ID };
+        return { result: currentNetwork().chainId };
     }
 
     if (method === "net_version") {
-        return { result: "1" };
+        return { result: currentNetwork().networkVersion };
     }
 
     if (method === "wallet_switchEthereumChain") {
         const chainId = params?.[0]?.chainId;
-        if (chainId === ETHEREUM_MAINNET_CHAIN_ID) {
+        if (chainId === currentNetwork().chainId) {
+            return { result: null };
+        }
+        if (SUPPORTED_CHAIN_IDS.has(chainId)) {
+            const target = networkByChainId(chainId);
+            await onChainSwitch(target.id);
+            broadcastChainChanged(target.chainId);
             return { result: null };
         }
         return {
             error: {
                 code: 4902,
-                message: "AutistMask only supports Ethereum mainnet.",
+                message:
+                    "AutistMask supports Ethereum Mainnet and Sepolia Testnet only.",
             },
         };
     }
 
     if (method === "wallet_addEthereumChain") {
+        const chainId = params?.[0]?.chainId;
+        if (SUPPORTED_CHAIN_IDS.has(chainId)) {
+            return { result: null };
+        }
         return {
             error: {
                 code: 4902,
-                message: "AutistMask only supports Ethereum mainnet.",
+                message:
+                    "AutistMask supports Ethereum Mainnet and Sepolia Testnet only.",
             },
         };
     }
@@ -499,6 +515,27 @@ async function handleRpc(method, params, origin) {
     return { error: { message: "Unsupported method: " + method } };
 }
 
+// Broadcast chainChanged to all tabs when the network is switched.
+function broadcastChainChanged(chainId) {
+    tabsApi.query({}, (tabs) => {
+        for (const tab of tabs) {
+            tabsApi.sendMessage(
+                tab.id,
+                {
+                    type: "AUTISTMASK_EVENT",
+                    eventName: "chainChanged",
+                    data: chainId,
+                },
+                () => {
+                    if (runtime.lastError) {
+                        // expected for tabs without our content script
+                    }
+                },
+            );
+        }
+    });
+}
+
 // Broadcast accountsChanged to all tabs, respecting per-address permissions
 async function broadcastAccountsChanged() {
     // Clear non-remembered approvals on address switch

src/content/inpage.js

@@ -2,7 +2,10 @@
 // Creates window.ethereum (EIP-1193 provider) and announces via EIP-6963.
 
 (function () {
-    const CHAIN_ID = "0x1"; // Ethereum mainnet
+    // Defaults to mainnet; updated dynamically via eth_chainId on init and
+    // chainChanged events from the extension.
+    let currentChainId = "0x1";
+    let currentNetworkVersion = "1";
 
     const listeners = {};
     let nextId = 1;
@@ -28,6 +31,12 @@
         if (event.source !== window) return;
         if (event.data?.type !== "AUTISTMASK_EVENT") return;
         const { eventName, data } = event.data;
+        if (eventName === "chainChanged") {
+            currentChainId = data;
+            currentNetworkVersion = String(parseInt(data, 16));
+            provider.chainId = currentChainId;
+            provider.networkVersion = currentNetworkVersion;
+        }
         emit(eventName, data);
     });
 
@@ -57,8 +66,8 @@
     const provider = {
         isAutistMask: true,
         isMetaMask: true, // compatibility — many dApps check this
-        chainId: CHAIN_ID,
-        networkVersion: "1",
+        chainId: currentChainId,
+        networkVersion: currentNetworkVersion,
         selectedAddress: null,
 
         async request(args) {
@@ -75,6 +84,12 @@
                         ? result[0]
                         : null;
             }
+            if (args.method === "eth_chainId" && result) {
+                currentChainId = result;
+                currentNetworkVersion = String(parseInt(result, 16));
+                provider.chainId = currentChainId;
+                provider.networkVersion = currentNetworkVersion;
+            }
             return result;
         },
 
@@ -189,4 +204,19 @@
 
     window.addEventListener("eip6963:requestProvider", announceProvider);
     announceProvider();
+
+    // Fetch the current chain ID from the extension on load so the provider
+    // reflects the selected network immediately (covers Sepolia etc.).
+    sendRequest({ method: "eth_chainId", params: [] })
+        .then((chainId) => {
+            if (chainId) {
+                currentChainId = chainId;
+                currentNetworkVersion = String(parseInt(chainId, 16));
+                provider.chainId = currentChainId;
+                provider.networkVersion = currentNetworkVersion;
+            }
+        })
+        .catch(() => {
+            // Best-effort — keep defaults.
+        });
 })();

src/popup/index.html

@@ -882,6 +882,24 @@
                     </div>
                 </div>
 
+                <div class="bg-well p-3 mx-1 mb-3">
+                    <h3 class="font-bold mb-1">Network</h3>
+                    <p class="text-xs text-muted mb-1">
+                        Select the Ethereum network. Switching networks will
+                        update the RPC and Blockscout endpoints to their
+                        defaults.
+                    </p>
+                    <div class="text-xs flex items-center gap-1">
+                        <select
+                            id="settings-network"
+                            class="border border-border p-1 bg-bg text-fg text-xs cursor-pointer"
+                        >
+                            <option value="mainnet">Ethereum Mainnet</option>
+                            <option value="sepolia">Sepolia Testnet</option>
+                        </select>
+                    </div>
+                </div>
+
                 <div class="bg-well p-3 mx-1 mb-3">
                     <h3 class="font-bold mb-1">Ethereum RPC</h3>
                     <p class="text-xs text-muted mb-1">
@@ -984,6 +1002,64 @@
                     </p>
                     <div id="settings-denied-sites"></div>
                 </div>
+
+                <div class="bg-well p-3 mx-1 mb-3">
+                    <h3 class="font-bold mb-1">About</h3>
+                    <p class="text-xs mb-2">
+                        <a
+                            href="https://git.eeqj.de/sneak/AutistMask"
+                            class="underline decoration-dashed"
+                            target="_blank"
+                            rel="noopener noreferrer"
+                            >AutistMask</a
+                        >
+                        — Minimal Ethereum wallet browser extension.
+                    </p>
+                    <div class="text-xs">
+                        <div class="mb-1">
+                            <span class="text-muted">License:</span>
+                            <span id="about-license"></span>
+                        </div>
+                        <div class="mb-1">
+                            <span class="text-muted">Author:</span>
+                            <span id="about-author"></span>
+                        </div>
+                        <div class="mb-1">
+                            <span class="text-muted">Version:</span>
+                            <span
+                                id="about-version"
+                                class="cursor-pointer select-none"
+                            ></span>
+                        </div>
+                        <div class="mb-1">
+                            <span class="text-muted">Release date:</span>
+                            <span id="about-release-date"></span>
+                        </div>
+                        <div>
+                            <span class="text-muted">Commit:</span>
+                            <a
+                                id="about-commit-link"
+                                class="underline decoration-dashed"
+                                target="_blank"
+                                rel="noopener noreferrer"
+                            ></a>
+                        </div>
+                    </div>
+                </div>
+
+                <div
+                    id="settings-debug-well"
+                    class="bg-well p-3 mx-1 mb-3"
+                    style="display: none"
+                >
+                    <h3 class="font-bold mb-1">Debug</h3>
+                    <label
+                        class="text-xs flex items-center gap-1 cursor-pointer"
+                    >
+                        <input type="checkbox" id="settings-debug-mode" />
+                        Enable debug mode
+                    </label>
+                </div>
             </div>
 
             <!-- ============ DELETE WALLET CONFIRM ============ -->

src/popup/index.js

@@ -1,11 +1,24 @@
 // AutistMask popup entry point.
 // Loads state, initializes views, triggers first render.
 
-const { DEBUG } = require("../shared/constants");
-const { state, saveState, loadState } = require("../shared/state");
+const {
+    state,
+    saveState,
+    loadState,
+    currentNetwork,
+} = require("../shared/state");
+const { isDebug, setRuntimeDebug } = require("../shared/log");
 const { refreshPrices } = require("../shared/prices");
 const { refreshBalances } = require("../shared/balances");
-const { $, showView } = require("./views/helpers");
+const {
+    $,
+    showView,
+    updateDebugBanner,
+    setRenderMain,
+    pushCurrentView,
+    goBack,
+    clearViewStack,
+} = require("./views/helpers");
 const { applyTheme } = require("./theme");
 
 const home = require("./views/home");
@@ -53,15 +66,42 @@ async function doRefreshAndRender() {
 const ctx = {
     renderWalletList,
     doRefreshAndRender,
-    showAddWalletView: () => addWallet.show(),
-    showAddressDetail: () => addressDetail.show(),
-    showAddressToken: () => addressToken.show(),
-    showAddTokenView: () => addToken.show(),
-    showConfirmTx: (txInfo) => confirmTx.show(txInfo),
-    showReceive: () => receive.show(),
-    showTransactionDetail: (tx) => transactionDetail.show(tx),
-    showSettingsView: () => settings.show(),
-    showSettingsAddTokenView: () => settingsAddToken.show(),
+    showAddWalletView: () => {
+        pushCurrentView();
+        addWallet.show();
+    },
+    showAddressDetail: () => {
+        pushCurrentView();
+        addressDetail.show();
+    },
+    showAddressToken: () => {
+        pushCurrentView();
+        addressToken.show();
+    },
+    showAddTokenView: () => {
+        pushCurrentView();
+        addToken.show();
+    },
+    showConfirmTx: (txInfo) => {
+        pushCurrentView();
+        confirmTx.show(txInfo);
+    },
+    showReceive: () => {
+        pushCurrentView();
+        receive.show();
+    },
+    showTransactionDetail: (tx) => {
+        pushCurrentView();
+        transactionDetail.show(tx);
+    },
+    showSettingsView: () => {
+        pushCurrentView();
+        settings.show();
+    },
+    showSettingsAddTokenView: () => {
+        pushCurrentView();
+        settingsAddToken.show();
+    },
 };
 
 // Views that can be fully re-rendered from persisted state.
@@ -167,18 +207,15 @@ function fallbackView() {
 }
 
 async function init() {
-    if (DEBUG) {
-        const banner = document.createElement("div");
-        banner.id = "debug-banner";
-        banner.textContent = "DEBUG / INSECURE";
-        banner.style.cssText =
-            "background:#c00;color:#fff;text-align:center;font-size:10px;padding:1px 0;font-family:monospace;position:sticky;top:0;z-index:9999;";
-        document.body.prepend(banner);
-    }
-
     await loadState();
     applyTheme(state.theme);
 
+    // Sync runtime debug flag from persisted state before first render
+    setRuntimeDebug(state.debugMode);
+
+    // Create the debug/testnet banner if needed (uses runtime debug state)
+    updateDebugBanner();
+
     // Auto-default active address
     if (
         state.activeAddress === null &&
@@ -208,13 +245,15 @@ async function init() {
                 .getElementById("view-settings")
                 .classList.contains("hidden")
         ) {
-            renderWalletList();
-            showView("main");
+            goBack();
             return;
         }
+        pushCurrentView();
         settings.show();
     });
 
+    setRenderMain(renderWalletList);
+
     welcome.init(ctx);
     addWallet.init(ctx);
     home.init(ctx);

src/popup/styles/main.css

@@ -10,7 +10,7 @@
     --color-border: #000000;
     --color-border-light: #cccccc;
     --color-hover: #eeeeee;
-    --color-well: #f5f5f5;
+    --color-well: #e8e8e8;
     --color-danger-well: #fef2f2;
     --color-section: #dddddd;
 }

src/popup/views/addToken.js

@@ -1,4 +1,4 @@
-const { $, showView, showFlash } = require("./helpers");
+const { $, showFlash, goBack } = require("./helpers");
 const { getTopTokens } = require("../../shared/tokenList");
 const { state, saveState } = require("../../shared/state");
 const { lookupTokenInfo } = require("../../shared/balances");
@@ -59,7 +59,12 @@ function init(ctx) {
             });
             await saveState();
             ctx.doRefreshAndRender();
-            ctx.showAddressDetail();
+            // Pop the stack (back to address detail) and re-render it
+            // so the newly added token is visible immediately.
+            if (state.viewStack.length > 0) {
+                state.viewStack.pop();
+            }
+            require("./addressDetail").show();
         } catch (e) {
             const detail = e.shortMessage || e.message || String(e);
             log.errorf("Token lookup failed for", contractAddr, detail);
@@ -69,7 +74,9 @@ function init(ctx) {
         }
     });
 
-    $("btn-add-token-back").addEventListener("click", ctx.showAddressDetail);
+    $("btn-add-token-back").addEventListener("click", () => {
+        goBack();
+    });
 }
 
 module.exports = { init, show };

src/popup/views/addWallet.js

@@ -1,4 +1,4 @@
-const { $, showView, showFlash } = require("./helpers");
+const { $, showView, showFlash, goBack, clearViewStack } = require("./helpers");
 const {
     generateMnemonic,
     hdWalletFromMnemonic,
@@ -143,6 +143,7 @@ async function importMnemonic(ctx) {
     state.wallets.push(wallet);
     state.hasWallet = true;
     await saveState();
+    clearViewStack();
     ctx.renderWalletList();
     showView("main");
 
@@ -198,6 +199,7 @@ async function importPrivateKey(ctx) {
     });
     state.hasWallet = true;
     await saveState();
+    clearViewStack();
     ctx.renderWalletList();
     showView("main");
 
@@ -249,6 +251,7 @@ async function importXprvKey(ctx) {
     state.wallets.push(wallet);
     state.hasWallet = true;
     await saveState();
+    clearViewStack();
     ctx.renderWalletList();
     showView("main");
 
@@ -297,12 +300,7 @@ function init(ctx) {
 
     // Back button
     $("btn-add-wallet-back").addEventListener("click", () => {
-        if (!state.hasWallet) {
-            showView("welcome");
-        } else {
-            ctx.renderWalletList();
-            showView("main");
-        }
+        goBack();
     });
 }
 

src/popup/views/addressDetail.js

@@ -10,6 +10,8 @@ const {
     truncateMiddle,
     renderAddressHtml,
     attachCopyHandlers,
+    goBack,
+    pushCurrentView,
 } = require("./helpers");
 const { state, currentAddress, saveState } = require("../../shared/state");
 const { formatUsd, getAddressValueUsd } = require("../../shared/prices");
@@ -247,8 +249,7 @@ function init(_ctx) {
     ctx = _ctx;
 
     $("btn-address-back").addEventListener("click", () => {
-        ctx.renderWalletList();
-        showView("main");
+        goBack();
     });
 
     $("btn-send").addEventListener("click", () => {
@@ -266,6 +267,7 @@ function init(_ctx) {
         $("send-token-static").classList.add("hidden");
         updateSendBalance();
         resetSendValidation();
+        pushCurrentView();
         showView("send");
     });
 
@@ -295,6 +297,7 @@ function init(_ctx) {
     $("btn-export-privkey").addEventListener("click", () => {
         moreDropdown.classList.add("hidden");
         moreBtn.classList.remove("bg-fg", "text-bg");
+        pushCurrentView();
         const wallet = state.wallets[state.selectedWallet];
         const addr = wallet.addresses[state.selectedAddress];
         const blockieEl = $("export-privkey-jazzicon");
@@ -367,7 +370,7 @@ function init(_ctx) {
     $("btn-export-privkey-back").addEventListener("click", () => {
         $("export-privkey-value").textContent = "";
         $("export-privkey-password").value = "";
-        show();
+        goBack();
     });
 }
 

src/popup/views/addressToken.js

@@ -13,6 +13,8 @@ const {
     balanceLine,
     renderAddressHtml,
     attachCopyHandlers,
+    goBack,
+    pushCurrentView,
 } = require("./helpers");
 const { state, currentAddress, saveState } = require("../../shared/state");
 const { TOKEN_BY_ADDRESS, resolveSymbol } = require("../../shared/tokenList");
@@ -148,7 +150,7 @@ function show() {
     attachCopyHandlers($("address-token-line"));
 
     // USD total for this token only
-    const usdVal = price ? amount * price : 0;
+    const usdVal = price ? amount * price : null;
     const usdStr = formatUsd(usdVal);
     $("address-token-usd-total").innerHTML = usdStr || " ";
 
@@ -331,7 +333,7 @@ function init(_ctx) {
     });
 
     $("btn-address-token-back").addEventListener("click", () => {
-        ctx.showAddressDetail();
+        goBack();
     });
 
     $("btn-address-token-send").addEventListener("click", () => {
@@ -365,6 +367,7 @@ function init(_ctx) {
         attachCopyHandlers($("send-token-static"));
         updateSendBalance();
         resetSendValidation();
+        pushCurrentView();
         showView("send");
     });
 

src/popup/views/approval.js

@@ -8,8 +8,9 @@ const {
     renderAddressHtml,
     attachCopyHandlers,
 } = require("./helpers");
-const { state, saveState } = require("../../shared/state");
+const { state, saveState, currentNetwork } = require("../../shared/state");
 const { formatEther, formatUnits, Interface, toUtf8String } = require("ethers");
+const { getPrice, formatUsd } = require("../../shared/prices");
 const { ERC20_ABI } = require("../../shared/constants");
 const { TOKEN_BY_ADDRESS } = require("../../shared/tokenList");
 const txStatus = require("./txStatus");
@@ -219,8 +220,14 @@ function showTxApproval(details) {
         $("approve-tx-to").innerHTML = escapeHtml("(contract creation)");
     }
 
+    const ethValueFormatted = formatTxValue(
+        formatEther(details.txParams.value || "0"),
+    );
+    const ethPrice = getPrice("ETH");
+    const ethUsd = ethPrice ? parseFloat(ethValueFormatted) * ethPrice : null;
+    const usdStr = formatUsd(ethUsd);
     $("approve-tx-value").textContent =
-        formatTxValue(formatEther(details.txParams.value || "0")) + " ETH";
+        ethValueFormatted + " ETH" + (usdStr ? " (" + usdStr + ")" : "");
 
     // Decode calldata (reuse decoded from above)
     const decodedEl = $("approve-tx-decoded");

src/popup/views/confirmTx.js

@@ -20,8 +20,9 @@ const {
     escapeHtml,
     renderAddressHtml,
     attachCopyHandlers,
+    goBack,
 } = require("./helpers");
-const { state } = require("../../shared/state");
+const { state, currentNetwork } = require("../../shared/state");
 const { getSignerForAddress } = require("../../shared/wallet");
 const { decryptWithPassword } = require("../../shared/vault");
 const { formatUsd, getPrice } = require("../../shared/prices");
@@ -355,7 +356,7 @@ function init(ctx) {
     });
 
     $("btn-confirm-back").addEventListener("click", () => {
-        showView("send");
+        goBack();
     });
 }
 

src/popup/views/deleteWallet.js

@@ -1,4 +1,4 @@
-const { $, showView, showFlash } = require("./helpers");
+const { $, showView, showFlash, goBack, clearViewStack } = require("./helpers");
 const { state, saveState } = require("../../shared/state");
 const { decryptWithPassword } = require("../../shared/vault");
 
@@ -21,7 +21,7 @@ function init(_ctx) {
 
     $("btn-delete-wallet-back").addEventListener("click", () => {
         deleteWalletIndex = null;
-        ctx.showSettingsView();
+        goBack();
     });
 
     $("btn-delete-wallet-confirm").addEventListener("click", async () => {
@@ -77,6 +77,7 @@ function init(_ctx) {
             state.selectedWallet = null;
             state.selectedAddress = null;
             state.activeAddress = null;
+            clearViewStack();
             await saveState();
             showView("welcome");
         } else {
@@ -86,8 +87,14 @@ function init(_ctx) {
             state.activeAddress =
                 state.wallets[0].addresses[0]?.address || null;
             await saveState();
+            // Reset stack to [main] so Settings back goes home.
+            // Use require() lazily to avoid circular dependency
+            // (settings.js requires deleteWallet.js).
+            clearViewStack();
+            state.viewStack.push("main");
             ctx.renderWalletList();
-            ctx.showSettingsView();
+            const settings = require("./settings");
+            settings.show();
             showFlash("Wallet deleted.");
         }
     });

src/popup/views/helpers.js

@@ -1,12 +1,13 @@
 // Shared DOM helpers used by all views.
 
 const { DEBUG } = require("../../shared/constants");
+const { isDebug } = require("../../shared/log");
 const {
     formatUsd,
     getPrice,
     getAddressValueUsd,
 } = require("../../shared/prices");
-const { state, saveState } = require("../../shared/state");
+const { state, saveState, currentNetwork } = require("../../shared/state");
 
 // When views are added, removed, or transitions between them change,
 // update the view-navigation documentation in README.md to match.
@@ -59,14 +60,77 @@ function showView(name) {
     clearFlash();
     state.currentView = name;
     saveState();
-    if (DEBUG) {
-        const banner = document.getElementById("debug-banner");
-        if (banner) {
-            banner.textContent = "DEBUG / INSECURE (" + name + ")";
+    updateDebugBanner(name);
+}
+
+// Create or update the debug/insecure warning banner.
+// Called on every view switch and after the settings debug toggle changes.
+// The banner is shown when the compile-time DEBUG constant is true OR when
+// the user has enabled runtime debug mode via the settings easter egg, OR
+// when the active network is a testnet.
+function updateDebugBanner(viewName) {
+    const debug = isDebug();
+    const net = currentNetwork();
+    const show = debug || net.isTestnet;
+    let banner = document.getElementById("debug-banner");
+    if (show) {
+        if (!banner) {
+            banner = document.createElement("div");
+            banner.id = "debug-banner";
+            banner.style.cssText =
+                "background:#c00;color:#fff;text-align:center;font-size:10px;padding:1px 0;font-family:monospace;position:sticky;top:0;z-index:9999;";
+            document.body.prepend(banner);
         }
+        const suffix = viewName ? " (" + viewName + ")" : "";
+        if (debug && net.isTestnet) {
+            banner.textContent = "DEBUG / INSECURE [TESTNET]" + suffix;
+        } else if (net.isTestnet) {
+            banner.textContent = "[TESTNET]" + suffix;
+        } else {
+            banner.textContent = "DEBUG / INSECURE" + suffix;
+        }
+    } else if (banner) {
+        banner.remove();
     }
 }
 
+// Callback to re-render the main/home view when navigating back to it.
+// Set once by index.js via setRenderMain().
+let _renderMain = null;
+
+function setRenderMain(fn) {
+    _renderMain = fn;
+}
+
+// Push the current view onto the navigation stack so goBack() can
+// return to it.  Call this before any forward navigation.
+function pushCurrentView() {
+    if (state.currentView) {
+        state.viewStack.push(state.currentView);
+    }
+}
+
+// Pop the navigation stack and show the previous view.  If the stack
+// is empty, fall back to the main (home) view.
+function goBack() {
+    let target;
+    if (state.viewStack.length > 0) {
+        target = state.viewStack.pop();
+    } else {
+        target = "main";
+    }
+    if (target === "main" && _renderMain) {
+        _renderMain();
+    }
+    showView(target);
+}
+
+// Clear the entire navigation stack (used when resetting to root,
+// e.g. after adding or deleting a wallet).
+function clearViewStack() {
+    state.viewStack = [];
+}
+
 let flashTimer = null;
 
 function clearFlash() {
@@ -278,7 +342,7 @@ const EXT_ICON =
     `</svg></span>`;
 
 function etherscanAddressUrl(address) {
-    return `https://etherscan.io/address/${address}`;
+    return `${currentNetwork().explorerUrl}/address/${address}`;
 }
 
 function etherscanLinkHtml(url) {
@@ -372,6 +436,11 @@ module.exports = {
     showError,
     hideError,
     showView,
+    updateDebugBanner,
+    setRenderMain,
+    pushCurrentView,
+    goBack,
+    clearViewStack,
     showFlash,
     flashCopyFeedback,
     balanceLine,

src/popup/views/home.js

@@ -12,6 +12,7 @@ const {
     truncateMiddle,
     renderAddressHtml,
     attachCopyHandlers,
+    pushCurrentView,
 } = require("./helpers");
 const { state, saveState, currentAddress } = require("../../shared/state");
 const {
@@ -381,6 +382,7 @@ function init(ctx) {
         renderSendTokenSelect(addr);
         updateSendBalance();
         resetSendValidation();
+        pushCurrentView();
         showView("send");
     });
 

src/popup/views/receive.js

@@ -6,8 +6,9 @@ const {
     formatAddressHtml,
     addressTitle,
     attachCopyHandlers,
+    goBack,
 } = require("./helpers");
-const { state, currentAddress } = require("../../shared/state");
+const { state, currentAddress, currentNetwork } = require("../../shared/state");
 const QRCode = require("qrcode");
 
 function show() {
@@ -44,7 +45,9 @@ function show() {
         warningEl.textContent =
             "This is an ERC-20 token. Only send " +
             symbol +
-            " on the Ethereum network to this address. Sending tokens on other networks will result in permanent loss.";
+            " on " +
+            currentNetwork().name +
+            " to this address. Sending tokens on other networks will result in permanent loss.";
         warningEl.style.visibility = "visible";
     } else {
         warningEl.textContent = "";
@@ -65,11 +68,7 @@ function init(ctx) {
     });
 
     $("btn-receive-back").addEventListener("click", () => {
-        if (state.selectedToken) {
-            ctx.showAddressToken();
-        } else {
-            ctx.showAddressDetail();
-        }
+        goBack();
     });
 }
 

src/popup/views/send.js

@@ -7,6 +7,7 @@ const {
     escapeHtml,
     renderAddressHtml,
     attachCopyHandlers,
+    goBack,
 } = require("./helpers");
 const { state, currentAddress } = require("../../shared/state");
 let ctx;
@@ -250,11 +251,7 @@ function init(_ctx) {
     $("btn-send-back").addEventListener("click", () => {
         $("send-token").classList.remove("hidden");
         $("send-token-static").classList.add("hidden");
-        if (state.selectedToken) {
-            ctx.showAddressToken();
-        } else {
-            ctx.showAddressDetail();
-        }
+        goBack();
     });
 }
 

src/popup/views/settings.js

@@ -1,13 +1,34 @@
-const { $, showView, showFlash, escapeHtml } = require("./helpers");
+const {
+    $,
+    showView,
+    updateDebugBanner,
+    showFlash,
+    escapeHtml,
+    flashCopyFeedback,
+    goBack,
+    pushCurrentView,
+} = require("./helpers");
 const { applyTheme } = require("../theme");
-const { state, saveState } = require("../../shared/state");
-const { ETHEREUM_MAINNET_CHAIN_ID } = require("../../shared/constants");
-const { log, debugFetch } = require("../../shared/log");
+const { state, saveState, currentNetwork } = require("../../shared/state");
+const { NETWORKS, SUPPORTED_CHAIN_IDS } = require("../../shared/networks");
+const { onChainSwitch } = require("../../shared/chainSwitch");
+const { log, debugFetch, setRuntimeDebug } = require("../../shared/log");
 const deleteWallet = require("./deleteWallet");
+const {
+    BUILD_VERSION,
+    BUILD_LICENSE,
+    BUILD_AUTHOR,
+    BUILD_COMMIT,
+    BUILD_DATE,
+    GITEA_COMMIT_URL,
+} = require("../../shared/buildInfo");
 
 const runtime =
     typeof browser !== "undefined" ? browser.runtime : chrome.runtime;
 
+let versionClickCount = 0;
+let versionClickTimer = null;
+
 function renderSiteList(containerId, siteMap, stateKey) {
     const container = $(containerId);
     const hostnames = [...new Set(Object.values(siteMap).flat())];
@@ -85,6 +106,7 @@ function renderWalletListSettings() {
     container.querySelectorAll(".btn-delete-wallet").forEach((btn) => {
         btn.addEventListener("click", () => {
             const idx = parseInt(btn.dataset.idx, 10);
+            pushCurrentView();
             deleteWallet.show(idx);
         });
     });
@@ -125,10 +147,36 @@ function renderWalletListSettings() {
 function show() {
     $("settings-rpc").value = state.rpcUrl;
     $("settings-blockscout").value = state.blockscoutUrl;
+    const networkSelect = $("settings-network");
+    if (networkSelect) {
+        networkSelect.value = state.networkId;
+    }
     renderTrackedTokens();
     renderSiteLists();
     renderWalletListSettings();
 
+    // Populate About well
+    $("about-license").textContent = BUILD_LICENSE;
+    // Show only the name part of the author field (strip email)
+    const authorName = BUILD_AUTHOR.replace(/\s*<[^>]+>/, "");
+    $("about-author").textContent = authorName;
+    $("about-version").textContent = BUILD_VERSION;
+    $("about-release-date").textContent = BUILD_DATE;
+    $("about-commit-link").textContent = BUILD_COMMIT;
+    $("about-commit-link").href = GITEA_COMMIT_URL;
+
+    // Reset version click counter each time settings opens
+    versionClickCount = 0;
+
+    // Show debug well if debug mode is already enabled
+    const debugWell = $("settings-debug-well");
+    if (state.debugMode) {
+        debugWell.style.display = "";
+    } else {
+        debugWell.style.display = "none";
+    }
+    $("settings-debug-mode").checked = state.debugMode;
+
     showView("settings");
 }
 
@@ -168,9 +216,12 @@ function init(ctx) {
                 showFlash("Endpoint returned error: " + json.error.message);
                 return;
             }
-            if (json.result !== ETHEREUM_MAINNET_CHAIN_ID) {
+            const net = currentNetwork();
+            if (json.result !== net.chainId) {
                 showFlash(
-                    "Wrong network (expected mainnet, got chain " +
+                    "Wrong network (expected " +
+                        net.name +
+                        ", got chain " +
                         json.result +
                         ").",
                 );
@@ -209,6 +260,17 @@ function init(ctx) {
         showFlash("Saved.");
     });
 
+    const networkSelect = $("settings-network");
+    if (networkSelect) {
+        networkSelect.addEventListener("change", async () => {
+            const newId = networkSelect.value;
+            const net = await onChainSwitch(newId);
+            $("settings-rpc").value = state.rpcUrl;
+            $("settings-blockscout").value = state.blockscoutUrl;
+            showFlash("Switched to " + net.name + ".");
+        });
+    }
+
     $("settings-show-zero-balances").checked = state.showZeroBalanceTokens;
     $("settings-show-zero-balances").addEventListener("change", async () => {
         state.showZeroBalanceTokens = $("settings-show-zero-balances").checked;
@@ -262,9 +324,68 @@ function init(ctx) {
         ctx.showSettingsAddTokenView,
     );
 
+    // Bright saturated colors for easter egg flashes (clicks 6–10)
+    const easterEggColors = [
+        "#ff0055", // hot pink
+        "#00cc44", // vivid green
+        "#3366ff", // electric blue
+        "#ff9900", // bright orange
+        "#aa00ff", // vivid purple
+    ];
+
+    // Easter egg: click version 10 times to reveal the debug well.
+    // Each click does a copy-flash animation. After 5 clicks, each
+    // additional click flashes a different bright saturated color.
+    $("about-version").addEventListener("click", () => {
+        versionClickCount++;
+        clearTimeout(versionClickTimer);
+        // Reset counter if user stops clicking for 3 seconds
+        versionClickTimer = setTimeout(() => {
+            versionClickCount = 0;
+        }, 3000);
+
+        const el = $("about-version");
+
+        if (versionClickCount > 5) {
+            // Colored flash for clicks 6–10
+            const colorIdx = versionClickCount - 6;
+            const color = easterEggColors[colorIdx % easterEggColors.length];
+            el.classList.remove("copy-flash-fade");
+            el.style.backgroundColor = color;
+            el.style.color = "#ffffff";
+            setTimeout(() => {
+                el.style.backgroundColor = "";
+                el.style.color = "";
+                el.classList.add("copy-flash-fade");
+                setTimeout(() => {
+                    el.classList.remove("copy-flash-fade");
+                }, 275);
+            }, 75);
+        } else {
+            // Standard copy-flash for clicks 1–5
+            flashCopyFeedback(el);
+        }
+
+        if (versionClickCount >= 10) {
+            versionClickCount = 0;
+            clearTimeout(versionClickTimer);
+            $("settings-debug-well").style.display = "";
+        }
+    });
+
+    // Debug mode toggle — update runtime flag, persist, and re-render banner
+    $("settings-debug-mode").addEventListener("change", async () => {
+        state.debugMode = $("settings-debug-mode").checked;
+        setRuntimeDebug(state.debugMode);
+        await saveState();
+        updateDebugBanner(state.currentView);
+    });
+
+    // Sync runtime debug flag on init
+    setRuntimeDebug(state.debugMode);
+
     $("btn-settings-back").addEventListener("click", () => {
-        ctx.renderWalletList();
-        showView("main");
+        goBack();
     });
 }
 

src/popup/views/settingsAddToken.js

@@ -1,4 +1,4 @@
-const { $, showView, showFlash } = require("./helpers");
+const { $, showView, showFlash, goBack } = require("./helpers");
 const { getTopTokens } = require("../../shared/tokenList");
 const { state, saveState } = require("../../shared/state");
 const { lookupTokenInfo } = require("../../shared/balances");
@@ -84,7 +84,7 @@ function init(_ctx) {
     ctx = _ctx;
 
     $("btn-settings-addtoken-back").addEventListener("click", () => {
-        ctx.showSettingsView();
+        goBack();
     });
 
     $("btn-settings-addtoken-select").addEventListener("click", async () => {

src/popup/views/transactionDetail.js

@@ -14,8 +14,9 @@ const {
     attachCopyHandlers,
     copyableHtml,
     etherscanLinkHtml,
+    goBack,
 } = require("./helpers");
-const { state } = require("../../shared/state");
+const { state, currentNetwork } = require("../../shared/state");
 const { formatEther, formatUnits } = require("ethers");
 const makeBlockie = require("ethereum-blockies-base64");
 const { log, debugFetch } = require("../../shared/log");
@@ -56,7 +57,7 @@ function txAddressHtml(address, ensName, title) {
 }
 
 function txHashHtml(hash) {
-    const link = `https://etherscan.io/tx/${hash}`;
+    const link = `${currentNetwork().explorerUrl}/tx/${hash}`;
     const extLink = etherscanLinkHtml(link);
     return copyableHtml(hash, "break-all") + extLink;
 }
@@ -133,7 +134,7 @@ function render() {
     if (tokenContractSection && tokenContractEl) {
         if (tx.contractAddress) {
             const dot = addressDotHtml(tx.contractAddress);
-            const link = `https://etherscan.io/token/${tx.contractAddress}`;
+            const link = `${currentNetwork().explorerUrl}/token/${tx.contractAddress}`;
             tokenContractEl.innerHTML =
                 `<div class="flex items-center">${dot}` +
                 copyableHtml(tx.contractAddress, "break-all") +
@@ -185,7 +186,7 @@ function showDetailField(sectionId, contentId, value) {
 function populateOnChainDetails(txData) {
     // Block number
     if (txData.block_number != null) {
-        const blockLink = `https://etherscan.io/block/${txData.block_number}`;
+        const blockLink = `${currentNetwork().explorerUrl}/block/${txData.block_number}`;
         const blockSection = $("tx-detail-block-section");
         const blockEl = $("tx-detail-block");
         if (blockSection && blockEl) {
@@ -350,11 +351,7 @@ async function loadFullTxDetails(txHash, toAddress, isContractCall) {
 function init(_ctx) {
     ctx = _ctx;
     $("btn-tx-back").addEventListener("click", () => {
-        if (state.selectedToken) {
-            ctx.showAddressToken();
-        } else {
-            ctx.showAddressDetail();
-        }
+        goBack();
     });
 }
 

src/popup/views/txStatus.js

@@ -9,9 +9,10 @@ const {
     attachCopyHandlers,
     copyableHtml,
     etherscanLinkHtml,
+    clearViewStack,
 } = require("./helpers");
 const { TOKEN_BY_ADDRESS } = require("../../shared/tokenList");
-const { state, saveState } = require("../../shared/state");
+const { state, saveState, currentNetwork } = require("../../shared/state");
 const { getProvider } = require("../../shared/balances");
 const { log } = require("../../shared/log");
 
@@ -36,13 +37,13 @@ function toAddressHtml(address) {
 }
 
 function txHashHtml(hash) {
-    const link = `https://etherscan.io/tx/${hash}`;
+    const link = `${currentNetwork().explorerUrl}/tx/${hash}`;
     return copyableHtml(hash, "break-all") + etherscanLinkHtml(link);
 }
 
 function blockNumberHtml(blockNumber) {
     const num = String(blockNumber);
-    const link = `https://etherscan.io/block/${num}`;
+    const link = `${currentNetwork().explorerUrl}/block/${num}`;
     return copyableHtml(num) + etherscanLinkHtml(link);
 }
 
@@ -110,7 +111,7 @@ function tokenLabel(address) {
 }
 
 function etherscanTokenLink(address) {
-    return `https://etherscan.io/token/${address}`;
+    return `${currentNetwork().explorerUrl}/token/${address}`;
 }
 
 function decodedDetailsHtml(decoded) {
@@ -221,10 +222,16 @@ function navigateBack() {
         window.close();
         return;
     }
+    // After a completed transaction, reset the navigation stack
+    // and go directly to the address view (token or detail).
+    // Use require() lazily to call show() without the ctx push wrapper.
+    clearViewStack();
+    state.viewStack.push("main");
     if (state.selectedToken) {
-        ctx.showAddressToken();
+        state.viewStack.push("address");
+        require("./addressToken").show();
     } else {
-        ctx.showAddressDetail();
+        require("./addressDetail").show();
     }
 }
 

src/shared/balances.js

@@ -15,10 +15,15 @@ const { KNOWN_SYMBOLS, TOKEN_BY_ADDRESS } = require("./tokenList");
 
 // Use a static network to skip auto-detection (which can fail and cause
 // "could not coalesce error" on some RPC endpoints like Cloudflare).
-const mainnet = Network.from("mainnet");
-
-function getProvider(rpcUrl) {
-    return new JsonRpcProvider(rpcUrl, mainnet, { staticNetwork: mainnet });
+// Accepts an optional networkName ("mainnet" or "sepolia") for the static
+// network hint so ethers picks the right chain parameters.  When omitted,
+// reads the currently selected network from extension state.
+function getProvider(rpcUrl, networkName) {
+    // Lazy require to avoid circular dependency issues at module scope.
+    const { currentNetwork } = require("./state");
+    const name = networkName || currentNetwork().id;
+    const net = Network.from(name);
+    return new JsonRpcProvider(rpcUrl, net, { staticNetwork: net });
 }
 
 function formatBalance(wei) {

src/shared/buildInfo.js

@@ -0,0 +1,35 @@
+// Build-time constants injected by esbuild define in build.js.
+// These globals are replaced at bundle time with string literals.
+
+/* global __BUILD_VERSION__, __BUILD_LICENSE__, __BUILD_AUTHOR__,
+          __BUILD_COMMIT__, __BUILD_COMMIT_FULL__, __BUILD_DATE__ */
+
+const BUILD_VERSION =
+    typeof __BUILD_VERSION__ !== "undefined" ? __BUILD_VERSION__ : "dev";
+const BUILD_LICENSE =
+    typeof __BUILD_LICENSE__ !== "undefined" ? __BUILD_LICENSE__ : "GPL-3.0";
+const BUILD_AUTHOR =
+    typeof __BUILD_AUTHOR__ !== "undefined"
+        ? __BUILD_AUTHOR__
+        : "sneak <sneak@sneak.berlin>";
+const BUILD_COMMIT =
+    typeof __BUILD_COMMIT__ !== "undefined" ? __BUILD_COMMIT__ : "unknown";
+const BUILD_COMMIT_FULL =
+    typeof __BUILD_COMMIT_FULL__ !== "undefined"
+        ? __BUILD_COMMIT_FULL__
+        : "unknown";
+const BUILD_DATE =
+    typeof __BUILD_DATE__ !== "undefined" ? __BUILD_DATE__ : "unknown";
+
+const GITEA_COMMIT_URL =
+    "https://git.eeqj.de/sneak/AutistMask/commit/" + BUILD_COMMIT_FULL;
+
+module.exports = {
+    BUILD_VERSION,
+    BUILD_LICENSE,
+    BUILD_AUTHOR,
+    BUILD_COMMIT,
+    BUILD_COMMIT_FULL,
+    BUILD_DATE,
+    GITEA_COMMIT_URL,
+};

src/shared/chainSwitch.js

@@ -0,0 +1,57 @@
+// Consolidated chain-switch handler.
+//
+// Every state change required when the active network changes is
+// performed here so that callers (settings UI, background
+// wallet_switchEthereumChain, future chain additions) all go
+// through a single code path.
+//
+// Adding a new chain (e.g. ETC) requires only a new entry in
+// networks.js — no per-caller wiring is needed.
+
+const { networkById } = require("./networks");
+const { clearPrices } = require("./prices");
+
+// Switch the active chain and reset all chain-specific cached state.
+// Returns the network configuration object for the new chain.
+async function onChainSwitch(newNetworkId) {
+    const { state, saveState } = require("./state");
+
+    const net = networkById(newNetworkId);
+
+    // --- core identity ---
+    state.networkId = net.id;
+    state.rpcUrl = net.defaultRpcUrl;
+    state.blockscoutUrl = net.defaultBlockscoutUrl;
+
+    // --- price cache ---
+    // Prices are chain-specific (testnet tokens are worthless,
+    // ETC has different pricing, etc.).
+    clearPrices();
+
+    // --- balance / refresh state ---
+    // Reset last-refresh timestamp so the next polling cycle
+    // triggers an immediate balance refresh on the new chain.
+    state.lastBalanceRefresh = 0;
+
+    // Clear per-address balances and token balances so stale data
+    // from the previous chain is never displayed while the first
+    // refresh on the new chain is in flight.
+    for (const wallet of state.wallets) {
+        for (const addr of wallet.addresses) {
+            addr.balance = "0";
+            addr.tokenBalances = [];
+        }
+    }
+
+    // --- chain-specific caches ---
+    // Token holder counts and fraud contract lists are
+    // chain-specific and must not carry over.
+    state.tokenHolderCache = {};
+    state.fraudContracts = [];
+
+    await saveState();
+
+    return net;
+}
+
+module.exports = { onChainSwitch };

src/shared/constants.js

@@ -3,6 +3,7 @@ const DEBUG_MNEMONIC =
     "cube evolve unfold result inch risk jealous skill hotel bulb night wreck";
 
 const ETHEREUM_MAINNET_CHAIN_ID = "0x1";
+const ETHEREUM_SEPOLIA_CHAIN_ID = "0xaa36a7";
 
 const DEFAULT_RPC_URL = "https://ethereum-rpc.publicnode.com";
 
@@ -37,6 +38,7 @@ module.exports = {
     DEBUG,
     DEBUG_MNEMONIC,
     ETHEREUM_MAINNET_CHAIN_ID,
+    ETHEREUM_SEPOLIA_CHAIN_ID,
     DEFAULT_RPC_URL,
     DEFAULT_BLOCKSCOUT_URL,
     BIP44_ETH_PATH,

src/shared/etherscanLabels.js

@@ -2,8 +2,6 @@
 // Extension users make the requests directly to Etherscan — no proxy needed.
 // This is a best-effort enrichment: network failures return null silently.
 
-const ETHERSCAN_BASE = "https://etherscan.io/address/";
-
 // Patterns in the page title that indicate a flagged address.
 // Title format: "Fake_Phishing184810 | Address: 0x... | Etherscan"
 const PHISHING_LABEL_PATTERNS = [/^Fake_Phishing/i, /^Phish:/i, /^Exploiter/i];
@@ -74,12 +72,19 @@ function parseEtherscanPage(html) {
  * Returns a warning object if the address is flagged, or null.
  * Network failures return null silently (best-effort check).
  *
+ * Uses the current network's explorer URL so the lookup works on both
+ * mainnet (etherscan.io) and Sepolia (sepolia.etherscan.io).
+ *
  * @param {string} address - Ethereum address to check.
  * @returns {Promise<{type: string, message: string, severity: string}|null>}
  */
 async function checkEtherscanLabel(address) {
     try {
-        const resp = await fetch(ETHERSCAN_BASE + address, {
+        // Lazy require to avoid pulling in chrome.storage at module scope
+        // (which breaks unit tests that only exercise parseEtherscanPage).
+        const { currentNetwork } = require("./state");
+        const etherscanBase = currentNetwork().explorerUrl + "/address/";
+        const resp = await fetch(etherscanBase + address, {
             headers: { Accept: "text/html" },
         });
         if (!resp.ok) return null;

src/shared/log.js

@@ -1,12 +1,27 @@
 // Leveled logger. Outputs to console with [AutistMask] prefix.
-// Level is DEBUG when the DEBUG constant is true, INFO otherwise.
+// Level is DEBUG when the compile-time DEBUG constant is true or the runtime
+// debugMode state flag is enabled.  The runtime flag is checked lazily so it
+// responds immediately when toggled in settings.
 
 const { DEBUG } = require("./constants");
 
 const LEVELS = { debug: 0, info: 1, warn: 2, error: 3 };
-const threshold = DEBUG ? LEVELS.debug : LEVELS.info;
+
+// Runtime debug mode flag — set by settings.js when the user toggles debug
+// mode via the easter egg.  Kept here as a simple mutable reference so it can
+// be updated without circular dependency issues with state.js.
+let _runtimeDebug = false;
+
+function setRuntimeDebug(enabled) {
+    _runtimeDebug = enabled;
+}
+
+function isDebug() {
+    return DEBUG || _runtimeDebug;
+}
 
 function emit(level, method, args) {
+    const threshold = isDebug() ? LEVELS.debug : LEVELS.info;
     if (LEVELS[level] >= threshold) {
         console[method]("[AutistMask]", ...args);
     }
@@ -37,4 +52,4 @@ async function debugFetch(url, opts) {
     return resp;
 }
 
-module.exports = { log, debugFetch };
+module.exports = { log, debugFetch, setRuntimeDebug, isDebug };

src/shared/networks.js

@@ -0,0 +1,57 @@
+// Network definitions for supported Ethereum networks.
+// Each network specifies its chain ID, default RPC and Blockscout endpoints,
+// and the block explorer base URL used for address/tx/token/block links.
+
+const NETWORKS = {
+    mainnet: {
+        id: "mainnet",
+        name: "Ethereum Mainnet",
+        chainId: "0x1",
+        networkVersion: "1",
+        nativeCurrency: "ETH",
+        defaultRpcUrl: "https://ethereum-rpc.publicnode.com",
+        defaultBlockscoutUrl: "https://eth.blockscout.com/api/v2",
+        explorerUrl: "https://etherscan.io",
+        isTestnet: false,
+    },
+    sepolia: {
+        id: "sepolia",
+        name: "Sepolia Testnet",
+        chainId: "0xaa36a7",
+        networkVersion: "11155111",
+        nativeCurrency: "SepoliaETH",
+        defaultRpcUrl: "https://ethereum-sepolia-rpc.publicnode.com",
+        defaultBlockscoutUrl: "https://eth-sepolia.blockscout.com/api/v2",
+        explorerUrl: "https://sepolia.etherscan.io",
+        isTestnet: true,
+    },
+};
+
+const SUPPORTED_CHAIN_IDS = new Set(
+    Object.values(NETWORKS).map((n) => n.chainId),
+);
+
+function networkById(id) {
+    return NETWORKS[id] || NETWORKS.mainnet;
+}
+
+function networkByChainId(chainId) {
+    for (const net of Object.values(NETWORKS)) {
+        if (net.chainId === chainId) return net;
+    }
+    return null;
+}
+
+// Build a block explorer link for the given path type and value.
+// type: "address" | "tx" | "token" | "block"
+function explorerLink(network, type, value) {
+    return `${network.explorerUrl}/${type}/${value}`;
+}
+
+module.exports = {
+    NETWORKS,
+    SUPPORTED_CHAIN_IDS,
+    networkById,
+    networkByChainId,
+    explorerLink,
+};

src/shared/prices.js

@@ -8,6 +8,13 @@ const prices = {};
 let lastFetchedAt = 0;
 
 async function refreshPrices() {
+    // Testnet tokens have no real market value — skip price fetching
+    // and clear any stale mainnet prices so the UI shows no USD values.
+    const { currentNetwork } = require("./state");
+    if (currentNetwork().isTestnet) {
+        clearPrices();
+        return;
+    }
     const now = Date.now();
     if (now - lastFetchedAt < PRICE_CACHE_TTL) return;
     try {
@@ -19,7 +26,19 @@ async function refreshPrices() {
     }
 }
 
+// Clear all cached prices and reset the fetch timestamp so the
+// next refreshPrices() call will fetch fresh data.
+function clearPrices() {
+    for (const key of Object.keys(prices)) {
+        delete prices[key];
+    }
+    lastFetchedAt = 0;
+}
+
+// Return the USD price for a symbol, or null on testnet / unknown.
 function getPrice(symbol) {
+    const { currentNetwork } = require("./state");
+    if (currentNetwork().isTestnet) return null;
     return prices[symbol] || null;
 }
 
@@ -37,6 +56,8 @@ function formatUsd(amount) {
 }
 
 function getAddressValueUsd(addr) {
+    const { currentNetwork } = require("./state");
+    if (currentNetwork().isTestnet) return null;
     if (!prices.ETH) return null;
     let total = 0;
     const ethBal = parseFloat(addr.balance || "0");
@@ -51,6 +72,8 @@ function getAddressValueUsd(addr) {
 }
 
 function getWalletValueUsd(wallet) {
+    const { currentNetwork } = require("./state");
+    if (currentNetwork().isTestnet) return null;
     if (!prices.ETH) return null;
     let total = 0;
     for (const addr of wallet.addresses) {
@@ -60,6 +83,8 @@ function getWalletValueUsd(wallet) {
 }
 
 function getTotalValueUsd(wallets) {
+    const { currentNetwork } = require("./state");
+    if (currentNetwork().isTestnet) return null;
     if (!prices.ETH) return null;
     let total = 0;
     for (const wallet of wallets) {
@@ -71,6 +96,7 @@ function getTotalValueUsd(wallets) {
 module.exports = {
     prices,
     refreshPrices,
+    clearPrices,
     getPrice,
     formatUsd,
     getAddressValueUsd,

src/shared/state.js

@@ -1,6 +1,7 @@
 // State management and extension storage persistence.
 
 const { DEFAULT_RPC_URL, DEFAULT_BLOCKSCOUT_URL } = require("./constants");
+const { networkById } = require("./networks");
 
 const storageApi =
     typeof browser !== "undefined"
@@ -11,6 +12,7 @@ const DEFAULT_STATE = {
     hasWallet: false,
     wallets: [],
     trackedTokens: [],
+    networkId: "mainnet",
     rpcUrl: DEFAULT_RPC_URL,
     blockscoutUrl: DEFAULT_BLOCKSCOUT_URL,
     lastBalanceRefresh: 0,
@@ -27,6 +29,7 @@ const DEFAULT_STATE = {
     fraudContracts: [],
     tokenHolderCache: {},
     theme: "system",
+    debugMode: false,
 };
 
 const state = {
@@ -36,13 +39,20 @@ const state = {
     selectedAddress: null,
     selectedToken: null,
     viewData: {},
+    viewStack: [],
 };
 
+// Return the network configuration for the currently selected network.
+function currentNetwork() {
+    return networkById(state.networkId);
+}
+
 async function saveState() {
     const persisted = {
         hasWallet: state.hasWallet,
         wallets: state.wallets,
         trackedTokens: state.trackedTokens,
+        networkId: state.networkId,
         rpcUrl: state.rpcUrl,
         blockscoutUrl: state.blockscoutUrl,
         lastBalanceRefresh: state.lastBalanceRefresh,
@@ -59,11 +69,13 @@ async function saveState() {
         fraudContracts: state.fraudContracts,
         tokenHolderCache: state.tokenHolderCache,
         theme: state.theme,
+        debugMode: state.debugMode,
         currentView: state.currentView,
         selectedWallet: state.selectedWallet,
         selectedAddress: state.selectedAddress,
         selectedToken: state.selectedToken,
         viewData: state.viewData,
+        viewStack: state.viewStack,
     };
     await storageApi.set({ autistmask: persisted });
 }
@@ -75,6 +87,7 @@ async function loadState() {
         state.hasWallet = saved.hasWallet;
         state.wallets = saved.wallets || [];
         state.trackedTokens = saved.trackedTokens || [];
+        state.networkId = saved.networkId || DEFAULT_STATE.networkId;
         state.rpcUrl = saved.rpcUrl || DEFAULT_STATE.rpcUrl;
         state.blockscoutUrl =
             saved.blockscoutUrl || DEFAULT_STATE.blockscoutUrl;
@@ -117,6 +130,8 @@ async function loadState() {
         state.fraudContracts = saved.fraudContracts || [];
         state.tokenHolderCache = saved.tokenHolderCache || {};
         state.theme = saved.theme || "system";
+        state.debugMode =
+            saved.debugMode !== undefined ? saved.debugMode : false;
         state.currentView = saved.currentView || null;
         state.selectedWallet =
             saved.selectedWallet !== undefined ? saved.selectedWallet : null;
@@ -124,6 +139,7 @@ async function loadState() {
             saved.selectedAddress !== undefined ? saved.selectedAddress : null;
         state.selectedToken = saved.selectedToken || null;
         state.viewData = saved.viewData || {};
+        state.viewStack = Array.isArray(saved.viewStack) ? saved.viewStack : [];
     }
 }
 
@@ -134,4 +150,10 @@ function currentAddress() {
     return state.wallets[state.selectedWallet].addresses[state.selectedAddress];
 }
 
-module.exports = { state, saveState, loadState, currentAddress };
+module.exports = {
+    state,
+    saveState,
+    loadState,
+    currentAddress,
+    currentNetwork,
+};