fix: unify address display with shared renderAddressHtml utility

All address rendering now uses a single renderAddressHtml() function in
helpers.js that produces consistent output everywhere:
- Color dot (deterministic from address)
- Full address with dashed-underline click-to-copy affordance
- Etherscan external link icon

Refactored all callsites across 9 view files:
- approval.js: approvalAddressHtml now delegates to renderAddressHtml,
  added attachCopyHandlers for click-to-copy on approve-tx/sign/site views
- confirmTx.js: confirmAddressHtml uses renderAddressHtml, token contract
  address uses renderAddressHtml with attachCopyHandlers
- txStatus.js: toAddressHtml delegates to renderAddressHtml
- transactionDetail.js: txAddressHtml delegates to renderAddressHtml,
  decoded calldata addresses use renderAddressHtml
- home.js: active address display uses renderAddressHtml
- send.js: from-address display uses renderAddressHtml
- receive.js: address block uses formatAddressHtml (which delegates to
  renderAddressHtml), removed separate etherscan link element
- addressDetail.js: address line uses renderAddressHtml, export-privkey
  address uses renderAddressHtml
- addressToken.js: address line and contract info use renderAddressHtml

Also consolidated:
- EXT_ICON SVG constant moved to helpers.js (removed 6 duplicates)
- copyableHtml() moved to helpers.js (removed duplicate in transactionDetail)
- etherscanLinkHtml() moved to helpers.js (removed duplicates)
- attachCopyHandlers() moved to helpers.js (removed duplicate in txStatus)
- Removed unused local functions (etherscanTokenLink, etherscanAddressLink)
- Cleaned up unused imports across all files

closes #97

src/background/index.js

@@ -2,12 +2,15 @@
 // Handles EIP-1193 RPC requests from content scripts and proxies
 // non-sensitive calls to the configured Ethereum JSON-RPC endpoint.
 
-const {
+const { DEFAULT_RPC_URL } = require("../shared/constants");
-    ETHEREUM_MAINNET_CHAIN_ID,
+const { SUPPORTED_CHAIN_IDS, networkByChainId } = require("../shared/networks");
-    DEFAULT_RPC_URL,
-} = require("../shared/constants");
 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 +332,47 @@ 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)) {
+            // Switch to the requested network
+            const target = networkByChainId(chainId);
+            state.networkId = target.id;
+            state.rpcUrl = target.defaultRpcUrl;
+            state.blockscoutUrl = target.defaultBlockscoutUrl;
+            await saveState();
+            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 +518,27 @@ 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,
+        chainId: currentChainId,
-        networkVersion: "1",
+        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">

src/popup/views/addressDetail.js

@@ -8,6 +8,8 @@ const {
     addressTitle,
     escapeHtml,
     truncateMiddle,
+    renderAddressHtml,
+    attachCopyHandlers,
 } = require("./helpers");
 const { state, currentAddress, saveState } = require("../../shared/state");
 const { formatUsd, getAddressValueUsd } = require("../../shared/prices");
@@ -28,17 +30,6 @@ const { getSignerForAddress } = require("../../shared/wallet");
 
 let ctx;
 
-const EXT_ICON =
-    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
-    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
-    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
-    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
-    `</svg></span>`;
-
-function etherscanAddressLink(address) {
-    return `https://etherscan.io/address/${address}`;
-}
-
 function show() {
     state.selectedToken = null;
     const wallet = state.wallets[state.selectedWallet];
@@ -56,22 +47,18 @@ function show() {
     img.style.imageRendering = "pixelated";
     img.style.borderRadius = "50%";
     blockieEl.appendChild(img);
-    $("address-dot").innerHTML = addressDotHtml(addr.address);
+    const addrTitle = addressTitle(addr.address, state.wallets);
-    $("address-full").dataset.full = addr.address;
+    $("address-line").innerHTML = renderAddressHtml(addr.address, {
-    $("address-full").textContent = addr.address;
+        title: addrTitle,
-    const addrLink = etherscanAddressLink(addr.address);
+        ensName: addr.ensName,
-    $("address-etherscan-link").innerHTML =
+    });
-        `<a href="${addrLink}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
+    $("address-line").dataset.full = addr.address;
+    attachCopyHandlers($("address-line"));
     const usdTotal = formatUsd(getAddressValueUsd(addr));
     $("address-usd-total").innerHTML = usdTotal || "&nbsp;";
     const ensEl = $("address-ens");
-    if (addr.ensName) {
+    // ENS is now shown inside renderAddressHtml, hide the separate element
-        ensEl.innerHTML =
+    ensEl.classList.add("hidden");
-            addressDotHtml(addr.address) + escapeHtml(addr.ensName);
-        ensEl.classList.remove("hidden");
-    } else {
-        ensEl.classList.add("hidden");
-    }
     $("address-balances").innerHTML = balanceLinesForAddress(
         addr,
         state.trackedTokens,
@@ -258,14 +245,6 @@ function renderTransactions(txs) {
 
 function init(_ctx) {
     ctx = _ctx;
-    $("address-full").addEventListener("click", () => {
-        const addr = $("address-full").dataset.full;
-        if (addr) {
-            navigator.clipboard.writeText(addr);
-            showFlash("Copied!");
-            flashCopyFeedback($("address-full"));
-        }
-    });
 
     $("btn-address-back").addEventListener("click", () => {
         ctx.renderWalletList();
@@ -329,9 +308,9 @@ function init(_ctx) {
         blockieEl.appendChild(bImg);
         $("export-privkey-title").textContent =
             wallet.name + " \u2014 Address " + (state.selectedAddress + 1);
-        $("export-privkey-dot").innerHTML = addressDotHtml(addr.address);
+        const exportAddrContainer = $("export-privkey-dot").parentElement;
-        $("export-privkey-address").textContent = addr.address;
+        exportAddrContainer.innerHTML = renderAddressHtml(addr.address);
-        $("export-privkey-address").dataset.full = addr.address;
+        attachCopyHandlers(exportAddrContainer);
         $("export-privkey-password").value = "";
         $("export-privkey-flash").textContent = "";
         $("export-privkey-flash").style.visibility = "hidden";
@@ -385,15 +364,6 @@ function init(_ctx) {
         }
     });
 
-    $("export-privkey-address").addEventListener("click", () => {
-        const full = $("export-privkey-address").dataset.full;
-        if (full) {
-            navigator.clipboard.writeText(full);
-            showFlash("Copied!");
-            flashCopyFeedback($("export-privkey-address"));
-        }
-    });
-
     $("btn-export-privkey-back").addEventListener("click", () => {
         $("export-privkey-value").textContent = "";
         $("export-privkey-password").value = "";

src/popup/views/addressToken.js

@@ -11,6 +11,8 @@ const {
     escapeHtml,
     truncateMiddle,
     balanceLine,
+    renderAddressHtml,
+    attachCopyHandlers,
 } = require("./helpers");
 const { state, currentAddress, saveState } = require("../../shared/state");
 const { TOKEN_BY_ADDRESS, resolveSymbol } = require("../../shared/tokenList");
@@ -34,17 +36,6 @@ const makeBlockie = require("ethereum-blockies-base64");
 
 let ctx;
 
-const EXT_ICON =
-    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
-    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
-    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
-    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
-    `</svg></span>`;
-
-function etherscanAddressLink(address) {
-    return `https://etherscan.io/address/${address}`;
-}
-
 function isoDate(timestamp) {
     const d = new Date(timestamp * 1000);
     const pad = (n) => String(n).padStart(2, "0");
@@ -148,12 +139,13 @@ function show() {
     blockieEl.appendChild(img);
 
     // Address line
-    $("address-token-dot").innerHTML = addressDotHtml(addr.address);
+    const addrTitle = addressTitle(addr.address, state.wallets);
-    $("address-token-full").dataset.full = addr.address;
+    $("address-token-line").innerHTML = renderAddressHtml(addr.address, {
-    $("address-token-full").textContent = addr.address;
+        title: addrTitle,
-    const addrLink = etherscanAddressLink(addr.address);
+        ensName: addr.ensName,
-    $("address-token-etherscan-link").innerHTML =
+    });
-        `<a href="${addrLink}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
+    $("address-token-line").dataset.full = addr.address;
+    attachCopyHandlers($("address-token-line"));
 
     // USD total for this token only
     const usdVal = price ? amount * price : 0;
@@ -193,15 +185,9 @@ function show() {
                     ? knownToken.decimals
                     : null;
         const tokenHolders = tb && tb.holders != null ? tb.holders : null;
-        const dot = addressDotHtml(tokenId);
-        const tokenLink = `https://etherscan.io/token/${escapeHtml(tokenId)}`;
         const projectUrl = knownToken && knownToken.url ? knownToken.url : null;
         let infoHtml = `<div class="font-bold mb-2">Contract Address</div>`;
-        infoHtml +=
+        infoHtml += `<div class="mb-2">${renderAddressHtml(tokenId)}</div>`;
-            `<div class="flex items-center mb-2">${dot}` +
-            `<span class="break-all underline decoration-dashed cursor-pointer" id="address-token-contract-copy" data-copy="${escapeHtml(tokenId)}">${escapeHtml(tokenId)}</span>` +
-            `<a href="${tokenLink}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>` +
-            `</div>`;
         if (tokenName)
             infoHtml += `<div class="mb-1"><span class="text-muted">Name:</span> ${tokenName}</div>`;
         if (tokenSymbol)
@@ -213,6 +199,7 @@ function show() {
         if (projectUrl)
             infoHtml += `<div class="mb-1"><span class="text-muted">Website:</span> <a href="${escapeHtml(projectUrl)}" target="_blank" rel="noopener" class="underline decoration-dashed">${escapeHtml(projectUrl)}</a></div>`;
         contractInfo.innerHTML = infoHtml;
+        attachCopyHandlers(contractInfo);
         contractInfo.classList.remove("hidden");
     } else {
         contractInfo.innerHTML = "";
@@ -334,15 +321,6 @@ function renderTransactions(txs) {
 
 function init(_ctx) {
     ctx = _ctx;
-    $("address-token-full").addEventListener("click", () => {
-        const addr = $("address-token-full").dataset.full;
-        if (addr) {
-            navigator.clipboard.writeText(addr);
-            showFlash("Copied!");
-            flashCopyFeedback($("address-token-full"));
-        }
-    });
-
     $("address-token-contract-info").addEventListener("click", (e) => {
         const copyEl = e.target.closest("[data-copy]");
         if (copyEl) {
@@ -380,26 +358,11 @@ function init(_ctx) {
         $("send-token").classList.add("hidden");
         let staticHtml = `<div class="font-bold">${escapeHtml(currentSymbol)}</div>`;
         if (tokenId !== "ETH") {
-            const dot = addressDotHtml(tokenId);
+            staticHtml += `<div class="text-xs">${renderAddressHtml(tokenId)}</div>`;
-            const link = `https://etherscan.io/token/${tokenId}`;
-            const extLink = `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
-            staticHtml +=
-                `<div class="flex items-center text-xs">${dot}` +
-                `<span class="break-all underline decoration-dashed cursor-pointer" data-copy="${escapeHtml(tokenId)}">${escapeHtml(tokenId)}</span>` +
-                extLink +
-                `</div>`;
         }
         $("send-token-static").innerHTML = staticHtml;
         $("send-token-static").classList.remove("hidden");
-        // Attach copy handler for the contract address
+        attachCopyHandlers($("send-token-static"));
-        const copyEl = $("send-token-static").querySelector("[data-copy]");
-        if (copyEl) {
-            copyEl.addEventListener("click", () => {
-                navigator.clipboard.writeText(copyEl.dataset.copy);
-                showFlash("Copied!");
-                flashCopyFeedback(copyEl);
-            });
-        }
         updateSendBalance();
         resetSendValidation();
         showView("send");

src/popup/views/approval.js

@@ -1,14 +1,16 @@
 const {
     $,
-    addressDotHtml,
     addressTitle,
     escapeHtml,
     showView,
     showError,
     hideError,
+    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");
@@ -16,28 +18,11 @@ const uniswap = require("../../shared/uniswap");
 const runtime =
     typeof browser !== "undefined" ? browser.runtime : chrome.runtime;
 
-const EXT_ICON =
-    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
-    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
-    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
-    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
-    `</svg></span>`;
-
 const erc20Iface = new Interface(ERC20_ABI);
 
 function approvalAddressHtml(address) {
-    const dot = addressDotHtml(address);
-    const link = `https://etherscan.io/address/${address}`;
-    const extLink = `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
     const title = addressTitle(address, state.wallets);
-    let html = "";
+    return renderAddressHtml(address, { title });
-    if (title) {
-        html += `<div class="flex items-center font-bold">${dot}${escapeHtml(title)}</div>`;
-        html += `<div class="break-all">${escapeHtml(address)}${extLink}</div>`;
-    } else {
-        html += `<div class="flex items-center">${dot}<span class="break-all">${escapeHtml(address)}</span>${extLink}</div>`;
-    }
-    return html;
 }
 
 function formatTxValue(val) {
@@ -52,10 +37,6 @@ function tokenLabel(address) {
     return t ? t.symbol : null;
 }
 
-function etherscanTokenLink(address) {
-    return `https://etherscan.io/token/${address}`;
-}
-
 // Try to decode calldata using known ABIs.
 // Returns { name, description, details } or null.
 function decodeCalldata(data, toAddress) {
@@ -234,17 +215,19 @@ function showTxApproval(details) {
             toHtml += `<div class="font-bold mb-1">${escapeHtml(symbol)}</div>`;
         }
         toHtml += approvalAddressHtml(toAddr);
-        if (symbol) {
-            const link = etherscanTokenLink(toAddr);
-            toHtml = toHtml.replace("</div>", "") + ""; // approvalAddressHtml already has etherscan link
-        }
         $("approve-tx-to").innerHTML = toHtml;
     } else {
         $("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 = $("approve-tx-decoded");
@@ -259,12 +242,9 @@ function showTxApproval(details) {
             detailsHtml += `<div class="text-muted">${escapeHtml(d.label)}</div>`;
             if (d.address) {
                 if (d.isToken) {
-                    const tLink = etherscanTokenLink(d.address);
                     detailsHtml += `<div class="font-bold">${escapeHtml(tokenLabel(d.address) || "Unknown token")}</div>`;
-                    detailsHtml += approvalAddressHtml(d.address);
-                } else {
-                    detailsHtml += approvalAddressHtml(d.address);
                 }
+                detailsHtml += approvalAddressHtml(d.address);
             } else {
                 detailsHtml += `<div class="font-bold">${escapeHtml(d.value)}</div>`;
             }
@@ -288,6 +268,7 @@ function showTxApproval(details) {
     hideError("approve-tx-error");
 
     showView("approve-tx");
+    attachCopyHandlers("view-approve-tx");
 }
 
 function decodeHexMessage(hex) {
@@ -385,6 +366,7 @@ function showSignApproval(details) {
     $("btn-approve-sign").classList.remove("text-muted");
 
     showView("approve-sign");
+    attachCopyHandlers("view-approve-sign");
 }
 
 function show(id) {
@@ -412,6 +394,7 @@ function show(id) {
         $("approve-address").innerHTML = approvalAddressHtml(
             state.activeAddress,
         );
+        attachCopyHandlers("view-approve-site");
         $("approve-remember").checked = state.rememberSiteChoice;
     });
 }

src/popup/views/confirmTx.js

@@ -17,10 +17,11 @@ const {
     showFlash,
     flashCopyFeedback,
     addressTitle,
-    addressDotHtml,
     escapeHtml,
+    renderAddressHtml,
+    attachCopyHandlers,
 } = 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");
@@ -34,13 +35,6 @@ const { log } = require("../../shared/log");
 const makeBlockie = require("ethereum-blockies-base64");
 const txStatus = require("./txStatus");
 
-const EXT_ICON =
-    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
-    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
-    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
-    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
-    `</svg></span>`;
-
 let pendingTx = null;
 
 function restore() {
@@ -50,14 +44,6 @@ function restore() {
     }
 }
 
-function etherscanTokenLink(address) {
-    return `https://etherscan.io/token/${address}`;
-}
-
-function etherscanAddressLink(address) {
-    return `https://etherscan.io/address/${address}`;
-}
-
 function blockieHtml(address) {
     const src = makeBlockie(address);
     return `<img src="${src}" width="48" height="48" style="image-rendering:pixelated;border-radius:50%;display:inline-block">`;
@@ -65,22 +51,10 @@ function blockieHtml(address) {
 
 function confirmAddressHtml(address, ensName, title) {
     const blockie = blockieHtml(address);
-    const dot = addressDotHtml(address);
+    return (
-    const link = etherscanAddressLink(address);
+        `<div class="mb-1">${blockie}</div>` +
-    const extLink = `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
+        renderAddressHtml(address, { title, ensName })
-    let html = `<div class="mb-1">${blockie}</div>`;
+    );
-    if (title) {
-        html += `<div class="flex items-center font-bold">${dot}${escapeHtml(title)}</div>`;
-    }
-    if (ensName) {
-        html += `<div class="flex items-center font-bold">${title ? "" : dot}${escapeHtml(ensName)}</div>`;
-    }
-    html +=
-        `<div class="flex items-center">${title || ensName ? "" : dot}` +
-        `<span class="break-all">${escapeHtml(address)}</span>` +
-        extLink +
-        `</div>`;
-    return html;
 }
 
 function valueWithUsd(text, usdAmount) {
@@ -107,23 +81,12 @@ function show(txInfo) {
     // Token contract section (ERC-20 only)
     const tokenSection = $("confirm-token-section");
     if (isErc20) {
-        const dot = addressDotHtml(txInfo.token);
+        $("confirm-token-contract").innerHTML = renderAddressHtml(
-        const link = etherscanTokenLink(txInfo.token);
+            txInfo.token,
-        $("confirm-token-contract").innerHTML =
+            {},
-            `<div class="flex items-center">${dot}` +
+        );
-            `<span class="break-all underline decoration-dashed cursor-pointer" data-copy="${escapeHtml(txInfo.token)}">${escapeHtml(txInfo.token)}</span>` +
-            `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>` +
-            `</div>`;
         tokenSection.classList.remove("hidden");
-        // Attach click-to-copy on the contract address
+        attachCopyHandlers(tokenSection);
-        const copyEl = tokenSection.querySelector("[data-copy]");
-        if (copyEl) {
-            copyEl.onclick = () => {
-                navigator.clipboard.writeText(copyEl.dataset.copy);
-                showFlash("Copied!");
-                flashCopyFeedback(copyEl);
-            };
-        }
     } else {
         tokenSection.classList.add("hidden");
     }
@@ -243,6 +206,7 @@ function show(txInfo) {
     $("confirm-fee-amount").textContent = "Estimating...";
     state.viewData = { pendingTx: txInfo };
     showView("confirm-tx");
+    attachCopyHandlers("view-confirm-tx");
 
     // Reset async warnings to hidden (space always reserved, no layout shift)
     $("confirm-recipient-warning").style.visibility = "hidden";

src/popup/views/helpers.js

@@ -6,7 +6,7 @@ const {
     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.
@@ -208,21 +208,9 @@ function addressTitle(address, wallets) {
 // Render an address with color dot, optional ENS name, optional title,
 // and optional truncation. Title and ENS are shown as bold labels above
 // the full address.
+// Delegates to renderAddressHtml for consistent output.
 function formatAddressHtml(address, ensName, maxLen, title) {
-    const dot = addressDotHtml(address);
+    return renderAddressHtml(address, { title, ensName, maxLen });
-    const displayAddr = maxLen ? truncateMiddle(address, maxLen) : address;
-    if (title || ensName) {
-        let html = "";
-        if (title) {
-            html += `<div class="flex items-center font-bold">${dot}${escapeHtml(title)}</div>`;
-        }
-        if (ensName) {
-            html += `<div class="flex items-center font-bold">${title ? "" : dot}${escapeHtml(ensName)}</div>`;
-        }
-        html += `<div class="break-all">${escapeHtml(displayAddr)}</div>`;
-        return html;
-    }
-    return `<div class="flex items-center">${dot}<span class="break-all">${escapeHtml(displayAddr)}</span></div>`;
 }
 
 function isoDate(timestamp) {
@@ -281,6 +269,91 @@ function timeAgo(timestamp) {
     return years + " year" + (years !== 1 ? "s" : "") + " ago";
 }
 
+// Shared external-link icon SVG used across all views.
+const EXT_ICON =
+    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
+    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
+    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
+    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
+    `</svg></span>`;
+
+function etherscanAddressUrl(address) {
+    return `${currentNetwork().explorerUrl}/address/${address}`;
+}
+
+function etherscanLinkHtml(url) {
+    return (
+        `<a href="${url}" target="_blank" rel="noopener" ` +
+        `class="inline-flex items-center">${EXT_ICON}</a>`
+    );
+}
+
+// Render a copyable text span with dashed underline affordance.
+// The caller must attach click handlers via attachCopyHandlers() or
+// manually wire up [data-copy] elements after inserting the HTML.
+function copyableHtml(text, extraClass) {
+    const cls =
+        "underline decoration-dashed cursor-pointer" +
+        (extraClass ? " " + extraClass : "");
+    return `<span class="${cls}" data-copy="${escapeHtml(text)}">${escapeHtml(text)}</span>`;
+}
+
+// Attach click-to-copy handlers to all [data-copy] elements within
+// a container.  Safe to call multiple times on the same container.
+function attachCopyHandlers(container) {
+    const root =
+        typeof container === "string"
+            ? document.getElementById(container)
+            : container;
+    if (!root) return;
+    root.querySelectorAll("[data-copy]").forEach((el) => {
+        el.onclick = () => {
+            navigator.clipboard.writeText(el.dataset.copy);
+            showFlash("Copied!");
+            flashCopyFeedback(el);
+        };
+    });
+}
+
+// Unified address rendering.
+//
+// Produces consistent HTML for any Ethereum address:
+//   • Color dot
+//   • Optional title (e.g. "Wallet 1 — Address 2") shown bold above address
+//   • Optional ENS name shown bold above address
+//   • Full address (or truncated via maxLen) with dashed-underline click-to-copy
+//   • Etherscan external link icon
+//
+// Options object:
+//   title    — wallet title string (from addressTitle)
+//   ensName  — ENS name string
+//   maxLen   — if set, truncate address display (min 32 chars enforced)
+//   noLink   — if true, omit etherscan link
+//
+// After inserting the returned HTML into the DOM, call
+// attachCopyHandlers() on the parent to wire up click-to-copy.
+function renderAddressHtml(address, opts) {
+    const { title, ensName, maxLen, noLink } = opts || {};
+    const dot = addressDotHtml(address);
+    const displayAddr = maxLen ? truncateMiddle(address, maxLen) : address;
+    const link = etherscanAddressUrl(address);
+    const extLink = noLink ? "" : etherscanLinkHtml(link);
+
+    let html = "";
+    if (title) {
+        html += `<div class="flex items-center font-bold">${dot}${escapeHtml(title)}</div>`;
+    }
+    if (ensName) {
+        html += `<div class="flex items-center font-bold">${title ? "" : dot}${escapeHtml(ensName)}</div>`;
+    }
+    if (title || ensName) {
+        html += `<div class="flex items-center">${copyableHtml(displayAddr, "break-all")}${extLink}</div>`;
+    } else {
+        html += `<div class="flex items-center">${dot}${copyableHtml(displayAddr, "break-all")}${extLink}</div>`;
+    }
+    return html;
+}
+
 function flashCopyFeedback(el) {
     if (!el) return;
     el.classList.remove("copy-flash-fade");
@@ -308,6 +381,12 @@ module.exports = {
     escapeHtml,
     addressTitle,
     formatAddressHtml,
+    renderAddressHtml,
+    copyableHtml,
+    attachCopyHandlers,
+    etherscanAddressUrl,
+    etherscanLinkHtml,
+    EXT_ICON,
     truncateMiddle,
     isoDate,
     timeAgo,

src/popup/views/home.js

@@ -10,6 +10,8 @@ const {
     addressTitle,
     escapeHtml,
     truncateMiddle,
+    renderAddressHtml,
+    attachCopyHandlers,
 } = require("./helpers");
 const { state, saveState, currentAddress } = require("../../shared/state");
 const {
@@ -69,28 +71,12 @@ function renderTotalValue() {
     }
 }
 
-const EXT_ICON =
-    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
-    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
-    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
-    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
-    `</svg></span>`;
-
 function renderActiveAddress() {
     const el = $("active-address-display");
     if (!el) return;
     if (state.activeAddress) {
-        const addr = state.activeAddress;
+        el.innerHTML = renderAddressHtml(state.activeAddress);
-        const dot = addressDotHtml(addr);
+        attachCopyHandlers(el);
-        const link = `https://etherscan.io/address/${addr}`;
-        el.innerHTML =
-            `<span class="underline decoration-dashed cursor-pointer" id="active-addr-copy">${dot}${escapeHtml(addr)}</span>` +
-            `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
-        $("active-addr-copy").addEventListener("click", (e) => {
-            navigator.clipboard.writeText(addr);
-            showFlash("Copied!");
-            flashCopyFeedback(e.currentTarget);
-        });
     } else {
         el.textContent = "";
     }

src/popup/views/receive.js

@@ -5,17 +5,11 @@ const {
     flashCopyFeedback,
     formatAddressHtml,
     addressTitle,
+    attachCopyHandlers,
 } = require("./helpers");
-const { state, currentAddress } = require("../../shared/state");
+const { state, currentAddress, currentNetwork } = require("../../shared/state");
 const QRCode = require("qrcode");
 
-const EXT_ICON =
-    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
-    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
-    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
-    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
-    `</svg></span>`;
-
 function show() {
     const addr = currentAddress();
     const address = addr ? addr.address : "";
@@ -25,10 +19,8 @@ function show() {
         ? formatAddressHtml(address, ensName, null, title)
         : "";
     $("receive-address-block").dataset.full = address;
-    const link = address ? `https://etherscan.io/address/${address}` : "";
+    // Etherscan link is now included in formatAddressHtml via renderAddressHtml
-    $("receive-etherscan-link").innerHTML = link
+    $("receive-etherscan-link").innerHTML = "";
-        ? `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`
-        : "";
     if (address) {
         QRCode.toCanvas($("receive-qr"), address, {
             width: 200,
@@ -52,25 +44,19 @@ 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 = "";
         warningEl.style.visibility = "hidden";
     }
     showView("receive");
+    attachCopyHandlers("view-receive");
 }
 
 function init(ctx) {
-    $("receive-address-block").addEventListener("click", (e) => {
-        const addr = $("receive-address-block").dataset.full;
-        if (addr) {
-            navigator.clipboard.writeText(addr);
-            showFlash("Copied!");
-            flashCopyFeedback(e.currentTarget);
-        }
-    });
-
     $("btn-receive-copy").addEventListener("click", () => {
         const addr = $("receive-address-block").dataset.full;
         if (addr) {

src/popup/views/send.js

@@ -3,9 +3,10 @@
 const {
     $,
     showFlash,
-    addressDotHtml,
     addressTitle,
     escapeHtml,
+    renderAddressHtml,
+    attachCopyHandlers,
 } = require("./helpers");
 const { state, currentAddress } = require("../../shared/state");
 let ctx;
@@ -113,13 +114,6 @@ function updateToValidation() {
     }
 }
 
-const EXT_ICON =
-    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
-    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
-    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
-    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
-    `</svg></span>`;
-
 function isSpoofedToken(t) {
     const upper = (t.symbol || "").toUpperCase();
     if (!KNOWN_SYMBOLS.has(upper)) return false;
@@ -148,24 +142,12 @@ function renderSendTokenSelect(addr) {
 function updateSendBalance() {
     const addr = currentAddress();
     if (!addr) return;
-    const dot = addressDotHtml(addr.address);
-    const link = `https://etherscan.io/address/${addr.address}`;
-    const extLink = `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
     const title = addressTitle(addr.address, state.wallets);
-    let fromHtml = "";
+    $("send-from").innerHTML = renderAddressHtml(addr.address, {
-    if (title) {
+        title,
-        fromHtml += `<div class="flex items-center font-bold">${dot}${escapeHtml(title)}</div>`;
+        ensName: addr.ensName,
-        if (addr.ensName) {
+    });
-            fromHtml += `<div>${escapeHtml(addr.ensName)}</div>`;
+    attachCopyHandlers($("send-from"));
-        }
-        fromHtml += `<div class="break-all">${escapeHtml(addr.address)}${extLink}</div>`;
-    } else if (addr.ensName) {
-        fromHtml += `<div class="flex items-center font-bold">${dot}${escapeHtml(addr.ensName)}</div>`;
-        fromHtml += `<div class="break-all">${escapeHtml(addr.address)}${extLink}</div>`;
-    } else {
-        fromHtml += `<div class="flex items-center">${dot}<span class="break-all">${escapeHtml(addr.address)}</span>${extLink}</div>`;
-    }
-    $("send-from").innerHTML = fromHtml;
     const token = state.selectedToken || $("send-token").value;
     if (token === "ETH") {
         $("send-balance").textContent =

src/popup/views/settings.js

@@ -1,7 +1,7 @@
 const { $, showView, showFlash, escapeHtml } = require("./helpers");
 const { applyTheme } = require("../theme");
-const { state, saveState } = require("../../shared/state");
+const { state, saveState, currentNetwork } = require("../../shared/state");
-const { ETHEREUM_MAINNET_CHAIN_ID } = require("../../shared/constants");
+const { NETWORKS, SUPPORTED_CHAIN_IDS } = require("../../shared/networks");
 const { log, debugFetch } = require("../../shared/log");
 const deleteWallet = require("./deleteWallet");
 
@@ -125,6 +125,10 @@ 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();
@@ -168,9 +172,12 @@ 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 +216,22 @@ function init(ctx) {
         showFlash("Saved.");
     });
 
+    const networkSelect = $("settings-network");
+    if (networkSelect) {
+        networkSelect.addEventListener("change", async () => {
+            const newId = networkSelect.value;
+            const net = NETWORKS[newId];
+            if (!net) return;
+            state.networkId = newId;
+            state.rpcUrl = net.defaultRpcUrl;
+            state.blockscoutUrl = net.defaultBlockscoutUrl;
+            $("settings-rpc").value = state.rpcUrl;
+            $("settings-blockscout").value = state.blockscoutUrl;
+            await saveState();
+            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;

src/popup/views/transactionDetail.js

@@ -6,25 +6,21 @@ const {
     showView,
     showFlash,
     flashCopyFeedback,
-    addressDotHtml,
     addressTitle,
     escapeHtml,
     isoDate,
     timeAgo,
+    renderAddressHtml,
+    attachCopyHandlers,
+    copyableHtml,
+    etherscanLinkHtml,
 } = 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");
 const { decodeCalldata } = require("./approval");
 
-const EXT_ICON =
-    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
-    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
-    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
-    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
-    `</svg></span>`;
-
 let ctx;
 
 /**
@@ -46,56 +42,21 @@ function getTransactionType(tx) {
     return "Native ETH Transfer";
 }
 
-function copyableHtml(text, extraClass) {
-    const cls =
-        "underline decoration-dashed cursor-pointer" +
-        (extraClass ? " " + extraClass : "");
-    return `<span class="${cls}" data-copy="${escapeHtml(text)}">${escapeHtml(text)}</span>`;
-}
-
 function blockieHtml(address) {
     const src = makeBlockie(address);
     return `<img src="${src}" width="48" height="48" style="image-rendering:pixelated;border-radius:50%;display:inline-block">`;
 }
 
-function etherscanLinkHtml(url) {
+function txAddressHtml(address, ensName, title) {
+    const blockie = blockieHtml(address);
     return (
-        `<a href="${url}" target="_blank" rel="noopener" ` +
+        `<div class="mb-1">${blockie}</div>` +
-        `class="inline-flex items-center"` +
+        renderAddressHtml(address, { title, ensName })
-        `>${EXT_ICON}</a>`
     );
 }
 
-function txAddressHtml(address, ensName, title) {
-    const blockie = blockieHtml(address);
-    const dot = addressDotHtml(address);
-    const link = `https://etherscan.io/address/${address}`;
-    const extLink = etherscanLinkHtml(link);
-    let html = `<div class="mb-1">${blockie}</div>`;
-    if (title) {
-        html += `<div class="font-bold">${escapeHtml(title)}</div>`;
-    }
-    if (ensName) {
-        html +=
-            `<div class="flex items-center">${dot}` +
-            copyableHtml(ensName, "") +
-            `</div>` +
-            `<div class="flex items-center">${dot}` +
-            copyableHtml(address, "break-all") +
-            extLink +
-            `</div>`;
-    } else {
-        html +=
-            `<div class="flex items-center">${dot}` +
-            copyableHtml(address, "break-all") +
-            extLink +
-            `</div>`;
-    }
-    return html;
-}
-
 function txHashHtml(hash) {
-    const link = `https://etherscan.io/tx/${hash}`;
+    const link = `${currentNetwork().explorerUrl}/tx/${hash}`;
     const extLink = etherscanLinkHtml(link);
     return copyableHtml(hash, "break-all") + extLink;
 }
@@ -172,7 +133,7 @@ function render() {
     if (tokenContractSection && tokenContractEl) {
         if (tx.contractAddress) {
             const dot = addressDotHtml(tx.contractAddress);
-            const link = `https://etherscan.io/token/${tx.contractAddress}`;
+            const link = `${currentNetwork().explorerUrl}/token/${tx.contractAddress}`;
             tokenContractEl.innerHTML =
                 `<div class="flex items-center">${dot}` +
                 copyableHtml(tx.contractAddress, "break-all") +
@@ -210,17 +171,7 @@ function render() {
         copyableHtml(isoStr) + " (" + escapeHtml(timeAgo(tx.timestamp)) + ")";
     $("tx-detail-status").textContent = tx.isError ? "Failed" : "Success";
     showView("transaction");
-
+    attachCopyHandlers("view-transaction");
-    document
-        .getElementById("view-transaction")
-        .querySelectorAll("[data-copy]")
-        .forEach((el) => {
-            el.onclick = () => {
-                navigator.clipboard.writeText(el.dataset.copy);
-                showFlash("Copied!");
-                flashCopyFeedback(el);
-            };
-        });
 }
 
 function showDetailField(sectionId, contentId, value) {
@@ -234,7 +185,7 @@ 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 = $("tx-detail-block");
         if (blockSection && blockEl) {
@@ -355,19 +306,14 @@ async function loadFullTxDetails(txHash, toAddress, isContractCall) {
                 detailsHtml += `<div class="mb-2">`;
                 detailsHtml += `<div class="text-muted">${escapeHtml(d.label)}</div>`;
                 if (d.address && d.isToken) {
-                    // Token entry: show symbol on its own line, then dot + address + Etherscan link
+                    // Token entry: show symbol on its own line, then address via shared renderer
-                    const dot = addressDotHtml(d.address);
                     const tokenSymbol = d.value.match(/^(\S+)\s*\(/)?.[1];
                     if (tokenSymbol) {
                         detailsHtml += `<div class="font-bold">${escapeHtml(tokenSymbol)}</div>`;
                     }
-                    const etherscanUrl = `https://etherscan.io/token/${d.address}`;
+                    detailsHtml += renderAddressHtml(d.address);
-                    detailsHtml += `<div class="flex items-center">${dot}${copyableHtml(d.address, "break-all")}${etherscanLinkHtml(etherscanUrl)}</div>`;
                 } else if (d.address) {
-                    // Protocol/contract entry: show name + Etherscan link
+                    detailsHtml += renderAddressHtml(d.address);
-                    const dot = addressDotHtml(d.address);
-                    const etherscanUrl = `https://etherscan.io/address/${d.address}`;
-                    detailsHtml += `<div class="flex items-center">${dot}${copyableHtml(d.value, "break-all")}${etherscanLinkHtml(etherscanUrl)}</div>`;
                 } else {
                     detailsHtml += `<div class="font-bold">${escapeHtml(d.value)}</div>`;
                 }
@@ -394,13 +340,7 @@ async function loadFullTxDetails(txHash, toAddress, isContractCall) {
         // Bind copy handlers for new elements (including raw data now outside section)
         const copyTargets = [section, rawSection].filter(Boolean);
         for (const container of copyTargets) {
-            container.querySelectorAll("[data-copy]").forEach((el) => {
+            attachCopyHandlers(container);
-                el.onclick = () => {
-                    navigator.clipboard.writeText(el.dataset.copy);
-                    showFlash("Copied!");
-                    flashCopyFeedback(el);
-                };
-            });
         }
     } catch (e) {
         log.errorf("loadCalldata failed:", e.message);

src/popup/views/txStatus.js

@@ -3,24 +3,18 @@
 const {
     $,
     showView,
-    showFlash,
-    flashCopyFeedback,
-    addressDotHtml,
     addressTitle,
     escapeHtml,
+    renderAddressHtml,
+    attachCopyHandlers,
+    copyableHtml,
+    etherscanLinkHtml,
 } = 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");
 
-const EXT_ICON =
-    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
-    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
-    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
-    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
-    `</svg></span>`;
-
 let ctx;
 let elapsedTimer = null;
 let pollTimer = null;
@@ -37,50 +31,19 @@ function clearTimers() {
 }
 
 function toAddressHtml(address) {
-    const dot = addressDotHtml(address);
-    const link = `https://etherscan.io/address/${address}`;
-    const extLink = `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
     const title = addressTitle(address, state.wallets);
-    if (title) {
+    return renderAddressHtml(address, { title });
-        return (
-            `<div class="flex items-center font-bold">${dot}${escapeHtml(title)}</div>` +
-            `<div class="break-all underline decoration-dashed cursor-pointer" data-copy="${escapeHtml(address)}">${escapeHtml(address)}</div>` +
-            extLink
-        );
-    }
-    return `<div class="flex items-center">${dot}<span class="break-all underline decoration-dashed cursor-pointer" data-copy="${escapeHtml(address)}">${escapeHtml(address)}</span>${extLink}</div>`;
 }
 
 function txHashHtml(hash) {
-    const link = `https://etherscan.io/tx/${hash}`;
+    const link = `${currentNetwork().explorerUrl}/tx/${hash}`;
-    const extLink = `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
+    return copyableHtml(hash, "break-all") + etherscanLinkHtml(link);
-    return (
-        `<span class="underline decoration-dashed cursor-pointer break-all" data-copy="${escapeHtml(hash)}">${escapeHtml(hash)}</span>` +
-        extLink
-    );
 }
 
 function blockNumberHtml(blockNumber) {
     const num = String(blockNumber);
-    const link = `https://etherscan.io/block/${num}`;
+    const link = `${currentNetwork().explorerUrl}/block/${num}`;
-    const extLink = `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
+    return copyableHtml(num) + etherscanLinkHtml(link);
-    return (
-        `<span class="underline decoration-dashed cursor-pointer" data-copy="${escapeHtml(num)}">${escapeHtml(num)}</span>` +
-        extLink
-    );
-}
-
-function attachCopyHandlers(viewId) {
-    document
-        .getElementById(viewId)
-        .querySelectorAll("[data-copy]")
-        .forEach((el) => {
-            el.onclick = () => {
-                navigator.clipboard.writeText(el.dataset.copy);
-                showFlash("Copied!");
-                flashCopyFeedback(el);
-            };
-        });
 }
 
 function showWait(txInfo, txHash) {
@@ -147,7 +110,7 @@ function tokenLabel(address) {
 }
 
 function etherscanTokenLink(address) {
-    return `https://etherscan.io/token/${address}`;
+    return `${currentNetwork().explorerUrl}/token/${address}`;
 }
 
 function decodedDetailsHtml(decoded) {

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");
+// Accepts an optional networkName ("mainnet" or "sepolia") for the static
-
+// network hint so ethers picks the right chain parameters.  When omitted,
-function getProvider(rpcUrl) {
+// reads the currently selected network from extension state.
-    return new JsonRpcProvider(rpcUrl, mainnet, { staticNetwork: mainnet });
+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/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/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 +8,9 @@ const prices = {};
 let lastFetchedAt = 0;
 
 async function refreshPrices() {
+    // Testnet tokens have no real market value — skip price fetching.
+    const { currentNetwork } = require("./state");
+    if (currentNetwork().isTestnet) return;
     const now = Date.now();
     if (now - lastFetchedAt < PRICE_CACHE_TTL) return;
     try {

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,
@@ -38,11 +40,17 @@ const state = {
     viewData: {},
 };
 
+// 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,
@@ -75,6 +83,7 @@ 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;
@@ -134,4 +143,10 @@ function currentAddress() {
     return state.wallets[state.selectedWallet].addresses[state.selectedAddress];
 }
 
-module.exports = { state, saveState, loadState, currentAddress };
+module.exports = {
+    state,
+    saveState,
+    loadState,
+    currentAddress,
+    currentNetwork,
+};