fix: consistent token contract display on confirm-tx page

The confirm-tx page displayed token contract addresses as plain text,
while addressToken used a styled container (bg-hover rounded-md) with
color dot, copy-on-click, etherscan link, and token metadata.

Changes:
- confirm-tx HTML: use bg-hover rounded-md container matching addressToken
- confirm-tx JS: render contract with addressDotHtml, copy-on-click span,
  etherscan link, and optional token name/symbol metadata
- send.js: pass tokenName to confirmTx for richer contract display
- Add click-to-copy handler for contract address on confirm-tx

Closes #70

.gitignore

@@ -25,3 +25,4 @@ dist/
 
 # Yarn
 .yarn-integrity
+package-lock.json

src/popup/index.html

@@ -463,12 +463,12 @@
                 </div>
 
                 <!-- ERC-20 token contract (hidden for ETH) -->
-                <div id="confirm-token-section" class="mb-3 hidden">
-                    <div class="text-xs text-muted mb-1">Token contract</div>
-                    <div
-                        id="confirm-token-contract"
-                        class="text-xs break-all"
-                    ></div>
+                <div
+                    id="confirm-token-section"
+                    class="bg-hover rounded-md mx-1 p-3 mb-3 text-xs hidden"
+                >
+                    <div class="font-bold mb-2">Token Contract</div>
+                    <div id="confirm-token-contract" class="break-all"></div>
                 </div>
 
                 <div class="mb-3">
@@ -531,6 +531,7 @@
             <!-- ============ TX SUCCESS ============ -->
             <div id="view-success-tx" class="view hidden">
                 <h2 class="font-bold mb-2">Transaction Confirmed</h2>
+                <div id="success-tx-decoded" class="mb-3 hidden text-xs"></div>
                 <div class="mb-3">
                     <div class="text-xs text-muted mb-1">Amount</div>
                     <div id="success-tx-summary" class="font-bold"></div>
@@ -636,9 +637,10 @@
                 <div class="flex justify-center mb-3">
                     <canvas id="receive-qr"></canvas>
                 </div>
-                <div class="border border-border p-2 break-all mb-3 text-xs">
-                    <span id="receive-dot"></span>
-                    <span id="receive-address" class="select-all"></span>
+                <div
+                    class="border border-border p-2 break-all mb-3 text-xs cursor-pointer"
+                >
+                    <span id="receive-address-block" class="select-all"></span>
                     <span id="receive-etherscan-link"></span>
                 </div>
                 <button

src/popup/views/addressToken.js

@@ -12,7 +12,7 @@ const {
     balanceLine,
 } = require("./helpers");
 const { state, currentAddress, saveState } = require("../../shared/state");
-const { TOKEN_BY_ADDRESS } = require("../../shared/tokenList");
+const { TOKEN_BY_ADDRESS, resolveSymbol } = require("../../shared/tokenList");
 const {
     formatUsd,
     getPrice,
@@ -96,14 +96,11 @@ function show() {
         const tb = (addr.tokenBalances || []).find(
             (t) => t.address.toLowerCase() === tokenId.toLowerCase(),
         );
-        const tracked = (state.trackedTokens || []).find(
-            (t) => t.address.toLowerCase() === tokenId.toLowerCase(),
+        symbol = resolveSymbol(
+            tokenId,
+            addr.tokenBalances,
+            state.trackedTokens,
         );
-        symbol =
-            (tb && tb.symbol) ||
-            (tracked && tracked.symbol) ||
-            (knownToken && knownToken.symbol) ||
-            "?";
         amount = tb ? parseFloat(tb.balance || "0") : 0;
         price = getPrice(symbol);
     }

src/popup/views/approval.js

@@ -78,10 +78,12 @@ function decodeCalldata(data, toAddress) {
                     "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
                 );
                 const isUnlimited = rawAmount === maxUint;
+                const amountRaw = isUnlimited
+                    ? "Unlimited"
+                    : formatTxValue(formatUnits(rawAmount, tokenDecimals));
                 const amountStr = isUnlimited
                     ? "Unlimited"
-                    : formatTxValue(formatUnits(rawAmount, tokenDecimals)) +
-                      (tokenSymbol ? " " + tokenSymbol : "");
+                    : amountRaw + (tokenSymbol ? " " + tokenSymbol : "");
 
                 return {
                     name: "Token Approval",
@@ -100,7 +102,11 @@ function decodeCalldata(data, toAddress) {
                             value: spender,
                             address: spender,
                         },
-                        { label: "Amount", value: amountStr },
+                        {
+                            label: "Amount",
+                            value: amountStr,
+                            rawValue: amountRaw,
+                        },
                     ],
                 };
             }
@@ -108,9 +114,11 @@ function decodeCalldata(data, toAddress) {
             if (parsed.name === "transfer") {
                 const to = parsed.args[0];
                 const rawAmount = parsed.args[1];
+                const amountRaw = formatTxValue(
+                    formatUnits(rawAmount, tokenDecimals),
+                );
                 const amountStr =
-                    formatTxValue(formatUnits(rawAmount, tokenDecimals)) +
-                    (tokenSymbol ? " " + tokenSymbol : "");
+                    amountRaw + (tokenSymbol ? " " + tokenSymbol : "");
 
                 return {
                     name: "Token Transfer",
@@ -125,7 +133,11 @@ function decodeCalldata(data, toAddress) {
                             isToken: true,
                         },
                         { label: "Recipient", value: to, address: to },
-                        { label: "Amount", value: amountStr },
+                        {
+                            label: "Amount",
+                            value: amountStr,
+                            rawValue: amountRaw,
+                        },
                     ],
                 };
             }
@@ -163,7 +175,7 @@ function showTxApproval(details) {
                 pendingTxDetails.to = d.address;
             }
             if (d.label === "Amount") {
-                pendingTxDetails.amount = d.value;
+                pendingTxDetails.amount = d.rawValue || d.value;
             }
         }
         if (token) {
@@ -172,6 +184,15 @@ function showTxApproval(details) {
         }
     }
 
+    // Carry decoded calldata info through to success/error views
+    if (decoded) {
+        pendingTxDetails.decoded = {
+            name: decoded.name,
+            description: decoded.description,
+            details: decoded.details,
+        };
+    }
+
     $("approve-tx-hostname").textContent = details.hostname;
     $("approve-tx-from").innerHTML = approvalAddressHtml(state.activeAddress);
 

src/popup/views/confirmTx.js

@@ -95,10 +95,22 @@ function show(txInfo) {
     // Token contract section (ERC-20 only)
     const tokenSection = $("confirm-token-section");
     if (isErc20) {
+        const dot = addressDotHtml(txInfo.token);
         const link = etherscanTokenLink(txInfo.token);
         $("confirm-token-contract").innerHTML =
-            escapeHtml(txInfo.token) +
-            ` <a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`;
+            `<div class="flex items-center">` +
+            dot +
+            `<span class="break-all underline decoration-dashed cursor-pointer" id="confirm-token-contract-copy" data-copy="${escapeHtml(txInfo.token)}">${escapeHtml(txInfo.token)}</span>` +
+            `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>` +
+            `</div>`;
+        if (txInfo.tokenName) {
+            $("confirm-token-contract").innerHTML +=
+                `<div class="mt-1"><span class="text-muted">Name:</span> ${escapeHtml(txInfo.tokenName)}</div>`;
+        }
+        if (txInfo.tokenSymbol) {
+            $("confirm-token-contract").innerHTML +=
+                `<div class="mt-1"><span class="text-muted">Symbol:</span> ${escapeHtml(txInfo.tokenSymbol)}</div>`;
+        }
         tokenSection.classList.remove("hidden");
     } else {
         tokenSection.classList.add("hidden");
@@ -273,6 +285,13 @@ function hidePasswordModal() {
 }
 
 function init(ctx) {
+    $("confirm-token-section").addEventListener("click", (e) => {
+        const copyEl = e.target.closest("[data-copy]");
+        if (copyEl) {
+            navigator.clipboard.writeText(copyEl.dataset.copy);
+        }
+    });
+
     $("btn-confirm-send").addEventListener("click", () => {
         showPasswordModal();
     });

src/popup/views/receive.js

@@ -1,4 +1,10 @@
-const { $, showView, showFlash, addressDotHtml } = require("./helpers");
+const {
+    $,
+    showView,
+    showFlash,
+    formatAddressHtml,
+    addressTitle,
+} = require("./helpers");
 const { state, currentAddress } = require("../../shared/state");
 const QRCode = require("qrcode");
 
@@ -12,8 +18,12 @@ const EXT_ICON =
 function show() {
     const addr = currentAddress();
     const address = addr ? addr.address : "";
-    $("receive-dot").innerHTML = address ? addressDotHtml(address) : "";
-    $("receive-address").textContent = address;
+    const title = address ? addressTitle(address, state.wallets) : null;
+    const ensName = addr ? addr.ensName || null : null;
+    $("receive-address-block").innerHTML = address
+        ? formatAddressHtml(address, ensName, null, title)
+        : "";
+    $("receive-address-block").dataset.full = address;
     const link = address ? `https://etherscan.io/address/${address}` : "";
     $("receive-etherscan-link").innerHTML = link
         ? `<a href="${link}" target="_blank" rel="noopener" class="inline-flex items-center">${EXT_ICON}</a>`
@@ -50,8 +60,16 @@ function show() {
 }
 
 function init(ctx) {
+    $("receive-address-block").addEventListener("click", () => {
+        const addr = $("receive-address-block").dataset.full;
+        if (addr) {
+            navigator.clipboard.writeText(addr);
+            showFlash("Copied!");
+        }
+    });
+
     $("btn-receive-copy").addEventListener("click", () => {
-        const addr = $("receive-address").textContent;
+        const addr = $("receive-address-block").dataset.full;
         if (addr) {
             navigator.clipboard.writeText(addr);
             showFlash("Copied!");

src/popup/views/send.js

@@ -10,7 +10,11 @@ const {
 const { state, currentAddress } = require("../../shared/state");
 let ctx;
 const { getProvider } = require("../../shared/balances");
-const { KNOWN_SYMBOLS, TOKEN_BY_ADDRESS } = require("../../shared/tokenList");
+const {
+    KNOWN_SYMBOLS,
+    TOKEN_BY_ADDRESS,
+    resolveSymbol,
+} = require("../../shared/tokenList");
 
 const EXT_ICON =
     `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
@@ -73,15 +77,11 @@ function updateSendBalance() {
         const tb = (addr.tokenBalances || []).find(
             (t) => t.address.toLowerCase() === token.toLowerCase(),
         );
-        const knownToken = TOKEN_BY_ADDRESS.get(token.toLowerCase());
-        const tracked = (state.trackedTokens || []).find(
-            (t) => t.address.toLowerCase() === token.toLowerCase(),
+        const symbol = resolveSymbol(
+            token,
+            addr.tokenBalances,
+            state.trackedTokens,
         );
-        const symbol =
-            (tb && tb.symbol) ||
-            (tracked && tracked.symbol) ||
-            (knownToken && knownToken.symbol) ||
-            "?";
         const bal = tb ? tb.balance || "0" : "0";
         $("send-balance").textContent =
             "Current balance: " + bal + " " + symbol;
@@ -128,20 +128,28 @@ function init(_ctx) {
 
         let tokenSymbol = null;
         let tokenBalance = null;
+        let tokenName = null;
         if (token !== "ETH") {
             const tb = (addr.tokenBalances || []).find(
                 (t) => t.address.toLowerCase() === token.toLowerCase(),
             );
-            const knownTk = TOKEN_BY_ADDRESS.get(token.toLowerCase());
-            const trackedTk = (state.trackedTokens || []).find(
-                (t) => t.address.toLowerCase() === token.toLowerCase(),
+            tokenSymbol = resolveSymbol(
+                token,
+                addr.tokenBalances,
+                state.trackedTokens,
             );
-            tokenSymbol =
-                (tb && tb.symbol) ||
-                (trackedTk && trackedTk.symbol) ||
-                (knownTk && knownTk.symbol) ||
-                "?";
             tokenBalance = tb ? tb.balance || "0" : "0";
+            // Resolve token name from balances, tracked tokens, or known list
+            const lower = token.toLowerCase();
+            tokenName =
+                (tb && tb.name) ||
+                (
+                    (state.trackedTokens || []).find(
+                        (t) => t.address.toLowerCase() === lower,
+                    ) || {}
+                ).name ||
+                (TOKEN_BY_ADDRESS.get(lower) || {}).name ||
+                null;
         }
 
         ctx.showConfirmTx({
@@ -153,6 +161,7 @@ function init(_ctx) {
             balance: addr.balance,
             tokenSymbol: tokenSymbol,
             tokenBalance: tokenBalance,
+            tokenName: tokenName,
         });
     });
 

src/popup/views/transactionDetail.js

@@ -40,7 +40,7 @@ function blockieHtml(address) {
 function etherscanLinkHtml(url) {
     return (
         `<a href="${url}" target="_blank" rel="noopener" ` +
-        `class="inline-flex items-center border border-border px-1 hover:bg-fg hover:text-bg cursor-pointer"` +
+        `class="inline-flex items-center"` +
         `>${EXT_ICON}</a>`
     );
 }
@@ -143,11 +143,10 @@ function render() {
             typeEl.textContent = tx.directionLabel;
             typeSection.classList.remove("hidden");
         }
-        if (headingEl) headingEl.textContent = tx.directionLabel;
     } else {
         if (typeSection) typeSection.classList.add("hidden");
-        if (headingEl) headingEl.textContent = "Transaction";
     }
+    if (headingEl) headingEl.textContent = "Transaction";
 
     // Hide calldata and raw data sections; re-fetch if this is a contract call
     const calldataSection = $("tx-detail-calldata-section");

src/popup/views/txStatus.js

@@ -8,6 +8,7 @@ const {
     addressTitle,
     escapeHtml,
 } = require("./helpers");
+const { TOKEN_BY_ADDRESS } = require("../../shared/tokenList");
 const { state, saveState } = require("../../shared/state");
 const { getProvider } = require("../../shared/balances");
 const { log } = require("../../shared/log");
@@ -121,11 +122,51 @@ function showSuccess(txInfo, txHash, blockNumber) {
         to: txInfo.to,
         hash: txHash,
         blockNumber: blockNumber,
+        decoded: txInfo.decoded || null,
     };
     renderSuccess();
     ctx.doRefreshAndRender();
 }
 
+function tokenLabel(address) {
+    const t = TOKEN_BY_ADDRESS.get(address.toLowerCase());
+    return t ? t.symbol : null;
+}
+
+function etherscanTokenLink(address) {
+    return `https://etherscan.io/token/${address}`;
+}
+
+function decodedDetailsHtml(decoded) {
+    if (!decoded || !decoded.details) return "";
+    let html = "";
+    if (decoded.name) {
+        html += `<div class="mb-2"><div class="text-xs text-muted mb-1">Action</div>`;
+        html += `<div class="font-bold">${escapeHtml(decoded.name)}</div></div>`;
+    }
+    if (decoded.description) {
+        html += `<div class="mb-2"><div class="text-xs text-muted mb-1">Description</div>`;
+        html += `<div>${escapeHtml(decoded.description)}</div></div>`;
+    }
+    for (const d of decoded.details) {
+        html += `<div class="mb-2">`;
+        html += `<div class="text-xs text-muted mb-1">${escapeHtml(d.label)}</div>`;
+        if (d.address) {
+            if (d.isToken) {
+                const sym = tokenLabel(d.address) || "Unknown token";
+                html += `<div class="font-bold">${escapeHtml(sym)}</div>`;
+                html += toAddressHtml(d.address);
+            } else {
+                html += toAddressHtml(d.address);
+            }
+        } else {
+            html += `<div class="font-bold">${escapeHtml(d.value)}</div>`;
+        }
+        html += `</div>`;
+    }
+    return html;
+}
+
 function renderSuccess() {
     const d = state.viewData;
     if (!d || !d.hash) return;
@@ -133,6 +174,16 @@ function renderSuccess() {
     $("success-tx-to").innerHTML = toAddressHtml(d.to);
     $("success-tx-block").textContent = String(d.blockNumber);
     $("success-tx-hash").innerHTML = txHashHtml(d.hash);
+
+    // Show decoded calldata details if present
+    const decodedEl = $("success-tx-decoded");
+    if (decodedEl && d.decoded) {
+        decodedEl.innerHTML = decodedDetailsHtml(d.decoded);
+        decodedEl.classList.remove("hidden");
+    } else if (decodedEl) {
+        decodedEl.classList.add("hidden");
+    }
+
     attachCopyHandlers("view-success-tx");
     showView("success-tx");
 }

src/shared/tokenList.js

@@ -3645,10 +3645,27 @@ async function getTopTokenPrices(n) {
     return prices;
 }
 
+// Resolve a token symbol from multiple sources, never returning "?".
+function resolveSymbol(tokenAddress, tokenBalances, trackedTokens) {
+    const lower = (tokenAddress || "").toLowerCase();
+    const tb = (tokenBalances || []).find(
+        (t) => t.address.toLowerCase() === lower,
+    );
+    if (tb && tb.symbol) return tb.symbol;
+    const known = TOKEN_BY_ADDRESS.get(lower);
+    if (known && known.symbol) return known.symbol;
+    const tracked = (trackedTokens || []).find(
+        (t) => t.address.toLowerCase() === lower,
+    );
+    if (tracked && tracked.symbol) return tracked.symbol;
+    return lower.slice(0, 10) + "\u2026";
+}
+
 module.exports = {
     TOKENS,
     TOKEN_BY_ADDRESS,
     KNOWN_SYMBOLS,
     getTopTokens,
     getTopTokenPrices,
+    resolveSymbol,
 };

src/shared/uniswap.js

@@ -161,6 +161,157 @@ function decodeWrapEth(input) {
     }
 }
 
+// V4 inner action IDs
+const V4_SWAP_EXACT_IN_SINGLE = 0x06;
+const V4_SWAP_EXACT_IN = 0x07;
+const V4_SWAP_EXACT_OUT_SINGLE = 0x08;
+const V4_SWAP_EXACT_OUT = 0x09;
+const V4_SETTLE = 0x0b;
+const V4_TAKE = 0x0e;
+
+// Decode V4_SWAP (command 0x10) input bytes.
+// The input is ABI-encoded as (bytes actions, bytes[] params).
+// We extract token addresses from SETTLE (input) and TAKE (output) sub-actions,
+// and swap amounts from the swap sub-actions.
+function decodeV4Swap(input) {
+    try {
+        const d = coder.decode(["bytes", "bytes[]"], input);
+        const actions = getBytes(d[0]);
+        const params = d[1];
+
+        let settleToken = null;
+        let takeToken = null;
+        let amountIn = null;
+        let amountOutMin = null;
+
+        for (let i = 0; i < actions.length; i++) {
+            const actionId = actions[i];
+            try {
+                if (actionId === V4_SETTLE) {
+                    // SETTLE: (address currency, uint256 maxAmount, bool payerIsUser)
+                    const s = coder.decode(
+                        ["address", "uint256", "bool"],
+                        params[i],
+                    );
+                    settleToken = s[0];
+                } else if (actionId === V4_TAKE) {
+                    // TAKE: (address currency, address recipient, uint256 amount)
+                    const t = coder.decode(
+                        ["address", "address", "uint256"],
+                        params[i],
+                    );
+                    takeToken = t[0];
+                } else if (
+                    actionId === V4_SWAP_EXACT_IN ||
+                    actionId === V4_SWAP_EXACT_IN_SINGLE
+                ) {
+                    // Extract amounts from exact-in swap actions
+                    if (actionId === V4_SWAP_EXACT_IN) {
+                        // ExactInputParams: (address currencyIn,
+                        //   tuple(address,uint24,int24,address,bytes)[] path,
+                        //   uint128 amountIn, uint128 amountOutMin)
+                        try {
+                            const s = coder.decode(
+                                [
+                                    "tuple(address,tuple(address,uint24,int24,address,bytes)[],uint128,uint128)",
+                                ],
+                                params[i],
+                            );
+                            if (!settleToken) settleToken = s[0][0];
+                            const path = s[0][1];
+                            if (path.length > 0 && !takeToken) {
+                                takeToken = path[path.length - 1][0];
+                            }
+                            if (!amountIn) amountIn = s[0][2];
+                            if (!amountOutMin) amountOutMin = s[0][3];
+                        } catch {
+                            // Fall through — SETTLE/TAKE will provide tokens
+                        }
+                    } else {
+                        // ExactInputSingleParams: (tuple(address,address,uint24,int24,address) poolKey,
+                        //   bool zeroForOne, uint128 amountIn, uint128 amountOutMin, bytes hookData)
+                        try {
+                            const s = coder.decode(
+                                [
+                                    "tuple(tuple(address,address,uint24,int24,address),bool,uint128,uint128,bytes)",
+                                ],
+                                params[i],
+                            );
+                            const poolKey = s[0][0];
+                            const zeroForOne = s[0][1];
+                            if (!settleToken)
+                                settleToken = zeroForOne
+                                    ? poolKey[0]
+                                    : poolKey[1];
+                            if (!takeToken)
+                                takeToken = zeroForOne
+                                    ? poolKey[1]
+                                    : poolKey[0];
+                            if (!amountIn) amountIn = s[0][2];
+                            if (!amountOutMin) amountOutMin = s[0][3];
+                        } catch {
+                            // Fall through
+                        }
+                    }
+                } else if (
+                    actionId === V4_SWAP_EXACT_OUT ||
+                    actionId === V4_SWAP_EXACT_OUT_SINGLE
+                ) {
+                    if (actionId === V4_SWAP_EXACT_OUT) {
+                        try {
+                            const s = coder.decode(
+                                [
+                                    "tuple(address,tuple(address,uint24,int24,address,bytes)[],uint128,uint128)",
+                                ],
+                                params[i],
+                            );
+                            if (!takeToken) takeToken = s[0][0];
+                            const path = s[0][1];
+                            if (path.length > 0 && !settleToken) {
+                                settleToken = path[path.length - 1][0];
+                            }
+                        } catch {
+                            // Fall through
+                        }
+                    } else {
+                        try {
+                            const s = coder.decode(
+                                [
+                                    "tuple(tuple(address,address,uint24,int24,address),bool,uint128,uint128,bytes)",
+                                ],
+                                params[i],
+                            );
+                            const poolKey = s[0][0];
+                            const zeroForOne = s[0][1];
+                            if (!settleToken)
+                                settleToken = zeroForOne
+                                    ? poolKey[0]
+                                    : poolKey[1];
+                            if (!takeToken)
+                                takeToken = zeroForOne
+                                    ? poolKey[1]
+                                    : poolKey[0];
+                        } catch {
+                            // Fall through
+                        }
+                    }
+                }
+            } catch {
+                // Skip sub-actions we can't decode
+            }
+        }
+
+        return {
+            tokenIn: settleToken,
+            tokenOut: takeToken,
+            amountIn,
+            amountOutMin,
+        };
+    } catch {
+        return null;
+    }
+}
+
 // Try to decode a Universal Router execute() call.
 // Returns { name, description, details } matching the format used by
 // the approval UI, or null if the calldata is not a recognised execute().
@@ -233,6 +384,19 @@ function decode(data, toAddress) {
                     }
                 }
 
+                if (cmdId === 0x10) {
+                    const v4 = decodeV4Swap(inputs[i]);
+                    if (v4) {
+                        if (!inputToken && v4.tokenIn) inputToken = v4.tokenIn;
+                        if (!outputToken && v4.tokenOut)
+                            outputToken = v4.tokenOut;
+                        if (!inputAmount && v4.amountIn)
+                            inputAmount = v4.amountIn;
+                        if (!minOutput && v4.amountOutMin)
+                            minOutput = v4.amountOutMin;
+                    }
+                }
+
                 if (cmdId === 0x0c) {
                     hasUnwrapWeth = true;
                 }

tests/uniswap.test.js

@@ -1,9 +1,10 @@
-const { AbiCoder, Interface, solidityPacked } = require("ethers");
+const { AbiCoder, Interface, solidityPacked, getBytes } = require("ethers");
 const uniswap = require("../src/shared/uniswap");
 
 const ROUTER_ADDR = "0x66a9893cc07d91d95644aedd05d03f95e1dba8af";
 const USDT_ADDR = "0xdAC17F958D2ee523a2206206994597C13D831ec7";
 const WETH_ADDR = "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2";
+const USDC_ADDR = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48";
 const USER_ADDR = "0x66133E8ea0f5D1d612D2502a968757D1048c214a";
 
 // AutistMask's first-ever swap, 2026-02-27.
@@ -256,6 +257,87 @@ describe("uniswap decoder", () => {
         expect(amount.value).toBe("5.0000 USDT");
     });
 
+    // This test validates the decodeV4Swap() fix: a V4 ERC20→ERC20 swap
+    // (USDT→USDC) where the token addresses are ONLY discoverable inside
+    // the V4_SWAP sub-actions (SETTLE/TAKE). Before decodeV4Swap() was added,
+    // command 0x10 was opaque and this would decode as "Uniswap Swap" with
+    // no token info (or "ETH → ETH"). Now it correctly shows "USDT → USDC".
+    test("decodes V4_SWAP ERC20→ERC20 tokens via SETTLE/TAKE (regression: #59)", () => {
+        // Build a V4_SWAP input with SETTLE(USDT) + SWAP_EXACT_IN_SINGLE + TAKE(USDC)
+        const V4_SETTLE = 0x0b;
+        const V4_SWAP_EXACT_IN_SINGLE = 0x06;
+        const V4_TAKE = 0x0e;
+
+        // actions: SETTLE, SWAP_EXACT_IN_SINGLE, TAKE
+        const actions = new Uint8Array([
+            V4_SETTLE,
+            V4_SWAP_EXACT_IN_SINGLE,
+            V4_TAKE,
+        ]);
+
+        // SETTLE params: (address currency, uint256 maxAmount, bool payerIsUser)
+        const settleParam = coder.encode(
+            ["address", "uint256", "bool"],
+            [USDT_ADDR, 5000000n, true],
+        );
+
+        // SWAP_EXACT_IN_SINGLE params:
+        // (tuple(address,address,uint24,int24,address) poolKey, bool zeroForOne, uint128 amountIn, uint128 amountOutMin, bytes hookData)
+        const swapParam = coder.encode(
+            [
+                "tuple(tuple(address,address,uint24,int24,address),bool,uint128,uint128,bytes)",
+            ],
+            [
+                [
+                    [
+                        USDT_ADDR,
+                        USDC_ADDR,
+                        100, // fee
+                        1, // tickSpacing
+                        "0x0000000000000000000000000000000000000000", // hooks
+                    ],
+                    true, // zeroForOne
+                    5000000n, // amountIn (5 USDT)
+                    4900000n, // amountOutMin (4.9 USDC)
+                    "0x", // hookData
+                ],
+            ],
+        );
+
+        // TAKE params: (address currency, address recipient, uint256 amount)
+        const takeParam = coder.encode(
+            ["address", "address", "uint256"],
+            [USDC_ADDR, USER_ADDR, 0n],
+        );
+
+        // Encode the V4_SWAP input: (bytes actions, bytes[] params)
+        const v4Input = coder.encode(
+            ["bytes", "bytes[]"],
+            [actions, [settleParam, swapParam, takeParam]],
+        );
+
+        // Build execute() with PERMIT2_PERMIT (0x0a) + V4_SWAP (0x10)
+        // The permit provides the input token, but V4_SWAP must provide
+        // the OUTPUT token — without decodeV4Swap, output would be unknown.
+        const data = buildExecute(
+            solidityPacked(["uint8", "uint8"], [0x0a, 0x10]),
+            [encodePermit2(USDT_ADDR, 5000000n, ROUTER_ADDR), v4Input],
+            9999999999n,
+        );
+
+        const result = uniswap.decode(data, ROUTER_ADDR);
+        expect(result).not.toBeNull();
+        // Before decodeV4Swap fix: name would be "Swap USDT → ETH" or "Uniswap Swap"
+        // After fix: correctly identifies both tokens from V4 sub-actions
+        expect(result.name).toBe("Swap USDT \u2192 USDC");
+
+        const tokenIn = result.details.find((d) => d.label === "Token In");
+        expect(tokenIn.value).toContain("USDT");
+
+        const steps = result.details.find((d) => d.label === "Steps");
+        expect(steps.value).toContain("V4 Swap");
+    });
+
     test("handles unknown tokens gracefully", () => {
         const fakeToken = "0x1111111111111111111111111111111111111111";
         const data = buildExecute(