README.md

@@ -15,9 +15,10 @@ Hence, a minimally viable ERC20 browser wallet/signer that works cross-platform.
 Everything you need, nothing you don't. We import as few libraries as possible,
 don't implement any crypto, and don't send user-specific data anywhere but a
 (user-configurable) Ethereum RPC endpoint (which defaults to a public node). The
-extension contacts precisely two external services: the configured RPC node for
-blockchain interactions, and a public CoinDesk API (no API key) to get realtime
-price information.
+extension contacts exactly three external services: the configured RPC node for
+blockchain interactions, a public CoinDesk API (no API key) for realtime price
+information, and a Blockscout block-explorer API for transaction history and
+token balances. All three endpoints are user-configurable.
 
 In the extension is a hardcoded list of the top ERC20 contract addresses. You
 can add any ERC20 contract by contract address if you wish, but the hardcoded
@@ -534,7 +535,7 @@ transitions.
 ### External Services
 
 AutistMask is not a fully self-contained offline tool. It necessarily
-communicates with two external services to function as a wallet:
+communicates with three external services to function as a wallet:
 
 - **Ethereum JSON-RPC endpoint**: The extension needs an Ethereum node to query
   balances (`eth_getBalance`), read ERC-20 token contracts (`eth_call`),
@@ -543,11 +544,24 @@ communicates with two external services to function as a wallet:
   receipts. The default endpoint is a public RPC (configurable by the user to
   any endpoint they prefer, including a local node). By default the extension
   talks to `https://ethereum-rpc.publicnode.com`.
+    - **Data sent**: Ethereum addresses, transaction data, contract call
+      parameters. The RPC endpoint can see all on-chain queries and submitted
+      transactions.
 
 - **CoinDesk CADLI price API**: Used to fetch ETH/USD and token/USD prices for
   displaying fiat values. The price is cached for 5 minutes to avoid excessive
   requests. No API key required. No user data is sent — only a list of token
   symbols. Note that CoinDesk will receive your client IP.
+    - **Data sent**: Token symbol strings only (e.g. "ETH", "USDC"). No
+      addresses or user-specific data.
+
+- **Blockscout block-explorer API**: Used to fetch transaction history (normal
+  transactions and ERC-20 token transfers), ERC-20 token balances, and token
+  holder counts (for spam filtering). The default endpoint is
+  `https://eth.blockscout.com/api/v2` (configurable by the user in Settings).
+    - **Data sent**: Ethereum addresses. Blockscout receives the user's
+      addresses to query their transaction history and token balances. No
+      private keys, passwords, or signing operations are sent.
 
 What the extension does NOT do:
 
@@ -557,9 +571,10 @@ What the extension does NOT do:
 - No Infura/Alchemy dependency (any JSON-RPC endpoint works)
 - No backend servers operated by the developer
 
-The user's RPC endpoint and the CoinDesk price API are the only external
-services. Users who want maximum privacy can point the RPC at their own node
-(price fetching can be disabled in a future version).
+These three services (RPC endpoint, CoinDesk price API, and Blockscout API) are
+the only external services. All three endpoints are user-configurable. Users who
+want maximum privacy can point the RPC and Blockscout URLs at their own
+self-hosted instances (price fetching can be disabled in a future version).
 
 ### Dependencies
 

RULES.md

@@ -1,3 +1,8 @@
+> **⚠️ THIS FILE MUST NEVER BE MODIFIED BY AGENTS.** RULES.md is maintained
+> exclusively by the project owner. AI agents, bots, and automated tools must
+> treat this file as read-only. If an audit finds a divergence between the code
+> and this file, the code must be changed to match — never the other way around.
+
 # AutistMask Rules Checklist
 
 This file is derived from README.md and REPO_POLICIES.md for use as an audit
@@ -17,8 +22,8 @@ contradicts either, the originals govern.
 
 ## External Communication
 
-- [ ] Extension contacts exactly two external services: configured RPC endpoint
-      and CoinDesk price API
+- [ ] Extension contacts exactly three external services: configured RPC
+      endpoint, CoinDesk price API, and Blockscout block-explorer API
 - [ ] No analytics, telemetry, or tracking
 - [ ] No user-specific data sent except to the configured RPC endpoint
 - [ ] No Infura/Alchemy hard dependency

src/popup/views/helpers.js

@@ -85,7 +85,7 @@ function showFlash(msg, duration = 2000) {
 
 function balanceLine(symbol, amount, price, tokenId) {
     const qty = amount.toFixed(4);
-    const usd = price ? formatUsd(amount * price) : "";
+    const usd = price ? formatUsd(amount * price) || " " : " ";
     const tokenAttr = tokenId ? ` data-token="${tokenId}"` : "";
     const clickClass = tokenId
         ? " cursor-pointer hover:bg-hover balance-row"
@@ -222,6 +222,41 @@ function formatAddressHtml(address, ensName, maxLen, title) {
     return `<div class="flex items-center">${dot}<span class="break-all">${escapeHtml(displayAddr)}</span></div>`;
 }
 
+function isoDate(timestamp) {
+    const d = new Date(timestamp * 1000);
+    const pad = (n) => String(n).padStart(2, "0");
+    return (
+        d.getFullYear() +
+        "-" +
+        pad(d.getMonth() + 1) +
+        "-" +
+        pad(d.getDate()) +
+        " " +
+        pad(d.getHours()) +
+        ":" +
+        pad(d.getMinutes()) +
+        ":" +
+        pad(d.getSeconds())
+    );
+}
+
+function timeAgo(timestamp) {
+    const seconds = Math.floor(Date.now() / 1000 - timestamp);
+    if (seconds < 60) return seconds + " seconds ago";
+    const minutes = Math.floor(seconds / 60);
+    if (minutes < 60)
+        return minutes + " minute" + (minutes !== 1 ? "s" : "") + " ago";
+    const hours = Math.floor(minutes / 60);
+    if (hours < 24) return hours + " hour" + (hours !== 1 ? "s" : "") + " ago";
+    const days = Math.floor(hours / 24);
+    if (days < 30) return days + " day" + (days !== 1 ? "s" : "") + " ago";
+    const months = Math.floor(days / 30);
+    if (months < 12)
+        return months + " month" + (months !== 1 ? "s" : "") + " ago";
+    const years = Math.floor(days / 365);
+    return years + " year" + (years !== 1 ? "s" : "") + " ago";
+}
+
 module.exports = {
     $,
     showError,
@@ -236,4 +271,6 @@ module.exports = {
     addressTitle,
     formatAddressHtml,
     truncateMiddle,
+    isoDate,
+    timeAgo,
 };

src/popup/views/home.js

@@ -3,6 +3,8 @@ const {
     showView,
     showFlash,
     balanceLinesForAddress,
+    isoDate,
+    timeAgo,
     addressDotHtml,
     escapeHtml,
     truncateMiddle,
@@ -87,41 +89,6 @@ function renderActiveAddress() {
     }
 }
 
-function timeAgo(timestamp) {
-    const seconds = Math.floor(Date.now() / 1000 - timestamp);
-    if (seconds < 60) return seconds + " seconds ago";
-    const minutes = Math.floor(seconds / 60);
-    if (minutes < 60)
-        return minutes + " minute" + (minutes !== 1 ? "s" : "") + " ago";
-    const hours = Math.floor(minutes / 60);
-    if (hours < 24) return hours + " hour" + (hours !== 1 ? "s" : "") + " ago";
-    const days = Math.floor(hours / 24);
-    if (days < 30) return days + " day" + (days !== 1 ? "s" : "") + " ago";
-    const months = Math.floor(days / 30);
-    if (months < 12)
-        return months + " month" + (months !== 1 ? "s" : "") + " ago";
-    const years = Math.floor(days / 365);
-    return years + " year" + (years !== 1 ? "s" : "") + " ago";
-}
-
-function isoDate(timestamp) {
-    const d = new Date(timestamp * 1000);
-    const pad = (n) => String(n).padStart(2, "0");
-    return (
-        d.getFullYear() +
-        "-" +
-        pad(d.getMonth() + 1) +
-        "-" +
-        pad(d.getDate()) +
-        " " +
-        pad(d.getHours()) +
-        ":" +
-        pad(d.getMinutes()) +
-        ":" +
-        pad(d.getSeconds())
-    );
-}
-
 let homeTxs = [];
 
 function renderHomeTxList(ctx) {

src/popup/views/transactionDetail.js

@@ -8,6 +8,8 @@ const {
     addressDotHtml,
     addressTitle,
     escapeHtml,
+    isoDate,
+    timeAgo,
 } = require("./helpers");
 const { state } = require("../../shared/state");
 const makeBlockie = require("ethereum-blockies-base64");
@@ -21,41 +23,6 @@ const EXT_ICON =
 
 let ctx;
 
-function isoDate(timestamp) {
-    const d = new Date(timestamp * 1000);
-    const pad = (n) => String(n).padStart(2, "0");
-    return (
-        d.getFullYear() +
-        "-" +
-        pad(d.getMonth() + 1) +
-        "-" +
-        pad(d.getDate()) +
-        " " +
-        pad(d.getHours()) +
-        ":" +
-        pad(d.getMinutes()) +
-        ":" +
-        pad(d.getSeconds())
-    );
-}
-
-function timeAgo(timestamp) {
-    const seconds = Math.floor(Date.now() / 1000 - timestamp);
-    if (seconds < 60) return seconds + " seconds ago";
-    const minutes = Math.floor(seconds / 60);
-    if (minutes < 60)
-        return minutes + " minute" + (minutes !== 1 ? "s" : "") + " ago";
-    const hours = Math.floor(minutes / 60);
-    if (hours < 24) return hours + " hour" + (hours !== 1 ? "s" : "") + " ago";
-    const days = Math.floor(hours / 24);
-    if (days < 30) return days + " day" + (days !== 1 ? "s" : "") + " ago";
-    const months = Math.floor(days / 30);
-    if (months < 12)
-        return months + " month" + (months !== 1 ? "s" : "") + " ago";
-    const years = Math.floor(days / 365);
-    return years + " year" + (years !== 1 ? "s" : "") + " ago";
-}
-
 function copyableHtml(text, extraClass) {
     const cls =
         "underline decoration-dashed cursor-pointer" +