diff --git a/lib/config.js b/lib/config.js
index c5b69d8..8045b65 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -128,6 +128,15 @@ function loadConfig() {
   return config;
 }
 
+function getConfigBaseDir(config) {
+  const configPath = config && (config.__configPath || config.configPath);
+  if (configPath) {
+    return path.dirname(configPath);
+  }
+
+  return process.cwd();
+}
+
 function resolveOutputPath(outputDir, filename) {
   if (!path.isAbsolute(outputDir)) {
     outputDir = path.resolve(process.cwd(), outputDir);
@@ -203,6 +212,8 @@ function validateConfig(config) {
 
   // Ensure service account credential paths are unique when using serviceAccounts
   if (hasSvcAccounts) {
+    const baseDir = getConfigBaseDir(config);
+
     for (const item of config.serviceAccounts) {
       if (typeof item === 'string') {
         if (!item.trim()) {
@@ -231,7 +242,7 @@ function validateConfig(config) {
       if (typeof item === 'string') p = item.trim();
       else if (item && typeof item === 'object') p = (item.path || item.file || item.credentialsPath || '').toString().trim();
       if (!p) return '';
-      const full = path.isAbsolute(p) ? p : path.resolve(process.cwd(), p);
+      const full = path.isAbsolute(p) ? p : path.resolve(baseDir, p);
       if (!fs.existsSync(full)) {
         throw new Error(`Service account file not found: ${p}`);
       }
diff --git a/lib/onboarding.js b/lib/onboarding.js
index 53b4fed..f7298f1 100644
--- a/lib/onboarding.js
+++ b/lib/onboarding.js
@@ -1,3 +1,5 @@
+const fs = require('fs');
+const path = require('path');
 const readline = require('readline');
 const {createStarterConfig, getDefaultConfigPath, writeConfigFile} = require('./config');
 const {getFirstServiceAccountAuthClient} = require('./auth');
@@ -78,6 +80,52 @@ async function askOptionalPositiveInteger(ask, question, defaultValue) {
   }
 }
 
+function getServiceAccountIdentity(inputPath, baseDir) {
+  const value = (inputPath || '').trim();
+  if (!value) {
+    return '';
+  }
+
+  const fullPath = path.isAbsolute(value) ? value : path.resolve(baseDir || process.cwd(), value);
+  if (!fs.existsSync(fullPath)) {
+    return value;
+  }
+
+  const raw = fs.readFileSync(fullPath, 'utf8').trim();
+  try {
+    const parsed = JSON.parse(raw);
+    const canonicalize = obj => {
+      if (obj === null || typeof obj !== 'object') return JSON.stringify(obj);
+      if (Array.isArray(obj)) return '[' + obj.map(canonicalize).join(',') + ']';
+      const keys = Object.keys(obj).sort();
+      return '{' + keys.map(key => JSON.stringify(key) + ':' + canonicalize(obj[key])).join(',') + '}';
+    };
+    return canonicalize(parsed);
+  } catch (_) {
+    return raw;
+  }
+}
+
+function getServiceAccountsFolderPath(configPath) {
+  return path.join(path.dirname(configPath), 'serviceAccounts');
+}
+
+function listServiceAccountFiles(folderPath) {
+  if (!fs.existsSync(folderPath)) {
+    return [];
+  }
+
+  return fs.readdirSync(folderPath)
+    .map(fileName => path.join(folderPath, fileName))
+    .filter(filePath => {
+      try {
+        return fs.statSync(filePath).isFile();
+      } catch (_) {
+        return false;
+      }
+    });
+}
+
 function extractSpreadsheetId(input) {
   const value = (input || '').trim();
   if (!value) {
@@ -164,11 +212,6 @@ async function runOnboarding() {
       console.log('');
     }
 
-    const credentialCount = await askPositiveInteger(
-      ask,
-      `How many ${authMode === 'apiKeys' ? 'API keys' : 'service accounts'} do you want to add? `
-    );
-
     const config = {
       apiKeys: [],
       serviceAccounts: [],
@@ -182,26 +225,69 @@ async function runOnboarding() {
     });
 
     if (authMode === 'apiKeys') {
+      const credentialCount = await askPositiveInteger(
+        ask,
+        'How many API keys do you want to add? '
+      );
+
+      const seenKeys = new Set();
+
       for (let index = 0; index < credentialCount; index += 1) {
-        const key = await askNonEmpty(ask, `Enter API key ${index + 1}: `);
+        let key;
+        while (true) {
+          key = await askNonEmpty(ask, `Enter API key ${index + 1}: `);
+          if (seenKeys.has(key)) {
+            console.log('That API key was already entered. Please enter a unique API key.');
+            continue;
+          }
+          break;
+        }
+
         const rateLimitPerMinute = await askOptionalPositiveInteger(
           ask,
           `Rate limit per minute for API key ${index + 1} (press Enter for 50): `,
           50
         );
 
+        seenKeys.add(key);
         config.apiKeys.push({key, rateLimitPerMinute});
       }
     } else {
-      for (let index = 0; index < credentialCount; index += 1) {
-        const pathValue = await askNonEmpty(ask, `Enter service account path ${index + 1}: `);
+      const serviceAccountsFolder = getServiceAccountsFolderPath(configPath);
+      if (!fs.existsSync(serviceAccountsFolder)) {
+        fs.mkdirSync(serviceAccountsFolder, {recursive: true});
+      }
+
+      console.log(`A serviceAccounts folder has been created at ${serviceAccountsFolder}.`);
+      console.log('Paste your service account files into that folder, then press Enter to continue.');
+      await pauseForEnter(ask);
+
+      const serviceAccountFiles = listServiceAccountFiles(serviceAccountsFolder);
+      console.log(`Found ${serviceAccountFiles.length} service account${serviceAccountFiles.length === 1 ? '' : 's'}.`);
+
+      if (serviceAccountFiles.length === 0) {
+        throw new Error(`No service account files were found in ${serviceAccountsFolder}`);
+      }
+
+      const seenServiceAccounts = new Set();
+
+      for (const filePath of serviceAccountFiles) {
+        const relativePath = path.relative(path.dirname(configPath), filePath).split(path.sep).join('/');
+        const serviceAccountIdentity = getServiceAccountIdentity(relativePath, path.dirname(configPath));
+
+        if (seenServiceAccounts.has(serviceAccountIdentity)) {
+          console.log(`Skipping duplicate service account file: ${path.basename(filePath)}`);
+          continue;
+        }
+
+        seenServiceAccounts.add(serviceAccountIdentity);
         const rateLimitPerMinute = await askOptionalPositiveInteger(
           ask,
-          `Rate limit per minute for service account ${index + 1} (press Enter for 50): `,
+          `Rate limit per minute for ${path.basename(filePath)} (press Enter for 50): `,
           50
         );
 
-        config.serviceAccounts.push({path: pathValue, rateLimitPerMinute});
+        config.serviceAccounts.push({path: relativePath, rateLimitPerMinute});
       }
     }
 
diff --git a/package.json b/package.json
index 9fd54ab..2581fa9 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "google-sheets-rate-assistant",
-  "version": "2.1.5",
+  "version": "2.1.6",
   "description": "Pull Google Sheets data and export to CSV with configurable schedules and rate limiting.",
   "main": "index.js",
   "bin": "index.js",