diff --git a/.github/workflows/security.yml b/.github/workflows/security.yml
new file mode 100644
index 0000000..2483514
--- /dev/null
+++ b/.github/workflows/security.yml
@@ -0,0 +1,140 @@
+name: Security Scan
+
+on:
+  pull_request:
+    branches: [main]
+
+jobs:
+  contract-audit:
+    name: Rust / Soroban Audit
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: contracts
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: clippy
+
+      - uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: contracts
+
+      - name: clippy
+        run: cargo clippy --all-targets -- -D warnings
+
+      - name: cargo audit
+        run: |
+          cargo install cargo-audit --locked --quiet
+          cargo audit 2>&1 | tee /tmp/audit-output.txt
+          exit ${PIPESTATUS[0]}
+
+      - name: Soroban pattern check
+        run: node ../scripts/soroban-security-check.mjs 2>&1 | tee /tmp/soroban-output.txt
+
+      - name: Post contract audit summary
+        if: always()
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const fs = require('fs')
+            const audit = fs.existsSync('/tmp/audit-output.txt')
+              ? fs.readFileSync('/tmp/audit-output.txt', 'utf8').trim()
+              : '(no output)'
+            const soroban = fs.existsSync('/tmp/soroban-output.txt')
+              ? fs.readFileSync('/tmp/soroban-output.txt', 'utf8').trim()
+              : '(no output)'
+            const body = [
+              '## 🔐 Contract Security Scan',
+              '',
+              '<details><summary>cargo audit</summary>',
+              '',
+              '```',
+              audit,
+              '```',
+              '',
+              '</details>',
+              '',
+              '<details><summary>Soroban pattern check</summary>',
+              '',
+              '```',
+              soroban,
+              '```',
+              '',
+              '</details>',
+            ].join('\n')
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              body,
+            })
+
+  frontend-audit:
+    name: Frontend Audit
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+
+      - run: npm ci
+
+      - name: npm audit
+        run: npm audit --audit-level=high 2>&1 | tee /tmp/npm-audit.txt; exit ${PIPESTATUS[0]}
+
+      - name: ESLint security
+        run: npm run lint 2>&1 | tee /tmp/eslint-output.txt; exit ${PIPESTATUS[0]}
+
+      - name: Check for hardcoded secrets
+        run: |
+          node scripts/check-secrets.mjs 2>&1 | tee /tmp/secrets-output.txt
+          exit ${PIPESTATUS[0]}
+
+      - name: Post frontend audit summary
+        if: always()
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const fs = require('fs')
+            const read = (p) => fs.existsSync(p) ? fs.readFileSync(p, 'utf8').trim() : '(no output)'
+            const body = [
+              '## 🛡️ Frontend Security Scan',
+              '',
+              '<details><summary>npm audit</summary>',
+              '',
+              '```',
+              read('/tmp/npm-audit.txt'),
+              '```',
+              '',
+              '</details>',
+              '',
+              '<details><summary>ESLint</summary>',
+              '',
+              '```',
+              read('/tmp/eslint-output.txt'),
+              '```',
+              '',
+              '</details>',
+              '',
+              '<details><summary>Hardcoded secrets check</summary>',
+              '',
+              '```',
+              read('/tmp/secrets-output.txt'),
+              '```',
+              '',
+              '</details>',
+            ].join('\n')
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              body,
+            })
diff --git a/eslint.config.mjs b/eslint.config.mjs
index 703b010..03f16f7 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -1,6 +1,7 @@
 import globals from 'globals'
 import js from '@eslint/js'
 import nextPlugin from '@next/eslint-plugin-next'
+import security from 'eslint-plugin-security'
 
 export default [
   {
@@ -13,6 +14,7 @@ export default [
     ],
   },
   js.configs.recommended,
+  security.configs.recommended,
   {
     plugins: {
       '@next/next': nextPlugin,
diff --git a/package-lock.json b/package-lock.json
index fa12b69..f2bca8a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4267,6 +4267,7 @@
       "version": "2.3.2",
       "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
       "integrity": "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==",
+      "dev": true,
       "hasInstallScript": true,
       "license": "MIT",
       "optional": true,
diff --git a/package.json b/package.json
index 27fb90e..01d73ef 100644
--- a/package.json
+++ b/package.json
@@ -37,6 +37,7 @@
     "@types/react": "^19",
     "@types/react-dom": "^19",
     "eslint": "^10.5.0",
+    "eslint-plugin-security": "^3.0.1",
     "globals": "^17.7.0",
     "postcss": "^8.5",
     "tailwindcss": "^4.2.0",
diff --git a/scripts/check-secrets.mjs b/scripts/check-secrets.mjs
new file mode 100644
index 0000000..dea70d9
--- /dev/null
+++ b/scripts/check-secrets.mjs
@@ -0,0 +1,65 @@
+#!/usr/bin/env node
+// scripts/check-secrets.mjs
+// Scan source files for hardcoded secrets and API keys.
+// Exits 1 if any HIGH-severity pattern is found.
+
+import { readFileSync, readdirSync, statSync } from 'fs'
+import { join, extname } from 'path'
+
+const ROOT = new URL('..', import.meta.url).pathname
+
+const IGNORED_DIRS = new Set(['.git', '.next', 'node_modules', 'target', 'public', 'test_snapshots'])
+const ALLOWED_EXTS = new Set(['.ts', '.tsx', '.js', '.mjs', '.env.example', '.yml', '.yaml', '.json'])
+
+// Patterns that indicate a hardcoded secret value (not just a variable name).
+// Note: Stellar public keys (G…/C… strkey) are intentionally excluded — they're public identifiers, not secrets.
+const SECRET_PATTERNS = [
+  // Real base64 secrets: must contain + or / (Stellar strkeys use only A-Z0-9, so this excludes them)
+  { re: /['"`][A-Za-z0-9+/]{40,}={0,2}['"`](?=.*[+/])/, label: 'possible base64 secret' },
+  { re: /sk_live_[A-Za-z0-9]{24,}/, label: 'Stripe live secret key' },
+  { re: /sk_test_[A-Za-z0-9]{24,}/, label: 'Stripe test secret key' },
+  { re: /AKIA[0-9A-Z]{16}/, label: 'AWS access key ID' },
+  { re: /ghp_[A-Za-z0-9]{36}/, label: 'GitHub personal access token' },
+  { re: /-----BEGIN (RSA |EC |OPENSSH )?PRIVATE KEY-----/, label: 'private key' },
+  { re: /xoxb-[0-9A-Za-z-]{50,}/, label: 'Slack bot token' },
+]
+
+function walk(dir, files = []) {
+  for (const entry of readdirSync(dir)) {
+    if (IGNORED_DIRS.has(entry)) continue
+    const full = join(dir, entry)
+    const st = statSync(full)
+    if (st.isDirectory()) {
+      walk(full, files)
+    } else if (ALLOWED_EXTS.has(extname(entry)) || entry.startsWith('.env')) {
+      // Skip .env.local (contains real values) — only scan example/template files
+      if (entry === '.env.local') continue
+      files.push(full)
+    }
+  }
+  return files
+}
+
+const files = walk(ROOT)
+let found = 0
+
+for (const file of files) {
+  const src = readFileSync(file, 'utf8')
+  src.split('\n').forEach((line, i) => {
+    for (const { re, label } of SECRET_PATTERNS) {
+      if (re.test(line)) {
+        const rel = file.replace(ROOT, '')
+        console.log(`❌ HIGH [SECRETS-001] ${rel}:${i + 1} — ${label}: ${line.trim().slice(0, 80)}`)
+        found++
+      }
+    }
+  })
+}
+
+if (found === 0) {
+  console.log('✅ No hardcoded secrets found.')
+  process.exit(0)
+} else {
+  console.log(`\n${found} potential secret(s) found. Remove before merging.`)
+  process.exit(1)
+}
diff --git a/scripts/soroban-security-check.mjs b/scripts/soroban-security-check.mjs
new file mode 100644
index 0000000..337ff25
--- /dev/null
+++ b/scripts/soroban-security-check.mjs
@@ -0,0 +1,160 @@
+#!/usr/bin/env node
+// scripts/soroban-security-check.mjs
+// Custom Soroban/Rust security pattern checker.
+// Exits 1 if any HIGH-severity issue is found; warns on LOW.
+
+import { readFileSync, readdirSync, statSync } from 'fs'
+import { join, extname } from 'path'
+
+const ROOT = new URL('..', import.meta.url).pathname
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+
+function walkRust(dir, files = []) {
+  for (const entry of readdirSync(dir)) {
+    const full = join(dir, entry)
+    if (statSync(full).isDirectory()) {
+      walkRust(full, files)
+    } else if (extname(entry) === '.rs') {
+      files.push(full)
+    }
+  }
+  return files
+}
+
+function lines(src) {
+  return src.split('\n')
+}
+
+// ── Rules ─────────────────────────────────────────────────────────────────────
+
+// Each rule: { id, severity, description, check(src, filePath) -> [{line, col, msg}] }
+
+const rules = [
+  {
+    id: 'SOROBAN-001',
+    severity: 'HIGH',
+    description: 'Unchecked arithmetic on i128/u128/u64 — use checked_add / checked_mul',
+    check(src) {
+      const findings = []
+      // Flag bare `+`, `-`, `*` on i128/u128 variables.
+      // Heuristic: look for `withdrawn_amount +=` or similar without checked_ call on the same line.
+      const uncheckedOps = /\b(withdrawn_amount|deposited_amount|amount_per_second|cliff_amount|linear_amount)\s*(\+=|-=|\*=)/g
+      lines(src).forEach((line, i) => {
+        if (uncheckedOps.test(line) && !line.includes('checked_')) {
+          findings.push({ line: i + 1, msg: `Unchecked compound assignment: ${line.trim()}` })
+        }
+        uncheckedOps.lastIndex = 0
+      })
+      return findings
+    },
+  },
+
+  {
+    id: 'SOROBAN-002',
+    severity: 'HIGH',
+    description: 'Public write function missing require_auth()',
+    check(src) {
+      const findings = []
+      // Collect all pub fn bodies; check that require_auth appears before any storage write.
+      const fnRegex = /pub fn (\w+)\s*\(env:\s*Env[^)]*\)/g
+      // Read-only patterns — skip them
+      const readOnly = /^(get_|bump_stream|load_stream)/
+      let match
+      while ((match = fnRegex.exec(src)) !== null) {
+        const name = match[1]
+        if (readOnly.test(name)) continue
+
+        // Slice from function start to next `pub fn` or end of file
+        const body = src.slice(match.index)
+        const nextFn = body.indexOf('\n    pub fn ', 1)
+        const fnBody = nextFn === -1 ? body : body.slice(0, nextFn)
+
+        if (!fnBody.includes('require_auth()')) {
+          const lineNo = src.slice(0, match.index).split('\n').length
+          findings.push({ line: lineNo, msg: `pub fn ${name} performs writes but has no require_auth()` })
+        }
+      }
+      return findings
+    },
+  },
+
+  {
+    id: 'SOROBAN-003',
+    severity: 'HIGH',
+    description: 'Persistent storage set() without a subsequent extend_ttl()',
+    check(src) {
+      const findings = []
+      // Each .persistent().set() call should be paired with an extend_ttl in the same function body.
+      const fnBodies = []
+      const fnRegex = /\bfn (\w+)\s*\(/g
+      let match
+      while ((match = fnRegex.exec(src)) !== null) {
+        const start = match.index
+        const after = src.indexOf('\n    fn ', start + 1)
+        const body = after === -1 ? src.slice(start) : src.slice(start, after)
+        fnBodies.push({ name: match[1], body, lineNo: src.slice(0, start).split('\n').length })
+      }
+
+      for (const { name, body, lineNo } of fnBodies) {
+        if (body.includes('.persistent().set(') && !body.includes('extend_ttl')) {
+          findings.push({ line: lineNo, msg: `fn ${name} writes to persistent storage without extend_ttl()` })
+        }
+      }
+      return findings
+    },
+  },
+
+  {
+    id: 'SOROBAN-004',
+    severity: 'LOW',
+    description: 'panic!() with string message — prefer ContractError enum + panic_with_error!()',
+    check(src) {
+      const findings = []
+      const panicRe = /panic!\s*\(\s*"/g
+      lines(src).forEach((line, i) => {
+        if (panicRe.test(line)) {
+          findings.push({ line: i + 1, msg: `panic! with string: ${line.trim()}` })
+        }
+        panicRe.lastIndex = 0
+      })
+      return findings
+    },
+  },
+]
+
+// ── Runner ────────────────────────────────────────────────────────────────────
+
+const contractsDir = join(ROOT, 'contracts')
+const rustFiles = walkRust(contractsDir).filter(f => !f.includes('/target/'))
+
+let totalHigh = 0
+let totalLow = 0
+
+for (const file of rustFiles) {
+  const src = readFileSync(file, 'utf8')
+  const rel = file.replace(ROOT, '')
+
+  for (const rule of rules) {
+    const findings = rule.check(src, file)
+    for (const f of findings) {
+      const prefix = rule.severity === 'HIGH' ? '❌ HIGH' : '⚠️  LOW '
+      console.log(`${prefix} [${rule.id}] ${rel}:${f.line} — ${f.msg}`)
+      if (rule.severity === 'HIGH') totalHigh++
+      else totalLow++
+    }
+  }
+}
+
+if (totalHigh === 0 && totalLow === 0) {
+  console.log('✅ No Soroban security issues found.')
+}
+
+if (totalHigh > 0) {
+  console.log(`\n${totalHigh} HIGH severity issue(s) found. Fix before merging.`)
+  process.exit(1)
+}
+
+if (totalLow > 0) {
+  console.log(`\n${totalLow} LOW severity issue(s) found (warnings only).`)
+}