Dgetsylver · Sikkra · May 19, 2026
diff --git a/alerts/package-lock.json b/alerts/package-lock.json
diff --git a/alerts/package.json b/alerts/package.json
@@ -9,7 +9,8 @@
     "db:migrate": "wrangler d1 execute turbolong-alerts --file=src/schema.sql"
   },
   "devDependencies": {
-    "wrangler": "^3.99.0",
-    "typescript": "^5.7.3"
+    "@cloudflare/workers-types": "^4.20260519.1",
+    "typescript": "^5.7.3",
+    "wrangler": "^3.99.0"
   }
 }
diff --git a/alerts/src/email.ts b/alerts/src/email.ts
@@ -41,7 +41,7 @@ export async function sendVerificationEmail(env: Env, to: string, verifyUrl: str
 <head><meta charset="utf-8"></head>
 <body style="font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; max-width: 480px; margin: 0 auto; padding: 32px 16px; color: #1a1a2e;">
   <h2 style="margin: 0 0 16px;">Verify your Turbolong alert</h2>
-  <p style="line-height: 1.6; color: #555;">Click the button below to verify your email and activate APY alerts.</p>
+  <p style="line-height: 1.6; color: #555;">Click the button below to verify your email and activate APY and health-factor alerts.</p>
   <a href="${verifyUrl}" style="display: inline-block; margin: 20px 0; padding: 12px 28px; background: #2DE8A3; color: #0B0E14; text-decoration: none; border-radius: 8px; font-weight: 600;">Verify Subscription</a>
   <p style="font-size: 13px; color: #888; margin-top: 24px;">If you didn't subscribe, ignore this email.</p>
 </body>
@@ -100,3 +100,54 @@ export async function sendApyAlert(
     html,
   );
 }
+
+export async function sendHfAlert(
+  env: Env,
+  to: string,
+  opts: {
+    poolName: string;
+    assetSymbol: string;
+    leverage: number;
+    healthFactor: number;
+    threshold: number;
+    netApy: number;
+    unsubscribeUrl: string;
+    appUrl: string;
+  },
+): Promise<SendResult> {
+  const { poolName, assetSymbol, leverage, healthFactor, threshold, netApy, unsubscribeUrl, appUrl } = opts;
+
+  const html = `
+<!DOCTYPE html>
+<html>
+<head><meta charset="utf-8"></head>
+<body style="font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; max-width: 480px; margin: 0 auto; padding: 32px 16px; color: #1a1a2e;">
+  <h2 style="margin: 0 0 8px; color: #FF4D6A;">Health Factor Alert</h2>
+  <p style="font-size: 14px; color: #555; margin: 0 0 20px;">${assetSymbol} at ${leverage}x on ${poolName}</p>
+
+  <div style="background: #f8f8fc; border-radius: 8px; padding: 16px; margin-bottom: 20px;">
+    <p style="margin: 0 0 8px; font-size: 13px; color: #888;">Current risk estimate</p>
+    <table style="width: 100%; font-size: 14px; border-collapse: collapse;">
+      <tr><td style="padding: 4px 0; color: #555;">Health factor</td><td style="padding: 4px 0; text-align: right; font-weight: 700; color: #FF4D6A;">${healthFactor.toFixed(3)}</td></tr>
+      <tr><td style="padding: 4px 0; color: #555;">Alert threshold</td><td style="padding: 4px 0; text-align: right; font-weight: 600;">${threshold.toFixed(3)}</td></tr>
+      <tr style="border-top: 1px solid #e0e0e8;"><td style="padding: 8px 0 4px; color: #555;">Net APY at ${leverage}x</td><td style="padding: 8px 0 4px; text-align: right; font-weight: 600;">${netApy.toFixed(2)}%</td></tr>
+    </table>
+  </div>
+
+  <p style="line-height: 1.6; color: #555;">Your selected leverage bracket is below the health-factor threshold you chose. Consider reducing leverage or adding collateral.</p>
+
+  <a href="${appUrl}" style="display: inline-block; margin: 16px 0; padding: 12px 28px; background: #2DE8A3; color: #0B0E14; text-decoration: none; border-radius: 8px; font-weight: 600;">Open Turbolong</a>
+
+  <p style="font-size: 12px; color: #aaa; margin-top: 32px;">
+    <a href="${unsubscribeUrl}" style="color: #aaa;">Unsubscribe</a> from this alert.
+  </p>
+</body>
+</html>`.trim();
+
+  return sendEmail(
+    env,
+    to,
+    `Health Factor Alert: ${assetSymbol} at ${leverage}x on ${poolName}`,
+    html,
+  );
+}
diff --git a/alerts/src/index.ts b/alerts/src/index.ts
@@ -10,8 +10,8 @@
  *   Fetch pool reserve rates, compute APY per bracket, alert subscribers.
  */
 
-import { POOLS, LEVERAGE_BRACKETS, POOL_NAMES, fetchReserveRates, computeNetApy, type ReserveRates } from "./stellar.ts";
-import { sendVerificationEmail, sendApyAlert } from "./email.ts";
+import { POOLS, LEVERAGE_BRACKETS, POOL_NAMES, fetchReserveRates, computeNetApy, computeHealthFactor, type ReserveRates } from "./stellar.ts";
+import { sendVerificationEmail, sendApyAlert, sendHfAlert } from "./email.ts";
 
 interface Env {
   DB: D1Database;
@@ -78,7 +78,7 @@ async function handleSubscribe(request: Request, env: Env): Promise<Response> {
     return jsonResponse({ ok: false, error: "Invalid JSON" }, 400, env);
   }
 
-  const { email, pool_id, asset_symbol, leverage_bracket } = body;
+  const { email, pool_id, asset_symbol, leverage_bracket, hf_threshold } = body;
 
   // Validate
   if (!email || !EMAIL_RE.test(email)) {
@@ -94,17 +94,21 @@ async function handleSubscribe(request: Request, env: Env): Promise<Response> {
   if (!LEVERAGE_BRACKETS.includes(lev)) {
     return jsonResponse({ ok: false, error: "Invalid leverage bracket. Must be one of: " + LEVERAGE_BRACKETS.join(", ") }, 400, env);
   }
+  const hfThreshold = hf_threshold == null || hf_threshold === "" ? 1.05 : Number(hf_threshold);
+  if (!Number.isFinite(hfThreshold) || hfThreshold < 1 || hfThreshold > 5) {
+    return jsonResponse({ ok: false, error: "Invalid HF threshold. Must be between 1.00 and 5.00." }, 400, env);
+  }
 
   const verifyToken = generateToken();
   const unsubToken  = generateToken();
 
   try {
     await env.DB.prepare(`
-      INSERT INTO subscriptions (email, pool_id, asset_symbol, leverage_bracket, verify_token, unsub_token)
-      VALUES (?1, ?2, ?3, ?4, ?5, ?6)
+      INSERT INTO subscriptions (email, pool_id, asset_symbol, leverage_bracket, hf_threshold, verify_token, unsub_token)
+      VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7)
       ON CONFLICT(email, pool_id, asset_symbol, leverage_bracket) DO UPDATE
-        SET verify_token = ?5, unsub_token = ?6, verified = 0
-    `).bind(email, pool_id, asset_symbol, lev, verifyToken, unsubToken).run();
+        SET hf_threshold = ?5, verify_token = ?6, unsub_token = ?7, verified = 0
+    `).bind(email, pool_id, asset_symbol, lev, hfThreshold, verifyToken, unsubToken).run();
   } catch (e: any) {
     console.error("DB insert failed:", e);
     return jsonResponse({ ok: false, error: "Database error" }, 500, env);
@@ -150,7 +154,7 @@ async function handleVerify(request: Request, env: Env): Promise<Response> {
 <head><meta charset="utf-8"><title>Verified</title></head>
 <body style="font-family: -apple-system, sans-serif; text-align: center; padding: 60px 20px;">
   <h2 style="color: #2DE8A3;">Subscription Verified!</h2>
-  <p>You'll receive an alert when your position's net APY turns negative.</p>
+  <p>You'll receive alerts when net APY turns negative or health factor crosses your threshold.</p>
 </body>
 </html>`);
 }
@@ -202,49 +206,95 @@ async function handleCron(env: Env): Promise<void> {
 
       for (const bracket of LEVERAGE_BRACKETS) {
         const netApy = computeNetApy(rates, bracket);
+        const healthFactor = computeHealthFactor(rates, bracket);
+
+        if (netApy < 0) {
+          console.log(`[cron] Negative APY: ${asset.symbol} at ${bracket}x on ${pool.name} = ${netApy.toFixed(2)}%`);
+
+          // Find verified subscribers who haven't been alerted in the last 24h
+          const subs = await env.DB.prepare(`
+            SELECT id, email, unsub_token
+            FROM subscriptions
+            WHERE pool_id = ?1
+              AND asset_symbol = ?2
+              AND leverage_bracket = ?3
+              AND verified = 1
+              AND (last_alerted_at IS NULL OR last_alerted_at < datetime('now', '-24 hours'))
+          `).bind(pool.id, asset.symbol, bracket).all();
+
+          if (subs.results?.length) {
+            console.log(`[cron] Alerting ${subs.results.length} subscriber(s) for ${asset.symbol}@${bracket}x on ${pool.name}`);
+
+            for (const sub of subs.results) {
+              const unsubUrl = `https://turbolong-alerts.workers.dev/unsubscribe?token=${sub.unsub_token}`;
+              const result = await sendApyAlert(
+                { RESEND_API_KEY: env.RESEND_API_KEY, RESEND_FROM: env.RESEND_FROM },
+                sub.email as string,
+                {
+                  poolName: pool.name,
+                  assetSymbol: asset.symbol,
+                  leverage: bracket,
+                  netApy,
+                  supplyApr: rates.netSupplyApr,
+                  borrowCost: rates.netBorrowCost,
+                  unsubscribeUrl: unsubUrl,
+                  appUrl: env.FRONTEND_ORIGIN,
+                },
+              );
+
+              if (result.ok) {
+                await env.DB.prepare(
+                  "UPDATE subscriptions SET last_alerted_at = datetime('now') WHERE id = ?1"
+                ).bind(sub.id).run();
+              } else {
+                console.error(`[cron] Failed to send alert to ${sub.email}:`, result.error);
+              }
+            }
+          }
+        }
 
-        if (netApy >= 0) continue; // APY is positive, no alert needed
-
-        console.log(`[cron] Negative APY: ${asset.symbol} at ${bracket}x on ${pool.name} = ${netApy.toFixed(2)}%`);
-
-        // Find verified subscribers who haven't been alerted in the last 24h
-        const subs = await env.DB.prepare(`
-          SELECT id, email, unsub_token
-          FROM subscriptions
-          WHERE pool_id = ?1
-            AND asset_symbol = ?2
-            AND leverage_bracket = ?3
-            AND verified = 1
-            AND (last_alerted_at IS NULL OR last_alerted_at < datetime('now', '-24 hours'))
-        `).bind(pool.id, asset.symbol, bracket).all();
-
-        if (!subs.results?.length) continue;
-
-        console.log(`[cron] Alerting ${subs.results.length} subscriber(s) for ${asset.symbol}@${bracket}x on ${pool.name}`);
-
-        for (const sub of subs.results) {
-          const unsubUrl = `https://turbolong-alerts.workers.dev/unsubscribe?token=${sub.unsub_token}`;
-          const result = await sendApyAlert(
-            { RESEND_API_KEY: env.RESEND_API_KEY, RESEND_FROM: env.RESEND_FROM },
-            sub.email as string,
-            {
-              poolName: pool.name,
-              assetSymbol: asset.symbol,
-              leverage: bracket,
-              netApy,
-              supplyApr: rates.netSupplyApr,
-              borrowCost: rates.netBorrowCost,
-              unsubscribeUrl: unsubUrl,
-              appUrl: env.FRONTEND_ORIGIN,
-            },
-          );
-
-          if (result.ok) {
-            await env.DB.prepare(
-              "UPDATE subscriptions SET last_alerted_at = datetime('now') WHERE id = ?1"
-            ).bind(sub.id).run();
-          } else {
-            console.error(`[cron] Failed to send alert to ${sub.email}:`, result.error);
+        if (Number.isFinite(healthFactor)) {
+          const hfSubs = await env.DB.prepare(`
+            SELECT id, email, unsub_token, hf_threshold
+            FROM subscriptions
+            WHERE pool_id = ?1
+              AND asset_symbol = ?2
+              AND leverage_bracket = ?3
+              AND verified = 1
+              AND hf_threshold IS NOT NULL
+              AND ?4 <= hf_threshold
+              AND (last_hf_alerted_at IS NULL OR last_hf_alerted_at < datetime('now', '-24 hours'))
+          `).bind(pool.id, asset.symbol, bracket, healthFactor).all();
+
+          if (!hfSubs.results?.length) continue;
+
+          console.log(`[cron] HF breach: ${asset.symbol} at ${bracket}x on ${pool.name} = ${healthFactor.toFixed(3)}; alerting ${hfSubs.results.length} subscriber(s)`);
+
+          for (const sub of hfSubs.results) {
+            const unsubUrl = `https://turbolong-alerts.workers.dev/unsubscribe?token=${sub.unsub_token}`;
+            const threshold = Number(sub.hf_threshold);
+            const result = await sendHfAlert(
+              { RESEND_API_KEY: env.RESEND_API_KEY, RESEND_FROM: env.RESEND_FROM },
+              sub.email as string,
+              {
+                poolName: pool.name,
+                assetSymbol: asset.symbol,
+                leverage: bracket,
+                healthFactor,
+                threshold,
+                netApy,
+                unsubscribeUrl: unsubUrl,
+                appUrl: env.FRONTEND_ORIGIN,
+              },
+            );
+
+            if (result.ok) {
+              await env.DB.prepare(
+                "UPDATE subscriptions SET last_hf_alerted_at = datetime('now') WHERE id = ?1"
+              ).bind(sub.id).run();
+            } else {
+              console.error(`[cron] Failed to send HF alert to ${sub.email}:`, result.error);
+            }
           }
         }
       }

diff --git a/alerts/src/schema.sql b/alerts/src/schema.sql
@@ -4,13 +4,18 @@ CREATE TABLE IF NOT EXISTS subscriptions (
   pool_id TEXT NOT NULL,
   asset_symbol TEXT NOT NULL,
   leverage_bracket REAL NOT NULL,
+  hf_threshold REAL NOT NULL DEFAULT 1.05,
   verified INTEGER DEFAULT 0,
   verify_token TEXT,
   unsub_token TEXT,
   created_at TEXT DEFAULT (datetime('now')),
   last_alerted_at TEXT,
+  last_hf_alerted_at TEXT,
   UNIQUE(email, pool_id, asset_symbol, leverage_bracket)
 );
 
 CREATE INDEX IF NOT EXISTS idx_subs_pool_asset_lev
   ON subscriptions(pool_id, asset_symbol, leverage_bracket);
+
+CREATE INDEX IF NOT EXISTS idx_subs_hf_due
+  ON subscriptions(pool_id, asset_symbol, leverage_bracket, hf_threshold, last_hf_alerted_at);
diff --git a/alerts/src/stellar.ts b/alerts/src/stellar.ts
@@ -72,18 +72,6 @@ function addressToScVal(addr: string): string {
   return JSON.stringify({ type: "Address", value: addr });
 }
 
-/** Build a simulateTransaction JSON-RPC request body. */
-function buildSimulateBody(contractId: string, method: string, args: any[]): object {
-  return {
-    jsonrpc: "2.0",
-    id: 1,
-    method: "simulateTransaction",
-    params: {
-      transaction: buildInvokeXdr(contractId, method, args),
-    },
-  };
-}
-
 // We need proper XDR encoding. Since we can't use the SDK in a worker easily,
 // we'll use the soroban-rpc's native JSON interface via stellar-sdk-like encoding.
 // Actually, the simplest approach: build a minimal transaction envelope in base64.
@@ -101,6 +89,8 @@ export interface ReserveRates {
   interestBorrowApr: number;
   blndSupplyApr: number;
   blndBorrowApr: number;
+  cFactor: number;
+  lFactor: number;
 }
 
 /** Simulate a contract call and return the decoded result. */
@@ -172,6 +162,8 @@ export async function fetchReserveRates(pool: PoolDef, asset: { id: string; symb
 
     const totalSupply = Number(bSupply * BigInt(Math.round(Number(bRate))) / BigInt(RATE_DEC)) / SCALAR;
     const totalBorrow = Number(dSupply * BigInt(Math.round(Number(dRate))) / BigInt(RATE_DEC)) / SCALAR;
+    const cFactor = Number(reserveRaw.config?.c_factor ?? 0) / SCALAR;
+    const lFactor = Number(reserveRaw.config?.l_factor ?? 0) / SCALAR;
 
     // ── Interest rate formula (Blend v2) ──
     const util = totalSupply > 0 ? totalBorrow / totalSupply : 0;
@@ -224,6 +216,8 @@ export async function fetchReserveRates(pool: PoolDef, asset: { id: string; symb
       interestBorrowApr,
       blndSupplyApr,
       blndBorrowApr,
+      cFactor,
+      lFactor,
     };
   } catch (e) {
     console.error(`fetchReserveRates failed for ${asset.symbol} on ${pool.name}:`, e);
@@ -235,3 +229,11 @@ export async function fetchReserveRates(pool: PoolDef, asset: { id: string; symb
 export function computeNetApy(rates: ReserveRates, leverage: number): number {
   return rates.netSupplyApr * leverage - rates.netBorrowCost * (leverage - 1);
 }
+
+/** Compute same-asset Blend health factor at a leverage bracket. */
+export function computeHealthFactor(rates: ReserveRates, leverage: number): number {
+  if (leverage <= 1) return Infinity;
+  const effectiveCollateral = rates.cFactor * leverage;
+  const effectiveDebt = (leverage - 1) / Math.max(rates.lFactor, Number.EPSILON);
+  return effectiveDebt > 0 ? effectiveCollateral / effectiveDebt : Infinity;
+}
diff --git a/alerts/tsconfig.json b/alerts/tsconfig.json
@@ -3,6 +3,7 @@
     "target": "ES2022",
     "module": "ES2022",
     "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
     "lib": ["ES2022"],
     "types": ["@cloudflare/workers-types"],
     "strict": true,

diff --git a/frontend/index.html b/frontend/index.html
@@ -763,8 +763,8 @@ <h3>Your Position</h3>
         <div id="alert-modal-overlay" class="alert-modal-overlay hidden">
           <div class="alert-modal">
             <button id="alert-modal-close" class="alert-modal-close">&times;</button>
-            <h3>APY Alerts</h3>
-            <p class="alert-modal-desc">Get notified when your position's net APY turns negative.</p>
+            <h3>APY &amp; HF Alerts</h3>
+            <p class="alert-modal-desc">Get notified when net APY turns negative or health factor drops below your threshold.</p>
             <div class="form-group">
               <label>Email</label>
               <input type="email" id="alert-email" class="input" placeholder="you@example.com" />
@@ -787,6 +787,11 @@ <h3>APY Alerts</h3>
                 <option value="10">10x</option>
               </select>
             </div>
+            <div class="form-group">
+              <label>HF threshold</label>
+              <input type="number" id="alert-hf-threshold" class="input mono" min="1" max="2" step="0.01" value="1.05" />
+              <span class="balance-hint">Alert once per day when estimated HF is at or below this value.</span>
+            </div>
             <button id="alert-subscribe-btn" class="btn btn-primary btn-lg">Subscribe</button>
             <p class="alert-hint">We never store your wallet address.</p>
           </div>