add project

apps/api/src/routes/btc-proxy.routes.ts

@@ -0,0 +1,148 @@
+import { Request, Response, Router } from 'express';
+
+const router = Router();
+const BLOCKSTREAM_BASE = 'https://blockstream.info/api';
+const BTC_TIMEOUT_MS = 10_000;
+
+// Validate Bitcoin address format (mainnet only)
+const BTC_ADDRESS_RE = /^(bc1[a-zA-HJ-NP-Z0-9]{25,62}|[13][a-km-zA-HJ-NP-Z1-9]{25,34})$/;
+
+router.get('/utxos/:address', getUtxos);
+router.get('/fee-estimates', getFeeEstimates);
+router.post('/broadcast', broadcastTx);
+
+export default router;
+
+/**
+ * GET /api/btc/utxos/:address
+ * Returns confirmed UTXOs for the given address.
+ */
+async function getUtxos(req: Request, res: Response) {
+  const address = String(req.params.address);
+
+  if (!BTC_ADDRESS_RE.test(address)) {
+    res.status(400).json({ success: false, error: 'Invalid Bitcoin address' });
+    return;
+  }
+
+  const controller = new AbortController();
+  const timeout = setTimeout(() => controller.abort(), BTC_TIMEOUT_MS);
+
+  try {
+    const response = await fetch(`${BLOCKSTREAM_BASE}/address/${address}/utxo`, {
+      headers: { Accept: 'application/json' },
+      signal: controller.signal,
+    });
+
+    if (!response.ok) {
+      res.status(response.status).json({ success: false, error: 'Blockstream API error' });
+      return;
+    }
+
+    const utxos = await response.json();
+
+    // Filter to confirmed only
+    const confirmed = (utxos as Array<{ status: { confirmed: boolean }; txid: string; vout: number; value: number }>)
+      .filter((u) => u.status?.confirmed)
+      .map((u) => ({
+        txid: u.txid,
+        vout: u.vout,
+        value: u.value,
+      }));
+
+    res.json({ success: true, data: confirmed });
+  } catch (error) {
+    if (controller.signal.aborted) {
+      res.status(504).json({ success: false, error: 'Blockstream request timeout' });
+      return;
+    }
+    res.status(502).json({ success: false, error: 'Failed to reach Blockstream' });
+  } finally {
+    clearTimeout(timeout);
+  }
+}
+
+/**
+ * GET /api/btc/fee-estimates
+ * Returns fee rate estimates in sat/vB for different confirmation targets.
+ */
+async function getFeeEstimates(_req: Request, res: Response) {
+  const controller = new AbortController();
+  const timeout = setTimeout(() => controller.abort(), BTC_TIMEOUT_MS);
+
+  try {
+    const response = await fetch(`${BLOCKSTREAM_BASE}/fee-estimates`, {
+      headers: { Accept: 'application/json' },
+      signal: controller.signal,
+    });
+
+    if (!response.ok) {
+      res.status(response.status).json({ success: false, error: 'Blockstream fee estimates error' });
+      return;
+    }
+
+    const data = await response.json();
+
+    // Return top 3 tiers: 1-block, 3-block, 6-block confirmation targets
+    const estimates = data as Record<string, number>;
+    res.json({
+      success: true,
+      data: {
+        fast: Math.ceil(estimates['1'] ?? estimates['2'] ?? 10),
+        normal: Math.ceil(estimates['3'] ?? estimates['6'] ?? 5),
+        slow: Math.ceil(estimates['6'] ?? estimates['12'] ?? 2),
+      },
+    });
+  } catch (error) {
+    if (controller.signal.aborted) {
+      res.status(504).json({ success: false, error: 'Blockstream fee estimates timeout' });
+      return;
+    }
+    res.status(502).json({ success: false, error: 'Failed to reach Blockstream' });
+  } finally {
+    clearTimeout(timeout);
+  }
+}
+
+/**
+ * POST /api/btc/broadcast
+ * Broadcasts a raw transaction hex.
+ */
+async function broadcastTx(req: Request, res: Response) {
+  const { hex } = req.body;
+
+  if (!hex || typeof hex !== 'string' || !/^[0-9a-fA-F]+$/.test(hex)) {
+    res.status(400).json({ success: false, error: 'Invalid transaction hex' });
+    return;
+  }
+
+  const controller = new AbortController();
+  const timeout = setTimeout(() => controller.abort(), BTC_TIMEOUT_MS);
+
+  try {
+    const response = await fetch(`${BLOCKSTREAM_BASE}/tx`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'text/plain' },
+      body: hex,
+      signal: controller.signal,
+    });
+
+    const text = await response.text();
+
+    if (!response.ok) {
+      res.status(response.status).json({ success: false, error: text || 'Broadcast failed' });
+      return;
+    }
+
+    // Blockstream returns the txid as plain text
+    res.json({ success: true, data: { txid: text.trim() } });
+  } catch (error) {
+    if (controller.signal.aborted) {
+      res.status(504).json({ success: false, error: 'Broadcast timeout' });
+      return;
+    }
+    res.status(502).json({ success: false, error: 'Failed to broadcast transaction' });
+  } finally {
+    clearTimeout(timeout);
+  }
+}