feat: implement payment retry with exponential backoff and vault secrets management

backend/src/index.ts

@@ -16,6 +16,7 @@ import { slaRouter } from './routes/sla.js';
 import { legacyRouter } from './routes/legacy.js';
 import { splitsRouter } from './routes/splits.js';
 import { refundsRouter } from './routes/refunds.js';
+import { allowancesRouter } from './routes/allowances.js';
 import { startJobs, getJobScheduler } from './jobs/index.js';
 import { errorHandler, notFoundHandler, AppError } from './middleware/errorHandler.js';
 import { messageQueue } from './services/queue.js';
@@ -231,6 +232,7 @@ apiV1Router.use('/sla', slaRouter);
 apiV1Router.use('/legacy', legacyRouter);
 apiV1Router.use('/splits', splitsRouter);
 apiV1Router.use('/refunds', refundsRouter);
+apiV1Router.use('/allowances', allowancesRouter);
 // Email delivery system
 apiV1Router.use('/emails', emailRouter);
 // Portfolio/wallet aggregation

backend/src/routes/allowances.ts

@@ -0,0 +1,153 @@
+import { Router } from 'express';
+import { z } from 'zod';
+import {
+  fetchAllowances,
+  approveToken,
+  revokeAllowance,
+  batchRevoke,
+  estimateGasForApproval,
+  getRecommendedAllowance,
+  getApprovalLogs,
+  getAllowanceStats,
+} from '../../services/allowances.js';
+
+const router = Router();
+
+const fetchQuerySchema = z.object({
+  owner: z.string(),
+  tokens: z.string().optional(),
+  spenders: z.string().optional(),
+});
+
+const approvalBodySchema = z.object({
+  token: z.string(),
+  spender: z.string(),
+  amount: z.string(),
+  unlimited: z.boolean().optional(),
+  expiresAt: z.number().optional(),
+});
+
+const revokeBodySchema = z.object({
+  token: z.string(),
+  spender: z.string(),
+});
+
+const batchRevokeBodySchema = z.array(
+  z.object({
+    token: z.string(),
+    spender: z.string(),
+  })
+);
+
+router.get('/', async (req, res) => {
+  try {
+    const { owner, tokens, spenders } = fetchQuerySchema.parse(req.query);
+    const tokensList = tokens ? tokens.split(',') : undefined;
+    const spendersList = spenders ? spenders.split(',') : undefined;
+
+    const allowances = await fetchAllowances(owner, tokensList, spendersList);
+    res.json({ success: true, data: allowances });
+  } catch (error) {
+    const message = error instanceof Error ? error.message : 'Failed to fetch allowances';
+    res.status(400).json({ success: false, error: message });
+  }
+});
+
+router.post('/approve', async (req, res) => {
+  try {
+    const body = approvalBodySchema.parse(req.body);
+    const result = await approveToken(
+      body.token,
+      body.spender,
+      body.amount,
+      body.unlimited,
+      body.expiresAt
+    );
+
+    if (result.success) {
+      res.json({ success: true, txHash: result.txHash });
+    } else {
+      res.status(400).json({ success: false, error: result.error });
+    }
+  } catch (error) {
+    const message = error instanceof Error ? error.message : 'Approval failed';
+    res.status(400).json({ success: false, error: message });
+  }
+});
+
+router.post('/revoke', async (req, res) => {
+  try {
+    const body = revokeBodySchema.parse(req.body);
+    const result = await revokeAllowance(body.token, body.spender);
+
+    if (result.success) {
+      res.json({ success: true });
+    } else {
+      res.status(400).json({ success: false, error: result.error });
+    }
+  } catch (error) {
+    const message = error instanceof Error ? error.message : 'Revocation failed';
+    res.status(400).json({ success: false, error: message });
+  }
+});
+
+router.post('/batch-revoke', async (req, res) => {
+  try {
+    const body = batchRevokeBodySchema.parse(req.body);
+    const result = await batchRevoke(body);
+
+    res.json(result);
+  } catch (error) {
+    const message = error instanceof Error ? error.message : 'Batch revocation failed';
+    res.status(400).json({ success: false, error: message });
+  }
+});
+
+router.get('/gas-estimate', async (req, res) => {
+  try {
+    const { token, spender, amount, unlimited } = approvalBodySchema.parse(req.query);
+    const result = await estimateGasForApproval(token, spender, amount, unlimited);
+
+    res.json(result);
+  } catch (error) {
+    const message = error instanceof Error ? error.message : 'Gas estimation failed';
+    res.status(400).json({ success: false, error: message });
+  }
+});
+
+router.get('/recommended', (req, res) => {
+  const { token, spender, typicalUsage } = req.query;
+
+  if (!token || !spender || !typicalUsage) {
+    return res.status(400).json({
+      success: false,
+      error: 'Missing required parameters: token, spender, typicalUsage',
+    });
+  }
+
+  const recommended = getRecommendedAllowance(
+    token as string,
+    spender as string,
+    typicalUsage as string
+  );
+
+  res.json({ success: true, recommended });
+});
+
+router.get('/logs', (req, res) => {
+  const { token, spender, limit } = req.query;
+  const logs = getApprovalLogs(
+    token as string | undefined,
+    spender as string | undefined,
+    limit ? parseInt(limit as string) : 100
+  );
+
+  res.json({ success: true, logs });
+});
+
+router.get('/stats', (req, res) => {
+  const stats = getAllowanceStats();
+  res.json({ success: true, stats });
+});
+
+export default router;