feat(obs): structured logging with request-id propagation

package.json

@@ -24,6 +24,8 @@
     "cors": "^2.8.5",
     "express": "^4.18.2",
     "pg": "^8.11.3",
+    "pino": "^10.3.1",
+    "pino-http": "^11.0.0",
     "swagger-ui-express": "^5.0.1",
     "yaml": "^2.8.2",
     "zod": "^4.3.6"

src/index.ts

@@ -52,6 +52,8 @@ app.use((req, res, next) => {
 // structured response.
 app.use(express.json({ limit: '100kb' }));
 
+app.use(requestLogger);
+
 app.use("/health", healthRouter);
 
 // ── Docs ────────────────────────────────────────────────────────────────────

src/middleware/requestLogger.ts

@@ -0,0 +1,73 @@
+import type { Request, Response, NextFunction } from "express";
+import { randomUUID } from "crypto";
+import { logger } from "../utils/logger.js";
+
+export const REQUEST_ID_HEADER = "x-request-id";
+
+/**
+ * Extend Express Request to include requestId
+ */
+declare module "express-serve-static-core" {
+  interface Request {
+    requestId?: string;
+  }
+}
+
+function sanitizeWallet(address?: string): string | undefined {
+  if (!address || typeof address !== "string") return undefined;
+
+  // Truncate to avoid logging full PII
+  return `${address.slice(0, 6)}...${address.slice(-4)}`;
+}
+
+export function requestLogger(
+  req: Request,
+  res: Response,
+  next: NextFunction,
+): void {
+  const start = Date.now();
+
+  // 1. Get or generate requestId
+  const incomingId = req.headers[REQUEST_ID_HEADER] as string | undefined;
+  const requestId = incomingId ?? randomUUID();
+
+  // 2. Attach to request
+  req.requestId = requestId;
+
+  // 3. Attach to response
+  res.setHeader(REQUEST_ID_HEADER, requestId);
+
+  // 4. Log request start
+  logger.info(
+    {
+      requestId,
+      method: req.method,
+      path: req.originalUrl,
+    },
+    "request:start",
+  );
+
+  // 5. Log response finish
+  res.on("finish", () => {
+    const duration = Date.now() - start;
+
+    const wallet =
+      typeof req.body?.walletAddress === "string"
+        ? sanitizeWallet(req.body.walletAddress)
+        : undefined;
+
+    logger.info(
+      {
+        requestId,
+        method: req.method,
+        path: req.originalUrl,
+        statusCode: res.statusCode,
+        durationMs: duration,
+        walletAddress: wallet, // sanitized
+      },
+      "request:end",
+    );
+  });
+
+  next();
+}

src/utils/logger.ts

@@ -0,0 +1,9 @@
+import pino from "pino";
+
+const isTest = process.env.NODE_ENV === "test";
+
+export const logger = pino({
+  level: isTest ? "silent" : "info",
+  base: undefined, // removes pid/hostname noise
+  timestamp: pino.stdTimeFunctions.isoTime,
+});