Initial import of verae-middleware from zapier monorepo

src/debug/trace-context.js

@@ -0,0 +1,39 @@
+/**
+ * @fileoverview AsyncLocalStorage-backed trace context (no logger dependency).
+ * Split from trace.js to avoid circular imports with logger.js.
+ * @module debug/trace-context
+ */
+
+import { AsyncLocalStorage } from 'node:async_hooks';
+import { randomBytes } from 'node:crypto';
+
+/**
+ * @typedef {Object} TraceContext
+ * @property {string} traceId
+ * @property {string} [span]
+ */
+
+/** @type {AsyncLocalStorage<TraceContext>} */
+export const traceStorage = new AsyncLocalStorage();
+
+/**
+ * Generate a short opaque trace id (16 hex chars).
+ * @returns {string}
+ */
+export function generateTraceId() {
+  return randomBytes(8).toString('hex');
+}
+
+/**
+ * @returns {string|null}
+ */
+export function getTraceId() {
+  return traceStorage.getStore()?.traceId ?? null;
+}
+
+/**
+ * @returns {TraceContext|null}
+ */
+export function getTraceContext() {
+  return traceStorage.getStore() ?? null;
+}