feat: add per-request store API (getRequestStore)

packages/vinext/package.json

@@ -48,6 +48,10 @@
     "./server/worker-utils": {
       "types": "./dist/server/worker-utils.d.ts",
       "import": "./dist/server/worker-utils.js"
+    },
+    "./request-store": {
+      "types": "./dist/shims/request-store.d.ts",
+      "import": "./dist/shims/request-store.js"
     }
   },
   "scripts": {

packages/vinext/src/entries/pages-server-entry.ts

@@ -1177,7 +1177,12 @@ export async function handleApiRoute(request, url) {
     }
 
     const { req, res, responsePromise } = createReqRes(request, url, query, body);
-    await handler(req, res);
+    // Wrap in unified request context so getRequestStore() and other
+    // per-request APIs work in Pages Router API routes.
+    const __apiCtx = _createUnifiedCtx({
+      executionContext: _getRequestExecutionContext(),
+    });
+    await _runWithUnifiedCtx(__apiCtx, () => handler(req, res));
     // If handler didn't call res.end(), end it now.
     // The end() method is idempotent — safe to call twice.
     res.end();

packages/vinext/src/server/api-handler.ts

@@ -12,6 +12,10 @@ import { decode as decodeQueryString } from "node:querystring";
 import { type Route, matchRoute } from "../routing/pages-router.js";
 import { reportRequestError, importModule, type ModuleImporter } from "./instrumentation.js";
 import { addQueryParam } from "../utils/query.js";
+import {
+  runWithRequestContext,
+  createRequestContext,
+} from "../shims/unified-request-context.js";
 
 /**
  * Extend the Node.js request with Next.js-style helpers.
@@ -230,8 +234,11 @@ export async function handleApiRoute(
     // Enhance req/res with Next.js helpers
     const { apiReq, apiRes } = enhanceApiObjects(req, res, query, body);
 
-    // Call the handler
-    await handler(apiReq, apiRes);
+    // Call the handler inside a unified request context so that
+    // getRequestStore() and other per-request APIs work in Pages Router
+    // API routes (previously only App Router had this scope).
+    const __uCtx = createRequestContext();
+    await runWithRequestContext(__uCtx, () => handler(apiReq, apiRes));
     return true;
   } catch (e) {
     if (e instanceof ApiBodyParseError) {

packages/vinext/src/shims/request-store.ts

@@ -0,0 +1,69 @@
+/**
+ * Per-request key-value store for user-defined data.
+ *
+ * Backed by vinext's unified AsyncLocalStorage scope — values are
+ * automatically isolated per request and garbage-collected when the
+ * request completes. No manual cleanup needed.
+ *
+ * Primary use case: per-request database clients (Prisma, Drizzle, etc.)
+ * on Cloudflare Workers, where global singletons cause alternating
+ * connection failures (see https://github.com/cloudflare/vinext/issues/537).
+ *
+ * @example
+ * ```ts
+ * import { getRequestStore } from "vinext/request-store";
+ * import { PrismaClient } from "@prisma/client";
+ * import { PrismaPg } from "@prisma/adapter-pg";
+ * import { Pool } from "@neondatabase/serverless"; // or pg
+ *
+ * export function getPrisma(connectionString: string): PrismaClient {
+ *   const store = getRequestStore();
+ *   let prisma = store.get("prisma") as PrismaClient | undefined;
+ *   if (!prisma) {
+ *     const pool = new Pool({ connectionString });
+ *     prisma = new PrismaClient({ adapter: new PrismaPg(pool) });
+ *     store.set("prisma", prisma);
+ *   }
+ *   return prisma;
+ * }
+ * ```
+ *
+ * @example
+ * ```ts
+ * // Works with Drizzle too:
+ * import { getRequestStore } from "vinext/request-store";
+ * import { drizzle } from "drizzle-orm/neon-http";
+ *
+ * export function getDb(connectionString: string) {
+ *   const store = getRequestStore();
+ *   let db = store.get("db");
+ *   if (!db) {
+ *     db = drizzle(connectionString);
+ *     store.set("db", db);
+ *   }
+ *   return db;
+ * }
+ * ```
+ *
+ * @module
+ */
+
+import { getRequestContext, isInsideUnifiedScope } from "./unified-request-context.js";
+
+/**
+ * Get the per-request key-value store.
+ *
+ * Inside a request scope: returns the request-scoped Map (isolated, auto-cleaned).
+ * Outside a request scope: returns a fresh empty Map each time to prevent
+ * cross-call data leakage and unbounded growth.
+ *
+ * @returns A Map<string, unknown> scoped to the current request.
+ */
+export function getRequestStore(): Map<string, unknown> {
+  if (!isInsideUnifiedScope()) {
+    // Return a fresh Map — not a shared global — to prevent data leaking
+    // across unrelated calls outside request scope (dev server, tests).
+    return new Map();
+  }
+  return getRequestContext().userStore;
+}

packages/vinext/src/shims/unified-request-context.ts

@@ -47,6 +47,10 @@ export interface UnifiedRequestContext
   // ── request-context.ts ─────────────────────────────────────────────
   /** Cloudflare Workers ExecutionContext, or null on Node.js dev. */
   executionContext: ExecutionContextLike | null;
+
+  // ── request-store.ts ─────────────────────────────────────────────
+  /** User-defined per-request key-value store. Auto-cleaned on request end. */
+  userStore: Map<string, unknown>;
 }
 
 // ---------------------------------------------------------------------------
@@ -92,6 +96,7 @@ export function createRequestContext(opts?: Partial<UnifiedRequestContext>): Uni
     _privateCache: null,
     currentRequestTags: [],
     executionContext: _getInheritedExecutionContext(), // inherits from standalone ALS if present
+    userStore: new Map(),
     ssrContext: null,
     ssrHeadChildren: [],
     ...opts,
@@ -129,8 +134,8 @@ export function runWithUnifiedStateMutation<T>(
   const childCtx = { ...parentCtx };
   // NOTE: This is a shallow clone. Array fields (pendingSetCookies,
   // serverInsertedHTMLCallbacks, currentRequestTags, ssrHeadChildren), the
-  // _privateCache Map, and object fields (headersContext, i18nContext,
-  // serverContext, ssrContext, executionContext, requestScopedCacheLife)
+  // _privateCache Map, the userStore Map, and object fields (headersContext,
+  // i18nContext, serverContext, ssrContext, executionContext, requestScopedCacheLife)
   // still share references with the parent until replaced. The mutate
   // callback must replace those reference-typed slices (for example
   // `ctx.currentRequestTags = []`) rather than mutating them in-place (for