feat(cache): add Valkey backend for act/agent cache via iovalkey

.changeset/valkey-cache-backend.md

@@ -0,0 +1,5 @@
+---
+"@browserbasehq/stagehand": minor
+---
+
+Add Valkey as an optional cache backend via iovalkey. Configure with `valkeyHost` (and optional `valkeyPort`, `valkeyTls`, `valkeyPassword`, `valkeyUsername`, `cacheTtl`, `valkeyKeyPrefix`, `valkeyRequestTimeout`, `valkeyMaxCacheValueBytes`) to store act/agent cache entries in Valkey instead of the local filesystem. Gracefully falls back to disabled caching if the connection fails.

packages/core/lib/v3/cache/ActCache.ts

@@ -80,7 +80,10 @@ export class ActCache {
       value: entry,
       error,
       path,
-    } = await this.storage.readJson<CachedActEntry>(`${context.cacheKey}.json`);
+    } = await this.storage.readJson<CachedActEntry>(
+      `${context.cacheKey}.json`,
+      "act",
+    );
     if (error && path) {
       this.logger({
         category: "cache",
@@ -161,6 +164,7 @@ export class ActCache {
     const { error, path } = await this.storage.writeJson(
       `${context.cacheKey}.json`,
       entry,
+      "act",
     );
     if (error && path) {
       this.logger({
@@ -334,6 +338,7 @@ export class ActCache {
         ...entry,
         variableKeys: context.variableKeys,
       },
+      "act",
     );
 
     if (error && path) {

packages/core/lib/v3/cache/AgentCache.ts

@@ -185,6 +185,12 @@ export class AgentCache {
       path,
     } = await this.storage.readJson<CachedAgentEntry>(
       `agent-${context.cacheKey}.json`,
+      // NOTE: The `category` parameter provides act/agent namespace isolation only for
+      // the Valkey backend (via key prefix). File and in-memory backends ignore it and
+      // store entries at `agent-${cacheKey}.json` — collisions don't occur in practice
+      // because act and agent hash different payloads, producing distinct SHA-256 keys,
+      // but the `agent-` prefix provides an additional layer of separation on disk.
+      "agent",
     );
     if (error && path) {
       this.logger({
@@ -365,6 +371,7 @@ export class AgentCache {
     const { error, path } = await this.storage.writeJson(
       `agent-${context.cacheKey}.json`,
       entry,
+      "agent",
     );
     if (error && path) {
       this.logger({
@@ -415,6 +422,7 @@ export class AgentCache {
     const { error, path } = await this.storage.writeJson(
       `agent-${payload.cacheKey}.json`,
       entry,
+      "agent",
     );
     if (error && path) {
       this.logger({
@@ -880,6 +888,7 @@ export class AgentCache {
     const { error, path } = await this.storage.writeJson(
       `agent-${context.cacheKey}.json`,
       updatedEntry,
+      "agent",
     );
     if (error && path) {
       this.logger({

packages/core/lib/v3/cache/CacheStorage.ts

@@ -1,7 +1,11 @@
 import fs from "fs";
 import path from "path";
 import type { Logger } from "../types/public/index.js";
-import { ReadJsonResult, WriteJsonResult } from "../types/private/index.js";
+import {
+  CacheCategory,
+  ReadJsonResult,
+  WriteJsonResult,
+} from "../types/private/index.js";
 
 const jsonClone = <T>(value: T): T => {
   const serialized = JSON.stringify(value);
@@ -11,11 +15,76 @@ const jsonClone = <T>(value: T): T => {
   return JSON.parse(serialized) as T;
 };
 
+/**
+ * Configuration for the Valkey cache backend.
+ */
+export interface ValkeyCacheOptions {
+  /** Valkey host address. */
+  host: string;
+  /** Valkey port (default: 6379). */
+  port?: number;
+  /** Enable TLS for the connection. */
+  useTls?: boolean;
+  /** Authentication password (IAM token or static auth token). */
+  password?: string;
+  /** Authentication username (for ACL-enabled instances). */
+  username?: string;
+  /** Default TTL in seconds for cache entries. Omit for no expiry. */
+  cacheTtl?: number;
+  /** Key prefix namespace (default: "stagehand"). */
+  keyPrefix?: string;
+  /** Request timeout in ms (default: 5000). */
+  requestTimeout?: number;
+  /** Max allowed cache value size in bytes (default: 5MB). Writes exceeding this are skipped. */
+  maxCacheValueBytes?: number;
+}
+
+/**
+ * Options shape for ValkeyClientLike.set(), matching GLIDE's expiry API.
+ */
+interface ValkeySetOptions {
+  expiry?: { type: "EX" | "PX" | "EXAT" | "PXAT"; count: number };
+}
+
+/**
+ * Minimal interface matching the subset of Valkey client methods used by
+ * CacheStorage. This avoids a hard compile-time dependency on iovalkey
+ * for users who don't need the Valkey backend.
+ */
+interface ValkeyClientLike {
+  get(key: string): Promise<string | null>;
+  set(
+    key: string,
+    value: string,
+    options?: ValkeySetOptions,
+  ): Promise<string | null>;
+  del(keys: string[]): Promise<number>;
+  close(): Promise<void>;
+}
+
+/**
+ * Minimal type shape for the dynamically imported iovalkey module.
+ */
+interface IovalkeyModule {
+  default: new (options: Record<string, unknown>) => IovalkeyClient;
+}
+
+interface IovalkeyClient {
+  connect(): Promise<void>;
+  get(key: string): Promise<string | null>;
+  set(key: string, value: string, ...args: unknown[]): Promise<string | null>;
+  del(...keys: string[]): Promise<number>;
+  quit(): Promise<string>;
+  disconnect(): void;
+}
+
 export class CacheStorage {
   private constructor(
     private readonly logger: Logger,
     private readonly dir?: string,
     private readonly memoryStore?: Map<string, unknown>,
+    private readonly valkeyClient?: ValkeyClientLike,
+    private readonly valkeyOptions?: ValkeyCacheOptions,
   ) {}
 
   static create(
@@ -49,20 +118,184 @@ export class CacheStorage {
     return new CacheStorage(logger, undefined, new Map());
   }
 
+  /**
+   * Create a CacheStorage backed by Valkey via iovalkey.
+   * Requires `iovalkey` to be installed as an optional dependency.
+   * Returns a disabled CacheStorage if the connection fails.
+   */
+  static async createValkey(
+    options: ValkeyCacheOptions,
+    logger: Logger,
+  ): Promise<CacheStorage> {
+    try {
+      const mod = (await import(
+        /* webpackIgnore: true */ /* @vite-ignore */ "iovalkey"
+      )) as unknown as IovalkeyModule;
+      const Valkey = mod.default;
+
+      if (options.username && !options.password) {
+        throw new Error(
+          "Valkey cache: username was provided without a password. " +
+            "Supply both username and password, or omit both.",
+        );
+      }
+
+      // Default TLS on when credentials are present to avoid plaintext transit.
+      const useTLS = options.useTls ?? !!options.password;
+      const port = options.port ?? 6379;
+
+      const iovalkeyOpts: Record<string, unknown> = {
+        host: options.host,
+        port,
+        ...(options.password ? { password: options.password } : {}),
+        ...(options.username ? { username: options.username } : {}),
+        ...(useTLS ? { tls: {} } : {}),
+        commandTimeout: options.requestTimeout ?? 5000,
+        maxRetriesPerRequest: 3,
+        retryStrategy: (times: number): number | null =>
+          times > 5 ? null : Math.min(times * 500, 5000),
+        connectionName: "stagehand-cache",
+        lazyConnect: true,
+      };
+
+      const rawClient = new Valkey(iovalkeyOpts);
+      await rawClient.connect();
+
+      // Adapt iovalkey's API to ValkeyClientLike
+      const client: ValkeyClientLike = {
+        get: (key) => rawClient.get(key),
+        set: (key, value, setOpts?) => {
+          if (setOpts?.expiry) {
+            return rawClient.set(
+              key,
+              value,
+              setOpts.expiry.type,
+              setOpts.expiry.count,
+            );
+          }
+          return rawClient.set(key, value);
+        },
+        del: (keys) =>
+          keys.length > 0 ? rawClient.del(...keys) : Promise.resolve(0),
+        close: (): Promise<void> => rawClient.quit().then((): void => {}),
+      };
+
+      logger({
+        category: "cache",
+        message: `valkey cache connected to ${options.host}:${port}`,
+        level: 1,
+      });
+
+      return new CacheStorage(logger, undefined, undefined, client, options);
+    } catch (err) {
+      const safeMessage = err instanceof Error ? err.message : "unknown error";
+      logger({
+        category: "cache",
+        message: `unable to initialize valkey cache: ${safeMessage}`,
+        level: 1,
+        auxiliary: {
+          error: { value: safeMessage, type: "string" },
+        },
+      });
+      return new CacheStorage(logger);
+    }
+  }
+
   get directory(): string | undefined {
     return this.dir;
   }
 
   get enabled(): boolean {
-    return !!this.dir || !!this.memoryStore;
+    return !!this.dir || !!this.memoryStore || !!this.valkeyClient;
+  }
+
+  /** True if this storage is backed by a Valkey client. */
+  get isValkey(): boolean {
+    return !!this.valkeyClient;
+  }
+
+  /**
+   * Close the underlying Valkey client connection, if any.
+   * Safe to call multiple times or when no Valkey client is attached.
+   */
+  async close(): Promise<void> {
+    if (this.valkeyClient) {
+      try {
+        await this.valkeyClient.close();
+      } catch (err) {
+        this.logger({
+          category: "cache",
+          message: `valkey close error (best-effort): ${err instanceof Error ? err.message : "unknown"}`,
+          level: 2,
+        });
+      }
+    }
   }
 
   private resolvePath(fileName: string): string | null {
     if (!this.dir) return null;
     return path.join(this.dir, fileName);
   }
 
-  async readJson<T>(fileName: string): Promise<ReadJsonResult<T>> {
+  /**
+   * Derive the Valkey key from a cache fileName and explicit category.
+   * Strips any redundant category prefix from the fileName (e.g. "agent-")
+   * since the category is already encoded in the key namespace.
+   */
+  private toValkeyKey(fileName: string, category: CacheCategory): string {
+    const prefix = this.valkeyOptions?.keyPrefix ?? "stagehand";
+    const base = fileName.replace(/\.json$/, "").replace(/^agent-/, "");
+    return `${prefix}:${category}:${base}`;
+  }
+
+  async readJson<T>(
+    fileName: string,
+    category: CacheCategory = "act",
+  ): Promise<ReadJsonResult<T>> {
+    if (this.valkeyClient) {
+      const key = this.toValkeyKey(fileName, category);
+      try {
+        const raw = await this.valkeyClient.get(key);
+        if (raw === null) {
+          return { value: null };
+        }
+        try {
+          return { value: JSON.parse(raw) as T };
+        } catch (parseErr) {
+          // Corrupt data — delete the poisoned key so subsequent reads don't
+          // keep failing until TTL expiry.
+          this.logger({
+            category: "cache",
+            message: `valkey key ${key} contains corrupt JSON; deleting`,
+            level: 1,
+            auxiliary: {
+              error: { value: String(parseErr), type: "string" },
+            },
+          });
+          try {
+            await this.valkeyClient.del([key]);
+          } catch (delErr) {
+            this.logger({
+              category: "cache",
+              message: `valkey del error for corrupt key ${key} (best-effort): ${delErr instanceof Error ? delErr.message : "unknown"}`,
+              level: 2,
+            });
+          }
+          return { value: null, error: parseErr, path: key };
+        }
+      } catch (err) {
+        this.logger({
+          category: "cache",
+          message: `valkey read error for key ${key}`,
+          level: 1,
+          auxiliary: {
+            error: { value: String(err), type: "string" },
+          },
+        });
+        return { value: null, error: err, path: key };
+      }
+    }
+
     if (this.memoryStore) {
       if (!this.memoryStore.has(fileName)) {
         return { value: null };
@@ -88,7 +321,49 @@ export class CacheStorage {
     }
   }
 
-  async writeJson(fileName: string, data: unknown): Promise<WriteJsonResult> {
+  async writeJson(
+    fileName: string,
+    data: unknown,
+    category: CacheCategory = "act",
+  ): Promise<WriteJsonResult> {
+    if (this.valkeyClient) {
+      const key = this.toValkeyKey(fileName, category);
+      try {
+        const serialized = JSON.stringify(data);
+        const maxBytes = this.valkeyOptions?.maxCacheValueBytes ?? 5_242_880;
+        if (Buffer.byteLength(serialized, "utf8") > maxBytes) {
+          this.logger({
+            category: "cache",
+            message: `valkey write skipped: payload exceeds ${maxBytes} byte limit`,
+            level: 1,
+          });
+          return {
+            error: new Error("cache value exceeds size limit"),
+            path: key,
+          };
+        }
+        const ttl = this.valkeyOptions?.cacheTtl;
+        if (ttl !== undefined && ttl > 0) {
+          await this.valkeyClient.set(key, serialized, {
+            expiry: { type: "EX", count: ttl },
+          });
+        } else {
+          await this.valkeyClient.set(key, serialized);
+        }
+        return {};
+      } catch (err) {
+        this.logger({
+          category: "cache",
+          message: `valkey write error for key ${key}`,
+          level: 1,
+          auxiliary: {
+            error: { value: String(err), type: "string" },
+          },
+        });
+        return { error: err, path: key };
+      }
+    }
+
     if (this.memoryStore) {
       this.memoryStore.set(fileName, jsonClone(data));
       return {};