diff --git a/lib/core/promises/promises.ts b/lib/core/promises/promises.ts
index ee23095..f9f1ae5 100644
--- a/lib/core/promises/promises.ts
+++ b/lib/core/promises/promises.ts
@@ -1,7 +1,7 @@
 import { IEncoder } from "../encoder";
 import { ErrorCodes, ResonateError } from "../errors";
 import { IPromiseStore } from "../store";
-import { PendingPromise, ResolvedPromise, RejectedPromise, CanceledPromise, TimedoutPromise } from "./types";
+import { DurablePromiseRecord } from "./types";
 
 /**
  * Durable Promise create options.
@@ -69,7 +69,7 @@ export class DurablePromise<T> {
   constructor(
     private store: IPromiseStore,
     private encoder: IEncoder<unknown, string | undefined>,
-    private promise: PendingPromise | ResolvedPromise | RejectedPromise | CanceledPromise | TimedoutPromise,
+    private promise: DurablePromiseRecord,
   ) {
     this.completed = new Promise((resolve) => {
       this.complete = resolve;
diff --git a/lib/core/promises/types.ts b/lib/core/promises/types.ts
index 02af121..b816cf1 100644
--- a/lib/core/promises/types.ts
+++ b/lib/core/promises/types.ts
@@ -1,45 +1,5 @@
-export type DurablePromise = PendingPromise | ResolvedPromise | RejectedPromise | CanceledPromise | TimedoutPromise;
-
-export type PendingPromise = {
-  state: "PENDING";
-  id: string;
-  timeout: number;
-  param: {
-    headers: Record<string, string> | undefined;
-    data: string | undefined;
-  };
-  value: {
-    headers: undefined;
-    data: undefined;
-  };
-  createdOn: number;
-  completedOn: undefined;
-  idempotencyKeyForCreate: string | undefined;
-  idempotencyKeyForComplete: undefined;
-  tags: Record<string, string> | undefined;
-};
-
-export type ResolvedPromise = {
-  state: "RESOLVED";
-  id: string;
-  timeout: number;
-  param: {
-    headers: Record<string, string> | undefined;
-    data: string | undefined;
-  };
-  value: {
-    headers: Record<string, string> | undefined;
-    data: string | undefined;
-  };
-  createdOn: number;
-  completedOn: number;
-  idempotencyKeyForCreate: string | undefined;
-  idempotencyKeyForComplete: string | undefined;
-  tags: Record<string, string> | undefined;
-};
-
-export type RejectedPromise = {
-  state: "REJECTED";
+export type DurablePromiseRecord = {
+  state: "PENDING" | "RESOLVED" | "REJECTED" | "REJECTED_CANCELED" | "REJECTED_TIMEDOUT";
   id: string;
   timeout: number;
   param: {
@@ -51,53 +11,14 @@ export type RejectedPromise = {
     data: string | undefined;
   };
   createdOn: number;
-  completedOn: number;
+  completedOn: number | undefined;
   idempotencyKeyForCreate: string | undefined;
   idempotencyKeyForComplete: string | undefined;
   tags: Record<string, string> | undefined;
 };
 
-export type CanceledPromise = {
-  state: "REJECTED_CANCELED";
-  id: string;
-  timeout: number;
-  param: {
-    headers: Record<string, string> | undefined;
-    data: string | undefined;
-  };
-  value: {
-    headers: Record<string, string> | undefined;
-    data: string | undefined;
-  };
-  createdOn: number;
-  completedOn: number;
-  idempotencyKeyForCreate: string | undefined;
-  idempotencyKeyForComplete: string | undefined;
-  tags: Record<string, string> | undefined;
-};
-
-export type TimedoutPromise = {
-  state: "REJECTED_TIMEDOUT";
-  id: string;
-  timeout: number;
-  param: {
-    headers: Record<string, string> | undefined;
-    data: string | undefined;
-  };
-  value: {
-    headers: undefined;
-    data: undefined;
-  };
-  createdOn: number;
-  completedOn: number;
-  idempotencyKeyForCreate: string | undefined;
-  idempotencyKeyForComplete: undefined;
-  tags: Record<string, string> | undefined;
-};
-
-// Type guards
-
-export function isDurablePromise(p: unknown): p is DurablePromise {
+// This is an unsound type guard, we should be more strict in what we call a DurablePromise
+export function isDurablePromiseRecord(p: unknown): p is DurablePromiseRecord {
   return (
     p !== null &&
     typeof p === "object" &&
@@ -107,28 +28,26 @@ export function isDurablePromise(p: unknown): p is DurablePromise {
   );
 }
 
-export function isPendingPromise(p: unknown): p is PendingPromise {
-  return isDurablePromise(p) && p.state === "PENDING";
+export function isPendingPromise(p: DurablePromiseRecord): boolean {
+  return p.state === "PENDING";
 }
 
-export function isResolvedPromise(p: unknown): p is ResolvedPromise {
-  return isDurablePromise(p) && p.state === "RESOLVED";
+export function isResolvedPromise(p: DurablePromiseRecord): boolean {
+  return p.state === "RESOLVED";
 }
 
-export function isRejectedPromise(p: unknown): p is RejectedPromise {
-  return isDurablePromise(p) && p.state === "REJECTED";
+export function isRejectedPromise(p: DurablePromiseRecord): boolean {
+  return p.state === "REJECTED";
 }
 
-export function isCanceledPromise(p: unknown): p is CanceledPromise {
-  return isDurablePromise(p) && p.state === "REJECTED_CANCELED";
+export function isCanceledPromise(p: DurablePromiseRecord): boolean {
+  return p.state === "REJECTED_CANCELED";
 }
 
-export function isTimedoutPromise(p: unknown): p is TimedoutPromise {
-  return isDurablePromise(p) && p.state === "REJECTED_TIMEDOUT";
+export function isTimedoutPromise(p: DurablePromiseRecord): boolean {
+  return p.state === "REJECTED_TIMEDOUT";
 }
 
-export function isCompletedPromise(
-  p: unknown,
-): p is ResolvedPromise | RejectedPromise | CanceledPromise | TimedoutPromise {
-  return isDurablePromise(p) && ["RESOLVED", "REJECTED", "REJECTED_CANCELED", "REJECTED_TIMEDOUT"].includes(p.state);
+export function isCompletedPromise(p: DurablePromiseRecord): boolean {
+  return ["RESOLVED", "REJECTED", "REJECTED_CANCELED", "REJECTED_TIMEDOUT"].includes(p.state);
 }
diff --git a/lib/core/storages/memory.ts b/lib/core/storages/memory.ts
index a33b4b6..d49603f 100644
--- a/lib/core/storages/memory.ts
+++ b/lib/core/storages/memory.ts
@@ -3,6 +3,7 @@ import { IStorage } from "../storage";
 export class MemoryStorage<T> implements IStorage<T> {
   private items: Record<string, T> = {};
 
+  // read-modify-write
   async rmw<X extends T | undefined>(id: string, func: (item: T | undefined) => X): Promise<X> {
     const item = func(this.items[id]);
     if (item) {
@@ -12,6 +13,7 @@ export class MemoryStorage<T> implements IStorage<T> {
     return item;
   }
 
+  // read-modify-delete
   async rmd(id: string, func: (item: T) => boolean): Promise<boolean> {
     const item = this.items[id];
     let result = false;
diff --git a/lib/core/storages/withTimeout.ts b/lib/core/storages/withTimeout.ts
index ff61a5e..063777c 100644
--- a/lib/core/storages/withTimeout.ts
+++ b/lib/core/storages/withTimeout.ts
@@ -1,28 +1,32 @@
-import { DurablePromise, ResolvedPromise, TimedoutPromise, isPendingPromise } from "../promises/types";
+import { DurablePromiseRecord, isPendingPromise } from "../promises/types";
 import { IStorage } from "../storage";
 import { MemoryStorage } from "./memory";
 
-export class WithTimeout implements IStorage<DurablePromise> {
-  constructor(private storage: IStorage<DurablePromise> = new MemoryStorage<DurablePromise>()) {}
+export class WithTimeout implements IStorage<DurablePromiseRecord> {
+  constructor(private storage: IStorage<DurablePromiseRecord> = new MemoryStorage<DurablePromiseRecord>()) {}
 
-  rmw<T extends DurablePromise | undefined>(id: string, func: (item: DurablePromise | undefined) => T): Promise<T> {
+  rmw<T extends DurablePromiseRecord | undefined>(
+    id: string,
+    func: (item: DurablePromiseRecord | undefined) => T,
+  ): Promise<T> {
     return this.storage.rmw(id, (p) => func(p ? timeout(p) : undefined));
   }
 
-  rmd(id: string, func: (item: DurablePromise) => boolean): Promise<boolean> {
+  rmd(id: string, func: (item: DurablePromiseRecord) => boolean): Promise<boolean> {
     return this.storage.rmd(id, (p) => func(timeout(p)));
   }
 
-  async *all(): AsyncGenerator<DurablePromise[], void> {
+  async *all(): AsyncGenerator<DurablePromiseRecord[], void> {
     for await (const promises of this.storage.all()) {
       yield promises.map(timeout);
     }
   }
 }
 
-function timeout<T extends DurablePromise>(promise: T): T | ResolvedPromise | TimedoutPromise {
+function timeout<T extends DurablePromiseRecord>(promise: T): DurablePromiseRecord {
   if (isPendingPromise(promise) && Date.now() >= promise.timeout) {
-    const body = {
+    return {
+      state: promise.tags?.["resonate:timeout"] === "true" ? "RESOLVED" : "REJECTED_TIMEDOUT",
       id: promise.id,
       timeout: promise.timeout,
       param: promise.param,
@@ -36,18 +40,6 @@ function timeout<T extends DurablePromise>(promise: T): T | ResolvedPromise | Ti
       idempotencyKeyForComplete: undefined,
       tags: promise.tags,
     };
-
-    if (promise.tags?.["resonate:timeout"] === "true") {
-      return {
-        state: "RESOLVED",
-        ...body,
-      };
-    } else {
-      return {
-        state: "REJECTED_TIMEDOUT",
-        ...body,
-      };
-    }
   }
 
   return promise;
diff --git a/lib/core/store.ts b/lib/core/store.ts
index 0a8de6f..51745a2 100644
--- a/lib/core/store.ts
+++ b/lib/core/store.ts
@@ -1,11 +1,4 @@
-import {
-  DurablePromise,
-  PendingPromise,
-  ResolvedPromise,
-  RejectedPromise,
-  CanceledPromise,
-  TimedoutPromise,
-} from "./promises/types";
+import { DurablePromiseRecord } from "./promises/types";
 
 import { Schedule } from "./schedules/types";
 
@@ -42,7 +35,7 @@ export interface IPromiseStore {
     data: string | undefined,
     timeout: number,
     tags: Record<string, string> | undefined,
-  ): Promise<PendingPromise | CanceledPromise | ResolvedPromise | RejectedPromise | TimedoutPromise>;
+  ): Promise<DurablePromiseRecord>;
 
   /**
    * Cancels a new promise.
@@ -60,7 +53,7 @@ export interface IPromiseStore {
     strict: boolean,
     headers: Record<string, string> | undefined,
     data: string | undefined,
-  ): Promise<CanceledPromise | ResolvedPromise | RejectedPromise | TimedoutPromise>;
+  ): Promise<DurablePromiseRecord>;
 
   /**
    * Resolves a promise.
@@ -78,7 +71,7 @@ export interface IPromiseStore {
     strict: boolean,
     headers: Record<string, string> | undefined,
     data: string | undefined,
-  ): Promise<CanceledPromise | ResolvedPromise | RejectedPromise | TimedoutPromise>;
+  ): Promise<DurablePromiseRecord>;
 
   /**
    * Rejects a promise
@@ -96,7 +89,7 @@ export interface IPromiseStore {
     strict: boolean,
     headers: Record<string, string> | undefined,
     data: string | undefined,
-  ): Promise<CanceledPromise | ResolvedPromise | RejectedPromise | TimedoutPromise>;
+  ): Promise<DurablePromiseRecord>;
 
   /**
    * Retrieves a promise based on its id.
@@ -104,7 +97,7 @@ export interface IPromiseStore {
    * @param id Unique identifier for the promise to be retrieved.
    * @returns A durable promise that is pending, canceled, resolved, or rejected.
    */
-  get(id: string): Promise<DurablePromise>;
+  get(id: string): Promise<DurablePromiseRecord>;
 
   /**
    * Search for promises.
@@ -120,7 +113,7 @@ export interface IPromiseStore {
     state: string | undefined,
     tags: Record<string, string> | undefined,
     limit?: number,
-  ): AsyncGenerator<DurablePromise[], void>;
+  ): AsyncGenerator<DurablePromiseRecord[], void>;
 }
 
 /**
diff --git a/lib/core/stores/local.ts b/lib/core/stores/local.ts
index 7b9d3b8..71570c1 100644
--- a/lib/core/stores/local.ts
+++ b/lib/core/stores/local.ts
@@ -4,12 +4,7 @@ import { ILogger } from "../logger";
 import { Logger } from "../loggers/logger";
 import { StoreOptions } from "../options";
 import {
-  DurablePromise,
-  PendingPromise,
-  ResolvedPromise,
-  RejectedPromise,
-  CanceledPromise,
-  TimedoutPromise,
+  DurablePromiseRecord,
   isPendingPromise,
   isResolvedPromise,
   isRejectedPromise,
@@ -34,7 +29,7 @@ export class LocalStore implements IStore {
 
   constructor(
     opts: Partial<StoreOptions> = {},
-    promiseStorage: IStorage<DurablePromise> = new WithTimeout(new MemoryStorage<DurablePromise>()),
+    promiseStorage: IStorage<DurablePromiseRecord> = new WithTimeout(new MemoryStorage<DurablePromiseRecord>()),
     scheduleStorage: IStorage<Schedule> = new MemoryStorage<Schedule>(),
     lockStorage: IStorage<{ id: string; eid: string }> = new MemoryStorage<{ id: string; eid: string }>(),
   ) {
@@ -122,7 +117,7 @@ export class LocalStore implements IStore {
 export class LocalPromiseStore implements IPromiseStore {
   constructor(
     private store: LocalStore,
-    private storage: IStorage<DurablePromise>,
+    private storage: IStorage<DurablePromiseRecord>,
   ) {}
 
   async create(
@@ -133,7 +128,7 @@ export class LocalPromiseStore implements IPromiseStore {
     data: string | undefined,
     timeout: number,
     tags: Record<string, string> | undefined,
-  ): Promise<PendingPromise | ResolvedPromise | RejectedPromise | CanceledPromise | TimedoutPromise> {
+  ): Promise<DurablePromiseRecord> {
     return this.storage.rmw(id, (promise) => {
       if (!promise) {
         return {
@@ -174,7 +169,7 @@ export class LocalPromiseStore implements IPromiseStore {
     strict: boolean,
     headers: Record<string, string> | undefined,
     data: string | undefined,
-  ): Promise<ResolvedPromise | RejectedPromise | CanceledPromise | TimedoutPromise> {
+  ): Promise<DurablePromiseRecord> {
     return this.storage.rmw(id, (promise) => {
       if (!promise) {
         throw new ResonateError("Not found", ErrorCodes.STORE_NOT_FOUND);
@@ -219,7 +214,7 @@ export class LocalPromiseStore implements IPromiseStore {
     strict: boolean,
     headers: Record<string, string> | undefined,
     data: string | undefined,
-  ): Promise<ResolvedPromise | RejectedPromise | CanceledPromise | TimedoutPromise> {
+  ): Promise<DurablePromiseRecord> {
     return this.storage.rmw(id, (promise) => {
       if (!promise) {
         throw new ResonateError("Not found", ErrorCodes.STORE_NOT_FOUND);
@@ -264,7 +259,7 @@ export class LocalPromiseStore implements IPromiseStore {
     strict: boolean,
     headers: Record<string, string> | undefined,
     data: string | undefined,
-  ): Promise<ResolvedPromise | RejectedPromise | CanceledPromise | TimedoutPromise> {
+  ): Promise<DurablePromiseRecord> {
     return this.storage.rmw(id, (promise) => {
       if (!promise) {
         throw new ResonateError("Not found", ErrorCodes.STORE_NOT_FOUND);
@@ -303,7 +298,7 @@ export class LocalPromiseStore implements IPromiseStore {
     });
   }
 
-  async get(id: string): Promise<DurablePromise> {
+  async get(id: string): Promise<DurablePromiseRecord> {
     const promise = await this.storage.rmw(id, (p) => p);
 
     if (!promise) {
@@ -318,7 +313,7 @@ export class LocalPromiseStore implements IPromiseStore {
     state?: string,
     tags?: Record<string, string>,
     limit?: number,
-  ): AsyncGenerator<DurablePromise[], void> {
+  ): AsyncGenerator<DurablePromiseRecord[], void> {
     //  filter the promises returned from all storage
     const regex = new RegExp(id.replaceAll("*", ".*"));
     const states = searchStates(state);
diff --git a/lib/core/stores/remote.ts b/lib/core/stores/remote.ts
index 863a18d..aa49463 100644
--- a/lib/core/stores/remote.ts
+++ b/lib/core/stores/remote.ts
@@ -4,16 +4,7 @@ import { ErrorCodes, ResonateError } from "../errors";
 import { ILogger } from "../logger";
 import { Logger } from "../loggers/logger";
 import { StoreOptions } from "../options";
-import {
-  DurablePromise,
-  PendingPromise,
-  ResolvedPromise,
-  RejectedPromise,
-  CanceledPromise,
-  TimedoutPromise,
-  isDurablePromise,
-  isCompletedPromise,
-} from "../promises/types";
+import { DurablePromiseRecord, isDurablePromiseRecord, isCompletedPromise } from "../promises/types";
 import { Schedule, isSchedule } from "../schedules/types";
 import { IStore, IPromiseStore, IScheduleStore, ILockStore } from "../store";
 import * as utils from "../utils";
@@ -125,7 +116,7 @@ export class RemotePromiseStore implements IPromiseStore {
     data: string | undefined,
     timeout: number,
     tags: Record<string, string> | undefined,
-  ): Promise<PendingPromise | CanceledPromise | ResolvedPromise | RejectedPromise | TimedoutPromise> {
+  ): Promise<DurablePromiseRecord> {
     const reqHeaders: Record<string, string> = {
       Strict: JSON.stringify(strict),
     };
@@ -134,7 +125,7 @@ export class RemotePromiseStore implements IPromiseStore {
       reqHeaders["Idempotency-Key"] = ikey;
     }
 
-    const promise = await this.store.call("promises", isDurablePromise, {
+    const promise = await this.store.call("promises", isDurablePromiseRecord, {
       method: "POST",
       headers: reqHeaders,
       body: JSON.stringify({
@@ -157,7 +148,7 @@ export class RemotePromiseStore implements IPromiseStore {
     strict: boolean,
     headers: Record<string, string> | undefined,
     data: string | undefined,
-  ): Promise<ResolvedPromise | RejectedPromise | CanceledPromise | TimedoutPromise> {
+  ): Promise<DurablePromiseRecord> {
     const reqHeaders: Record<string, string> = {
       Strict: JSON.stringify(strict),
     };
@@ -166,7 +157,7 @@ export class RemotePromiseStore implements IPromiseStore {
       reqHeaders["Idempotency-Key"] = ikey;
     }
 
-    const promise = await this.store.call(`promises/${id}`, isCompletedPromise, {
+    const promise = await this.store.call(`promises/${id}`, isDurablePromiseRecord, {
       method: "PATCH",
       headers: reqHeaders,
       body: JSON.stringify({
@@ -178,6 +169,10 @@ export class RemotePromiseStore implements IPromiseStore {
       }),
     });
 
+    if (!isCompletedPromise(promise)) {
+      throw new ResonateError("Invalid response", ErrorCodes.STORE_PAYLOAD, promise);
+    }
+
     return decode(promise, this.store.encoder);
   }
 
@@ -187,7 +182,7 @@ export class RemotePromiseStore implements IPromiseStore {
     strict: boolean,
     headers: Record<string, string> | undefined,
     data: string | undefined,
-  ): Promise<ResolvedPromise | RejectedPromise | CanceledPromise | TimedoutPromise> {
+  ): Promise<DurablePromiseRecord> {
     const reqHeaders: Record<string, string> = {
       Strict: JSON.stringify(strict),
     };
@@ -196,7 +191,7 @@ export class RemotePromiseStore implements IPromiseStore {
       reqHeaders["Idempotency-Key"] = ikey;
     }
 
-    const promise = await this.store.call(`promises/${id}`, isCompletedPromise, {
+    const promise = await this.store.call(`promises/${id}`, isDurablePromiseRecord, {
       method: "PATCH",
       headers: reqHeaders,
       body: JSON.stringify({
@@ -208,6 +203,10 @@ export class RemotePromiseStore implements IPromiseStore {
       }),
     });
 
+    if (!isCompletedPromise(promise)) {
+      throw new ResonateError("Invalid response", ErrorCodes.STORE_PAYLOAD, promise);
+    }
+
     return decode(promise, this.store.encoder);
   }
 
@@ -217,7 +216,7 @@ export class RemotePromiseStore implements IPromiseStore {
     strict: boolean,
     headers: Record<string, string> | undefined,
     data: string | undefined,
-  ): Promise<ResolvedPromise | RejectedPromise | CanceledPromise | TimedoutPromise> {
+  ): Promise<DurablePromiseRecord> {
     const reqHeaders: Record<string, string> = {
       Strict: JSON.stringify(strict),
     };
@@ -226,7 +225,7 @@ export class RemotePromiseStore implements IPromiseStore {
       reqHeaders["Idempotency-Key"] = ikey;
     }
 
-    const promise = await this.store.call(`promises/${id}`, isCompletedPromise, {
+    const promise = await this.store.call(`promises/${id}`, isDurablePromiseRecord, {
       method: "PATCH",
       headers: reqHeaders,
       body: JSON.stringify({
@@ -238,11 +237,15 @@ export class RemotePromiseStore implements IPromiseStore {
       }),
     });
 
+    if (!isCompletedPromise(promise)) {
+      throw new ResonateError("Invalid response", ErrorCodes.STORE_PAYLOAD, promise);
+    }
+
     return decode(promise, this.store.encoder);
   }
 
-  async get(id: string): Promise<DurablePromise> {
-    const promise = await this.store.call(`promises/${id}`, isDurablePromise, {
+  async get(id: string): Promise<DurablePromiseRecord> {
+    const promise = await this.store.call(`promises/${id}`, isDurablePromiseRecord, {
       method: "GET",
     });
 
@@ -254,7 +257,7 @@ export class RemotePromiseStore implements IPromiseStore {
     state: string | undefined,
     tags: Record<string, string> | undefined,
     limit: number | undefined,
-  ): AsyncGenerator<DurablePromise[], void> {
+  ): AsyncGenerator<DurablePromiseRecord[], void> {
     let cursor: string | null | undefined = undefined;
 
     while (cursor !== null) {
@@ -472,7 +475,7 @@ function encode(value: string, encoder: IEncoder<string, string>): string {
   }
 }
 
-function decode<P extends DurablePromise>(promise: P, encoder: IEncoder<string, string>): P {
+function decode<P extends DurablePromiseRecord>(promise: P, encoder: IEncoder<string, string>): P {
   try {
     if (promise.param?.data) {
       promise.param.data = encoder.decode(promise.param.data);
@@ -490,7 +493,7 @@ function decode<P extends DurablePromise>(promise: P, encoder: IEncoder<string,
 
 // Type guards
 
-function isSearchPromiseResult(obj: unknown): obj is { cursor: string; promises: DurablePromise[] } {
+function isSearchPromiseResult(obj: unknown): obj is { cursor: string; promises: DurablePromiseRecord[] } {
   return (
     typeof obj === "object" &&
     obj !== null &&
@@ -500,7 +503,7 @@ function isSearchPromiseResult(obj: unknown): obj is { cursor: string; promises:
     "promises" in obj &&
     obj.promises !== undefined &&
     Array.isArray(obj.promises) &&
-    obj.promises.every(isDurablePromise)
+    obj.promises.every(isDurablePromiseRecord)
   );
 }