diff --git a/package.json b/package.json
index 85f0c4f..7605486 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@eppo/js-client-sdk-common",
-  "version": "4.3.1-alpha.1",
+  "version": "4.3.1-alpha.2",
   "description": "Eppo SDK for client-side JavaScript applications (base for both web and react native)",
   "main": "dist/index.js",
   "files": [
diff --git a/src/client/eppo-precomputed-client.spec.ts b/src/client/eppo-precomputed-client.spec.ts
index 05e6922..ad24824 100644
--- a/src/client/eppo-precomputed-client.spec.ts
+++ b/src/client/eppo-precomputed-client.spec.ts
@@ -84,7 +84,9 @@ describe('EppoPrecomputedClient E2E test', () => {
       },
     });
     const httpClient = new FetchHttpClient(apiEndpoints, 1000);
-    const precomputedFlagRequestor = new PrecomputedRequestor(httpClient, storage);
+    const precomputedFlagRequestor = new PrecomputedRequestor(httpClient, storage, 'subject-key', {
+      'attribute-key': 'attribute-value',
+    });
     await precomputedFlagRequestor.fetchAndStorePrecomputedFlags();
   });
 
diff --git a/src/client/eppo-precomputed-client.ts b/src/client/eppo-precomputed-client.ts
index d47784e..7e99fed 100644
--- a/src/client/eppo-precomputed-client.ts
+++ b/src/client/eppo-precomputed-client.ts
@@ -102,10 +102,15 @@ export default class EppoPrecomputedClient {
     // todo: Inject the chain of dependencies below
     const apiEndpoints = new ApiEndpoints({
       baseUrl: baseUrl ?? PRECOMPUTED_BASE_URL,
-      queryParams: { apiKey, sdkName, sdkVersion, subjectKey, subjectAttributes },
+      queryParams: { apiKey, sdkName, sdkVersion },
     });
     const httpClient = new FetchHttpClient(apiEndpoints, requestTimeoutMs);
-    const precomputedRequestor = new PrecomputedRequestor(httpClient, this.precomputedFlagStore);
+    const precomputedRequestor = new PrecomputedRequestor(
+      httpClient,
+      this.precomputedFlagStore,
+      subjectKey,
+      subjectAttributes,
+    );
 
     const pollingCallback = async () => {
       if (await this.precomputedFlagStore.isExpired()) {
diff --git a/src/http-client.ts b/src/http-client.ts
index e850912..35f8c97 100644
--- a/src/http-client.ts
+++ b/src/http-client.ts
@@ -6,7 +6,9 @@ import {
   Flag,
   FormatEnum,
   PrecomputedFlag,
+  PrecomputedFlagsPayload,
 } from './interfaces';
+import { Attributes } from './types';
 
 export interface IQueryParams {
   apiKey: string;
@@ -16,7 +18,7 @@ export interface IQueryParams {
 
 export interface IQueryParamsWithSubject extends IQueryParams {
   subjectKey: string;
-  subjectAttributes: Record<string, any>;
+  subjectAttributes: Attributes;
 }
 
 export class HttpRequestError extends Error {
@@ -50,8 +52,11 @@ export interface IPrecomputedFlagsResponse {
 export interface IHttpClient {
   getUniversalFlagConfiguration(): Promise<IUniversalFlagConfigResponse | undefined>;
   getBanditParameters(): Promise<IBanditParametersResponse | undefined>;
-  getPrecomputedFlags(): Promise<IPrecomputedFlagsResponse | undefined>;
+  getPrecomputedFlags(
+    payload: PrecomputedFlagsPayload,
+  ): Promise<IPrecomputedFlagsResponse | undefined>;
   rawGet<T>(url: URL): Promise<T | undefined>;
+  rawPost<T, P>(url: URL, payload: P): Promise<T | undefined>;
 }
 
 export default class FetchHttpClient implements IHttpClient {
@@ -67,9 +72,11 @@ export default class FetchHttpClient implements IHttpClient {
     return await this.rawGet<IBanditParametersResponse>(url);
   }
 
-  async getPrecomputedFlags(): Promise<IPrecomputedFlagsResponse | undefined> {
+  async getPrecomputedFlags(
+    payload: PrecomputedFlagsPayload,
+  ): Promise<IPrecomputedFlagsResponse | undefined> {
     const url = this.apiEndpoints.precomputedFlagsEndpoint();
-    return await this.rawGet<IPrecomputedFlagsResponse>(url);
+    return await this.rawPost<IPrecomputedFlagsResponse, PrecomputedFlagsPayload>(url, payload);
   }
 
   async rawGet<T>(url: URL): Promise<T | undefined> {
@@ -97,4 +104,37 @@ export default class FetchHttpClient implements IHttpClient {
       throw new HttpRequestError('Network error', 0, error);
     }
   }
+
+  async rawPost<T, P>(url: URL, payload: P): Promise<T | undefined> {
+    try {
+      const controller = new AbortController();
+      const signal = controller.signal;
+      const timeoutId = setTimeout(() => controller.abort(), this.timeout);
+
+      const response = await fetch(url.toString(), {
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify(payload),
+        signal,
+      });
+
+      clearTimeout(timeoutId);
+
+      if (!response?.ok) {
+        const errorBody = await response.text();
+        throw new HttpRequestError(errorBody || 'Failed to post data', response?.status);
+      }
+      return await response.json();
+    } catch (error: any) {
+      if (error.name === 'AbortError') {
+        throw new HttpRequestError('Request timed out', 408, error);
+      } else if (error instanceof HttpRequestError) {
+        throw error;
+      }
+
+      throw new HttpRequestError('Network error', 0, error);
+    }
+  }
 }
diff --git a/src/interfaces.ts b/src/interfaces.ts
index ecbe0d8..3afcb21 100644
--- a/src/interfaces.ts
+++ b/src/interfaces.ts
@@ -1,4 +1,5 @@
 import { Rule } from './rules';
+import { Attributes } from './types';
 
 export enum VariationType {
   STRING = 'STRING',
@@ -155,3 +156,8 @@ export interface PrecomputedFlagsDetails {
   precomputedFlagsPublishedAt: string;
   precomputedFlagsEnvironment: Environment;
 }
+
+export interface PrecomputedFlagsPayload {
+  subject_key: string;
+  subject_attributes: Attributes;
+}
diff --git a/src/precomputed-requestor.spec.ts b/src/precomputed-requestor.spec.ts
index c89d368..1f258a7 100644
--- a/src/precomputed-requestor.spec.ts
+++ b/src/precomputed-requestor.spec.ts
@@ -3,7 +3,7 @@ import { IConfigurationStore } from './configuration-store/configuration-store';
 import { MemoryOnlyConfigurationStore } from './configuration-store/memory.store';
 import FetchHttpClient, { IHttpClient } from './http-client';
 import { PrecomputedFlag } from './interfaces';
-import ConfigurationRequestor from './precomputed-requestor';
+import PrecomputedFlagRequestor from './precomputed-requestor';
 
 const MOCK_PRECOMPUTED_RESPONSE = {
   flags: {
@@ -34,7 +34,7 @@ const MOCK_PRECOMPUTED_RESPONSE = {
 describe('PrecomputedRequestor', () => {
   let precomputedFlagStore: IConfigurationStore<PrecomputedFlag>;
   let httpClient: IHttpClient;
-  let configurationRequestor: ConfigurationRequestor;
+  let precomputedFlagRequestor: PrecomputedFlagRequestor;
   let fetchSpy: jest.Mock;
 
   beforeEach(() => {
@@ -48,7 +48,14 @@ describe('PrecomputedRequestor', () => {
     });
     httpClient = new FetchHttpClient(apiEndpoints, 1000);
     precomputedFlagStore = new MemoryOnlyConfigurationStore<PrecomputedFlag>();
-    configurationRequestor = new ConfigurationRequestor(httpClient, precomputedFlagStore);
+    precomputedFlagRequestor = new PrecomputedFlagRequestor(
+      httpClient,
+      precomputedFlagStore,
+      'subject-key',
+      {
+        'attribute-key': 'attribute-value',
+      },
+    );
 
     fetchSpy = jest.fn(() => {
       return Promise.resolve({
@@ -70,7 +77,7 @@ describe('PrecomputedRequestor', () => {
 
   describe('Precomputed flags', () => {
     it('Fetches and stores precomputed flag configuration', async () => {
-      await configurationRequestor.fetchAndStorePrecomputedFlags();
+      await precomputedFlagRequestor.fetchAndStorePrecomputedFlags();
 
       expect(fetchSpy).toHaveBeenCalledTimes(1);
 
@@ -110,7 +117,7 @@ describe('PrecomputedRequestor', () => {
         }),
       );
 
-      await configurationRequestor.fetchAndStorePrecomputedFlags();
+      await precomputedFlagRequestor.fetchAndStorePrecomputedFlags();
 
       expect(fetchSpy).toHaveBeenCalledTimes(1);
       expect(precomputedFlagStore.getKeys().length).toBe(0);
diff --git a/src/precomputed-requestor.ts b/src/precomputed-requestor.ts
index d9ed45c..7e349be 100644
--- a/src/precomputed-requestor.ts
+++ b/src/precomputed-requestor.ts
@@ -2,16 +2,23 @@ import { IConfigurationStore } from './configuration-store/configuration-store';
 import { hydrateConfigurationStore } from './configuration-store/configuration-store-utils';
 import { IHttpClient } from './http-client';
 import { PrecomputedFlag } from './interfaces';
+import { Attributes } from './types';
 
 // Requests AND stores precomputed flags, reuses the configuration store
 export default class PrecomputedFlagRequestor {
   constructor(
     private readonly httpClient: IHttpClient,
     private readonly precomputedFlagStore: IConfigurationStore<PrecomputedFlag>,
+    private readonly subjectKey: string,
+    private readonly subjectAttributes: Attributes,
   ) {}
 
   async fetchAndStorePrecomputedFlags(): Promise<void> {
-    const precomputedResponse = await this.httpClient.getPrecomputedFlags();
+    const precomputedResponse = await this.httpClient.getPrecomputedFlags({
+      subject_key: this.subjectKey,
+      subject_attributes: this.subjectAttributes,
+    });
+
     if (!precomputedResponse?.flags) {
       return;
     }