diff --git a/backend/.eslintrc.js b/backend/.eslintrc.js
index 798bef1e6..78ac9e41e 100644
--- a/backend/.eslintrc.js
+++ b/backend/.eslintrc.js
@@ -27,7 +27,8 @@ module.exports = {
     },
   },
   rules: {
-    'no-console': ['error'],
+    'no-console': 'error',
+    camelcase: ['error', { allow: ['FederationClient_*'] }],
     'no-debugger': 'error',
     'prettier/prettier': [
       'error',
@@ -184,6 +185,7 @@ module.exports = {
         tsconfigRootDir: __dirname,
         project: ['./tsconfig.json', '**/tsconfig.json'],
         // this is to properly reference the referenced project database without requirement of compiling it
+        // eslint-disable-next-line camelcase
         EXPERIMENTAL_useSourceOfProjectReferenceRedirect: true,
       },
     },
diff --git a/backend/src/federation/client/FederationClient.ts b/backend/src/federation/client/FederationClient.ts
new file mode 100644
index 000000000..db1e5e3b2
--- /dev/null
+++ b/backend/src/federation/client/FederationClient.ts
@@ -0,0 +1,55 @@
+import { FederatedCommunity as DbFederatedCommunity } from '@entity/FederatedCommunity'
+
+import { ApiVersionType } from '@/federation/enum/apiVersionType'
+
+import { FederationClient_1_0 } from './FederationClient_1_0'
+import { FederationClient_1_1 } from './FederationClient_1_1'
+
+type FederationClientType = FederationClient_1_0 | FederationClient_1_1
+
+interface ClientInstance {
+  id: number
+  // eslint-disable-next-line no-use-before-define
+  client: FederationClientType
+}
+
+// eslint-disable-next-line @typescript-eslint/no-extraneous-class
+export class FederationClient {
+  private static instanceArray: ClientInstance[] = []
+
+  /**
+   * The Singleton's constructor should always be private to prevent direct
+   * construction calls with the `new` operator.
+   */
+  // eslint-disable-next-line no-useless-constructor, @typescript-eslint/no-empty-function
+  private constructor() {}
+
+  private static createFederationClient = (dbCom: DbFederatedCommunity) => {
+    switch (dbCom.apiVersion) {
+      case ApiVersionType.V1_0:
+        return new FederationClient_1_0(dbCom)
+      case ApiVersionType.V1_1:
+        return new FederationClient_1_1(dbCom)
+      default:
+        return null
+    }
+  }
+
+  /**
+   * The static method that controls the access to the singleton instance.
+   *
+   * This implementation let you subclass the Singleton class while keeping
+   * just one instance of each subclass around.
+   */
+  public static getInstance(dbCom: DbFederatedCommunity): FederationClientType | null {
+    const instance = FederationClient.instanceArray.find((instance) => instance.id === dbCom.id)
+    if (instance) {
+      return instance.client
+    }
+    const client = FederationClient.createFederationClient(dbCom)
+    if (client) {
+      FederationClient.instanceArray.push({ id: dbCom.id, client } as ClientInstance)
+    }
+    return client
+  }
+}
diff --git a/backend/src/federation/client/FederationClient_1_0.ts b/backend/src/federation/client/FederationClient_1_0.ts
new file mode 100644
index 000000000..c8e878ded
--- /dev/null
+++ b/backend/src/federation/client/FederationClient_1_0.ts
@@ -0,0 +1,48 @@
+import { FederatedCommunity as DbFederatedCommunity } from '@entity/FederatedCommunity'
+import { GraphQLClient } from 'graphql-request'
+
+import { getPublicKey } from '@/federation/query/getPublicKey'
+import { backendLogger as logger } from '@/server/logger'
+
+export class FederationClient_1_0 {
+  dbCom: DbFederatedCommunity
+  endpoint: string
+  client: GraphQLClient
+
+  constructor(dbCom: DbFederatedCommunity) {
+    this.dbCom = dbCom
+    this.endpoint = `${dbCom.endPoint.endsWith('/') ? dbCom.endPoint : dbCom.endPoint + '/'}${
+      dbCom.apiVersion
+    }/`
+    this.client = new GraphQLClient(this.endpoint, {
+      method: 'GET',
+      jsonSerializer: {
+        parse: JSON.parse,
+        stringify: JSON.stringify,
+      },
+    })
+  }
+
+  getPublicKey = async (): Promise<string | undefined> => {
+    logger.info('Federation: getPublicKey from endpoint', this.endpoint)
+    try {
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+      const { data } = await this.client.rawRequest(getPublicKey, {})
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
+      if (!data?.getPublicKey?.publicKey) {
+        logger.warn('Federation: getPublicKey without response data from endpoint', this.endpoint)
+        return
+      }
+      logger.info(
+        'Federation: getPublicKey successful from endpoint',
+        this.endpoint,
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
+        data.getPublicKey.publicKey,
+      )
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-return, @typescript-eslint/no-unsafe-member-access
+      return data.getPublicKey.publicKey
+    } catch (err) {
+      logger.warn('Federation: getPublicKey failed for endpoint', this.endpoint)
+    }
+  }
+}
diff --git a/backend/src/federation/client/FederationClient_1_1.ts b/backend/src/federation/client/FederationClient_1_1.ts
new file mode 100644
index 000000000..27679b423
--- /dev/null
+++ b/backend/src/federation/client/FederationClient_1_1.ts
@@ -0,0 +1,3 @@
+import { FederationClient_1_0 } from './FederationClient_1_0'
+
+export class FederationClient_1_1 extends FederationClient_1_0 {}
diff --git a/backend/src/federation/validateCommunities.test.ts b/backend/src/federation/validateCommunities.test.ts
index 0da5914bd..16f396260 100644
--- a/backend/src/federation/validateCommunities.test.ts
+++ b/backend/src/federation/validateCommunities.test.ts
@@ -83,6 +83,7 @@ describe('validate Communities', () => {
           .into(DbFederatedCommunity)
           .values(variables1)
           .orUpdate({
+            // eslint-disable-next-line camelcase
             conflict_target: ['id', 'publicKey', 'apiVersion'],
             overwrite: ['end_point', 'last_announced_at'],
           })
@@ -134,6 +135,7 @@ describe('validate Communities', () => {
           .into(DbFederatedCommunity)
           .values(variables2)
           .orUpdate({
+            // eslint-disable-next-line camelcase
             conflict_target: ['id', 'publicKey', 'apiVersion'],
             overwrite: ['end_point', 'last_announced_at'],
           })
@@ -172,6 +174,7 @@ describe('validate Communities', () => {
           .into(DbFederatedCommunity)
           .values(variables3)
           .orUpdate({
+            // eslint-disable-next-line camelcase
             conflict_target: ['id', 'publicKey', 'apiVersion'],
             overwrite: ['end_point', 'last_announced_at'],
           })