diff --git a/README.md b/README.md
index 2e48b44..dfe2460 100644
--- a/README.md
+++ b/README.md
@@ -85,6 +85,137 @@ for try await chunk in stream {
 }
 ```
 
+### [Message Batches (beta)](https://docs.anthropic.com/en/docs/build-with-claude/message-batches)
+
+The Message Batches API is a powerful, cost-effective way to asynchronously process large volumes of [Messages](https://docs.anthropic.com/en/api/messages) requests. This approach is well-suited to tasks that do not require immediate responses, reducing costs by 50% while increasing throughput.
+
+This is especially useful for bulk operations that don’t require immediate results.
+
+Here's an example of how to process many messages with the Message Batches API:
+
+```swift
+let anthropic = Anthropic(apiKey: "YOUR_OWN_API_KEY")
+
+let messages = [
+    Message(role: .user, content: [.text("Write a haiku about robots.")]),
+    Message(role: .user, content: [.text("Write a haiku about robots. Skip the preamble; go straight into the poem.")]),
+    Message(role: .user, content: [.text("Who is the best basketball player of all time?")]),
+    Message(role: .user, content: [.text("Who is the best basketball player of all time? Yes, there are differing opinions, but if you absolutely had to pick one player, who would it be?")])
+    // ....
+]
+
+let batch = MessageBatch(
+    customId: "my-first-batch-request",
+    parameter: .init(
+        messages: messages,
+        maxTokens: 1024
+    )
+)
+
+let response = try await anthropic.messageBatches.createBatches(batches: [batch])
+```
+
+### [Admin API](https://docs.anthropic.com/en/docs/administration/administration-api)
+
+This library also supports an Admin API for managing workspaces and organization members.
+
+#### [Organization Members API](https://docs.anthropic.com/en/docs/administration/administration-api#organization-members)
+
+- **Get Organization Member**: Retrieve details about a specific organization member.
+- **List Organization Members**: List organization members.
+- **Remove Organization Member**: Remove a member from the organization.
+- **Update Organization Member**: Update the role or details of an existing organization member.
+
+Example of updating an organization member:
+
+```swift
+let admin = AnthropicAdmin(adminAPIKey: "YOUR_OWN_ADMIN_API_KEY")
+try await admin.organizationMembers.get(userId: "user_01WCz1FkmYMm4gnmykNKUu3Q")
+```
+
+#### [Organization Invites API](https://docs.anthropic.com/en/docs/administration/administration-api#organization-invites)
+
+- **Get Organization Invites**: Retrieve details about a specific organization invitation.
+- **List Organization Invites**: List organization invitations.
+- **Remove Organization Invites**: Remove a invitation from the organization.
+- **Create Organization Invites**: Create a new organization invitation.
+
+Example of updating an organization invitation:
+
+```swift
+let admin = AnthropicAdmin(adminAPIKey: "YOUR_OWN_ADMIN_API_KEY")
+try await admin.organizationInvites.list()
+```
+
+#### [Workspaces API](https://docs.anthropic.com/en/docs/administration/administration-api#workspaces)
+
+- **Get Workspace**: Retrieve details about a specific workspace.
+- **List Workspaces**: List workspaces.
+- **Create Workspace**: Create a new workspace.
+- **Archive Workspace**: Archive an existing workspace.
+- **Update Workspace**: Update the details of an existing workspace.
+
+Example of creating a workspace:
+
+```swift
+let admin = AnthropicAdmin(adminAPIKey: "YOUR_OWN_ADMIN_API_KEY")
+try await admin.workspaces.get(workspaceId: "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+```
+
+#### [Workspace Members API](https://docs.anthropic.com/en/docs/administration/administration-api#workspace-members)
+
+- **Get Workspace Member**: Retrieve details about a specific workspace member.
+- **List Workspace Members**: List workspace members.
+- **Create Workspace Member**: Add a new member for the workspace.
+- **Remove Workspace Member**: Remove a member from the workspace.
+- **Update Workspace Member**: Update the role or details of an existing workspace member.
+
+Example of updating an workspace member:
+
+```swift
+let admin = AnthropicAdmin(adminAPIKey: "YOUR_OWN_ADMIN_API_KEY")
+try await admin.workspaceMembers.get(userId: "user_01WCz1FkmYMm4gnmykNKUu3Q")
+```
+
+#### [API Keys API](https://docs.anthropic.com/en/docs/administration/administration-api#api-keys)
+
+- **Get Organization Member**: Retrieve details about a specific API key.
+- **List Organization Members**: List API keys.
+- **Update Organization Member**: Update the status or name of an existing API key.
+
+Example of updating an organization member:
+
+```swift
+let admin = AnthropicAdmin(adminAPIKey: "YOUR_OWN_ADMIN_API_KEY")
+try await admin.apiKeys.get(apiKeyId: "apikey_01Rj2N8SVvo6BePZj99NhmiT")
+```
+
+### [Token Counting](https://docs.anthropic.com/en/docs/build-with-claude/token-counting)
+
+Token counting enables you to determine the number of tokens in a message before sending it to Claude, helping you make informed decisions about your prompts and usage. With token counting, you can
+
+- Proactively manage rate limits and costs
+- Make smart model routing decisions
+- Optimize prompts to be a specific length
+
+```swift
+let anthropic = Anthropic(apiKey: "YOUR_OWN_API_KEY")
+
+let message = Message(role: .user, content: [.text("Find flights from San Francisco to a place with warmer weather.")])
+let response = try await anthropic.countTokens.countTokens(
+    [message],
+    maxTokens: 1024,
+    tools: [
+        .computer(.init(name: "my_computer", displayWidthPx: 1024, displayHeightPx: 768, displayNumber: 1),
+        .bash(.init(name: "bash"))
+    ]
+)
+```
+
+The token counting endpoint accepts the same structured list of inputs for creating a message, including support for system prompts, tools, images, and PDFs. The response contains the total number of input tokens.
+
+## Supporting Features
+
 ### [Tool Use](https://docs.anthropic.com/en/docs/build-with-claude/tool-use)
 
 Claude is capable of interacting with external client-side tools and functions, allowing you to equip Claude with your own custom tools to perform a wider variety of tasks.
@@ -134,36 +265,6 @@ let response = try await anthropic.messages.createMessage(
 )
 ```
 
-### [Message Batches (beta)](https://docs.anthropic.com/en/docs/build-with-claude/message-batches)
-
-The Message Batches API is a powerful, cost-effective way to asynchronously process large volumes of [Messages](https://docs.anthropic.com/en/api/messages) requests. This approach is well-suited to tasks that do not require immediate responses, reducing costs by 50% while increasing throughput.
-
-This is especially useful for bulk operations that don’t require immediate results.
-
-Here's an example of how to process many messages with the Message Bathches API:
-
-```swift
-let anthropic = Anthropic(apiKey: "YOUR_OWN_API_KEY")
-
-let messages = [
-    Message(role: .user, content: [.text("Write a haiku about robots.")]),
-    Message(role: .user, content: [.text("Write a haiku about robots. Skip the preamble; go straight into the poem.")]),
-    Message(role: .user, content: [.text("Who is the best basketball player of all time?")]),
-    Message(role: .user, content: [.text("Who is the best basketball player of all time? Yes, there are differing opinions, but if you absolutely had to pick one player, who would it be?")])
-    // ....
-]
-
-let batch = MessageBatch(
-    customId: "my-first-batch-request",
-    parameter: .init(
-        messages: messages,
-        maxTokens: 1024
-    )
-)
-
-let response = try await anthropic.messageBatches.createBatches(batches: [batch])
-```
-
 ### [Computer Use (beta)](https://docs.anthropic.com/en/docs/build-with-claude/computer-use#computer-tool)
 
 The upgraded Claude 3.5 Sonnet model is capable of interacting with tools that can manipulate a computer desktop environment.
@@ -184,30 +285,6 @@ let response = try await anthropic.messages.createMessage(
 )
 ```
 
-### [Token Counting](https://docs.anthropic.com/en/docs/build-with-claude/token-counting)
-
-Token counting enables you to determine the number of tokens in a message before sending it to Claude, helping you make informed decisions about your prompts and usage. With token counting, you can
-
-- Proactively manage rate limits and costs
-- Make smart model routing decisions
-- Optimize prompts to be a specific length
-
-```swift
-let anthropic = Anthropic(apiKey: "YOUR_OWN_API_KEY")
-
-let message = Message(role: .user, content: [.text("Find flights from San Francisco to a place with warmer weather.")])
-let response = try await anthropic.countTokens.countTokens(
-    [message],
-    maxTokens: 1024,
-    tools: [
-        .computer(.init(name: "my_computer", displayWidthPx: 1024, displayHeightPx: 768, displayNumber: 1),
-        .bash(.init(name: "bash"))
-    ]
-)
-```
-
-The token counting endpoint accepts the same structured list of inputs for creating a message, including support for system prompts, tools, images, and PDFs. The response contains the total number of input tokens.
-
 ## Extensions
 
 By introducing an extension Swift package, it is possible to access the Anthropic Claude API through AWS Bedrock and Vertex AI. The supported services are as follows:
diff --git a/Sources/AnthropicSwiftSDK-TestUtils/HTTPMock.swift b/Sources/AnthropicSwiftSDK-TestUtils/HTTPMock.swift
index 6044bfa..225a885 100644
--- a/Sources/AnthropicSwiftSDK-TestUtils/HTTPMock.swift
+++ b/Sources/AnthropicSwiftSDK-TestUtils/HTTPMock.swift
@@ -45,6 +45,7 @@ public class HTTPMock: URLProtocol {
                 client?.urlProtocol(self, didLoad: getBasicJSONStringData())
             case .request(_, nil), .requestHeader(_, nil):
                 client?.urlProtocol(self, didReceive: succeedResponse, cacheStoragePolicy: .notAllowed)
+                client?.urlProtocol(self, didLoad: getBasicJSONStringData())
             case .request(_, let jsonString), .requestHeader(_, let jsonString):
                 client?.urlProtocol(self, didReceive: succeedResponse, cacheStoragePolicy: .notAllowed)
                 guard let jsonString, let data = jsonString.data(using: .utf8) else {
diff --git a/Sources/AnthropicSwiftSDK-TestUtils/MessagesRequest+Extensions.swift b/Sources/AnthropicSwiftSDK-TestUtils/MessagesRequest+Extensions.swift
index 7744d4e..5db67cd 100644
--- a/Sources/AnthropicSwiftSDK-TestUtils/MessagesRequest+Extensions.swift
+++ b/Sources/AnthropicSwiftSDK-TestUtils/MessagesRequest+Extensions.swift
@@ -11,7 +11,7 @@ import AnthropicSwiftSDK
 public struct NopRequest: Request {
     public let method: HttpMethod
     public let path: String
-    public let queries: [String : any CustomStringConvertible]? = nil
+    public let queries: [String: any CustomStringConvertible]? = nil
     public let body: Never? = nil
 
     public init(
diff --git a/Sources/AnthropicSwiftSDK/API/Admin/APIKeys.swift b/Sources/AnthropicSwiftSDK/API/Admin/APIKeys.swift
new file mode 100644
index 0000000..aae31b7
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/API/Admin/APIKeys.swift
@@ -0,0 +1,106 @@
+//
+//  APIKeys.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+import Foundation
+
+public struct APIKeys {
+    private let apiKey: String
+    private let session: URLSession
+
+    init(adminAPIKey: String, session: URLSession) {
+        self.apiKey = adminAPIKey
+        self.session = session
+    }
+
+    public func get(apiKeyId: String) async throws -> APIKeyResponse {
+        try await get(
+            apiKeyId: apiKeyId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func get(
+        apiKeyId: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> APIKeyResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: GetAPIKeyRequest(apiKeyId: apiKeyId))
+    }
+
+    public func list(
+        limit: Int = 20,
+        beforeId: String? = nil,
+        afterId: String? = nil,
+        status: APIKeyStatus? = nil,
+        workspaceId: String? = nil,
+        createdByUserId: String? = nil
+    ) async throws -> ObjectListResponse<APIKeyResponse> {
+        fatalError("not implemented")
+    }
+
+    public func list(
+        limit: Int = 20,
+        beforeId: String? = nil,
+        afterId: String? = nil,
+        status: APIKeyStatus? = nil,
+        workspaceId: String? = nil,
+        createdByUserId: String? = nil,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> ObjectListResponse<APIKeyResponse> {
+        try await list(
+            session: session,
+            type: .apiKey,
+            limit: limit,
+            beforeId: beforeId,
+            afterId: afterId,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+    }
+
+    public func update(apiKeyId: String, name: String, status: APIKeyStatus? = nil) async throws -> APIKeyResponse {
+        try await update(
+            apiKeyId: apiKeyId,
+            name: name,
+            status: status,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func update(
+        apiKeyId: String,
+        name: String,
+        status: APIKeyStatus? = nil,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> APIKeyResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(
+            request: UpdateAPIKeyRequest(
+                body: .init(name: name, status: status),
+                apiKeyId: apiKeyId
+            )
+        )
+    }
+}
+
+extension APIKeys: ObjectListable {
+    typealias Object = APIKeyResponse
+}
diff --git a/Sources/AnthropicSwiftSDK/API/Admin/Admin.swift b/Sources/AnthropicSwiftSDK/API/Admin/Admin.swift
new file mode 100644
index 0000000..024e539
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/API/Admin/Admin.swift
@@ -0,0 +1,23 @@
+//
+//  Admin.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+import Foundation
+
+public struct Admin {
+    public let organizationMembers: OrganizationMembers
+    public let organizationInvites: OrganizationInvites
+    public let workspaces: Workspaces
+    public let workspaceMembers: WorkspaceMembers
+    public let apiKeys: APIKeys
+
+    public init(adminAPIKey apiKey: String, session: URLSession = .shared) {
+        self.organizationMembers = OrganizationMembers(adminAPIKey: apiKey, session: session)
+        self.organizationInvites = OrganizationInvites(adminAPIKey: apiKey, session: session)
+        self.workspaces = Workspaces(adminAPIKey: apiKey, session: session)
+        self.workspaceMembers = WorkspaceMembers(adminAPIKey: apiKey, session: session)
+        self.apiKeys = APIKeys(adminAPIKey: apiKey, session: session)
+    }
+}
diff --git a/Sources/AnthropicSwiftSDK/API/Admin/OrganizationInvites.swift b/Sources/AnthropicSwiftSDK/API/Admin/OrganizationInvites.swift
new file mode 100644
index 0000000..6f42a0e
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/API/Admin/OrganizationInvites.swift
@@ -0,0 +1,122 @@
+//
+//  OrganizationInvites.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+import Foundation
+
+public struct OrganizationInvites {
+    private let apiKey: String
+    private let session: URLSession
+
+    init(adminAPIKey: String, session: URLSession) {
+        self.apiKey = adminAPIKey
+        self.session = session
+    }
+
+    public func get(invitationId: String) async throws -> InvitationResponse {
+        try await get(
+            invitationId: invitationId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func get(
+        invitationId: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> InvitationResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: GetOrganizationInviteRequest(invitationId: invitationId))
+    }
+
+    public func list(limit: Int = 20, beforeId: String? = nil, afterId: String? = nil) async throws -> ObjectListResponse<InvitationResponse> {
+        try await list(
+            limit: limit,
+            beforeId: beforeId,
+            afterId: afterId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func list(
+        limit: Int = 20,
+        beforeId: String? = nil,
+        afterId: String? = nil,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> ObjectListResponse<InvitationResponse> {
+        try await list(
+            session: session,
+            type: .organizationInvite,
+            limit: limit,
+            beforeId: beforeId,
+            afterId: afterId,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+    }
+
+    public func send(invitation: Invitation) async throws -> InvitationResponse {
+        try await send(
+            invitation: invitation,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func send(
+        invitation: Invitation,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> InvitationResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(
+            request: CreateOrganizationInviteRequest(
+                body: .init(
+                    email: invitation.email,
+                    role: invitation.role
+                )
+            )
+        )
+    }
+
+    public func remove(invitationId: String) async throws -> InvitationRemoveResponse {
+        try await remove(
+            invitationId: invitationId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func remove(
+        invitationId: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> InvitationRemoveResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: DeleteOrganizationInviteRequest(invitationId: invitationId))
+    }
+}
+
+extension OrganizationInvites: ObjectListable {
+    typealias Object = InvitationResponse
+}
diff --git a/Sources/AnthropicSwiftSDK/API/Admin/OrganizationMembers.swift b/Sources/AnthropicSwiftSDK/API/Admin/OrganizationMembers.swift
new file mode 100644
index 0000000..03be294
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/API/Admin/OrganizationMembers.swift
@@ -0,0 +1,117 @@
+//
+//  OrganizationMembers.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+import Foundation
+
+public struct OrganizationMembers {
+    let apiKey: String
+    let session: URLSession
+
+    init(adminAPIKey apiKey: String, session: URLSession) {
+        self.apiKey = apiKey
+        self.session = session
+    }
+
+    public func get(userId: String) async throws -> OrganizationMemberResponse {
+        try await get(
+            userId: userId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func get(
+        userId: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> OrganizationMemberResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: GetOrganizationMemberRequest(userId: userId))
+    }
+
+    public func list(limit: Int = 20, beforeId: String? = nil, afterId: String? = nil) async throws -> ObjectListResponse<OrganizationMemberResponse> {
+        try await list(
+            limit: limit,
+            beforeId: beforeId,
+            afterId: afterId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func list(
+        limit: Int = 20,
+        beforeId: String? = nil,
+        afterId: String? = nil,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> ObjectListResponse<OrganizationMemberResponse> {
+        try await list(
+            session: session,
+            type: .organizationMember,
+            limit: limit,
+            beforeId: beforeId,
+            afterId: afterId,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+    }
+
+    public func update(userId: String, role: OrganizationRole) async throws -> OrganizationMemberResponse {
+        try await update(
+            userId: userId,
+            role: role,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func update(
+        userId: String,
+        role: OrganizationRole,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> OrganizationMemberResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: UpdateOrganizationMemberRequest(body: .init(role: role), userId: userId))
+    }
+
+    public func remove(userId: String) async throws -> OrganizationMemberRemoveResponse {
+        try await remove(
+            userId: userId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func remove(
+        userId: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> OrganizationMemberRemoveResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: RemoveOrganizationMemberRequest(userId: userId))
+    }
+}
+
+extension OrganizationMembers: ObjectListable {
+    typealias Object = OrganizationMemberResponse
+}
diff --git a/Sources/AnthropicSwiftSDK/API/Admin/WorkspaceMembers.swift b/Sources/AnthropicSwiftSDK/API/Admin/WorkspaceMembers.swift
new file mode 100644
index 0000000..ef1ab46
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/API/Admin/WorkspaceMembers.swift
@@ -0,0 +1,154 @@
+//
+//  WorkspaceMembers.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+import Foundation
+
+public struct WorkspaceMembers {
+    private let apiKey: String
+    private let session: URLSession
+
+    init(adminAPIKey: String, session: URLSession) {
+        self.apiKey = adminAPIKey
+        self.session = session
+    }
+
+    public func get(userId: String, workspaceId: String) async throws -> WorkspaceMemberResponse {
+        try await get(
+            userId: userId,
+            workspaceId: workspaceId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func get(
+        userId: String,
+        workspaceId: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> WorkspaceMemberResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: GetWorkspaceMemberRequest(workspaceId: workspaceId, userId: userId))
+    }
+
+    public func list(workspaceId: String, limit: Int = 20, beforeId: String? = nil, afterId: String? = nil) async throws -> ObjectListResponse<WorkspaceMemberResponse> {
+        try await list(
+            workspaceId: workspaceId,
+            limit: limit,
+            beforeId: beforeId,
+            afterId: afterId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func list(
+        workspaceId: String,
+        limit: Int = 20,
+        beforeId: String? = nil,
+        afterId: String? = nil,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> ObjectListResponse<WorkspaceMemberResponse> {
+        try await list(
+            session: session,
+            type: .workspaceMember(workspaceId: workspaceId),
+            limit: limit,
+            beforeId: beforeId,
+            afterId: afterId,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+    }
+
+    public func add(registration: Registration, workspaceId: String) async throws -> WorkspaceMemberResponse {
+        try await add(
+            registration: registration,
+            workspaceId: workspaceId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func add(
+        registration: Registration,
+        workspaceId: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> WorkspaceMemberResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(
+            request: CreateWorkspaceMemberRequest(
+                body: registration,
+                workspaceId: workspaceId
+            )
+        )
+    }
+
+    public func update(userId: String, workspaceId: String, role: WorkspaceRole) async throws -> WorkspaceMemberResponse {
+        try await update(
+            userId: userId,
+            workspaceId: workspaceId,
+            role: role,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func update(
+        userId: String,
+        workspaceId: String,
+        role: WorkspaceRole,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> WorkspaceMemberResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: UpdateWorkspaceMemberRequest(body: .init(role: role), userId: userId, workspaceId: workspaceId))
+    }
+
+    public func remove(userId: String, workspaceId: String) async throws -> WorkspaceMemberRemoveResponse {
+        try await remove(
+            userId: userId,
+            workspaceId: workspaceId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func remove(
+        userId: String,
+        workspaceId: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> WorkspaceMemberRemoveResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: DeleteWorkspaceMemberRequest(userId: userId, workspaceId: workspaceId))
+    }
+}
+
+extension WorkspaceMembers: ObjectListable {
+    typealias Object = WorkspaceMemberResponse
+}
diff --git a/Sources/AnthropicSwiftSDK/API/Admin/Workspaces.swift b/Sources/AnthropicSwiftSDK/API/Admin/Workspaces.swift
new file mode 100644
index 0000000..0e20a21
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/API/Admin/Workspaces.swift
@@ -0,0 +1,151 @@
+//
+//  Workspaces.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+import Foundation
+
+public struct Workspaces {
+    private let apiKey: String
+    private let session: URLSession
+
+    init(adminAPIKey: String, session: URLSession) {
+        self.apiKey = adminAPIKey
+        self.session = session
+    }
+
+    public func get(workspaceId: String) async throws -> WorkspaceResponse {
+        try await get(
+            workspaceId: workspaceId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func get(
+        workspaceId: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> WorkspaceResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: GetWorkspaceRequest(workspaceId: workspaceId))
+    }
+
+    public func list(limit: Int = 20, includeArchive: Bool = false, beforeId: String? = nil, afterId: String? = nil) async throws -> ObjectListResponse<WorkspaceResponse> {
+        try await list(
+            limit: limit,
+            includeArchive: includeArchive,
+            beforeId: beforeId,
+            afterId: afterId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func list(
+        limit: Int = 20,
+        includeArchive: Bool = false,
+        beforeId: String? = nil,
+        afterId: String? = nil,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> ObjectListResponse<WorkspaceResponse> {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        let queries: [String: CustomStringConvertible] = {
+            var queries: [String: CustomStringConvertible] = [ListObjectRequest.Parameter.limit.rawValue: limit]
+            queries["include_archived"] = includeArchive
+            if let beforeId {
+                queries[ListObjectRequest.Parameter.beforeId.rawValue] = beforeId
+            }
+            if let afterId {
+                queries[ListObjectRequest.Parameter.afterId.rawValue] = afterId
+            }
+            return queries
+        }()
+
+        return try await client.send(request: ListObjectRequest(queries: queries, type: .workspace))
+    }
+
+    public func update(name: String, workspaceId: String) async throws -> WorkspaceResponse {
+        try await update(
+            name: name,
+            workspaceId: workspaceId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func update(
+        name: String,
+        workspaceId: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> WorkspaceResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: UpdateWorkspaceRequest(body: .init(name: name), workspaceId: workspaceId))
+    }
+
+    public func create(name: String) async throws -> WorkspaceResponse {
+        try await create(
+            name: name,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func create(
+        name: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> WorkspaceResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: CreateWorkspaceRequest(body: .init(name: name)))
+    }
+
+    public func archive(_ workspaceId: String) async throws -> WorkspaceResponse {
+        try await archive(
+            workspaceId,
+            anthropicHeaderProvider: DefaultAnthropicHeaderProvider(),
+            authenticationHeaderProvider: APIKeyAuthenticationHeaderProvider(apiKey: apiKey)
+        )
+    }
+
+    public func archive(
+        _ workspaceId: String,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> WorkspaceResponse {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        return try await client.send(request: ArchiveWorkspaceRequest(workspaceId: workspaceId))
+    }
+}
+
+extension Workspaces: ObjectListable {
+    typealias Object = WorkspaceResponse
+}
diff --git a/Sources/AnthropicSwiftSDK/CountTokens.swift b/Sources/AnthropicSwiftSDK/API/CountTokens.swift
similarity index 86%
rename from Sources/AnthropicSwiftSDK/CountTokens.swift
rename to Sources/AnthropicSwiftSDK/API/CountTokens.swift
index c2eb5cc..ca6cd50 100644
--- a/Sources/AnthropicSwiftSDK/CountTokens.swift
+++ b/Sources/AnthropicSwiftSDK/API/CountTokens.swift
@@ -90,16 +90,6 @@ public struct CountTokens {
             )
         )
 
-        let (data, response) = try await client.send(request: request)
-
-        guard let httpResponse = response as? HTTPURLResponse else {
-            throw ClientError.cannotHandleURLResponse(response)
-        }
-
-        guard httpResponse.statusCode == 200 else {
-            throw AnthropicAPIError(fromHttpStatusCode: httpResponse.statusCode)
-        }
-
-        return try anthropicJSONDecoder.decode(CountTokenResponse.self, from: data)
+        return try await client.send(request: request)
     }
 }
diff --git a/Sources/AnthropicSwiftSDK/MessageBatches.swift b/Sources/AnthropicSwiftSDK/API/MessageBatches.swift
similarity index 83%
rename from Sources/AnthropicSwiftSDK/MessageBatches.swift
rename to Sources/AnthropicSwiftSDK/API/MessageBatches.swift
index 2f745f0..bcebfe3 100644
--- a/Sources/AnthropicSwiftSDK/MessageBatches.swift
+++ b/Sources/AnthropicSwiftSDK/API/MessageBatches.swift
@@ -59,18 +59,7 @@ public struct MessageBatches {
             authenticationHeaderProvider: authenticationHeaderProvider
         )
 
-        let request = MessageBatchesRequest(body: .init(from: batches))
-        let (data, response) = try await client.send(request: request)
-
-        guard let httpResponse = response as? HTTPURLResponse else {
-            throw ClientError.cannotHandleURLResponse(response)
-        }
-
-        guard httpResponse.statusCode == 200 else {
-            throw AnthropicAPIError(fromHttpStatusCode: httpResponse.statusCode)
-        }
-
-        return try anthropicJSONDecoder.decode(BatchResponse.self, from: data)
+        return try await client.send(request: MessageBatchesRequest(body: .init(from: batches)))
     }
 
     /// Retrieves a specific message batch by its ID.
@@ -105,18 +94,7 @@ public struct MessageBatches {
             authenticationHeaderProvider: authenticationHeaderProvider
         )
 
-        let request = RetrieveMessageBatchesRequest(batchId: batchId)
-        let (data, response) = try await client.send(request: request)
-
-        guard let httpResponse = response as? HTTPURLResponse else {
-            throw ClientError.cannotHandleURLResponse(response)
-        }
-
-        guard httpResponse.statusCode == 200 else {
-            throw AnthropicAPIError(fromHttpStatusCode: httpResponse.statusCode)
-        }
-
-        return try anthropicJSONDecoder.decode(BatchResponse.self, from: data)
+        return try await client.send(request: RetrieveMessageBatchesRequest(batchId: batchId))
     }
 
     /// Retrieves the results of a specific message batch by its ID.
@@ -231,9 +209,9 @@ public struct MessageBatches {
     ///   - beforeId: The ID to list batches before.
     ///   - afterId: The ID to list batches after.
     ///   - limit: The maximum number of batches to list.
-    /// - Returns: A `BatchListResponse` containing the list of batches.
+    /// - Returns: A `ObjectListResponse<BatchResponse>` containing the list of batches.
     /// - Throws: An error if the request fails.
-    public func list(beforeId: String? = nil, afterId: String? = nil, limit: Int = 20) async throws -> BatchListResponse {
+    public func list(beforeId: String? = nil, afterId: String? = nil, limit: Int = 20) async throws -> ObjectListResponse<BatchResponse> {
         try await list(
             beforeId: beforeId,
             afterId: afterId,
@@ -251,7 +229,7 @@ public struct MessageBatches {
     ///   - limit: The maximum number of batches to list.
     ///   - anthropicHeaderProvider: The provider for Anthropic-specific headers.
     ///   - authenticationHeaderProvider: The provider for authentication headers.
-    /// - Returns: A `BatchListResponse` containing the list of batches.
+    /// - Returns: A `ObjectListResponse<BatchResponse>` containing the list of batches.
     /// - Throws: An error if the request fails.
     public func list(
         beforeId: String?,
@@ -259,7 +237,7 @@ public struct MessageBatches {
         limit: Int,
         anthropicHeaderProvider: AnthropicHeaderProvider,
         authenticationHeaderProvider: AuthenticationHeaderProvider
-    ) async throws -> BatchListResponse  {
+    ) async throws -> ObjectListResponse<BatchResponse>  {
         let client = APIClient(
             session: session,
             anthropicHeaderProvider: anthropicHeaderProvider,
@@ -267,29 +245,18 @@ public struct MessageBatches {
         )
 
         let queries: [String: CustomStringConvertible] = {
-            var queries: [String: CustomStringConvertible] = [ListMessageBatchesRequest.Parameter.limit.rawValue: limit]
+            var queries: [String: CustomStringConvertible] = [ListObjectRequest.Parameter.limit.rawValue: limit]
             if let beforeId {
-                queries[ListMessageBatchesRequest.Parameter.beforeId.rawValue] = beforeId
+                queries[ListObjectRequest.Parameter.beforeId.rawValue] = beforeId
             }
             if let afterId {
-                queries[ListMessageBatchesRequest.Parameter.afterId.rawValue] = afterId
+                queries[ListObjectRequest.Parameter.afterId.rawValue] = afterId
             }
 
             return queries
         }()
 
-        let request = ListMessageBatchesRequest(queries: queries)
-        let (data, response) = try await client.send(request: request)
-
-        guard let httpResponse = response as? HTTPURLResponse else {
-            throw ClientError.cannotHandleURLResponse(response)
-        }
-
-        guard httpResponse.statusCode == 200 else {
-            throw AnthropicAPIError(fromHttpStatusCode: httpResponse.statusCode)
-        }
-
-        return try anthropicJSONDecoder.decode(BatchListResponse.self, from: data)
+        return try await client.send(request: ListObjectRequest(queries: queries, type: .batches))
     }
 
     /// Cancels a specific message batch by its ID.
@@ -324,18 +291,7 @@ public struct MessageBatches {
             authenticationHeaderProvider: authenticationHeaderProvider
         )
 
-        let request = CancelMessageBatchRequest(batchId: batchId)
-        let (data, response) = try await client.send(request: request)
-
-        guard let httpResponse = response as? HTTPURLResponse else {
-            throw ClientError.cannotHandleURLResponse(response)
-        }
-
-        guard httpResponse.statusCode == 200 else {
-            throw AnthropicAPIError(fromHttpStatusCode: httpResponse.statusCode)
-        }
-
-        return try anthropicJSONDecoder.decode(BatchResponse.self, from: data)
+        return try await client.send(request: CancelMessageBatchRequest(batchId: batchId))
     }
 }
 
diff --git a/Sources/AnthropicSwiftSDK/Messages.swift b/Sources/AnthropicSwiftSDK/API/Messages.swift
similarity index 96%
rename from Sources/AnthropicSwiftSDK/Messages.swift
rename to Sources/AnthropicSwiftSDK/API/Messages.swift
index 536e941..0212f28 100644
--- a/Sources/AnthropicSwiftSDK/Messages.swift
+++ b/Sources/AnthropicSwiftSDK/API/Messages.swift
@@ -120,17 +120,7 @@ public struct Messages {
             )
         )
 
-        let (data, response) = try await client.send(request: request)
-
-        guard let httpResponse = response as? HTTPURLResponse else {
-            throw ClientError.cannotHandleURLResponse(response)
-        }
-
-        guard httpResponse.statusCode == 200 else {
-            throw AnthropicAPIError(fromHttpStatusCode: httpResponse.statusCode)
-        }
-
-        return try anthropicJSONDecoder.decode(MessagesResponse.self, from: data)
+        return try await client.send(request: request)
     }
 
     /// Streams messages using the specified parameters and sends a request to the Anthropic API asynchronously.
diff --git a/Sources/AnthropicSwiftSDK/Anthropic.swift b/Sources/AnthropicSwiftSDK/Anthropic.swift
index 24ab227..a6d200d 100644
--- a/Sources/AnthropicSwiftSDK/Anthropic.swift
+++ b/Sources/AnthropicSwiftSDK/Anthropic.swift
@@ -26,3 +26,15 @@ public final class Anthropic {
         self.countTokens = CountTokens(apiKey: apiKey, session: .shared)
     }
 }
+
+public final class AnthropicAdmin {
+    /// Admin API interface
+    public let admin: Admin
+
+    /// Construction of Admin SDK
+    ///
+    /// - Parameter adminAPIKey: API key to access Anthropic Admin API
+    public init(adminAPIKey: String, session: URLSession = .shared) {
+        self.admin = Admin(adminAPIKey: adminAPIKey, session: session)
+    }
+}
diff --git a/Sources/AnthropicSwiftSDK/Entity/Admin/Invitation.swift b/Sources/AnthropicSwiftSDK/Entity/Admin/Invitation.swift
new file mode 100644
index 0000000..eb960f7
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Entity/Admin/Invitation.swift
@@ -0,0 +1,13 @@
+//
+//  Invitation.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+public struct Invitation: Encodable {
+    /// Email of the User.
+    public let email: String
+    /// Role for the invited User. Cannot be "admin".
+    public let role: OrganizationRole
+}
diff --git a/Sources/AnthropicSwiftSDK/Entity/Admin/OrganizationRole.swift b/Sources/AnthropicSwiftSDK/Entity/Admin/OrganizationRole.swift
new file mode 100644
index 0000000..67977a3
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Entity/Admin/OrganizationRole.swift
@@ -0,0 +1,17 @@
+//
+//  OrganizationRole.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/27.
+//
+
+public enum OrganizationRole: String, Codable {
+    /// Can use Workbench
+    case user
+    /// Can use Workbench and manage API keys
+    case developer
+    /// Can use Workbench and manage billing details
+    case billing
+    /// Can do all of the above, plus manage users
+    case admin
+}
diff --git a/Sources/AnthropicSwiftSDK/Entity/Admin/Registration.swift b/Sources/AnthropicSwiftSDK/Entity/Admin/Registration.swift
new file mode 100644
index 0000000..bead933
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Entity/Admin/Registration.swift
@@ -0,0 +1,13 @@
+//
+//  Registration.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+public struct Registration: Encodable {
+    /// ID of the User.
+    public let userId: String
+    /// Role of the new Workspace Member. Cannot be "workspace_billing".
+    public let workspaceRole: WorkspaceRole
+}
diff --git a/Sources/AnthropicSwiftSDK/Entity/Admin/WorkspaceRole.swift b/Sources/AnthropicSwiftSDK/Entity/Admin/WorkspaceRole.swift
new file mode 100644
index 0000000..0505076
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Entity/Admin/WorkspaceRole.swift
@@ -0,0 +1,14 @@
+//
+//  WorkspaceRole.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+/// workspace role for the user.
+public enum WorkspaceRole: String, Codable {
+    case user = "workspace_user"
+    case developer = "workspace_developer"
+    case admin = "workspace_admin"
+    case billing = "workspace_billing"
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/AnthropicAPIClient.swift b/Sources/AnthropicSwiftSDK/Network/AnthropicAPIClient.swift
index 5cfcbcb..f4ff1db 100644
--- a/Sources/AnthropicSwiftSDK/Network/AnthropicAPIClient.swift
+++ b/Sources/AnthropicSwiftSDK/Network/AnthropicAPIClient.swift
@@ -52,6 +52,21 @@ struct APIClient {
         return try await session.data(for: urlRequest)
     }
 
+    func send<Object: Decodable>(request: any Request) async throws -> Object {
+        let (data, response) = try await self.send(request: request)
+
+        guard let httpResponse = response as? HTTPURLResponse else {
+            throw ClientError.cannotHandleURLResponse(response)
+        }
+
+        guard httpResponse.statusCode == 200 else {
+            throw AnthropicAPIError(fromHttpStatusCode: httpResponse.statusCode)
+        }
+
+        return try anthropicJSONDecoder.decode(Object.self, from: data)
+    }
+
+
     /// Send messages API request. This method read the API response sequentially.
     ///
     /// - Parameter request: request body for api request
diff --git a/Sources/AnthropicSwiftSDK/Network/ObjectListable.swift b/Sources/AnthropicSwiftSDK/Network/ObjectListable.swift
new file mode 100644
index 0000000..ceed9d7
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/ObjectListable.swift
@@ -0,0 +1,44 @@
+//
+//  ObjectListable.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/03.
+//
+import Foundation
+
+protocol ObjectListable<Object> {
+    associatedtype Object: Decodable
+}
+
+extension ObjectListable {
+    // swiftlint:disable:next function_parameter_count
+    func list(
+        session: URLSession,
+        type: RequestType,
+        limit: Int,
+        beforeId: String?,
+        afterId: String?,
+        anthropicHeaderProvider: AnthropicHeaderProvider,
+        authenticationHeaderProvider: AuthenticationHeaderProvider
+    ) async throws -> ObjectListResponse<Object> {
+        let client = APIClient(
+            session: session,
+            anthropicHeaderProvider: anthropicHeaderProvider,
+            authenticationHeaderProvider: authenticationHeaderProvider
+        )
+
+        let queries: [String: CustomStringConvertible] = {
+            var queries: [String: CustomStringConvertible] = [ListObjectRequest.Parameter.limit.rawValue: limit]
+            if let beforeId {
+                queries[ListObjectRequest.Parameter.beforeId.rawValue] = beforeId
+            }
+            if let afterId {
+                queries[ListObjectRequest.Parameter.afterId.rawValue] = afterId
+            }
+
+            return queries
+        }()
+
+        return try await client.send(request: ListObjectRequest(queries: queries, type: type))
+    }
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/APIKeys/GetAPIKeyRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/APIKeys/GetAPIKeyRequest.swift
new file mode 100644
index 0000000..a8d216e
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/APIKeys/GetAPIKeyRequest.swift
@@ -0,0 +1,17 @@
+//
+//  GetAPIKeyRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct GetAPIKeyRequest: Request {
+    let method: HttpMethod = .get
+    var path: String {
+        "\(RequestType.apiKey.basePath)/\(apiKeyId)"
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+    let body: Never? = nil
+
+    let apiKeyId: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/APIKeys/UpdateAPIKeyRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/APIKeys/UpdateAPIKeyRequest.swift
new file mode 100644
index 0000000..b286d56
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/APIKeys/UpdateAPIKeyRequest.swift
@@ -0,0 +1,23 @@
+//
+//  UpdateAPIKeyRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct UpdateAPIKeyRequest: Request {
+    typealias Body = APIKeyRequestBody
+    let method: HttpMethod = .post
+    var path: String {
+        "\(RequestType.apiKey.basePath)/\(apiKeyId)"
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+
+    let body: APIKeyRequestBody?
+    let apiKeyId: String
+}
+
+struct APIKeyRequestBody: Encodable {
+    let name: String
+    let status: APIKeyStatus?
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/ListMessageBatchesRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/ListObjectRequest.swift
similarity index 68%
rename from Sources/AnthropicSwiftSDK/Network/Request/ListMessageBatchesRequest.swift
rename to Sources/AnthropicSwiftSDK/Network/Request/ListObjectRequest.swift
index 59fdcc5..2e0498d 100644
--- a/Sources/AnthropicSwiftSDK/Network/Request/ListMessageBatchesRequest.swift
+++ b/Sources/AnthropicSwiftSDK/Network/Request/ListObjectRequest.swift
@@ -1,17 +1,11 @@
 //
-//  ListMessageBatchesRequest.swift
+//  ListObjectRequest.swift
 //  AnthropicSwiftSDK
 //
 //  Created by 伊藤史 on 2024/10/16.
 //
 
-/// List all Message Batches within a Workspace. Most recently created batches are returned first.
-struct ListMessageBatchesRequest: Request {
-    let method: HttpMethod = .get
-    let path: String = RequestType.batches.basePath
-    let queries: [String: CustomStringConvertible]?
-    let body: Never? = nil
-
+struct ListObjectRequest: Request {
     enum Parameter: String {
         /// ID of the object to use as a cursor for pagination. When provided, returns the page of results immediately before this object.
         case beforeId = "before_id"
@@ -22,4 +16,17 @@ struct ListMessageBatchesRequest: Request {
         /// Defaults to 20. Ranges from 1 to 100.
         case limit
     }
+
+    /// HTTP method of request. It's always `GET`
+    let method: HttpMethod = .get
+    /// HTTP request path. It's always base path of `type`.
+    var path: String {
+        type.basePath
+    }
+    /// HTTP request body. It's always empty
+    let body: Never? = nil
+
+    let queries: [String: CustomStringConvertible]?
+    /// type of objects
+    let type: RequestType
 }
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/CancelMessageBatchRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/MessageBatches/CancelMessageBatchRequest.swift
similarity index 100%
rename from Sources/AnthropicSwiftSDK/Network/Request/CancelMessageBatchRequest.swift
rename to Sources/AnthropicSwiftSDK/Network/Request/MessageBatches/CancelMessageBatchRequest.swift
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/MessageBatchesRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/MessageBatches/MessageBatchesRequest.swift
similarity index 100%
rename from Sources/AnthropicSwiftSDK/Network/Request/MessageBatchesRequest.swift
rename to Sources/AnthropicSwiftSDK/Network/Request/MessageBatches/MessageBatchesRequest.swift
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/RetrieveMessageBatchResultsRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/MessageBatches/RetrieveMessageBatchResultsRequest.swift
similarity index 100%
rename from Sources/AnthropicSwiftSDK/Network/Request/RetrieveMessageBatchResultsRequest.swift
rename to Sources/AnthropicSwiftSDK/Network/Request/MessageBatches/RetrieveMessageBatchResultsRequest.swift
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/RetrieveMessageBatchesRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/MessageBatches/RetrieveMessageBatchesRequest.swift
similarity index 100%
rename from Sources/AnthropicSwiftSDK/Network/Request/RetrieveMessageBatchesRequest.swift
rename to Sources/AnthropicSwiftSDK/Network/Request/MessageBatches/RetrieveMessageBatchesRequest.swift
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/OrganizationInvites/CreateOrganizationInviteRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationInvites/CreateOrganizationInviteRequest.swift
new file mode 100644
index 0000000..5a925ff
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationInvites/CreateOrganizationInviteRequest.swift
@@ -0,0 +1,16 @@
+//
+//  CreateOrganizationInviteRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct CreateOrganizationInviteRequest: Request {
+    typealias Body = Invitation
+
+    let method: HttpMethod = .post
+    let path: String = RequestType.organizationInvite.basePath
+    let queries: [String: any CustomStringConvertible]? = nil
+
+    let body: Invitation?
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/OrganizationInvites/DeleteOrganizationInviteRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationInvites/DeleteOrganizationInviteRequest.swift
new file mode 100644
index 0000000..b7fbb1d
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationInvites/DeleteOrganizationInviteRequest.swift
@@ -0,0 +1,17 @@
+//
+//  DeleteOrganizationInviteRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct DeleteOrganizationInviteRequest: Request {
+    let method: HttpMethod = .delete
+    var path: String {
+        "\(RequestType.organizationInvite.basePath)/\(invitationId)"
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+    let body: Never? = nil
+
+    let invitationId: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/OrganizationInvites/GetOrganizationInviteRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationInvites/GetOrganizationInviteRequest.swift
new file mode 100644
index 0000000..8fd4eee
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationInvites/GetOrganizationInviteRequest.swift
@@ -0,0 +1,17 @@
+//
+//  GetOrganizationInviteRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct GetOrganizationInviteRequest: Request {
+    let method: HttpMethod = .get
+    var path: String {
+        "\(RequestType.organizationInvite.basePath)/\(invitationId)"
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+    let body: Never? = nil
+
+    let invitationId: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/OrganizationMembers/GetOrganizationMemberRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationMembers/GetOrganizationMemberRequest.swift
new file mode 100644
index 0000000..77fa477
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationMembers/GetOrganizationMemberRequest.swift
@@ -0,0 +1,19 @@
+//
+//  GetOrganizationMemberRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+/// https://docs.anthropic.com/en/api/admin-api/users/get-user
+struct GetOrganizationMemberRequest: Request {
+    let method: HttpMethod = .get
+    var path: String {
+        "\(RequestType.organizationMember.basePath)/\(userId)"
+    }
+    let queries: [String: CustomStringConvertible]? = nil
+    let body: Never? = nil
+
+    /// ID of the User.
+    let userId: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/OrganizationMembers/RemoveOrganizationMemberRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationMembers/RemoveOrganizationMemberRequest.swift
new file mode 100644
index 0000000..8333340
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationMembers/RemoveOrganizationMemberRequest.swift
@@ -0,0 +1,17 @@
+//
+//  RemoveOrganizationMemberRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct RemoveOrganizationMemberRequest: Request {
+    let method: HttpMethod = .delete
+    var path: String {
+        "\(RequestType.organizationMember.basePath)/\(userId)"
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+    let body: Never? = nil
+
+    let userId: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/OrganizationMembers/UpdateOrganizationMemberRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationMembers/UpdateOrganizationMemberRequest.swift
new file mode 100644
index 0000000..9289213
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/OrganizationMembers/UpdateOrganizationMemberRequest.swift
@@ -0,0 +1,23 @@
+//
+//  UpdateOrganizationMemberRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct UpdateOrganizationMemberRequest: Request {
+    typealias Body = OrganizationMememberRequestBody
+
+    let method: HttpMethod = .post
+    var path: String {
+        "\(RequestType.organizationMember.basePath)/\(userId)"
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+
+    let body: OrganizationMememberRequestBody?
+    let userId: String
+}
+
+struct OrganizationMememberRequestBody: Encodable {
+    let role: OrganizationRole
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/Request.swift b/Sources/AnthropicSwiftSDK/Network/Request/Request.swift
index 80e7b8d..117c700 100644
--- a/Sources/AnthropicSwiftSDK/Network/Request/Request.swift
+++ b/Sources/AnthropicSwiftSDK/Network/Request/Request.swift
@@ -10,12 +10,18 @@ import Foundation
 public enum HttpMethod: String {
     case post = "POST"
     case get = "GET"
+    case delete = "DELETE"
 }
 
 enum RequestType {
     case messages
     case batches
     case countTokens
+    case organizationMember
+    case organizationInvite
+    case workspace
+    case workspaceMember(workspaceId: String)
+    case apiKey
 
     var basePath: String {
         switch self {
@@ -24,7 +30,17 @@ enum RequestType {
         case .batches:
             return "/v1/messages/batches"
         case .countTokens:
-            return "v1/messages/count_tokens"
+            return "/v1/messages/count_tokens"
+        case .organizationMember:
+            return "/v1/organizations/users"
+        case .organizationInvite:
+            return "/v1/organizations/invites"
+        case .workspace:
+            return "/v1/organizations/workspaces"
+        case .workspaceMember(let workspaceId):
+            return "/v1/organizations/workspaces/\(workspaceId)/members"
+        case .apiKey:
+            return "/v1/organizations/api_keys"
         }
     }
 }
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/CreateWorkspaceMemberRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/CreateWorkspaceMemberRequest.swift
new file mode 100644
index 0000000..4ec0e65
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/CreateWorkspaceMemberRequest.swift
@@ -0,0 +1,19 @@
+//
+//  CreateWorkspaceMemberRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct CreateWorkspaceMemberRequest: Request {
+    typealias Body = Registration
+
+    let method: HttpMethod = .post
+    var path: String {
+        RequestType.workspaceMember(workspaceId: workspaceId).basePath
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+
+    let body: Registration?
+    let workspaceId: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/DeleteWorkspaceMemberRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/DeleteWorkspaceMemberRequest.swift
new file mode 100644
index 0000000..7430460
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/DeleteWorkspaceMemberRequest.swift
@@ -0,0 +1,18 @@
+//
+//  DeleteWorkspaceMemberRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct DeleteWorkspaceMemberRequest: Request {
+    let method: HttpMethod = .delete
+    var path: String {
+        "\(RequestType.workspaceMember(workspaceId: workspaceId).basePath)/\(userId)"
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+    let body: Never? = nil
+
+    let userId: String
+    let workspaceId: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/GetWorkspaceMemberRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/GetWorkspaceMemberRequest.swift
new file mode 100644
index 0000000..7350a35
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/GetWorkspaceMemberRequest.swift
@@ -0,0 +1,18 @@
+//
+//  GetWorkspaceMemberRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct GetWorkspaceMemberRequest: Request {
+    let method: HttpMethod = .get
+    var path: String {
+        "\(RequestType.workspaceMember(workspaceId: workspaceId).basePath)/\(userId)"
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+    let body: Never? = nil
+
+    let workspaceId: String
+    let userId: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/UpdateWorkspaceMemberRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/UpdateWorkspaceMemberRequest.swift
new file mode 100644
index 0000000..b7a3d44
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/WorkspaceMembers/UpdateWorkspaceMemberRequest.swift
@@ -0,0 +1,24 @@
+//
+//  UpdateWorkspaceMemberRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct UpdateWorkspaceMemberRequest: Request {
+    typealias Body = WorkspaceMemberRequestBody
+
+    let method: HttpMethod = .post
+    var path: String {
+        "\(RequestType.workspaceMember(workspaceId: workspaceId).basePath)/\(userId)"
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+
+    let body: WorkspaceMemberRequestBody?
+    let userId: String
+    let workspaceId: String
+}
+
+struct WorkspaceMemberRequestBody: Encodable {
+    let role: WorkspaceRole
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/ArchiveWorkspaceRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/ArchiveWorkspaceRequest.swift
new file mode 100644
index 0000000..206a2c2
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/ArchiveWorkspaceRequest.swift
@@ -0,0 +1,17 @@
+//
+//  ArchiveWorkspaceRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct ArchiveWorkspaceRequest: Request {
+    let method: HttpMethod = .post
+    var path: String {
+        "\(RequestType.workspace.basePath)/\(workspaceId)/archive"
+    }
+    var queries: [String: any CustomStringConvertible]?
+    let body: Never? = nil
+
+    let workspaceId: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/CreateWorkspaceRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/CreateWorkspaceRequest.swift
new file mode 100644
index 0000000..bb8e728
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/CreateWorkspaceRequest.swift
@@ -0,0 +1,16 @@
+//
+//  CreateWorkspaceRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct CreateWorkspaceRequest: Request {
+    typealias Body = WorkspaceRequestBody
+
+    let method: HttpMethod = .post
+    let path: String = RequestType.workspace.basePath
+    let queries: [String: any CustomStringConvertible]? = nil
+
+    let body: WorkspaceRequestBody?
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/GetWorkspaceRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/GetWorkspaceRequest.swift
new file mode 100644
index 0000000..47444aa
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/GetWorkspaceRequest.swift
@@ -0,0 +1,17 @@
+//
+//  GetWorkspaceRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct GetWorkspaceRequest: Request {
+    let method: HttpMethod = .get
+    var path: String {
+        "\(RequestType.workspace.basePath)/\(workspaceId)"
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+    let body: Never? = nil
+
+    let workspaceId: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/UpdateWorkspaceRequest.swift b/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/UpdateWorkspaceRequest.swift
new file mode 100644
index 0000000..e6ab5ed
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Request/Workspaces/UpdateWorkspaceRequest.swift
@@ -0,0 +1,23 @@
+//
+//  UpdateWorkspaceRequest.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/29.
+//
+
+struct UpdateWorkspaceRequest: Request {
+    typealias Body = WorkspaceRequestBody
+
+    let method: HttpMethod = .post
+    var path: String {
+        "\(RequestType.workspace.basePath)/\(workspaceId)"
+    }
+    let queries: [String: any CustomStringConvertible]? = nil
+
+    let body: WorkspaceRequestBody?
+    let workspaceId: String
+}
+
+struct WorkspaceRequestBody: Encodable {
+    let name: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Response/APIKeyResponse.swift b/Sources/AnthropicSwiftSDK/Network/Response/APIKeyResponse.swift
new file mode 100644
index 0000000..2695127
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Response/APIKeyResponse.swift
@@ -0,0 +1,45 @@
+//
+//  APIKeyResponse.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+/// Object type for API Keys, this is always "api_key".
+public enum APIKeyType: String, Decodable {
+    case apiKey = "api_key"
+}
+
+/// The ID and type of the actor that created the API key.
+public struct APIKeyActor: Decodable {
+    /// ID of the actor that created the object.
+    public let id: String
+    /// Type of the actor that created the object.
+    public let type: String
+}
+
+/// Status of the API key.
+public enum APIKeyStatus: String, Codable {
+    case active
+    case inactive
+    case archived
+}
+
+public struct APIKeyResponse: Decodable {
+    /// ID of the API key.
+    public let id: String
+    /// Object type for API Keys, this is always "api_key".
+    public let type: APIKeyType
+    /// Name of the API key.
+    public let name: String
+    /// ID of the Workspace associated with the API key, or null if the API key belongs to the default Workspace.
+    public let workspaceId: String?
+    /// RFC 3339 datetime string indicating when the API Key was created.
+    public let createdAt: String
+    /// The ID and type of the actor that created the API key.
+    public let createdBy: APIKeyActor
+    /// Partially redacted hint for the API key.
+    public let partialKeyHint: String?
+    /// Status of the API key.
+    public let status: APIKeyStatus
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Response/BatchListResponse.swift b/Sources/AnthropicSwiftSDK/Network/Response/BatchListResponse.swift
deleted file mode 100644
index a73ca81..0000000
--- a/Sources/AnthropicSwiftSDK/Network/Response/BatchListResponse.swift
+++ /dev/null
@@ -1,18 +0,0 @@
-//
-//  BatchListResponse.swift
-//  AnthropicSwiftSDK
-//
-//  Created by 伊藤史 on 2024/10/09.
-//
-
-/// https://docs.anthropic.com/en/api/listing-message-batches
-public struct BatchListResponse: Decodable {
-    /// List of `BatchResponse` object.
-    public let data: [BatchResponse]
-    /// Indicates if there are more results in the requested page direction.
-    public let hasMore: Bool
-    /// First ID in the `data` list. Can be used as the `before_id` for the previous page.
-    public let firstId: String?
-    /// Last ID in the `data` list. Can be used as the `after_id` for the next page.
-    public let lastId: String?
-}
diff --git a/Sources/AnthropicSwiftSDK/Network/Response/InvitationRemoveResponse.swift b/Sources/AnthropicSwiftSDK/Network/Response/InvitationRemoveResponse.swift
new file mode 100644
index 0000000..68121ea
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Response/InvitationRemoveResponse.swift
@@ -0,0 +1,18 @@
+//
+//  InvitationRemoveResponse.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+/// Deleted object type for Invites, this is always "invite_deleted".
+public enum InvitationDeletedType: String, Decodable {
+    case deleted = "invite_deleted"
+}
+
+public struct InvitationRemoveResponse: Decodable {
+    /// ID of the Invite.
+    public let id: String
+    /// Deleted object type for Invites, this is always "invite_deleted".
+    public let type: InvitationDeletedType
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Response/InvitationResponse.swift b/Sources/AnthropicSwiftSDK/Network/Response/InvitationResponse.swift
new file mode 100644
index 0000000..1e4b8d5
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Response/InvitationResponse.swift
@@ -0,0 +1,36 @@
+//
+//  InvitationResponse.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+/// Object type for Invites, this is always "invite".
+public enum InvitationType: String, Decodable {
+    case invite
+}
+
+/// Status of the Invite.
+public enum InvitationStatus: String, Decodable {
+    case accepted
+    case expired
+    case deleted
+    case pending
+}
+
+public struct InvitationResponse: Decodable {
+    /// ID of the Invite.
+    public let id: String
+    /// Object type for Invites, this is always "invite".
+    public let type: InvitationType
+    /// Email of the User being invited.
+    public let email: String
+    /// Organization role of the User.
+    public let role: OrganizationRole
+    /// RFC 3339 datetime string indicating when the Invite was created.
+    public let invitedAt: String
+    /// RFC 3339 datetime string indicating when the Invite expires.
+    public let expiresAt: String
+    /// Status of the Invite.
+    public let status: InvitationStatus
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Response/ObjectListResponse.swift b/Sources/AnthropicSwiftSDK/Network/Response/ObjectListResponse.swift
new file mode 100644
index 0000000..38cfe06
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Response/ObjectListResponse.swift
@@ -0,0 +1,13 @@
+//
+//  ObjectListResponse.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+public struct ObjectListResponse<Object: Decodable>: Decodable {
+    public let data: [Object]
+    public let hasMore: Bool
+    public let firstId: String?
+    public let lastId: String?
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Response/OrganizationMemberRemoveResponse.swift b/Sources/AnthropicSwiftSDK/Network/Response/OrganizationMemberRemoveResponse.swift
new file mode 100644
index 0000000..2032256
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Response/OrganizationMemberRemoveResponse.swift
@@ -0,0 +1,18 @@
+//
+//  OrganizationMemberRemoveResponse.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+/// Deleted object type for Users, this is always "user_deleted".
+public enum OrganizationMemberDeletedType: String, Decodable {
+    case deleted = "user_deleted"
+}
+
+public struct OrganizationMemberRemoveResponse: Decodable {
+    /// ID of the User.
+    public let id: String
+    /// Deleted object type for Users, this is always "user_deleted".
+    public let type: OrganizationMemberDeletedType
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Response/OrganizationMemberResponse.swift b/Sources/AnthropicSwiftSDK/Network/Response/OrganizationMemberResponse.swift
new file mode 100644
index 0000000..3ace29a
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Response/OrganizationMemberResponse.swift
@@ -0,0 +1,26 @@
+//
+//  OrganizationMemberResponse.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+/// Object type for Users, this is always "user".
+public enum OrganizationMemberType: String, Decodable {
+    case user
+}
+
+public struct OrganizationMemberResponse: Decodable {
+    /// ID of the User.
+    public let id: String
+    /// Object type for Users, this is always "user".
+    public let type: OrganizationMemberType
+    /// Email of the User.
+    public let email: String
+    /// Name of the User.
+    public let name: String
+    /// Organization role of the User.
+    public let role: OrganizationRole
+    /// RFC 3339 datetime string indicating when the User joined the Organization.
+    public let addedAt: String
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Response/WorkspaceMemberRemoveResponse.swift b/Sources/AnthropicSwiftSDK/Network/Response/WorkspaceMemberRemoveResponse.swift
new file mode 100644
index 0000000..61be82a
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Response/WorkspaceMemberRemoveResponse.swift
@@ -0,0 +1,20 @@
+//
+//  WorkspaceMemberRemoveResponse.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+public struct WorkspaceMemberRemoveResponse: Decodable {
+    /// ID of the User.
+    public let userId: String
+    /// ID of the Workspace.
+    public let workspaceId: String
+    /// Deleted object type for Workspace Members, this is always
+    public let type: WorkspaceMemberDeletedType
+}
+
+/// Deleted object type for Invites, this is always "invite_deleted".
+public enum WorkspaceMemberDeletedType: String, Decodable {
+    case deleted = "workspace_member_deleted"
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Response/WorkspaceMemberResponse.swift b/Sources/AnthropicSwiftSDK/Network/Response/WorkspaceMemberResponse.swift
new file mode 100644
index 0000000..204ba90
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Response/WorkspaceMemberResponse.swift
@@ -0,0 +1,21 @@
+//
+//  WorkspaceMemberResponse.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+public enum WorkspaceMemberType: String, Decodable {
+    case workspaceMember = "workspace_member"
+}
+
+public struct WorkspaceMemberResponse: Decodable {
+    /// Object type for Workspace Members, this is always
+    public let type: WorkspaceMemberType
+    /// ID of the User.
+    public let userId: String
+    /// ID of the Workspace.
+    public let workspaceId: String
+    /// Role of the Workspace Member.
+    public let workspaceRole: WorkspaceRole
+}
diff --git a/Sources/AnthropicSwiftSDK/Network/Response/WorkspaceResponse.swift b/Sources/AnthropicSwiftSDK/Network/Response/WorkspaceResponse.swift
new file mode 100644
index 0000000..857e6dc
--- /dev/null
+++ b/Sources/AnthropicSwiftSDK/Network/Response/WorkspaceResponse.swift
@@ -0,0 +1,26 @@
+//
+//  WorkspaceResponse.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/11/28.
+//
+
+/// Object type for Workspaces, this is always "workspace".
+public enum WorkspaceType: String, Decodable {
+    case workspace
+}
+
+public struct WorkspaceResponse: Decodable {
+    /// ID of the Workspace.
+    public let id: String
+    /// Object type for Workspaces, this is always "workspace".
+    public let type: WorkspaceType
+    /// Name of the Workspace.
+    public let name: String
+    /// RFC 3339 datetime string indicating when the Workspace was created.
+    public let createdAt: String
+    /// RFC 3339 datetime string indicating when the Workspace was archived, or null if the Workspace is not archived.
+    public let archivedAt: String?
+    /// Hex color code representing the Workspace in the Anthropic Console.
+    public let displayColor: String
+}
diff --git a/Tests/AnthropicSwiftSDKTests/API/APIKeysTests.swift b/Tests/AnthropicSwiftSDKTests/API/APIKeysTests.swift
new file mode 100644
index 0000000..22c239e
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/API/APIKeysTests.swift
@@ -0,0 +1,94 @@
+//
+//  APIKeysTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+import AnthropicSwiftSDK_TestUtils
+@testable import AnthropicSwiftSDK
+
+final class APIKeysTests: XCTestCase {
+    var session: URLSession!
+    var apiKeys: APIKeys!
+
+    override func setUp() {
+        super.setUp()
+        let configuration = URLSessionConfiguration.default
+        configuration.protocolClasses = [HTTPMock.self]
+        session = URLSession(configuration: configuration)
+
+        let apiKey = "test-api-key"
+        apiKeys = APIKeys(adminAPIKey: apiKey, session: session)
+    }
+
+    func testGetAPIKey() async throws {
+        let expectation = XCTestExpectation(description: "Get API Key response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "apikey_01Rj2N8SVvo6BePZj99NhmiT",
+          "type": "api_key",
+          "name": "Developer Key",
+          "workspace_id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "created_at": "2024-10-30T23:58:27.427722Z",
+          "created_by": {
+            "id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+            "type": "user"
+          },
+          "partial_key_hint": "sk-ant-api03-R2D...igAA",
+          "status": "active"
+        }
+        """)
+
+        let response = try await apiKeys.get(apiKeyId: "test-key-id")
+        XCTAssertEqual(response.id, "apikey_01Rj2N8SVvo6BePZj99NhmiT")
+        XCTAssertEqual(response.type, .apiKey)
+        XCTAssertEqual(response.name, "Developer Key")
+        XCTAssertEqual(response.workspaceId, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.createdAt, "2024-10-30T23:58:27.427722Z")
+        XCTAssertEqual(response.createdBy.id, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.createdBy.type, "user")
+        XCTAssertEqual(response.partialKeyHint, "sk-ant-api03-R2D...igAA")
+        XCTAssertEqual(response.status, .active)
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+
+    func testUpdateAPIKey() async throws {
+        let expectation = XCTestExpectation(description: "Update API Key response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "apikey_01Rj2N8SVvo6BePZj99NhmiT",
+          "type": "api_key",
+          "name": "Updated API Key",
+          "workspace_id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "created_at": "2024-10-30T23:58:27.427722Z",
+          "created_by": {
+            "id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+            "type": "user"
+          },
+          "partial_key_hint": "sk-ant-api03-R2D...igAA",
+          "status": "inactive"
+        }
+        """)
+
+        let updatedResponse = try await apiKeys.update(apiKeyId: "test-key-id", name: "Updated API Key", status: .inactive)
+        XCTAssertEqual(updatedResponse.id, "apikey_01Rj2N8SVvo6BePZj99NhmiT")
+        XCTAssertEqual(updatedResponse.type, .apiKey)
+        XCTAssertEqual(updatedResponse.name, "Updated API Key")
+        XCTAssertEqual(updatedResponse.workspaceId, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(updatedResponse.createdAt, "2024-10-30T23:58:27.427722Z")
+        XCTAssertEqual(updatedResponse.createdBy.id, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(updatedResponse.createdBy.type, "user")
+        XCTAssertEqual(updatedResponse.partialKeyHint, "sk-ant-api03-R2D...igAA")
+        XCTAssertEqual(updatedResponse.status, .inactive)
+
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/MessageBatchesTests.swift b/Tests/AnthropicSwiftSDKTests/API/MessageBatchesTests.swift
similarity index 100%
rename from Tests/AnthropicSwiftSDKTests/MessageBatchesTests.swift
rename to Tests/AnthropicSwiftSDKTests/API/MessageBatchesTests.swift
diff --git a/Tests/AnthropicSwiftSDKTests/MessagesTests.swift b/Tests/AnthropicSwiftSDKTests/API/MessagesTests.swift
similarity index 100%
rename from Tests/AnthropicSwiftSDKTests/MessagesTests.swift
rename to Tests/AnthropicSwiftSDKTests/API/MessagesTests.swift
diff --git a/Tests/AnthropicSwiftSDKTests/API/OrganizationInvitesTests.swift b/Tests/AnthropicSwiftSDKTests/API/OrganizationInvitesTests.swift
new file mode 100644
index 0000000..977e8a4
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/API/OrganizationInvitesTests.swift
@@ -0,0 +1,100 @@
+//
+//  OrganizationInvitesTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+import AnthropicSwiftSDK_TestUtils
+@testable import AnthropicSwiftSDK
+
+final class OrganizationInvitesTests: XCTestCase {
+    var session: URLSession!
+    var organizationInvites: OrganizationInvites!
+
+    override func setUp() {
+        super.setUp()
+        let configuration = URLSessionConfiguration.default
+        configuration.protocolClasses = [HTTPMock.self]
+        session = URLSession(configuration: configuration)
+
+        let apiKey = "test-api-key"
+        organizationInvites = OrganizationInvites(adminAPIKey: apiKey, session: session)
+    }
+
+    func testGetOrganizationInvite() async throws {
+        let expectation = XCTestExpectation(description: "Get Organization Invite response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "invite_015gWxCN9Hfg2QhZwTK7Mdeu",
+          "type": "invite",
+          "email": "user@emaildomain.com",
+          "role": "user",
+          "invited_at": "2024-10-30T23:58:27.427722Z",
+          "expires_at": "2024-11-20T23:58:27.427722Z",
+          "status": "pending"
+        }
+        """)
+
+        let response = try await organizationInvites.get(invitationId: "invite_015gWxCN9Hfg2QhZwTK7Mdeu")
+        XCTAssertEqual(response.id, "invite_015gWxCN9Hfg2QhZwTK7Mdeu")
+        XCTAssertEqual(response.type, .invite)
+        XCTAssertEqual(response.email, "user@emaildomain.com")
+        XCTAssertEqual(response.role, .user)
+        XCTAssertEqual(response.invitedAt, "2024-10-30T23:58:27.427722Z")
+        XCTAssertEqual(response.expiresAt, "2024-11-20T23:58:27.427722Z")
+        XCTAssertEqual(response.status, .pending)
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+
+    func testRemoveOrganizationInvite() async throws {
+        let expectation = XCTestExpectation(description: "Remove Organization Invite response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "invite_015gWxCN9Hfg2QhZwTK7Mdeu",
+          "type": "invite_deleted"
+        }
+        """)
+
+        let response = try await organizationInvites.remove(invitationId: "invite_015gWxCN9Hfg2QhZwTK7Mdeu")
+        XCTAssertEqual(response.id, "invite_015gWxCN9Hfg2QhZwTK7Mdeu")
+        XCTAssertEqual(response.type, .deleted)
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+
+    func testSendOrganizationInvite() async throws {
+        let expectation = XCTestExpectation(description: "Send Organization Invite response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "invite_015gWxCN9Hfg2QhZwTK7Mdeu",
+          "type": "invite",
+          "email": "user@emaildomain.com",
+          "role": "user",
+          "invited_at": "2024-10-30T23:58:27.427722Z",
+          "expires_at": "2024-11-20T23:58:27.427722Z",
+          "status": "pending"
+        }
+        """)
+
+        let invite = Invitation(email: "user@emaildomain.com", role: .user)
+        let response = try await organizationInvites.send(invitation: invite)
+        XCTAssertEqual(response.id, "invite_015gWxCN9Hfg2QhZwTK7Mdeu")
+        XCTAssertEqual(response.type, .invite)
+        XCTAssertEqual(response.email, "user@emaildomain.com")
+        XCTAssertEqual(response.role, .user)
+        XCTAssertEqual(response.invitedAt, "2024-10-30T23:58:27.427722Z")
+        XCTAssertEqual(response.expiresAt, "2024-11-20T23:58:27.427722Z")
+        XCTAssertEqual(response.status, .pending)
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/API/OrganizationMembersTests.swift b/Tests/AnthropicSwiftSDKTests/API/OrganizationMembersTests.swift
new file mode 100644
index 0000000..c9563b1
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/API/OrganizationMembersTests.swift
@@ -0,0 +1,95 @@
+//
+//  OrganizationMembersTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+import AnthropicSwiftSDK_TestUtils
+@testable import AnthropicSwiftSDK
+
+final class OrganizationMembersTests: XCTestCase {
+    var session: URLSession!
+    var organizationMembers: OrganizationMembers!
+
+    override func setUp() {
+        super.setUp()
+        let configuration = URLSessionConfiguration.default
+        configuration.protocolClasses = [HTTPMock.self]
+        session = URLSession(configuration: configuration)
+
+        let apiKey = "test-api-key"
+        organizationMembers = OrganizationMembers(adminAPIKey: apiKey, session: session)
+    }
+
+    func testGetOrganizationMember() async throws {
+        let expectation = XCTestExpectation(description: "Get Organization Member response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+          "type": "user",
+          "email": "user@emaildomain.com",
+          "name": "Jane Doe",
+          "role": "user",
+          "added_at": "2024-10-30T23:58:27.427722Z"
+        }
+        """)
+
+        let response = try await organizationMembers.get(userId: "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.id, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.type, .user)
+        XCTAssertEqual(response.email, "user@emaildomain.com")
+        XCTAssertEqual(response.name, "Jane Doe")
+        XCTAssertEqual(response.role, .user)
+        XCTAssertEqual(response.addedAt, "2024-10-30T23:58:27.427722Z")
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+
+    func testRemoveOrganizationMember() async throws {
+        let expectation = XCTestExpectation(description: "Remove Organization Member response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+          "type": "user_deleted"
+        }
+        """)
+
+        let response = try await organizationMembers.remove(userId: "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.id, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.type, .deleted)
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+
+    func testUpdateOrganizationMember() async throws {
+        let expectation = XCTestExpectation(description: "Update Organization Member response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+          "type": "user",
+          "email": "updated_user@emaildomain.com",
+          "name": "Updated Jane Doe",
+          "role": "admin",
+          "added_at": "2024-10-30T23:58:27.427722Z"
+        }
+        """)
+
+        let response = try await organizationMembers.update(userId: "user_01WCz1FkmYMm4gnmykNKUu3Q", role: .admin)
+        XCTAssertEqual(response.id, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.type, .user)
+        XCTAssertEqual(response.email, "updated_user@emaildomain.com")
+        XCTAssertEqual(response.name, "Updated Jane Doe")
+        XCTAssertEqual(response.role, .admin)
+        XCTAssertEqual(response.addedAt, "2024-10-30T23:58:27.427722Z")
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/API/WorkspaceMembersTests.swift b/Tests/AnthropicSwiftSDKTests/API/WorkspaceMembersTests.swift
new file mode 100644
index 0000000..3b87da4
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/API/WorkspaceMembersTests.swift
@@ -0,0 +1,89 @@
+//
+//  WorkspaceMembersTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+import AnthropicSwiftSDK_TestUtils
+@testable import AnthropicSwiftSDK
+
+final class WorkspaceMembersTests: XCTestCase {
+    var session: URLSession!
+    var workspaceMembers: WorkspaceMembers!
+
+    override func setUp() {
+        super.setUp()
+        let configuration = URLSessionConfiguration.default
+        configuration.protocolClasses = [HTTPMock.self]
+        session = URLSession(configuration: configuration)
+
+        let apiKey = "test-api-key"
+        workspaceMembers = WorkspaceMembers(adminAPIKey: apiKey, session: session)
+    }
+
+    func testGetWorkspaceMember() async throws {
+        let expectation = XCTestExpectation(description: "Get Workspace Member response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "type": "workspace_member",
+          "user_id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+          "workspace_id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "workspace_role": "workspace_user"
+        }
+        """)
+
+        let response = try await workspaceMembers.get(userId: "user_01WCz1FkmYMm4gnmykNKUu3Q", workspaceId: "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.userId, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.workspaceId, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.workspaceRole, .user)
+        XCTAssertEqual(response.type, .workspaceMember)
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+
+    func testRemoveWorkspaceMember() async throws {
+        let expectation = XCTestExpectation(description: "Remove Workspace Member response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "user_id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+          "workspace_id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "type": "workspace_member_deleted"
+        }
+        """)
+
+        let response = try await workspaceMembers.remove(userId: "user_01WCz1FkmYMm4gnmykNKUu3Q", workspaceId: "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.userId, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.workspaceId, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.type, .deleted)
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+
+    func testUpdateWorkspaceMember() async throws {
+        let expectation = XCTestExpectation(description: "Update Workspace Member response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "type": "workspace_member",
+          "user_id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+          "workspace_id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "workspace_role": "workspace_admin"
+        }
+        """)
+
+        let response = try await workspaceMembers.update(userId: "user_01WCz1FkmYMm4gnmykNKUu3Q", workspaceId: "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ", role: .admin)
+        XCTAssertEqual(response.userId, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.workspaceId, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.workspaceRole, .admin)
+        XCTAssertEqual(response.type, .workspaceMember)
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/API/WorkspacesTests.swift b/Tests/AnthropicSwiftSDKTests/API/WorkspacesTests.swift
new file mode 100644
index 0000000..52a7313
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/API/WorkspacesTests.swift
@@ -0,0 +1,129 @@
+//
+//  WorkspacesTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+import AnthropicSwiftSDK_TestUtils
+@testable import AnthropicSwiftSDK
+
+final class WorkspacesTests: XCTestCase {
+    var session: URLSession!
+    var workspaces: Workspaces!
+
+    override func setUp() {
+        super.setUp()
+        let configuration = URLSessionConfiguration.default
+        configuration.protocolClasses = [HTTPMock.self]
+        session = URLSession(configuration: configuration)
+
+        let apiKey = "test-api-key"
+        workspaces = Workspaces(adminAPIKey: apiKey, session: session)
+    }
+
+    func testGetWorkspace() async throws {
+        let expectation = XCTestExpectation(description: "Get Workspace response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "type": "workspace",
+          "name": "Workspace Name",
+          "created_at": "2024-10-30T23:58:27.427722Z",
+          "archived_at": "2024-11-01T23:59:27.427722Z",
+          "display_color": "#6C5BB9"
+        }
+        """)
+
+        let response = try await workspaces.get(workspaceId: "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.id, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.type, .workspace)
+        XCTAssertEqual(response.name, "Workspace Name")
+        XCTAssertEqual(response.createdAt, "2024-10-30T23:58:27.427722Z")
+        XCTAssertEqual(response.archivedAt, "2024-11-01T23:59:27.427722Z")
+        XCTAssertEqual(response.displayColor, "#6C5BB9")
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+
+    func testCreateWorkspace() async throws {
+        let expectation = XCTestExpectation(description: "Create Workspace response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "type": "workspace",
+          "name": "New Workspace",
+          "created_at": "2024-10-30T23:58:27.427722Z",
+          "archived_at": null,
+          "display_color": "#6C5BB9"
+        }
+        """)
+
+        let response = try await workspaces.create(name: "New Workspace")
+        XCTAssertEqual(response.id, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.type, .workspace)
+        XCTAssertEqual(response.name, "New Workspace")
+        XCTAssertEqual(response.createdAt, "2024-10-30T23:58:27.427722Z")
+        XCTAssertNil(response.archivedAt)
+        XCTAssertEqual(response.displayColor, "#6C5BB9")
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+
+    func testArchiveWorkspace() async throws {
+        let expectation = XCTestExpectation(description: "Archive Workspace response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "type": "workspace",
+          "name": "Workspace Name",
+          "created_at": "2024-10-30T23:58:27.427722Z",
+          "archived_at": "2024-11-01T23:59:27.427722Z",
+          "display_color": "#6C5BB9"
+        }
+        """)
+
+        let response = try await workspaces.archive("wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.id, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.type, .workspace)
+        XCTAssertEqual(response.name, "Workspace Name")
+        XCTAssertEqual(response.createdAt, "2024-10-30T23:58:27.427722Z")
+        XCTAssertEqual(response.archivedAt, "2024-11-01T23:59:27.427722Z")
+        XCTAssertEqual(response.displayColor, "#6C5BB9")
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+
+    func testUpdateWorkspace() async throws {
+        let expectation = XCTestExpectation(description: "Update Workspace response")
+
+        HTTPMock.inspectType = .response("""
+        {
+          "id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "type": "workspace",
+          "name": "Updated Workspace Name",
+          "created_at": "2024-10-30T23:58:27.427722Z",
+          "archived_at": "2024-11-01T23:59:27.427722Z",
+          "display_color": "#6C5BB9"
+        }
+        """)
+
+        let response = try await workspaces.update(name: "Updated Workspace Name", workspaceId: "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.id, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.type, .workspace)
+        XCTAssertEqual(response.name, "Updated Workspace Name")
+        XCTAssertEqual(response.createdAt, "2024-10-30T23:58:27.427722Z")
+        XCTAssertEqual(response.archivedAt, "2024-11-01T23:59:27.427722Z")
+        XCTAssertEqual(response.displayColor, "#6C5BB9")
+
+        expectation.fulfill()
+        await fulfillment(of: [expectation], timeout: 1.0)
+    }
+}
\ No newline at end of file
diff --git a/Tests/AnthropicSwiftSDKTests/Network/AnthropicAPIClientTests.swift b/Tests/AnthropicSwiftSDKTests/Network/AnthropicAPIClientTests.swift
index 3d73270..481d1d5 100644
--- a/Tests/AnthropicSwiftSDKTests/Network/AnthropicAPIClientTests.swift
+++ b/Tests/AnthropicSwiftSDKTests/Network/AnthropicAPIClientTests.swift
@@ -34,7 +34,7 @@ final class AnthropicAPIClientTests: XCTestCase {
             expectation.fulfill()
         }, nil)
 
-        let _ = try await client.send(request: NopRequest())
+        let _: MessagesResponse = try await client.send(request: NopRequest())
         await fulfillment(of: [expectation], timeout: 1.0)
     }
 
@@ -74,7 +74,7 @@ final class AnthropicAPIClientTests: XCTestCase {
             expectation.fulfill()
         }, nil)
 
-        let _ = try await client.send(request: NopRequest())
+        let _: MessagesResponse = try await client.send(request: NopRequest())
         await fulfillment(of: [expectation], timeout: 1.0)
     }
 
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/ArchiveWorkspaceRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/ArchiveWorkspaceRequestTests.swift
new file mode 100644
index 0000000..52b703a
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/ArchiveWorkspaceRequestTests.swift
@@ -0,0 +1,20 @@
+//
+//  ArchiveWorkspaceRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class ArchiveWorkspaceRequestTests: XCTestCase {
+    func testArchiveWorkspaceRequest() throws {
+        let request = ArchiveWorkspaceRequest(workspaceId: "test-workspace-id")
+
+        XCTAssertEqual(request.method, HttpMethod.post)
+        XCTAssertEqual(request.path, "\(RequestType.workspace.basePath)/test-workspace-id/archive")
+        XCTAssertNil(request.queries)
+        XCTAssertNil(request.body)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/CreateOrganizationInviteRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/CreateOrganizationInviteRequestTests.swift
new file mode 100644
index 0000000..fde6d41
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/CreateOrganizationInviteRequestTests.swift
@@ -0,0 +1,23 @@
+//
+//  CreateOrganizationInviteRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class CreateOrganizationInviteRequestTests: XCTestCase {
+    func testCreateOrganizationInviteRequest() throws {
+        let invite = Invitation(email: "test@example.com", role: .user)
+        let request = CreateOrganizationInviteRequest(body: invite)
+
+        XCTAssertEqual(request.method, HttpMethod.post)
+        XCTAssertEqual(request.path, RequestType.organizationInvite.basePath)
+        XCTAssertNil(request.queries)
+        XCTAssertNotNil(request.body)
+        XCTAssertEqual(request.body?.email, invite.email)
+        XCTAssertEqual(request.body?.role, invite.role)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/CreateWorkspaceMemberRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/CreateWorkspaceMemberRequestTests.swift
new file mode 100644
index 0000000..9b54fc9
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/CreateWorkspaceMemberRequestTests.swift
@@ -0,0 +1,23 @@
+//
+//  CreateWorkspaceMemberRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class CreateWorkspaceMemberRequestTests: XCTestCase {
+    func testCreateWorkspaceMemberRequest() throws {
+        let registration = Registration(userId: "1234wert", workspaceRole: .developer)
+        let request = CreateWorkspaceMemberRequest(body: registration, workspaceId: "test-workspace-id")
+
+        XCTAssertEqual(request.method, HttpMethod.post)
+        XCTAssertEqual(request.path, RequestType.workspaceMember(workspaceId: "test-workspace-id").basePath)
+        XCTAssertNil(request.queries)
+        XCTAssertNotNil(request.body)
+        XCTAssertEqual(request.body?.userId, registration.userId)
+        XCTAssertEqual(request.body?.workspaceRole, registration.workspaceRole)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/CreateWorkspaceRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/CreateWorkspaceRequestTests.swift
new file mode 100644
index 0000000..39c88df
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/CreateWorkspaceRequestTests.swift
@@ -0,0 +1,21 @@
+//
+//  CreateWorkspaceRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class CreateWorkspaceRequestTests: XCTestCase {
+    func testCreateWorkspaceRequest() throws {
+        let request = CreateWorkspaceRequest(body: .init(name: "Test Workspace"))
+
+        XCTAssertEqual(request.method, HttpMethod.post)
+        XCTAssertEqual(request.path, RequestType.workspace.basePath)
+        XCTAssertNil(request.queries)
+        XCTAssertNotNil(request.body)
+        XCTAssertEqual(request.body?.name, "Test Workspace")
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/DeleteOrganizationInviteRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/DeleteOrganizationInviteRequestTests.swift
new file mode 100644
index 0000000..033c512
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/DeleteOrganizationInviteRequestTests.swift
@@ -0,0 +1,20 @@
+//
+//  DeleteOrganizationInviteRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class DeleteOrganizationInviteRequestTests: XCTestCase {
+    func testDeleteOrganizationInviteRequest() throws {
+        let request = DeleteOrganizationInviteRequest(invitationId: "foo-bar")
+
+        XCTAssertEqual(request.method, HttpMethod.delete)
+        XCTAssertEqual(request.path, "\(RequestType.organizationInvite.basePath)/foo-bar")
+        XCTAssertNil(request.queries)
+        XCTAssertNil(request.body)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/DeleteWorkspaceMemberRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/DeleteWorkspaceMemberRequestTests.swift
new file mode 100644
index 0000000..56c9bfb
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/DeleteWorkspaceMemberRequestTests.swift
@@ -0,0 +1,22 @@
+//
+//  DeleteWorkspaceMemberRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class DeleteWorkspaceMemberRequestTests: XCTestCase {
+    func testDeleteWorkspaceMemberRequest() throws {
+        let userId = "test-user-id"
+        let workspaceId = "test-workspace-id"
+        let request = DeleteWorkspaceMemberRequest(userId: userId, workspaceId: workspaceId)
+
+        XCTAssertEqual(request.method, HttpMethod.delete)
+        XCTAssertEqual(request.path, "\(RequestType.workspaceMember(workspaceId: workspaceId).basePath)/\(userId)")
+        XCTAssertNil(request.queries)
+        XCTAssertNil(request.body)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetAPIKeyRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetAPIKeyRequestTests.swift
new file mode 100644
index 0000000..3f88108
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetAPIKeyRequestTests.swift
@@ -0,0 +1,20 @@
+//
+//  GetAPIKeyRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class GetAPIKeyRequestTests: XCTestCase {
+    func testGetAPIKeyRequest() throws {
+        let request = GetAPIKeyRequest(apiKeyId: "apikeyid")
+
+        XCTAssertEqual(request.method, HttpMethod.get)
+        XCTAssertEqual(request.path, "\(RequestType.apiKey.basePath)/apikeyid")
+        XCTAssertNil(request.queries)
+        XCTAssertNil(request.body)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetOrganizationInviteRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetOrganizationInviteRequestTests.swift
new file mode 100644
index 0000000..ccda114
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetOrganizationInviteRequestTests.swift
@@ -0,0 +1,21 @@
+//
+//  GetOrganizationInviteRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class GetOrganizationInviteRequestTests: XCTestCase {
+    func testGetOrganizationInviteRequest() throws {
+        let invitationId = "invite-id"
+        let request = GetOrganizationInviteRequest(invitationId: invitationId)
+
+        XCTAssertEqual(request.method, HttpMethod.get)
+        XCTAssertEqual(request.path, "\(RequestType.organizationInvite.basePath)/\(invitationId)")
+        XCTAssertNil(request.queries)
+        XCTAssertNil(request.body)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetOrganizationMemberRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetOrganizationMemberRequestTests.swift
new file mode 100644
index 0000000..2fbebac
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetOrganizationMemberRequestTests.swift
@@ -0,0 +1,21 @@
+//
+//  GetOrganizationMemberRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class GetOrganizationMemberRequestTests: XCTestCase {
+    func testGetOrganizationMemberRequest() throws {
+        let userId = "test-user-id"
+        let request = GetOrganizationMemberRequest(userId: userId)
+
+        XCTAssertEqual(request.method, HttpMethod.get)
+        XCTAssertEqual(request.path, "\(RequestType.organizationMember.basePath)/\(userId)")
+        XCTAssertNil(request.queries)
+        XCTAssertNil(request.body)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetWorkspaceMemberRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetWorkspaceMemberRequestTests.swift
new file mode 100644
index 0000000..24b8695
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetWorkspaceMemberRequestTests.swift
@@ -0,0 +1,22 @@
+//
+//  GetWorkspaceMemberRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class GetWorkspaceMemberRequestTests: XCTestCase {
+    func testGetWorkspaceMemberRequest() throws {
+        let userId = "test-user-id"
+        let workspaceId = "test-workspace-id"
+        let request = GetWorkspaceMemberRequest(workspaceId: workspaceId, userId: userId)
+
+        XCTAssertEqual(request.method, HttpMethod.get)
+        XCTAssertEqual(request.path, "\(RequestType.workspaceMember(workspaceId: workspaceId).basePath)/\(userId)")
+        XCTAssertNil(request.queries)
+        XCTAssertNil(request.body)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetWorkspaceRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetWorkspaceRequestTests.swift
new file mode 100644
index 0000000..4914813
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/GetWorkspaceRequestTests.swift
@@ -0,0 +1,21 @@
+//
+//  GetWorkspaceRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class GetWorkspaceRequestTests: XCTestCase {
+    func testGetWorkspaceRequest() throws {
+        let workspaceId = "test-workspace-id"
+        let request = GetWorkspaceRequest(workspaceId: workspaceId)
+
+        XCTAssertEqual(request.method, HttpMethod.get)
+        XCTAssertEqual(request.path, "\(RequestType.workspace.basePath)/\(workspaceId)")
+        XCTAssertNil(request.queries)
+        XCTAssertNil(request.body)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/RemoveOrganizationMemberRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/RemoveOrganizationMemberRequestTests.swift
new file mode 100644
index 0000000..570b704
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/RemoveOrganizationMemberRequestTests.swift
@@ -0,0 +1,21 @@
+//
+//  RemoveOrganizationMemberRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class RemoveOrganizationMemberRequestTests: XCTestCase {
+    func testRemoveOrganizationMemberRequest() throws {
+        let userId = "test-user-id"
+        let request = RemoveOrganizationMemberRequest(userId: userId)
+
+        XCTAssertEqual(request.method, HttpMethod.delete)
+        XCTAssertEqual(request.path, "\(RequestType.organizationMember.basePath)/\(userId)")
+        XCTAssertNil(request.queries)
+        XCTAssertNil(request.body)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateAPIKeyRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateAPIKeyRequestTests.swift
new file mode 100644
index 0000000..0b2a952
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateAPIKeyRequestTests.swift
@@ -0,0 +1,24 @@
+//
+//  UpdateAPIKeyRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class UpdateAPIKeyRequestTests: XCTestCase {
+    func testUpdateAPIKeyRequest() throws {
+        let apiKeyId = "apikeyid"
+        let newKeyName = "newkeyname"
+        let request = UpdateAPIKeyRequest(body: .init(name: newKeyName, status: .inactive), apiKeyId: apiKeyId)
+
+        XCTAssertEqual(request.method, .post)
+        XCTAssertEqual(request.path, "\(RequestType.apiKey.basePath)/\(apiKeyId)")
+        XCTAssertNil(request.queries)
+        XCTAssertNotNil(request.body)
+        XCTAssertEqual(request.body?.name, newKeyName)
+        XCTAssertEqual(request.body?.status, .inactive)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateOrganizationMemberRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateOrganizationMemberRequestTests.swift
new file mode 100644
index 0000000..2fd75ae
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateOrganizationMemberRequestTests.swift
@@ -0,0 +1,23 @@
+//
+//  UpdateOrganizationMemberRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class UpdateOrganizationMemberRequestTests: XCTestCase {
+    func testUpdateOrganizationMemberRequest() throws {
+        let userId = "test-user-id"
+        let role = OrganizationRole.admin
+        let request = UpdateOrganizationMemberRequest(body: .init(role: role), userId: userId)
+
+        XCTAssertEqual(request.method, .post)
+        XCTAssertEqual(request.path, "\(RequestType.organizationMember.basePath)/\(userId)")
+        XCTAssertNil(request.queries)
+        XCTAssertNotNil(request.body)
+        XCTAssertEqual(request.body?.role, role)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateWorkspaceMemberRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateWorkspaceMemberRequestTests.swift
new file mode 100644
index 0000000..129bffc
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateWorkspaceMemberRequestTests.swift
@@ -0,0 +1,24 @@
+//
+//  UpdateWorkspaceMemberRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+@testable import AnthropicSwiftSDK
+
+final class UpdateWorkspaceMemberRequestTests: XCTestCase {
+    func testUpdateWorkspaceMemberRequest() throws {
+        let userId = "test-user-id"
+        let workspaceId = "test-workspace-id"
+        let role = WorkspaceRole.developer
+        let request = UpdateWorkspaceMemberRequest(body: .init(role: role), userId: userId, workspaceId: workspaceId)
+
+        XCTAssertEqual(request.method, HttpMethod.post)
+        XCTAssertEqual(request.path, "\(RequestType.workspaceMember(workspaceId: workspaceId).basePath)/\(userId)")
+        XCTAssertNil(request.queries)
+        XCTAssertNotNil(request.body)
+        XCTAssertEqual(request.body?.role, role)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateWorkspaceRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateWorkspaceRequestTests.swift
new file mode 100644
index 0000000..a47081e
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/Admin/UpdateWorkspaceRequestTests.swift
@@ -0,0 +1,35 @@
+//
+//  UpdateWorkspaceRequestTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/07.
+//
+
+import XCTest
+
+final class UpdateWorkspaceRequestTests: XCTestCase {
+
+    override func setUpWithError() throws {
+        // Put setup code here. This method is called before the invocation of each test method in the class.
+    }
+
+    override func tearDownWithError() throws {
+        // Put teardown code here. This method is called after the invocation of each test method in the class.
+    }
+
+    func testExample() throws {
+        // This is an example of a functional test case.
+        // Use XCTAssert and related functions to verify your tests produce the correct results.
+        // Any test you write for XCTest can be annotated as throws and async.
+        // Mark your test throws to produce an unexpected failure when your test encounters an uncaught error.
+        // Mark your test async to allow awaiting for asynchronous code to complete. Check the results with assertions afterwards.
+    }
+
+    func testPerformanceExample() throws {
+        // This is an example of a performance test case.
+        self.measure {
+            // Put the code you want to measure the time of here.
+        }
+    }
+
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Request/ListMessageBatchesRequestTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Request/ListMessageBatchesRequestTests.swift
index e0f8018..dfd63c7 100644
--- a/Tests/AnthropicSwiftSDKTests/Network/Request/ListMessageBatchesRequestTests.swift
+++ b/Tests/AnthropicSwiftSDKTests/Network/Request/ListMessageBatchesRequestTests.swift
@@ -8,15 +8,15 @@
 import XCTest
 @testable import AnthropicSwiftSDK
 
-final class ListMessageBatchesRequestTests: XCTestCase {
+final class ListObjectRequestTests: XCTestCase {
 
-    func testListMessageBatchesRequestProperties() {
+    func testListObjectRequestProperties() {
         let queries: [String: CustomStringConvertible] = [
             "before_id": "batch123",
             "after_id": "batch456",
             "limit": 10
         ]
-        let request = ListMessageBatchesRequest(queries: queries)
+        let request = ListObjectRequest(queries: queries, type: .batches)
 
         XCTAssertEqual(request.method, .get)
         XCTAssertEqual(request.path, RequestType.batches.basePath)
@@ -27,8 +27,8 @@ final class ListMessageBatchesRequestTests: XCTestCase {
     }
 
     func testParameterRawValues() {
-        XCTAssertEqual(ListMessageBatchesRequest.Parameter.beforeId.rawValue, "before_id")
-        XCTAssertEqual(ListMessageBatchesRequest.Parameter.afterId.rawValue, "after_id")
-        XCTAssertEqual(ListMessageBatchesRequest.Parameter.limit.rawValue, "limit")
+        XCTAssertEqual(ListObjectRequest.Parameter.beforeId.rawValue, "before_id")
+        XCTAssertEqual(ListObjectRequest.Parameter.afterId.rawValue, "after_id")
+        XCTAssertEqual(ListObjectRequest.Parameter.limit.rawValue, "limit")
     }
 }
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Response/APIKeyResponseTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Response/APIKeyResponseTests.swift
new file mode 100644
index 0000000..ac9588c
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Response/APIKeyResponseTests.swift
@@ -0,0 +1,42 @@
+//
+//  APIKeyResponseTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/06.
+//
+
+import XCTest
+import AnthropicSwiftSDK
+
+final class APIKeyResponseTests: XCTestCase {
+    func testDecodeAPIKeyResponse() throws {
+        let json = """
+        {
+          "id": "apikey_01Rj2N8SVvo6BePZj99NhmiT",
+          "type": "api_key",
+          "name": "Developer Key",
+          "workspace_id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "created_at": "2024-10-30T23:58:27.427722Z",
+          "created_by": {
+            "id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+            "type": "user"
+          },
+          "partial_key_hint": "sk-ant-api03-R2D...igAA",
+          "status": "active"
+        }
+        """
+
+        let jsonData = json.data(using: .utf8)!
+        let response = try anthropicJSONDecoder.decode(APIKeyResponse.self, from: jsonData)
+
+        XCTAssertEqual(response.id, "apikey_01Rj2N8SVvo6BePZj99NhmiT")
+        XCTAssertEqual(response.type, .apiKey)
+        XCTAssertEqual(response.name, "Developer Key")
+        XCTAssertEqual(response.workspaceId, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.createdAt, "2024-10-30T23:58:27.427722Z")
+        XCTAssertEqual(response.createdBy.id, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.createdBy.type, "user")
+        XCTAssertEqual(response.partialKeyHint, "sk-ant-api03-R2D...igAA")
+        XCTAssertEqual(response.status, .active)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/BatchResponseTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Response/BatchResponseTests.swift
similarity index 100%
rename from Tests/AnthropicSwiftSDKTests/Network/BatchResponseTests.swift
rename to Tests/AnthropicSwiftSDKTests/Network/Response/BatchResponseTests.swift
diff --git a/Tests/AnthropicSwiftSDKTests/Network/BatchResultResponseTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Response/BatchResultResponseTests.swift
similarity index 100%
rename from Tests/AnthropicSwiftSDKTests/Network/BatchResultResponseTests.swift
rename to Tests/AnthropicSwiftSDKTests/Network/Response/BatchResultResponseTests.swift
diff --git a/Tests/AnthropicSwiftSDKTests/Network/MessagesResponseTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Response/MessagesResponseTests.swift
similarity index 100%
rename from Tests/AnthropicSwiftSDKTests/Network/MessagesResponseTests.swift
rename to Tests/AnthropicSwiftSDKTests/Network/Response/MessagesResponseTests.swift
diff --git a/Tests/AnthropicSwiftSDKTests/Network/BatchListResponseTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Response/ObjectListResponseTests.swift
similarity index 95%
rename from Tests/AnthropicSwiftSDKTests/Network/BatchListResponseTests.swift
rename to Tests/AnthropicSwiftSDKTests/Network/Response/ObjectListResponseTests.swift
index 3d024f4..88203aa 100644
--- a/Tests/AnthropicSwiftSDKTests/Network/BatchListResponseTests.swift
+++ b/Tests/AnthropicSwiftSDKTests/Network/Response/ObjectListResponseTests.swift
@@ -1,5 +1,5 @@
 //
-//  BatchListResponseTests.swift
+//  ObjectListResponseTests.swift
 //  AnthropicSwiftSDK
 //
 //  Created by 伊藤史 on 2024/10/18.
@@ -8,7 +8,7 @@
 import XCTest
 @testable import AnthropicSwiftSDK
 
-final class BatchListResponseTests: XCTestCase {
+final class ObjectListResponseTests: XCTestCase {
     func testDecodeBatchListResponse() throws {
         let json = """
         {
@@ -56,7 +56,7 @@ final class BatchListResponseTests: XCTestCase {
         
         let jsonData = json.data(using: .utf8)!
         
-        let response = try anthropicJSONDecoder.decode(BatchListResponse.self, from: jsonData)
+        let response = try anthropicJSONDecoder.decode(ObjectListResponse<BatchResponse>.self, from: jsonData)
         
         XCTAssertEqual(response.data.count, 2)
         
@@ -96,4 +96,4 @@ final class BatchListResponseTests: XCTestCase {
         XCTAssertEqual(response.firstId, "batch_123")
         XCTAssertEqual(response.lastId, "batch_456")
     }
-}
\ No newline at end of file
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Response/OrganizationInviteResponseTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Response/OrganizationInviteResponseTests.swift
new file mode 100644
index 0000000..98a2024
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Response/OrganizationInviteResponseTests.swift
@@ -0,0 +1,51 @@
+//
+//  OrganizationInviteResponseTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/06.
+//
+
+import XCTest
+import AnthropicSwiftSDK
+
+final class OrganizationInviteResponseTests: XCTestCase {
+    func testDecodeOrganizationInviteResponse() throws {
+        let json = """
+        {
+          "id": "invite_015gWxCN9Hfg2QhZwTK7Mdeu",
+          "type": "invite",
+          "email": "user@emaildomain.com",
+          "role": "user",
+          "invited_at": "2024-10-30T23:58:27.427722Z",
+          "expires_at": "2024-11-20T23:58:27.427722Z",
+          "status": "pending"
+        }
+        """
+
+        let jsonData = json.data(using: .utf8)!
+        let response = try anthropicJSONDecoder.decode(InvitationResponse.self, from: jsonData)
+
+        XCTAssertEqual(response.id, "invite_015gWxCN9Hfg2QhZwTK7Mdeu")
+        XCTAssertEqual(response.type, .invite)
+        XCTAssertEqual(response.email, "user@emaildomain.com")
+        XCTAssertEqual(response.role, .user)
+        XCTAssertEqual(response.invitedAt, "2024-10-30T23:58:27.427722Z")
+        XCTAssertEqual(response.expiresAt, "2024-11-20T23:58:27.427722Z")
+        XCTAssertEqual(response.status, .pending)
+    }
+
+    func testDecodeOrganizationInviteRemoveResponse() throws {
+        let json = """
+        {
+          "id": "invite_015gWxCN9Hfg2QhZwTK7Mdeu",
+          "type": "invite_deleted"
+        }
+        """
+
+        let jsonData = json.data(using: .utf8)!
+        let response = try anthropicJSONDecoder.decode(InvitationRemoveResponse.self, from: jsonData)
+
+        XCTAssertEqual(response.id, "invite_015gWxCN9Hfg2QhZwTK7Mdeu")
+        XCTAssertEqual(response.type, .deleted)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Response/OrganizationMemberResponseTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Response/OrganizationMemberResponseTests.swift
new file mode 100644
index 0000000..5c5cdb3
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Response/OrganizationMemberResponseTests.swift
@@ -0,0 +1,49 @@
+//
+//  OrganizationMemberResponseTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/06.
+//
+
+import XCTest
+import AnthropicSwiftSDK
+
+final class OrganizationMemberResponseTests: XCTestCase {
+    func testDecodeOrganizationMemberResponse() throws {
+        let json = """
+        {
+          "id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+          "type": "user",
+          "email": "user@emaildomain.com",
+          "name": "Jane Doe",
+          "role": "user",
+          "added_at": "2024-10-30T23:58:27.427722Z"
+        }
+        """
+
+        let jsonData = json.data(using: .utf8)!
+        let response = try anthropicJSONDecoder.decode(OrganizationMemberResponse.self, from: jsonData)
+
+        XCTAssertEqual(response.id, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.type, .user)
+        XCTAssertEqual(response.email, "user@emaildomain.com")
+        XCTAssertEqual(response.name, "Jane Doe")
+        XCTAssertEqual(response.role, .user)
+        XCTAssertEqual(response.addedAt, "2024-10-30T23:58:27.427722Z")
+    }
+
+    func testDecodeOrganizationMemberRemoveResponse() throws {
+        let json = """
+        {
+          "id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+          "type": "user_deleted"
+        }
+        """
+
+        let jsonData = json.data(using: .utf8)!
+        let response = try anthropicJSONDecoder.decode(OrganizationMemberRemoveResponse.self, from: jsonData)
+
+        XCTAssertEqual(response.id, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.type, .deleted)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Response/WorkspaceMemberResponseTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Response/WorkspaceMemberResponseTests.swift
new file mode 100644
index 0000000..98eab2b
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Response/WorkspaceMemberResponseTests.swift
@@ -0,0 +1,47 @@
+//
+//  WorkspaceMemberResponseTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/06.
+//
+
+import XCTest
+import AnthropicSwiftSDK
+
+final class WorkspaceMemberResponseTests: XCTestCase {
+    func testDecodeWorkspaceMemberResponse() throws {
+        let json = """
+        {
+          "type": "workspace_member",
+          "user_id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+          "workspace_id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "workspace_role": "workspace_user"
+        }
+        """
+
+        let jsonData = json.data(using: .utf8)!
+        let response = try anthropicJSONDecoder.decode(WorkspaceMemberResponse.self, from: jsonData)
+
+        XCTAssertEqual(response.type, .workspaceMember)
+        XCTAssertEqual(response.userId, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.workspaceId, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.workspaceRole, .user)
+    }
+
+    func testDecodeWorkspaceMemberRemoveResponse() throws {
+        let json = """
+        {
+          "user_id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
+          "workspace_id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "type": "workspace_member_deleted"
+        }
+        """
+
+        let jsonData = json.data(using: .utf8)!
+        let response = try anthropicJSONDecoder.decode(WorkspaceMemberRemoveResponse.self, from: jsonData)
+
+        XCTAssertEqual(response.userId, "user_01WCz1FkmYMm4gnmykNKUu3Q")
+        XCTAssertEqual(response.workspaceId, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.type, .deleted)
+    }
+}
diff --git a/Tests/AnthropicSwiftSDKTests/Network/Response/WorkspaceResponseTests.swift b/Tests/AnthropicSwiftSDKTests/Network/Response/WorkspaceResponseTests.swift
new file mode 100644
index 0000000..0b2fc25
--- /dev/null
+++ b/Tests/AnthropicSwiftSDKTests/Network/Response/WorkspaceResponseTests.swift
@@ -0,0 +1,34 @@
+//
+//  WorkspaceResponseTests.swift
+//  AnthropicSwiftSDK
+//
+//  Created by 伊藤史 on 2024/12/06.
+//
+
+import XCTest
+import AnthropicSwiftSDK
+
+final class WorkspaceResponseTests: XCTestCase {
+    func testDecodeWorkspaceResponse() throws {
+        let json = """
+        {
+          "id": "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ",
+          "type": "workspace",
+          "name": "Workspace Name",
+          "created_at": "2024-10-30T23:58:27.427722Z",
+          "archived_at": "2024-11-01T23:59:27.427722Z",
+          "display_color": "#6C5BB9"
+        }
+        """
+
+        let jsonData = json.data(using: .utf8)!
+        let response = try anthropicJSONDecoder.decode(WorkspaceResponse.self, from: jsonData)
+
+        XCTAssertEqual(response.id, "wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ")
+        XCTAssertEqual(response.type, .workspace)
+        XCTAssertEqual(response.name, "Workspace Name")
+        XCTAssertEqual(response.createdAt, "2024-10-30T23:58:27.427722Z")
+        XCTAssertEqual(response.archivedAt, "2024-11-01T23:59:27.427722Z")
+        XCTAssertEqual(response.displayColor, "#6C5BB9")
+    }
+}