diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5998d8c..b514580 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,15 +7,15 @@ jobs:
   SwiftLint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: SwiftLint
         uses: norio-nomura/action-swiftlint@3.2.1
   Test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Cache Swift build
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: .build
           key: ${{ runner.os }}-build
diff --git a/.swiftlint.yml b/.swiftlint.yml
index 80c9d09..2416a49 100644
--- a/.swiftlint.yml
+++ b/.swiftlint.yml
@@ -2,6 +2,7 @@ disabled_rules:
   - closure_parameter_position
   - identifier_name
   - multiple_closures_with_trailing_closure
+  - type_name
 opt_in_rules:
   - attributes
   - closure_end_indentation
@@ -11,7 +12,6 @@ opt_in_rules:
   - contains_over_filter_is_empty
   - contains_over_first_not_nil
   - contains_over_range_nil_comparison
-  - convenience_type
   - empty_count
   - empty_string
   - explicit_init
diff --git a/Package.swift b/Package.swift
index 05c87ec..3b562c2 100644
--- a/Package.swift
+++ b/Package.swift
@@ -11,7 +11,7 @@ let package = Package(
 		.visionOS(.v1)
 	],
 	products: [
-		.library(name: "EndpointBuilderURLSession", targets: ["EndpointBuilderURLSession"]),
+		.library(name: "EndpointBuilderURLSession", targets: ["EndpointBuilderURLSession"])
 	],
 	dependencies: [
 		.package(url: "https://github.com/apple/swift-http-types", from: "1.0.0"),
@@ -24,6 +24,12 @@ let package = Package(
 				.product(name: "EndpointBuilder", package: "endpoint-builder"),
 				.product(name: "HTTPTypes", package: "swift-http-types")
 			]
+		),
+		.testTarget(
+			name: "EndpointBuilderURLSessionTests",
+			dependencies: [
+				.byName(name: "EndpointBuilderURLSession")
+			]
 		)
 	]
 )
diff --git a/Sources/EndpointBuilderURLSession/EndpointBuilderURLSession.swift b/Sources/EndpointBuilderURLSession/EndpointBuilderURLSession.swift
index ab293bf..e1c3616 100644
--- a/Sources/EndpointBuilderURLSession/EndpointBuilderURLSession.swift
+++ b/Sources/EndpointBuilderURLSession/EndpointBuilderURLSession.swift
@@ -6,31 +6,35 @@ import FoundationNetworking
 import HTTPTypes
 
 /// An API endpoint client that uses `URLSession` to create requests
-public struct EndpointBuilderURLSession: Sendable {
+public protocol EndpointBuilderURLSession: Sendable {
 
 	/// The base server URL on which endpoint paths will be appended
-	public let serverBaseURL: URL
+	var serverBaseURL: URL { get }
 
 	/// The URLSession object that will make requests
-	public let urlSession: @Sendable () -> URLSession
+	var urlSession: @Sendable () -> URLRequestHandler { get }
 
 	/// JSON encoder
-	public let encoder: @Sendable () -> JSONEncoder
+	var encoder: @Sendable () -> JSONEncoder { get }
 
 	/// JSON decoder
-	public let decoder: @Sendable () -> JSONDecoder
-
-	/// Creates a new `EndpointBuilderURLSession`.
-	public init(
-		serverBaseURL: URL,
-		urlSession: @Sendable @escaping () -> URLSession = { URLSession.shared },
-		encoder: @Sendable @escaping () -> JSONEncoder = { JSONEncoder() },
-		decoder: @Sendable @escaping () -> JSONDecoder = { JSONDecoder() }
-	) {
-		self.serverBaseURL = serverBaseURL
-		self.urlSession = urlSession
-		self.encoder = encoder
-		self.decoder = decoder
+	var decoder: @Sendable () -> JSONDecoder { get }
+
+}
+
+// Default values
+extension EndpointBuilderURLSession {
+
+	public var urlSession: @Sendable () -> URLSession {
+		{ URLSession.shared }
+	}
+
+	public var encoder: @Sendable () -> JSONEncoder {
+		{ JSONEncoder() }
+	}
+
+	var decoder: @Sendable () -> JSONDecoder {
+		{ JSONDecoder() }
 	}
 
 }
@@ -70,7 +74,8 @@ extension EndpointBuilderURLSession {
 		}
 
 		// perform request
-		return try await urlSession().responseData(for: request)
+		let (data, _) = try await urlSession().data(for: request)
+		return data
 	}
 
 }
@@ -90,24 +95,3 @@ extension URL {
 	}
 
 }
-
-extension URLSession {
-
-	func responseData(for request: URLRequest) async throws -> Data {
-		#if canImport(FoundationNetworking)
-		await withCheckedContinuation { continuation in
-			self.dataTask(with: request) { data, _, _ in
-				guard let data = data else {
-					continuation.resume(returning: Data())
-					return
-				}
-				continuation.resume(returning: data)
-			}.resume()
-		}
-		#else
-		let (data, _) = try await self.data(for: request)
-		return data
-		#endif
-	}
-
-}
diff --git a/Sources/EndpointBuilderURLSession/URLRequestHandler.swift b/Sources/EndpointBuilderURLSession/URLRequestHandler.swift
new file mode 100644
index 0000000..e693f8f
--- /dev/null
+++ b/Sources/EndpointBuilderURLSession/URLRequestHandler.swift
@@ -0,0 +1,34 @@
+import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
+
+public protocol URLRequestHandler: Sendable {
+
+	func data(for request: URLRequest) async throws -> (Data, URLResponse)
+
+}
+
+extension URLSession: URLRequestHandler {}
+
+#if canImport(FoundationNetworking)
+enum URLRequestHandlerError: Error {
+	case noResponse
+}
+
+extension URLSession {
+
+	public func data(for request: URLRequest) async throws -> (Data, URLResponse) {
+		try await withCheckedThrowingContinuation { continuation in
+			self.dataTask(with: request) { data, response, error in
+				guard let data = data, let response = response else {
+					continuation.resume(throwing: error ?? URLRequestHandlerError.noResponse)
+					return
+				}
+				continuation.resume(returning: (data, response))
+			}.resume()
+		}
+	}
+
+}
+#endif
diff --git a/Tests/EndpointBuilderURLSessionTests/EndpointBuilderURLSessionTests.swift b/Tests/EndpointBuilderURLSessionTests/EndpointBuilderURLSessionTests.swift
new file mode 100644
index 0000000..20262a7
--- /dev/null
+++ b/Tests/EndpointBuilderURLSessionTests/EndpointBuilderURLSessionTests.swift
@@ -0,0 +1,77 @@
+import EndpointBuilder
+@testable import EndpointBuilderURLSession
+import HTTPTypes
+import RoutingKit
+import XCTest
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
+
+struct MockURLSession: URLRequestHandler {
+
+	let requestHandler: @Sendable (URLRequest) -> Data
+
+	func data(for request: URLRequest) async throws -> (Data, URLResponse) {
+		let data = requestHandler(request)
+		return (
+			data,
+			URLResponse(url: request.url!, mimeType: nil, expectedContentLength: 0, textEncodingName: nil)
+		)
+	}
+
+}
+
+final class EndpointBuilderURLSessionTests: XCTestCase {
+
+	@Endpoint
+	struct EndpointWithNoResponse {
+		static let path: [PathComponent] = ["blank"]
+		static let httpMethod = HTTPRequest.Method.get
+	}
+
+	@Endpoint
+	struct EndpointWithStringResponseAndPathComponent {
+		static let path: [PathComponent] = ["echo", ":id"]
+		static let httpMethod = HTTPRequest.Method.post
+		static let responseType = String.self
+		let body: String
+	}
+
+	struct APIClient: EndpointBuilderURLSession {
+
+		let serverBaseURL = URL(string: "https://api.shipyard.studio")!
+		let urlSession: @Sendable () -> URLRequestHandler
+
+		init(mockSession: MockURLSession) {
+			let session: @Sendable () -> URLRequestHandler = { mockSession }
+			self.urlSession = session
+		}
+
+	}
+
+	func testEndpointWithNoResponse() async throws {
+		let endpoint = EndpointWithNoResponse()
+		let client = APIClient(mockSession: MockURLSession(requestHandler: { urlRequest in
+			XCTAssertEqual(urlRequest.url?.pathComponents, ["/", "blank"])
+			XCTAssertEqual(urlRequest.httpMethod, "GET")
+			return Data()
+		}))
+		try await client.request(endpoint)
+	}
+
+	func testEndpointWithStringResponse() async throws {
+		let endpoint = EndpointWithStringResponseAndPathComponent(
+			body: "hello",
+			pathParameters: EndpointWithStringResponseAndPathComponent.PathParameters(id: "my-ids")
+		)
+		let client = APIClient(mockSession: MockURLSession(requestHandler: { urlRequest in
+			XCTAssertEqual(urlRequest.url?.pathComponents, ["/", "echo", "my-ids"])
+			XCTAssertEqual(urlRequest.httpMethod, "POST")
+			XCTAssertEqual(urlRequest.httpBody, try? JSONEncoder().encode("hello"))
+			return (try? JSONEncoder().encode("world")) ?? Data()
+		}))
+		let response = try await client.request(endpoint)
+		XCTAssertEqual(response, "world")
+	}
+
+}