diff --git a/.gitignore b/.gitignore
index d8d32c87..ae8e14c9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -60,3 +60,5 @@ Carthage/Build
 
 fastlane/report.xml
 fastlane/screenshots
+
+.DS_Store
\ No newline at end of file
diff --git a/APIKit.xcodeproj/project.pbxproj b/APIKit.xcodeproj/project.pbxproj
index 8fc0f748..256ebe51 100644
--- a/APIKit.xcodeproj/project.pbxproj
+++ b/APIKit.xcodeproj/project.pbxproj
@@ -7,6 +7,9 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		0ED17E891E229EC700EC1114 /* QueryParameters.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0ED17E881E229EC700EC1114 /* QueryParameters.swift */; };
+		0ED17E8B1E22A22900EC1114 /* URLEncodedQueryParameters.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0ED17E8A1E22A22900EC1114 /* URLEncodedQueryParameters.swift */; };
+		0ED17E8E1E22AC8300EC1114 /* URLEncodedQueryParametersTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0ED17E8D1E22AC8300EC1114 /* URLEncodedQueryParametersTests.swift */; };
 		0969AE0F259DEC6D00C498AF /* Combine.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0969AE0E259DEC6D00C498AF /* Combine.swift */; };
 		0973EE35259E2DDC00879BA2 /* CombineTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0973EE34259E2DDC00879BA2 /* CombineTests.swift */; };
 		7F698E501D9D680C00F1561D /* FormURLEncodedBodyParametersTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7F698E3C1D9D680C00F1561D /* FormURLEncodedBodyParametersTests.swift */; };
@@ -78,6 +81,9 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		0ED17E881E229EC700EC1114 /* QueryParameters.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = QueryParameters.swift; sourceTree = "<group>"; };
+		0ED17E8A1E22A22900EC1114 /* URLEncodedQueryParameters.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = URLEncodedQueryParameters.swift; sourceTree = "<group>"; };
+		0ED17E8D1E22AC8300EC1114 /* URLEncodedQueryParametersTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = URLEncodedQueryParametersTests.swift; sourceTree = "<group>"; };
 		0969AE0E259DEC6D00C498AF /* Combine.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Combine.swift; sourceTree = "<group>"; };
 		0973EE34259E2DDC00879BA2 /* CombineTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CombineTests.swift; sourceTree = "<group>"; };
 		141F120F1C1C96820026D415 /* Base.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; name = Base.xcconfig; path = Configurations/Base.xcconfig; sourceTree = "<group>"; };
@@ -153,6 +159,24 @@
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
+		0ED17E871E229EAC00EC1114 /* QueryParameters */ = {
+			isa = PBXGroup;
+			children = (
+				0ED17E881E229EC700EC1114 /* QueryParameters.swift */,
+				0ED17E8A1E22A22900EC1114 /* URLEncodedQueryParameters.swift */,
+			);
+			name = QueryParameters;
+			path = APIKit/QueryParameters;
+			sourceTree = "<group>";
+		};
+		0ED17E8C1E22AC5D00EC1114 /* QueryParameters */ = {
+			isa = PBXGroup;
+			children = (
+				0ED17E8D1E22AC8300EC1114 /* URLEncodedQueryParametersTests.swift */,
+			);
+			path = QueryParameters;
+			sourceTree = "<group>";
+		};
 		0969AE0D259DEC3C00C498AF /* Combine */ = {
 			isa = PBXGroup;
 			children = (
@@ -240,6 +264,7 @@
 				7F698E451D9D680C00F1561D /* RequestTests.swift */,
 				7F698E491D9D680C00F1561D /* SessionCallbackQueueTests.swift */,
 				7F698E4A1D9D680C00F1561D /* SessionTests.swift */,
+				0ED17E8C1E22AC5D00EC1114 /* QueryParameters */,
 				0973EE33259E2DD000879BA2 /* Combine */,
 				7F698E3B1D9D680C00F1561D /* BodyParametersType */,
 				7F698E401D9D680C00F1561D /* DataParserType */,
@@ -312,6 +337,7 @@
 				7F7048CC1D9D89BE003C99F6 /* Unavailable.swift */,
 				0969AE0D259DEC3C00C498AF /* Combine */,
 				7F85FB8B1C9D317300CEE132 /* SessionAdapter */,
+				0ED17E871E229EAC00EC1114 /* QueryParameters */,
 				7F18BD0D1C972C38003A31DF /* BodyParameters */,
 				7FA19A441C9CC9A2005D25AE /* DataParser */,
 				7F18BD161C9730ED003A31DF /* Serializations */,
@@ -477,12 +503,14 @@
 			files = (
 				7F7048D31D9D89BE003C99F6 /* Unavailable.swift in Sources */,
 				7F7048D11D9D89BE003C99F6 /* Request.swift in Sources */,
+				0ED17E891E229EC700EC1114 /* QueryParameters.swift in Sources */,
 				7F7048E81D9D8A08003C99F6 /* DataParser.swift in Sources */,
 				7F7048CE1D9D89BE003C99F6 /* CallbackQueue.swift in Sources */,
 				7F7048DE1D9D89FB003C99F6 /* AbstractInputStream.m in Sources */,
 				7F7048E31D9D89FB003C99F6 /* MultipartFormDataBodyParameters.swift in Sources */,
 				7F7048F01D9D8A12003C99F6 /* ResponseError.swift in Sources */,
 				7F7048EA1D9D8A08003C99F6 /* JSONDataParser.swift in Sources */,
+				0ED17E8B1E22A22900EC1114 /* URLEncodedQueryParameters.swift in Sources */,
 				7F7048D21D9D89BE003C99F6 /* Session.swift in Sources */,
 				7F7048E01D9D89FB003C99F6 /* Data+InputStream.swift in Sources */,
 				7F7048DF1D9D89FB003C99F6 /* BodyParameters.swift in Sources */,
@@ -512,6 +540,7 @@
 				7F698E501D9D680C00F1561D /* FormURLEncodedBodyParametersTests.swift in Sources */,
 				7F698E581D9D680C00F1561D /* RequestTests.swift in Sources */,
 				ECA8314A1DE4DEBE004EB1B5 /* ProtobufDataParserTests.swift in Sources */,
+				0ED17E8E1E22AC8300EC1114 /* URLEncodedQueryParametersTests.swift in Sources */,
 				7F698E5E1D9D680C00F1561D /* TestRequest.swift in Sources */,
 				7F698E601D9D680C00F1561D /* TestSessionTask.swift in Sources */,
 				0973EE35259E2DDC00879BA2 /* CombineTests.swift in Sources */,
diff --git a/Sources/APIKit/DataParser/DataParser.swift b/Sources/APIKit/DataParser/DataParser.swift
index 304db092..7e0ffbc3 100644
--- a/Sources/APIKit/DataParser/DataParser.swift
+++ b/Sources/APIKit/DataParser/DataParser.swift
@@ -2,10 +2,12 @@ import Foundation
 
 /// `DataParser` protocol provides interface to parse HTTP response body and to state Content-Type to accept.
 public protocol DataParser {
+    associatedtype Parsed
+
     /// Value for `Accept` header field of HTTP request.
     var contentType: String? { get }
 
     /// Return `Any` that expresses structure of response such as JSON and XML.
     /// - Throws: `Error` when parser encountered invalid format data.
-    func parse(data: Data) throws -> Any
+    func parse(data: Data) throws -> Parsed
 }
diff --git a/Sources/APIKit/QueryParameters/QueryParameters.swift b/Sources/APIKit/QueryParameters/QueryParameters.swift
new file mode 100644
index 00000000..6e9f16a5
--- /dev/null
+++ b/Sources/APIKit/QueryParameters/QueryParameters.swift
@@ -0,0 +1,7 @@
+import Foundation
+
+/// `QueryParameters` provides interface to generate HTTP URL query strings.
+public protocol QueryParameters {
+    /// Generate URL query strings.
+    func encode() -> String?
+}
diff --git a/Sources/APIKit/QueryParameters/URLEncodedQueryParameters.swift b/Sources/APIKit/QueryParameters/URLEncodedQueryParameters.swift
new file mode 100644
index 00000000..e4c0f476
--- /dev/null
+++ b/Sources/APIKit/QueryParameters/URLEncodedQueryParameters.swift
@@ -0,0 +1,20 @@
+import Foundation
+
+/// `URLEncodedQueryParameters` serializes form object for HTTP URL query.
+public struct URLEncodedQueryParameters: QueryParameters {
+    /// The parameters to be url encoded.
+    public let parameters: Any
+
+    /// Returns `URLEncodedQueryParameters` that is initialized with parameters.
+    public init(parameters: Any) {
+        self.parameters = parameters
+    }
+
+    /// Generate url encoded `String`.
+    public func encode() -> String? {
+        guard let parameters = parameters as? [String: Any], !parameters.isEmpty else {
+            return nil
+        }
+        return URLEncodedSerialization.string(from: parameters)
+    }
+}
diff --git a/Sources/APIKit/Request.swift b/Sources/APIKit/Request.swift
index efe68c97..115d75c8 100644
--- a/Sources/APIKit/Request.swift
+++ b/Sources/APIKit/Request.swift
@@ -10,6 +10,7 @@ import Foundation
 public protocol Request {
     /// The response type associated with the request type.
     associatedtype Response
+    associatedtype DataParser: APIKit.DataParser
 
     /// The base URL.
     var baseURL: URL { get }
@@ -28,7 +29,7 @@ public protocol Request {
     /// The actual parameters for the URL query. The values of this property will be escaped using `URLEncodedSerialization`.
     /// If this property is not implemented and `method.prefersQueryParameter` is `true`, the value of this property
     /// will be computed from `parameters`.
-    var queryParameters: [String: Any]? { get }
+    var queryParameters: QueryParameters? { get }
 
     /// The actual parameters for the HTTP body. If this property is not implemented and `method.prefersQueryParameter` is `false`,
     /// the value of this property will be computed from `parameters` using `JSONBodyParameters`.
@@ -52,12 +53,12 @@ public protocol Request {
     /// The default implementation of this method is provided to throw `ResponseError.unacceptableStatusCode`
     /// if the HTTP status code is not in `200..<300`.
     /// - Throws: `Error`
-    func intercept(object: Any, urlResponse: HTTPURLResponse) throws -> Any
+    func intercept(object: DataParser.Parsed, urlResponse: HTTPURLResponse) throws -> DataParser.Parsed
 
     /// Build `Response` instance from raw response object. This method is called after
     /// `intercept(object:urlResponse:)` if it does not throw any error.
     /// - Throws: `Error`
-    func response(from object: Any, urlResponse: HTTPURLResponse) throws -> Response
+    func response(from object: DataParser.Parsed, urlResponse: HTTPURLResponse) throws -> Response
 }
 
 public extension Request {
@@ -65,12 +66,12 @@ public extension Request {
         return nil
     }
 
-    var queryParameters: [String: Any]? {
-        guard let parameters = parameters as? [String: Any], method.prefersQueryParameters else {
+    var queryParameters: QueryParameters? {
+        guard let parameters = parameters, method.prefersQueryParameters else {
             return nil
         }
 
-        return parameters
+        return URLEncodedQueryParameters(parameters: parameters)
     }
 
     var bodyParameters: BodyParameters? {
@@ -85,15 +86,11 @@ public extension Request {
         return [:]
     }
 
-    var dataParser: DataParser {
-        return JSONDataParser(readingOptions: [])
-    }
-
     func intercept(urlRequest: URLRequest) throws -> URLRequest {
         return urlRequest
     }
 
-    func intercept(object: Any, urlResponse: HTTPURLResponse) throws -> Any {
+    func intercept(object: DataParser.Parsed, urlResponse: HTTPURLResponse) throws -> DataParser.Parsed {
         guard 200..<300 ~= urlResponse.statusCode else {
             throw ResponseError.unacceptableStatusCode(urlResponse.statusCode)
         }
@@ -110,8 +107,8 @@ public extension Request {
 
         var urlRequest = URLRequest(url: url)
 
-        if let queryParameters = queryParameters, !queryParameters.isEmpty {
-            components.percentEncodedQuery = URLEncodedSerialization.string(from: queryParameters)
+        if let queryString = queryParameters?.encode(), !queryString.isEmpty {
+            components.percentEncodedQuery = queryString
         }
 
         if let bodyParameters = bodyParameters {
@@ -145,3 +142,11 @@ public extension Request {
         return try response(from: passedObject, urlResponse: urlResponse)
     }
 }
+
+public protocol JSONRequest: Request {}
+
+public extension JSONRequest {
+    var dataParser: JSONDataParser {
+        return JSONDataParser(readingOptions: [])
+    }
+}
diff --git a/Sources/APIKit/Session.swift b/Sources/APIKit/Session.swift
index 4406fca9..0bd73d56 100644
--- a/Sources/APIKit/Session.swift
+++ b/Sources/APIKit/Session.swift
@@ -36,8 +36,8 @@ open class Session {
     /// - parameter handler: The closure that receives result of the request.
     /// - returns: The new session task.
     @discardableResult
-    open class func send<Request: APIKit.Request>(_ request: Request, callbackQueue: CallbackQueue? = nil, handler: @escaping (Result<Request.Response, SessionTaskError>) -> Void = { _ in }) -> SessionTask? {
-        return shared.send(request, callbackQueue: callbackQueue, handler: handler)
+    open class func send<Request: APIKit.Request>(_ request: Request, callbackQueue: CallbackQueue? = nil, progressHandler: @escaping (Int64, Int64, Int64) -> Void = { _,_,_ in }, completionHandler: @escaping (Result<Request.Response, SessionTaskError>) -> Void = { _ in }) -> SessionTask? {
+        return shared.send(request, callbackQueue: callbackQueue, progressHandler: progressHandler, completionHandler: completionHandler)
     }
 
     /// Calls `cancelRequests(with:passingTest:)` of `Session.shared`.
@@ -54,7 +54,7 @@ open class Session {
     /// - parameter handler: The closure that receives result of the request.
     /// - returns: The new session task.
     @discardableResult
-    open func send<Request: APIKit.Request>(_ request: Request, callbackQueue: CallbackQueue? = nil, handler: @escaping (Result<Request.Response, SessionTaskError>) -> Void = { _ in }) -> SessionTask? {
+    open func send<Request: APIKit.Request>(_ request: Request, callbackQueue: CallbackQueue? = nil, progressHandler: @escaping (Int64, Int64, Int64) -> Void = { _,_,_ in }, completionHandler: @escaping (Result<Request.Response, SessionTaskError>) -> Void = { _ in }) -> SessionTask? {
         let callbackQueue = callbackQueue ?? self.callbackQueue
 
         let urlRequest: URLRequest
@@ -62,33 +62,38 @@ open class Session {
             urlRequest = try request.buildURLRequest()
         } catch {
             callbackQueue.execute {
-                handler(.failure(.requestError(error)))
+                completionHandler(.failure(.requestError(error)))
             }
             return nil
         }
 
-        let task = adapter.createTask(with: urlRequest) { data, urlResponse, error in
-            let result: Result<Request.Response, SessionTaskError>
-
-            switch (data, urlResponse, error) {
-            case (_, _, let error?):
-                result = .failure(.connectionError(error))
+        let task = adapter.createTask(with: urlRequest,
+            progressHandler: { bytesSent, totalBytesSent, totalBytesExpectedToSend in
+                progressHandler(bytesSent, totalBytesSent, totalBytesExpectedToSend)
+            },
+            completionHandler: { data, urlResponse, error in
+                let result: Result<Request.Response, SessionTaskError>
+
+                switch (data, urlResponse, error) {
+                case (_, _, let error?):
+                    result = .failure(.connectionError(error))
+
+                case (let data?, let urlResponse as HTTPURLResponse, _):
+                    do {
+                        result = .success(try request.parse(data: data as Data, urlResponse: urlResponse))
+                    } catch {
+                        result = .failure(.responseError(error))
+                    }
 
-            case (let data?, let urlResponse as HTTPURLResponse, _):
-                do {
-                    result = .success(try request.parse(data: data as Data, urlResponse: urlResponse))
-                } catch {
-                    result = .failure(.responseError(error))
+                default:
+                    result = .failure(.responseError(ResponseError.nonHTTPURLResponse(urlResponse)))
                 }
 
-            default:
-                result = .failure(.responseError(ResponseError.nonHTTPURLResponse(urlResponse)))
-            }
-
-            callbackQueue.execute {
-                handler(result)
+                callbackQueue.execute {
+                    completionHandler(result)
+                }
             }
-        }
+        )
 
         setRequest(request, forTask: task)
         task.resume()
diff --git a/Sources/APIKit/SessionAdapter/SessionAdapter.swift b/Sources/APIKit/SessionAdapter/SessionAdapter.swift
index d123dae0..3db2b583 100644
--- a/Sources/APIKit/SessionAdapter/SessionAdapter.swift
+++ b/Sources/APIKit/SessionAdapter/SessionAdapter.swift
@@ -11,7 +11,7 @@ public protocol SessionTask: class {
 /// with `Session`.
 public protocol SessionAdapter {
     /// Returns instance that conforms to `SessionTask`. `handler` must be called after success or failure.
-    func createTask(with URLRequest: URLRequest, handler: @escaping (Data?, URLResponse?, Error?) -> Void) -> SessionTask
+    func createTask(with URLRequest: URLRequest, progressHandler: @escaping (Int64, Int64, Int64) -> Void, completionHandler: @escaping (Data?, URLResponse?, Error?) -> Void) -> SessionTask
 
     /// Collects tasks from backend networking stack. `handler` must be called after collecting.
     func getTasks(with handler: @escaping ([SessionTask]) -> Void)
diff --git a/Sources/APIKit/SessionAdapter/URLSessionAdapter.swift b/Sources/APIKit/SessionAdapter/URLSessionAdapter.swift
index 38ac15ef..3077dc8c 100644
--- a/Sources/APIKit/SessionAdapter/URLSessionAdapter.swift
+++ b/Sources/APIKit/SessionAdapter/URLSessionAdapter.swift
@@ -6,6 +6,7 @@ extension URLSessionTask: SessionTask {
 
 private var dataTaskResponseBufferKey = 0
 private var taskAssociatedObjectCompletionHandlerKey = 0
+private var taskAssociatedObjectProgressHandlerKey = 0
 
 /// `URLSessionAdapter` connects `URLSession` with `Session`.
 ///
@@ -25,11 +26,12 @@ open class URLSessionAdapter: NSObject, SessionAdapter, URLSessionDelegate, URLS
     }
 
     /// Creates `URLSessionDataTask` instance using `dataTaskWithRequest(_:completionHandler:)`.
-    open func createTask(with URLRequest: URLRequest, handler: @escaping (Data?, URLResponse?, Error?) -> Void) -> SessionTask {
+    open func createTask(with URLRequest: URLRequest, progressHandler: @escaping (Int64, Int64, Int64) -> Void, completionHandler: @escaping (Data?, URLResponse?, Error?) -> Void) -> SessionTask {
         let task = urlSession.dataTask(with: URLRequest)
 
         setBuffer(NSMutableData(), forTask: task)
-        setHandler(handler, forTask: task)
+        setHandler(completionHandler, forTask: task)
+        setProgressHandler(progressHandler, forTask: task)
 
         return task
     }
@@ -58,6 +60,13 @@ open class URLSessionAdapter: NSObject, SessionAdapter, URLSessionDelegate, URLS
         return objc_getAssociatedObject(task, &taskAssociatedObjectCompletionHandlerKey) as? (Data?, URLResponse?, Error?) -> Void
     }
 
+    private func setProgressHandler(_ progressHandler: @escaping (Int64, Int64, Int64) -> Void, forTask task: URLSessionTask) {
+        objc_setAssociatedObject(task, &taskAssociatedObjectProgressHandlerKey, progressHandler as Any, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
+    }
+
+    private func progressHandler(for task: URLSessionTask) -> ((Int64, Int64, Int64) -> Void)? {
+        return objc_getAssociatedObject(task, &taskAssociatedObjectProgressHandlerKey) as? (Int64, Int64, Int64) -> Void
+    }
     // MARK: URLSessionTaskDelegate
     open func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) {
         handler(for: task)?(buffer(for: task) as Data?, task.response, error)
@@ -67,4 +76,9 @@ open class URLSessionAdapter: NSObject, SessionAdapter, URLSessionDelegate, URLS
     open func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
         buffer(for: dataTask)?.append(data)
     }
+
+    // MARK: URLSessionDataDelegate
+    open func urlSession(_ session: URLSession, task: URLSessionTask, didSendBodyData bytesSent: Int64, totalBytesSent: Int64, totalBytesExpectedToSend: Int64) {
+        progressHandler(for: task)?(bytesSent, totalBytesSent, totalBytesExpectedToSend)
+    }
 }
diff --git a/Tests/APIKitTests/QueryParameters/URLEncodedQueryParametersTests.swift b/Tests/APIKitTests/QueryParameters/URLEncodedQueryParametersTests.swift
new file mode 100644
index 00000000..a764e00c
--- /dev/null
+++ b/Tests/APIKitTests/QueryParameters/URLEncodedQueryParametersTests.swift
@@ -0,0 +1,19 @@
+import XCTest
+import APIKit
+
+class URLEncodedQueryParametersTests: XCTestCase {
+    func testURLEncodedSuccess() {
+        let object: [String: Any] = ["foo": "string", "bar": 1, "q": "こんにちは"]
+        let parameters = URLEncodedQueryParameters(parameters: object)
+        guard let query = parameters.encode() else {
+            XCTFail()
+            return
+        }
+
+        let items = query.components(separatedBy: "&")
+        XCTAssertEqual(items.count, 3)
+        XCTAssertTrue(items.contains("foo=string"))
+        XCTAssertTrue(items.contains("bar=1"))
+        XCTAssertTrue(items.contains("q=%E3%81%93%E3%82%93%E3%81%AB%E3%81%A1%E3%81%AF"))
+    }
+}
diff --git a/Tests/APIKitTests/SessionAdapterType/URLSessionAdapterSubclassTests.swift b/Tests/APIKitTests/SessionAdapterType/URLSessionAdapterSubclassTests.swift
index 4820dde3..a75b329e 100644
--- a/Tests/APIKitTests/SessionAdapterType/URLSessionAdapterSubclassTests.swift
+++ b/Tests/APIKitTests/SessionAdapterType/URLSessionAdapterSubclassTests.swift
@@ -15,6 +15,11 @@ class URLSessionAdapterSubclassTests: XCTestCase {
             functionCallFlags[(#function)] = true
             super.urlSession(session, dataTask: dataTask, didReceive: data)
         }
+
+        override func urlSession(_ session: URLSession, task: URLSessionTask, didSendBodyData bytesSent: Int64, totalBytesSent: Int64, totalBytesExpectedToSend: Int64) {
+            functionCallFlags[(#function)] = true
+            super.urlSession(session, task: task, didSendBodyData: bytesSent, totalBytesSent: totalBytesSent, totalBytesExpectedToSend: totalBytesExpectedToSend)
+        }
     }
 
     var adapter: SessionAdapter!
@@ -50,4 +55,20 @@ class URLSessionAdapterSubclassTests: XCTestCase {
         XCTAssertEqual(adapter.functionCallFlags["urlSession(_:task:didCompleteWithError:)"], true)
         XCTAssertEqual(adapter.functionCallFlags["urlSession(_:dataTask:didReceive:)"], true)
     }
+
+    // Limitation: 'urlSession:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:' delegate method will never be called when you stub the request using subclass of URLProtocol.
+    func testDelegateProgressMethodCall() {
+        let expectation = self.expectation(description: "wait for response")
+        let request = TestRequest(baseURL: "https://httpbin.org", path: "/post", method: .post)
+        let configuration = URLSessionConfiguration.default
+        let adapter = SessionAdapter(configuration: configuration)
+        let session = Session(adapter: adapter)
+
+        session.send(request, progressHandler: { _, _, _ in
+            expectation.fulfill()
+        })
+
+        waitForExpectations(timeout: 10.0, handler: nil)
+        XCTAssertEqual(adapter.functionCallFlags["urlSession(_:task:didSendBodyData:totalBytesSent:totalBytesExpectedToSend:)"], true)
+    }
 }
diff --git a/Tests/APIKitTests/SessionTests.swift b/Tests/APIKitTests/SessionTests.swift
index d65a235e..f4908a17 100644
--- a/Tests/APIKitTests/SessionTests.swift
+++ b/Tests/APIKitTests/SessionTests.swift
@@ -174,7 +174,7 @@ class SessionTests: XCTestCase {
         waitForExpectations(timeout: 1.0, handler: nil)
     }
 
-    struct AnotherTestRequest: Request {
+    struct AnotherTestRequest: JSONRequest {
         typealias Response = Void
 
         var baseURL: URL {
@@ -222,6 +222,23 @@ class SessionTests: XCTestCase {
         waitForExpectations(timeout: 1.0, handler: nil)
     }
 
+    func testProgress() {
+        let dictionary = ["key": "value"]
+        adapter.data = try! JSONSerialization.data(withJSONObject: dictionary, options: [])
+
+        let expectation = self.expectation(description: "wait for response")
+        let request = TestRequest(method: .post)
+
+        session.send(request, progressHandler: { bytesSent, totalBytesSent, totalBytesExpectedToSend in
+            XCTAssertNotNil(bytesSent)
+            XCTAssertNotNil(totalBytesSent)
+            XCTAssertNotNil(totalBytesExpectedToSend)
+            expectation.fulfill()
+        })
+
+        waitForExpectations(timeout: 1.0, handler: nil)
+    }
+
     // MARK: Class methods
     func testSharedSession() {
         XCTAssert(Session.shared === Session.shared)
@@ -237,12 +254,13 @@ class SessionTests: XCTestCase {
                 return testSesssion
             }
 
-            override func send<Request : APIKit.Request>(_ request: Request, callbackQueue: CallbackQueue?, handler: @escaping (Result<Request.Response, SessionTaskError>) -> Void) -> SessionTask? {
+            override func send<Request: APIKit.Request>(_ request: Request, callbackQueue: CallbackQueue?, progressHandler: @escaping (Int64, Int64, Int64) -> Void, completionHandler: @escaping (Result<Request.Response, SessionTaskError>) -> Void) -> SessionTask? {
+
                 functionCallFlags[(#function)] = true
                 return super.send(request)
             }
 
-            override func cancelRequests<Request : APIKit.Request>(with requestType: Request.Type, passingTest test: @escaping (Request) -> Bool) {
+            override func cancelRequests<Request: APIKit.Request>(with requestType: Request.Type, passingTest test: @escaping (Request) -> Bool) {
                 functionCallFlags[(#function)] = true
             }
         }
@@ -251,7 +269,7 @@ class SessionTests: XCTestCase {
         SessionSubclass.send(TestRequest())
         SessionSubclass.cancelRequests(with: TestRequest.self)
 
-        XCTAssertEqual(testSession.functionCallFlags["send(_:callbackQueue:handler:)"], true)
+        XCTAssertEqual(testSession.functionCallFlags["send(_:callbackQueue:progressHandler:completionHandler:)"], true)
         XCTAssertEqual(testSession.functionCallFlags["cancelRequests(with:passingTest:)"], true)
     }
 }
diff --git a/Tests/APIKitTests/TestComponents/TestRequest.swift b/Tests/APIKitTests/TestComponents/TestRequest.swift
index e3bc69aa..32cd5317 100644
--- a/Tests/APIKitTests/TestComponents/TestRequest.swift
+++ b/Tests/APIKitTests/TestComponents/TestRequest.swift
@@ -1,7 +1,7 @@
 import Foundation
 import APIKit
 
-struct TestRequest: Request {
+struct TestRequest: JSONRequest {
     var absoluteURL: URL? {
         let urlRequest = try? buildURLRequest()
         return urlRequest?.url
diff --git a/Tests/APIKitTests/TestComponents/TestSessionAdapter.swift b/Tests/APIKitTests/TestComponents/TestSessionAdapter.swift
index 4813c23c..b9c3cdb1 100644
--- a/Tests/APIKitTests/TestComponents/TestSessionAdapter.swift
+++ b/Tests/APIKitTests/TestComponents/TestSessionAdapter.swift
@@ -40,17 +40,18 @@ class TestSessionAdapter: SessionAdapter {
     func executeAllTasks() {
         for task in tasks {
             if task.cancelled {
-                task.handler(nil, nil, Error.cancelled)
+                task.completionHandler(nil, nil, Error.cancelled)
             } else {
-                task.handler(data, urlResponse, error)
+                task.progressHandler(1, 1, 1)
+                task.completionHandler(data, urlResponse, error)
             }
         }
 
         tasks = []
     }
 
-    func createTask(with URLRequest: URLRequest, handler: @escaping (Data?, URLResponse?, Swift.Error?) -> Void) -> SessionTask {
-        let task = TestSessionTask(handler: handler)
+    func createTask(with URLRequest: URLRequest, progressHandler: @escaping (Int64, Int64, Int64) -> Void, completionHandler: @escaping (Data?, URLResponse?, Swift.Error?) -> Void) -> SessionTask {
+        let task = TestSessionTask(progressHandler: progressHandler, completionHandler: completionHandler)
         tasks.append(task)
 
         return task
diff --git a/Tests/APIKitTests/TestComponents/TestSessionTask.swift b/Tests/APIKitTests/TestComponents/TestSessionTask.swift
index 5bf7927a..af230b48 100644
--- a/Tests/APIKitTests/TestComponents/TestSessionTask.swift
+++ b/Tests/APIKitTests/TestComponents/TestSessionTask.swift
@@ -2,12 +2,14 @@ import Foundation
 import APIKit
 
 class TestSessionTask: SessionTask {
-    
-    var handler: (Data?, URLResponse?, Error?) -> Void
+
+    var completionHandler: (Data?, URLResponse?, Error?) -> Void
+    var progressHandler: (Int64, Int64, Int64) -> Void
     var cancelled = false
 
-    init(handler: @escaping (Data?, URLResponse?, Error?) -> Void) {
-        self.handler = handler
+    init(progressHandler: @escaping  (Int64, Int64, Int64) -> Void, completionHandler: @escaping (Data?, URLResponse?, Error?) -> Void) {
+        self.completionHandler = completionHandler
+        self.progressHandler = progressHandler
     }
 
     func resume() {