Latest 1.1
License MIT
Platforms ios 8.0

What is it?

Packer is a networking library that makes your requests "plug and play". Easy!



github "stone-payments/packer"


pod ‘Packer’



Every request that one specific API has will need to be represented by a class/struct that implements the APIRequest protocol. It will require to specific a typealias for Response indicating what is expected to be the response for this request. You will also need to implement a property resourceName containing the endpoint for this request in the API. It’s good to use a read-only computed property for this so that the Codable will not consider this property in the serialization.

The Response’s type must implement the Decodable protocol. And any property in the request tree must implement the Encodable protocol.

Request example:
struct FooRequest: APIRequest {
    // this is the type of the response for this request
    typealias Response = FooResponse

    // the string containing the endpoing should be a computed property
    var resourceName: String {
        return "fooEndpoint"

    var foo: String
    var bar: Int
Response example:
struct FooResponse: Decodable {
    var status: Bool
    var message: String
What if I have a GET request that does not use query string?
struct FooRequest: APIRequest {
    typealias Response = FooResponse

    // build the URL using the ID property
    var resourceName: String {
        return "foo/(fooId)"

    // then make the property for the ID private so it will be ignored in the serialization
    private var fooId: String


For each API you consume in your app you will need to implement the protocol APIClient.
Initialize the baseUrl property with a string having the base URL for the API. The property session must be a URLSession and the dataTask a URLSessionDataTask. And finally, implement the function send.

class FooAPI: APIClient {
    // we initialize with a default configuration
    var session = URLSession(configuration: .default)
    // here we only declare it
    var dataTask: URLSessionDataTask?
    // the base URL for the API
    var baseUrl = ""
    var headers: [String : String] = ["Authorization":"API-TOKEN"]

    // this is how we implement the 'send' function for this example API
    func send<T>(_ request: T, method: HTTPMethod, completion: @escaping (Result<T.Response>) -> Void) where T : APIRequest {
        do {
            let urlRequest = try method.urlRequest(urlString: baseUrl, request: request, headers: headers)
            dataTask = session.dataTask(with: urlRequest) { data, response, error in
                if let data = data {
                    do {
                        if let response = response as? HTTPURLResponse,
                            (200...204).contains(response.statusCode) { // specify this according to the API

                            let objectResponse = try JSONDecoder().decode(T.Response.self, from: data)
                        else { // we are considering everything that's not 200 as an error
                            completion(.failure(APIError.server(errors: ["Error"], message: "API error.")))
                    } catch {
                else if let error = error {
                else {
                    completion(.failure(APIError.server(errors: ["Error"], message: nil)))
        catch {

Note that the HTTPMethod is an Enum and has a function called urlRequest that can be used to build the URLRequest that will be used in the DataTask.

Using the API client

Sending a FooRequest as POST
let fooRequest = FooRequest(foo: "Test", bar: 42)
let fooClient = FooAPI()
fooClient.send(fooRequest, method: .post) { result in
    switch result {
    case .success(let response):
    case .failure(let error):

Latest podspec

    "name": "Packer",
    "version": "1.1",
    "summary": "One more network library in Swift.",
    "description": "Packer is a networking library that makes your requests 'plug and play'. Easy!",
    "homepage": "",
    "license": {
        "type": "MIT",
        "file": "LICENSE"
    "authors": "Jaison Vieira",
    "social_media_url": "",
    "platforms": {
        "ios": "8.0"
    "source": {
        "git": "",
        "tag": "1.1"
    "source_files": [

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