[api-upload-refactor] API networking refactor (v2.0.0)

Typed request bodies (HTTPBody), first-class MultipartForm uploads, API as an
actor, Decodable & Sendable responses, bounded persistConnection retries, zero
force operations, deployment target iOS 15. Breaking change - see
Documentation/API.md and decisions/2026-08-29-api-typed-body-upload.md.

Documentation/API.md

@@ -0,0 +1,236 @@
+# `API` — networking for LCEssentials
+
+`API` is an `actor` that wraps `URLSession` for JSON REST calls and multipart
+uploads. One line to send a typed request, decode the response, and get a
+consistent error — instead of re-writing the same `URLRequest` / status-code /
+`JSONDecoder` boilerplate in every project.
+
+```swift
+import LCEssentials
+
+struct User: Decodable, Sendable { let id: Int; let name: String }
+
+let user: User = try await API.shared.request(
+    url: "https://api.example.com/users/{id}",
+    method: .get,
+    pathParams: ["id": "42"]
+)
+```
+
+---
+
+## Why not hand-rolled `URLSession`
+
+| Hand-rolled `URLSession` | `API` |
+|---|---|
+| Build `URLRequest`, set method, headers, body, `Content-Type`, `Content-Length` every call | `request(url:method:body:)` — headers and content metadata handled |
+| `switch` on `httpResponse.statusCode` in every call site, or forget to | 2xx decodes, 4xx/5xx throw a populated `NSError` (`.code` = HTTP status, failure reason = response body) |
+| `JSONDecoder().decode(T.self, from:)` + custom error messages each time | `JSONDecoder.decode` with keyed / type-mismatch / missing-value diagnostics baked in |
+| Multipart body assembled by hand with `\r\n` string concatenation and force-unwrapped `.data(using:)` | `MultipartForm` builder; body streamed from a temp file, never fully in memory |
+| Large file upload loads the whole file into a `Data` | `form.file(_:url:)` streams from disk in 64 KB chunks |
+| Retry logic copy-pasted, often unbounded | `persistConnection: true`, bounded by `API.maxPersistRetries` |
+| Client-certificate (mTLS) needs a custom `URLSessionDelegate` per project | `setupCertification(certData:password:)` |
+| Progress reporting needs a delegate + KVO wiring | `upload(..., onProgress:)` |
+| `@MainActor` hops or manual `DispatchQueue` juggling | `actor`-isolated, `Sendable`-checked, runs off the main thread |
+| Response types must be `Codable` even when only decoding | `T: Decodable & Sendable` |
+
+`API` is not a replacement for a full networking stack (no interceptors,
+caching policy DSL, or automatic token refresh). For simple typed REST it
+removes the boilerplate and the easy-to-get-wrong parts.
+
+---
+
+## Requests
+
+### GET
+
+```swift
+let items: [Item] = try await API.shared.request(
+    url: "https://api.example.com/items",
+    method: .get
+)
+```
+
+### POST / PUT / PATCH with a JSON body
+
+`body` takes any `HTTPBody`. `jsonBody(_:)` wraps an `Encodable & Sendable`
+value; `Content-Type: application/json; charset=UTF-8` is set for you.
+
+```swift
+struct CreateUser: Encodable, Sendable { let name: String; let email: String }
+
+let created: User = try await API.shared.request(
+    url: "https://api.example.com/users",
+    method: .post,
+    body: jsonBody(CreateUser(name: "Ana", email: "ana@example.com"))
+)
+```
+
+### Form-url-encoded body
+
+```swift
+let token: TokenDTO = try await API.shared.request(
+    url: "https://api.example.com/oauth/token",
+    method: .post,
+    body: .form([
+        "grant_type": "password",
+        "username": "ana",
+        "password": "s3cr3t"          // reserved chars are percent-escaped, never dropped
+    ])
+)
+```
+
+### Raw body (you control the bytes and content type)
+
+```swift
+body: RawBody(data: protobufData, contentType: "application/x-protobuf")
+```
+
+### Path parameters
+
+`{name}` placeholders in `url` are filled from `pathParams`:
+
+```swift
+url: "https://api.example.com/teams/{team}/members/{member}",
+pathParams: ["team": "42", "member": "7"]
+```
+
+### Custom headers
+
+Merged over the defaults — your value wins per key, the other defaults stay.
+
+```swift
+headers: ["Authorization": "Bearer \(accessToken)"]
+```
+
+### Plain-text / string responses
+
+When `T == String` the raw response body is returned without JSON decoding:
+
+```swift
+let csv: String = try await API.shared.request(url: "\(base)/export.csv", method: .get)
+```
+
+### Retry on transient 4xx
+
+```swift
+let data: Payload = try await API.shared.request(
+    url: "\(base)/flaky",
+    method: .get,
+    persistConnection: true      // retries up to API.maxPersistRetries, then throws
+)
+```
+
+### Other options
+
+| Parameter | Default | Meaning |
+|---|---|---|
+| `debug` | `true` | Print request/response logs |
+| `timeoutInterval` | `30` | Seconds |
+| `networkServiceType` | `.default` | `URLRequest.NetworkServiceType` |
+
+---
+
+## Errors
+
+Non-2xx responses throw an `NSError`:
+
+```swift
+do {
+    let u: User = try await API.shared.request(url: "\(base)/users/999", method: .get)
+} catch let error as NSError {
+    error.code                       // HTTP status, e.g. 404
+    error.localizedDescription       // from URLError
+    error.localizedFailureReason     // pretty-printed response body
+}
+```
+
+Transport failures surface as `URLError`. Malformed success bodies throw
+`DecodingError` with a readable message (missing key, type mismatch, …).
+
+---
+
+## Uploads
+
+### Build a multipart form
+
+```swift
+var form = MultipartForm()
+form.field("caption", "Sunset")
+form.file("thumbnail", data: jpegData, filename: "thumb.jpg")          // in memory
+form.file("video", url: localVideoURL)                                  // streamed from disk
+```
+
+- `field(_:_:)` — plain text field.
+- `file(_:data:filename:mime:)` — in-memory blob. MIME guessed from the
+  filename extension unless you pass `mime:`.
+- `file(_:url:filename:mime:)` — on-disk file, streamed straight into the body
+  so a large file never becomes fully resident in memory.
+
+### Send
+
+```swift
+let result: UploadResult = try await API.shared.upload(
+    url: "https://api.example.com/media",
+    form: form
+)
+```
+
+The body is serialised to a temp file and always removed afterwards, on success
+and on throw.
+
+### With progress
+
+```swift
+let result: UploadResult = try await API.shared.upload(
+    url: "https://api.example.com/media",
+    form: form,
+    onProgress: { fraction in
+        Task { @MainActor in progressView.progress = Float(fraction) }
+    }
+)
+```
+
+`onProgress` is called on an arbitrary queue with a value in `0.0...1.0`, then
+`1.0` once the body has been fully sent. Hop to the main actor yourself before
+touching UI.
+
+---
+
+## Client certificate (mutual TLS)
+
+```swift
+let p12 = try Data(contentsOf: certificateURL)
+await API.shared.setupCertification(certData: p12, password: "cert-password")
+// subsequent requests present the client certificate on TLS challenge
+```
+
+---
+
+## Extending: custom body types
+
+Conform to `HTTPBody`:
+
+```swift
+struct CSVBody: HTTPBody {
+    let rows: [[String]]
+    func encoded() throws -> (data: Data, contentType: String) {
+        let text = rows.map { $0.joined(separator: ",") }.joined(separator: "\n")
+        return (Data(text.utf8), "text/csv; charset=UTF-8")
+    }
+}
+
+try await API.shared.request(url: "\(base)/import", method: .post, body: CSVBody(rows: rows))
+```
+
+`API` needs no change to accept it.
+
+---
+
+## Notes
+
+- `API` is an `actor`. Every call is `await`; config setters
+  (`setupCertification`, `setPersistConnectionDelay`) are `await` too.
+- Response and body types must be `Sendable`. Value-type structs already are.
+- The shared instance is `API.shared`. Tests build isolated instances with
+  `API(testConfiguration:)` and a stub `URLProtocol`.

Package.resolved

@@ -1,13 +1,13 @@
 {
-  "originHash" : "967609fc5437e21be07c4206e2daefc73c3c7522601e64540f0dd5f115b19a6d",
+  "originHash" : "6e3fcf8724d6b7d2d0bbffc25b4ec3b9d8b65a6ef53d157498d5447fd26cf5db",
   "pins" : [
     {
       "identity" : "lcecryptokitbinary",
       "kind" : "remoteSourceControl",
       "location" : "https://60c260c85d3a2fe840411b0ff98f521b5eca3c56@git.loverde.com.br/Loverde-Company-LTDA/LCECryptoKitBinary.git",
       "state" : {
-        "revision" : "2c5c47cebef40a8adc5557d071a35be405c05e30",
+        "revision" : "11f66b1b9785b4965e027c2fa4742f61e8453403",
-        "version" : "1.0.3"
+        "version" : "1.0.4"
       }
     }
   ],

Package.swift

@@ -11,7 +11,7 @@ let cryptoPackageURL = isLocalDevelopment
 
 let packageDependencies: [Package.Dependency] = enableCryptoBinary
     ? [
-        .package(url: cryptoPackageURL, exact: "1.0.3")
+        .package(url: cryptoPackageURL, exact: "1.0.4")
       ]
     : []
 
@@ -24,10 +24,10 @@ let targetDependencies: [Target.Dependency] = enableCryptoBinary
 let package = Package(
     name: "LCEssentials",
     platforms: [
-        .iOS(.v13),
+        .iOS(.v15),
         .macOS(.v10_15),
         .tvOS(.v13),
-        .watchOS(.v6)
+        .watchOS(.v8)
     ],
     products: [
         .library(
@@ -39,5 +39,8 @@ let package = Package(
         .target(
             name: "LCEssentials",
             dependencies: targetDependencies),
+        .testTarget(
+            name: "LCEssentialsTests",
+            dependencies: ["LCEssentials"]),
     ]
 )

README.md

@@ -10,6 +10,7 @@ This is a repository of essential scripts written in Swift for Loverde Co. used
 
 ## Features
 - [x] Many usefull scripts extensions
+- [x] `API` — typed async networking + multipart uploads. See **[Documentation/API.md](Documentation/API.md)**
 
 
 Installation
@@ -50,6 +51,21 @@ self.navigationController?.popViewControllerWithHandler {
     //Do some stuff after pop
 }
 ```
+* Networking with `API`
+
+```swift
+struct User: Decodable, Sendable { let id: Int; let name: String }
+
+let user: User = try await API.shared.request(
+    url: "https://api.example.com/users/{id}",
+    method: .get,
+    pathParams: ["id": "42"]
+)
+```
+
+Full guide — requests, uploads, client certificates, error handling, and why it
+beats a hand-rolled `URLSession`: **[Documentation/API.md](Documentation/API.md)**
+
 ## Another components
 > LCESnackBarView - **great way to send feedback to user**
 

Sources/LCEssentials/Classes/LCEHTTPBody.swift

@@ -0,0 +1,116 @@
+//
+// Copyright (c) 2020 Loverde Co.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+
+import Foundation
+
+/// A request payload plus the `Content-Type` it implies.
+///
+/// Adopt this to teach `API.request` a new body encoding without changing `API`.
+public protocol HTTPBody: Sendable {
+    /// - Returns: the encoded bytes and the `Content-Type` header value to send with them.
+    func encoded() throws -> (data: Data, contentType: String)
+}
+
+// MARK: - JSON
+
+/// JSON-encodes an `Encodable` payload.
+public struct JSONBody<Payload: Encodable & Sendable>: HTTPBody {
+
+    public let payload: Payload
+    private let encoder: @Sendable () -> JSONEncoder
+
+    /// - Parameters:
+    ///   - payload: the value to encode.
+    ///   - encoderProvider: builds the `JSONEncoder` to use. Defaults to a plain encoder.
+    public init(_ payload: Payload,
+                encoderProvider: @escaping @Sendable () -> JSONEncoder = { JSONEncoder() }) {
+        self.payload = payload
+        self.encoder = encoderProvider
+    }
+
+    public func encoded() throws -> (data: Data, contentType: String) {
+        (try encoder().encode(payload), "application/json; charset=UTF-8")
+    }
+}
+
+// MARK: - Form URL Encoded
+
+/// `application/x-www-form-urlencoded` body. Every value is percent-escaped —
+/// nothing is silently dropped for containing reserved characters.
+public struct FormURLEncodedBody: HTTPBody {
+
+    public let fields: [String: String]
+
+    public init(_ fields: [String: String]) {
+        self.fields = fields
+    }
+
+    public func encoded() throws -> (data: Data, contentType: String) {
+        var allowed = CharacterSet.alphanumerics
+        allowed.insert(charactersIn: "-._~")   // RFC 3986 unreserved
+
+        let pairs: [String] = fields.map { key, value in
+            let k = key.addingPercentEncoding(withAllowedCharacters: allowed) ?? key
+            let v = value.addingPercentEncoding(withAllowedCharacters: allowed) ?? value
+            return "\(k)=\(v)"
+        }
+        let body = Data(pairs.joined(separator: "&").utf8)
+        return (body, "application/x-www-form-urlencoded; charset=UTF-8")
+    }
+}
+
+// MARK: - Raw
+
+/// A pre-encoded body with an explicit content type.
+public struct RawBody: HTTPBody {
+
+    public let data: Data
+    public let contentType: String
+
+    public init(data: Data, contentType: String) {
+        self.data = data
+        self.contentType = contentType
+    }
+
+    public func encoded() throws -> (data: Data, contentType: String) {
+        (data, contentType)
+    }
+}
+
+// MARK: - Factories
+
+/// JSON body from any `Encodable & Sendable` value.
+public func jsonBody<T: Encodable & Sendable>(_ value: T) -> JSONBody<T> {
+    JSONBody(value)
+}
+
+/// Form-url-encoded body from a string dictionary.
+public func formBody(_ fields: [String: String]) -> FormURLEncodedBody {
+    FormURLEncodedBody(fields)
+}
+
+public extension HTTPBody where Self == FormURLEncodedBody {
+    /// Call-site sugar for `request(body: .form([...]))`.
+    static func form(_ fields: [String: String]) -> FormURLEncodedBody {
+        FormURLEncodedBody(fields)
+    }
+}

Sources/LCEssentials/Classes/LCEMultipartForm.swift

@@ -0,0 +1,190 @@
+//
+// Copyright (c) 2020 Loverde Co.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+
+import Foundation
+
+/// A `multipart/form-data` body builder.
+///
+/// Text fields and small in-memory blobs are held as `Data`; on-disk files are
+/// referenced by `URL` and streamed straight into the serialised body, so a
+/// large upload never becomes fully resident in memory.
+public struct MultipartForm: Sendable {
+
+    /// Where a part's content comes from.
+    public enum Source: Sendable {
+        case data(Data)
+        case file(URL)
+    }
+
+    struct Part: Sendable {
+        let name: String
+        let filename: String?
+        let mimeType: String?
+        let source: Source
+        /// `true` → plain form field: no `filename` / `Content-Type` header lines.
+        let isField: Bool
+    }
+
+    /// Error thrown while serialising the body.
+    public enum SerializationError: Error {
+        case cannotCreateTempFile(URL)
+        case cannotOpenOutput(URL)
+        case cannotOpenInput(URL)
+        case writeFailed(underlying: Error?)
+        case readFailed(URL)
+    }
+
+    private(set) var parts: [Part] = []
+    public let boundary: String
+
+    private static let chunkSize = 64 * 1024
+    private static let crlf = "\r\n"
+
+    /// - Parameter boundary: multipart boundary token. Defaults to a random value.
+    public init(boundary: String = "LCEssentials-\(UUID().uuidString)") {
+        self.boundary = boundary
+    }
+
+    // MARK: - Building
+
+    /// Appends a plain text field.
+    public mutating func field(_ name: String, _ value: String) {
+        parts.append(Part(name: name, filename: nil, mimeType: nil,
+                          source: .data(Data(value.utf8)), isField: true))
+    }
+
+    /// Appends an in-memory file part.
+    public mutating func file(_ name: String, data: Data, filename: String, mime: String? = nil) {
+        parts.append(Part(name: name, filename: filename,
+                          mimeType: mime ?? Self.mimeType(for: filename),
+                          source: .data(data), isField: false))
+    }
+
+    /// Appends an on-disk file part. The file is streamed at serialisation time.
+    public mutating func file(_ name: String, url: URL, filename: String? = nil, mime: String? = nil) {
+        let resolvedName = filename ?? url.lastPathComponent
+        parts.append(Part(name: name, filename: resolvedName,
+                          mimeType: mime ?? Self.mimeType(for: resolvedName),
+                          source: .file(url), isField: false))
+    }
+
+    // MARK: - Serialisation
+
+    /// Writes the whole body to a temporary file.
+    ///
+    /// - Returns: the temp file URL (caller must delete it once the upload
+    ///   finishes) and the `multipart/form-data; boundary=…` content type.
+    public func serialize() throws -> (fileURL: URL, contentType: String) {
+        let fileURL = FileManager.default.temporaryDirectory
+            .appendingPathComponent("lce-multipart-\(UUID().uuidString).tmp")
+
+        guard FileManager.default.createFile(atPath: fileURL.path, contents: nil) else {
+            throw SerializationError.cannotCreateTempFile(fileURL)
+        }
+        guard let output = OutputStream(url: fileURL, append: false) else {
+            throw SerializationError.cannotOpenOutput(fileURL)
+        }
+        output.open()
+        defer { output.close() }
+
+        for part in parts {
+            try write(Data(header(for: part).utf8), to: output)
+            switch part.source {
+            case .data(let data):
+                try write(data, to: output)
+            case .file(let url):
+                try stream(fileAt: url, to: output)
+            }
+            try write(Data(Self.crlf.utf8), to: output)
+        }
+        try write(Data("--\(boundary)--\(Self.crlf)".utf8), to: output)
+
+        return (fileURL, "multipart/form-data; boundary=\(boundary)")
+    }
+
+    private func header(for part: Part) -> String {
+        var header = "--\(boundary)\(Self.crlf)"
+        header += "Content-Disposition: form-data; name=\"\(part.name)\""
+        if let filename = part.filename, !part.isField {
+            header += "; filename=\"\(filename)\""
+        }
+        header += Self.crlf
+        if !part.isField, let mime = part.mimeType {
+            header += "Content-Type: \(mime)\(Self.crlf)"
+        }
+        header += Self.crlf
+        return header
+    }
+
+    private func write(_ data: Data, to output: OutputStream) throws {
+        guard !data.isEmpty else { return }
+        var bytesRemaining = data
+        while !bytesRemaining.isEmpty {
+            let written = bytesRemaining.withUnsafeBytes { raw -> Int in
+                guard let base = raw.bindMemory(to: UInt8.self).baseAddress else { return -1 }
+                return output.write(base, maxLength: bytesRemaining.count)
+            }
+            guard written > 0 else {
+                throw SerializationError.writeFailed(underlying: output.streamError)
+            }
+            bytesRemaining.removeFirst(written)
+        }
+    }
+
+    private func stream(fileAt url: URL, to output: OutputStream) throws {
+        guard let input = InputStream(url: url) else {
+            throw SerializationError.cannotOpenInput(url)
+        }
+        input.open()
+        defer { input.close() }
+
+        var buffer = [UInt8](repeating: 0, count: Self.chunkSize)
+        while input.hasBytesAvailable {
+            let read = input.read(&buffer, maxLength: buffer.count)
+            if read == 0 { break }
+            guard read > 0 else { throw SerializationError.readFailed(url) }
+            try write(Data(buffer[0..<read]), to: output)
+        }
+    }
+
+    // MARK: - MIME
+
+    /// Best-effort MIME type from a file name's extension.
+    /// Falls back to `application/octet-stream`.
+    public static func mimeType(for path: String) -> String {
+        let ext = (path as NSString).pathExtension.lowercased()
+        return mimeTypes[ext] ?? "application/octet-stream"
+    }
+
+    private static let mimeTypes: [String: String] = [
+        "jpg": "image/jpeg", "jpeg": "image/jpeg", "png": "image/png", "gif": "image/gif",
+        "pdf": "application/pdf", "txt": "text/plain", "html": "text/html", "htm": "text/html",
+        "json": "application/json", "xml": "application/xml", "zip": "application/zip",
+        "mp3": "audio/mpeg", "mp4": "video/mp4", "mov": "video/quicktime",
+        "doc": "application/msword",
+        "docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+        "xls": "application/vnd.ms-excel",
+        "xlsx": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+        "ppt": "application/vnd.ms-powerpoint",
+        "pptx": "application/vnd.openxmlformats-officedocument.presentationml.presentation"
+    ]
+}

Sources/LCEssentials/Classes/LCEssentials+API+Logging.swift

@@ -0,0 +1,94 @@
+//
+// Copyright (c) 2020 Loverde Co.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+
+import Foundation
+#if os(iOS) || os(watchOS)
+
+@available(iOS 13.0.0, *)
+extension API {
+
+    /// Logs details of an outgoing network request for debugging purposes.
+    static func requestLOG(method: httpMethod, request: URLRequest) {
+        print("\n<========================= 🟠 INTERNET CONNECTION - REQUEST =========================>")
+        printLog(title: "DATE AND TIME", msg: Date().debugDescription)
+        printLog(title: "METHOD", msg: method.rawValue)
+        printLog(title: "REQUEST", msg: String(describing: request))
+        printLog(title: "HEADERS", msg: request.allHTTPHeaderFields?.debugDescription ?? "")
+        if let dataBody = request.httpBody, let prettyJson = dataBody.prettyJson {
+            printLog(title: "PARAMETERS", msg: prettyJson)
+        } else if let dataBody = request.httpBody {
+            printLog(title: "PARAMETERS", msg: String(data: dataBody, encoding: .utf8) ?? "-")
+        }
+        print("<======================================================================================>")
+    }
+
+    /// Logs details of an incoming network response for debugging purposes.
+    static func responseLOG(method: httpMethod, request: URLRequest, data: Data?, statusCode: Int, error: Error?) {
+        let icon = error != nil ? "🔴" : "🟢"
+        print("\n<========================= \(icon) INTERNET CONNECTION - RESPONSE =========================>")
+        printLog(title: "DATE AND TIME", msg: Date().debugDescription)
+        printLog(title: "METHOD", msg: method.rawValue)
+        printLog(title: "REQUEST", msg: String(describing: request))
+        printLog(title: "HEADERS", msg: request.allHTTPHeaderFields?.debugDescription ?? "")
+        if let dataBody = request.httpBody, let prettyJson = dataBody.prettyJson {
+            printLog(title: "PARAMETERS", msg: prettyJson)
+        } else if let dataBody = request.httpBody {
+            printLog(title: "PARAMETERS", msg: String(data: dataBody, encoding: .utf8) ?? "-")
+        }
+        printLog(title: "STATUS CODE", msg: String(describing: statusCode))
+        if let dataResponse = data, let prettyJson = dataResponse.prettyJson {
+            printLog(title: "RESPONSE", msg: prettyJson)
+        } else {
+            printLog(title: "RESPONSE", msg: String(data: data ?? Data(), encoding: .utf8) ?? "-")
+        }
+        logResponseError(error, data: data, statusCode: statusCode)
+        print("<======================================================================================>")
+    }
+
+    private static func logResponseError(_ error: Error?, data: Data?, statusCode: Int) {
+        if let error {
+            switch error.statusCode {
+            case NSURLErrorTimedOut:
+                printError(title: "RESPONSE ERROR TIMEOUT", msg: "DESCRICAO: \(error.localizedDescription)")
+            case NSURLErrorNotConnectedToInternet:
+                printError(title: "RESPONSE ERROR NO INTERNET", msg: "DESCRICAO: \(error.localizedDescription)")
+            case NSURLErrorNetworkConnectionLost:
+                printError(title: "RESPONSE ERROR CONNECTION LOST", msg: "DESCRICAO: \(error.localizedDescription)")
+            case NSURLErrorCancelledReasonUserForceQuitApplication:
+                printError(title: "RESPONSE ERROR APP QUIT", msg: "DESCRICAO: \(error.localizedDescription)")
+            case NSURLErrorCancelledReasonBackgroundUpdatesDisabled:
+                printError(title: "RESPONSE ERROR BG DISABLED", msg: "DESCRICAO: \(error.localizedDescription)")
+            case NSURLErrorBackgroundSessionWasDisconnected:
+                printError(title: "RESPONSE ERROR BG SESSION DISCONNECTED", msg: "DESCRICAO: \(error.localizedDescription)")
+            default:
+                printError(title: "GENERAL", msg: error.localizedDescription)
+            }
+        } else if let data, statusCode != 200 {
+            if let jsonString = String(data: data, encoding: .utf8) {
+                printError(title: "JSON STATUS CODE \(statusCode)", msg: jsonString)
+            } else {
+                printError(title: "DATA STATUS CODE \(statusCode)", msg: data.debugDescription)
+            }
+        }
+    }
+}
+#endif

Sources/LCEssentials/Classes/LCEssentials+API+Upload.swift

@@ -0,0 +1,179 @@
+//
+// Copyright (c) 2020 Loverde Co.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+
+import Foundation
+#if os(iOS) || os(watchOS)
+
+@available(iOS 13.0.0, *)
+public extension API {
+
+    /// Uploads a `multipart/form-data` body and decodes the JSON response.
+    ///
+    /// The body is serialised to a temporary file and streamed from disk, so a
+    /// large file never becomes fully resident in memory. The temp file is
+    /// always removed before returning, on success and on throw.
+    ///
+    /// - Parameters:
+    ///   - url: The URL string. `{name}` placeholders are filled from `pathParams`.
+    ///   - method: The HTTP method. Defaults to `.post`.
+    ///   - form: The multipart body (see ``MultipartForm``).
+    ///   - pathParams: Values substituted into `{name}` placeholders in `url`.
+    ///   - headers: Custom headers, merged over the defaults (custom wins). The
+    ///     `Content-Type` is always set to the multipart type.
+    ///   - debug: Print request/response debug logs. Defaults to `true`.
+    ///   - timeoutInterval: Request timeout in seconds. Defaults to `120`.
+    ///   - networkServiceType: `URLRequest.NetworkServiceType`. Defaults to `.default`.
+    /// - Returns: `T` decoded from the response body.
+    /// - Throws: `URLError` for transport failures, an `NSError` carrying the HTTP
+    ///   status for non-2xx responses, or `DecodingError` on a malformed body.
+    func upload<T: Decodable & Sendable>(
+        url: String,
+        method: httpMethod = .post,
+        form: MultipartForm,
+        pathParams: [String: String] = [:],
+        headers: [String: String] = [:],
+        debug: Bool = true,
+        timeoutInterval: TimeInterval = 120,
+        networkServiceType: URLRequest.NetworkServiceType = .default
+    ) async throws -> T {
+        try await runUpload(url: url, method: method, form: form, pathParams: pathParams,
+                            headers: headers, debug: debug, timeout: timeoutInterval,
+                            serviceType: networkServiceType, progressDelegate: nil)
+    }
+
+    /// Multipart upload that reports progress.
+    ///
+    /// Same as ``upload(url:method:form:pathParams:headers:debug:timeoutInterval:networkServiceType:)``
+    /// but calls `onProgress` with a fraction in `0.0...1.0` as bytes are sent,
+    /// then `1.0` once the body has been fully transmitted.
+    ///
+    /// - Parameter onProgress: invoked on an arbitrary queue; hop to the main
+    ///   actor yourself before touching UI.
+    func upload<T: Decodable & Sendable>(
+        url: String,
+        method: httpMethod = .post,
+        form: MultipartForm,
+        pathParams: [String: String] = [:],
+        headers: [String: String] = [:],
+        debug: Bool = true,
+        timeoutInterval: TimeInterval = 120,
+        networkServiceType: URLRequest.NetworkServiceType = .default,
+        onProgress: @escaping @Sendable (Double) -> Void
+    ) async throws -> T {
+        let result: T = try await runUpload(url: url, method: method, form: form,
+                                            pathParams: pathParams, headers: headers, debug: debug,
+                                            timeout: timeoutInterval, serviceType: networkServiceType,
+                                            progressDelegate: UploadProgressDelegate(onProgress: onProgress))
+        onProgress(1.0)
+        return result
+    }
+}
+
+// MARK: - Shared internals
+
+@available(iOS 13.0.0, *)
+extension API {
+
+    private func runUpload<T: Decodable & Sendable>(
+        url: String,
+        method: httpMethod,
+        form: MultipartForm,
+        pathParams: [String: String],
+        headers: [String: String],
+        debug: Bool,
+        timeout: TimeInterval,
+        serviceType: URLRequest.NetworkServiceType,
+        progressDelegate: UploadProgressDelegate?
+    ) async throws -> T {
+        let prepared = try buildUploadRequest(url: url, method: method, form: form,
+                                              pathParams: pathParams, headers: headers,
+                                              timeout: timeout, serviceType: serviceType)
+        defer { try? FileManager.default.removeItem(at: prepared.bodyFile) }
+
+        if debug { API.requestLOG(method: method, request: prepared.request) }
+        let (session, mustInvalidate) = makeSession()
+        defer { if mustInvalidate { session.finishTasksAndInvalidate() } }
+
+        let (data, response) = try await session.upload(for: prepared.request,
+                                                        fromFile: prepared.bodyFile,
+                                                        delegate: progressDelegate)
+        return try API.finishUpload(data: data, response: response,
+                                    method: method, request: prepared.request, debug: debug)
+    }
+
+    private func buildUploadRequest(
+        url: String,
+        method: httpMethod,
+        form: MultipartForm,
+        pathParams: [String: String],
+        headers: [String: String],
+        timeout: TimeInterval,
+        serviceType: URLRequest.NetworkServiceType
+    ) throws -> (request: URLRequest, bodyFile: URL) {
+        let resolvedURL = try makeURL(url, pathParams: pathParams)
+        var request = buildRequest(url: resolvedURL, method: method, headers: headers,
+                                   timeout: timeout, serviceType: serviceType)
+        let serialized = try form.serialize()
+        request.setValue(serialized.contentType, forHTTPHeaderField: "Content-Type")
+        return (request, serialized.fileURL)
+    }
+
+    fileprivate static func finishUpload<T: Decodable & Sendable>(
+        data: Data,
+        response: URLResponse,
+        method: httpMethod,
+        request: URLRequest,
+        debug: Bool
+    ) throws -> T {
+        let code = (response as? HTTPURLResponse)?.statusCode ?? LCEssentials.DEFAULT_ERROR_CODE
+        switch classify(code: code, data: data, method: method, request: request, debug: debug) {
+        case .success:
+            return try decodeResponse(data)
+        case .clientError, .otherError:
+            throw friendlyError(code: code, data: data)
+        }
+    }
+}
+
+/// Forwards `URLSession` upload progress to a `@Sendable` closure. Immutable
+/// after `init`, safe to hand to `URLSession` as a task delegate.
+@available(iOS 13.0.0, *)
+private final class UploadProgressDelegate: NSObject, URLSessionTaskDelegate, @unchecked Sendable {
+
+    private let onProgress: @Sendable (Double) -> Void
+
+    init(onProgress: @escaping @Sendable (Double) -> Void) {
+        self.onProgress = onProgress
+        super.init()
+    }
+
+    func urlSession(_ session: URLSession,
+                    task: URLSessionTask,
+                    didSendBodyData bytesSent: Int64,
+                    totalBytesSent: Int64,
+                    totalBytesExpectedToSend: Int64) {
+        guard totalBytesExpectedToSend > 0 else { return }
+        let fraction = Double(totalBytesSent) / Double(totalBytesExpectedToSend)
+        onProgress(min(max(fraction, 0), 1))
+    }
+}
+#endif

Sources/LCEssentials/Classes/LCEssentials+API.swift

@@ -29,14 +29,6 @@ import Security
 import UIKit
 #endif
 
-/// A generic `Result` enumeration to represent either a success `Value` or a failure `Error`.
-public enum Result<Value, Error: Swift.Error> {
-    /// Indicates a successful operation with an associated `Value`.
-    case success(Value)
-    /// Indicates a failed operation with an associated `Error`.
-    case failure(Error)
-}
-
 /// Enumeration defining common HTTP methods.
 public enum httpMethod: String {
     /// The POST method.
@@ -51,240 +43,200 @@ public enum httpMethod: String {
     case delete = "DELETE"
 }
 
-/// Loverde Co.: API generic struct for simple requests.
+/// Loverde Co.: API entry point for simple requests.
 ///
-/// This struct provides a convenient way to perform network requests with various configurations,
+/// An `actor`, so callers are never forced onto the main thread. It performs
-/// including handling different HTTP methods, parameter encoding, and certificate-based authentication.
+/// network requests with various configurations, handling different HTTP
+/// methods, typed request bodies, multipart uploads, and certificate-based
+/// authentication.
 @available(iOS 13.0.0, *)
-@MainActor
+public actor API {
-public struct API {
 
-    private static var certData: Data?
+    /// Client-certificate data (`.p12`) for mutual-TLS, if configured.
-    private static var certPassword: String?
+    private var certData: Data?
+    /// Password for `certData`, if any.
+    private var certPassword: String?
+
+    /// Session configuration used to build `URLSession`s. `nil` in production
+    /// (the shared session / a dedicated cert session is used); injected by
+    /// tests to register a stub `URLProtocol`.
+    private let sessionConfiguration: URLSessionConfiguration?
 
     /// The default error used when an unexpected issue occurs during a request.
-    static let defaultError = NSError.createErrorWith(code: LCEssentials.DEFAULT_ERROR_CODE,
+    nonisolated static var defaultError: NSError {
-                                                      description: LCEssentials.DEFAULT_ERROR_MSG,
+        NSError.createErrorWith(code: LCEssentials.DEFAULT_ERROR_CODE,
-                                                      reasonForError: LCEssentials.DEFAULT_ERROR_MSG)
+                                description: LCEssentials.DEFAULT_ERROR_MSG,
+                                reasonForError: LCEssentials.DEFAULT_ERROR_MSG)
+    }
 
     /// The delay in seconds before retrying a persistent connection request.
-    public static var persistConnectionDelay: Double = 3
+    public private(set) var persistConnectionDelay: Double = 3
-    
-    /// Default parameters that will be included in all requests unless explicitly overridden.
-    public static var defaultParams: [String:Any] = [String: Any]()
 
     /// Default HTTP headers for requests.
     ///
     /// By default, it includes "Accept", "Content-Type", and "Accept-Encoding" headers.
-    var defaultHeaders: [String: String] = ["Accept": "application/json",
+    nonisolated let defaultHeaders: [String: String] = ["Accept": "application/json",
-                                            "Content-Type": "application/json; charset=UTF-8",
+                                                        "Content-Type": "application/json; charset=UTF-8",
-                                            "Accept-Encoding": "gzip"]
+                                                        "Accept-Encoding": "gzip"]
 
-    /// The shared singleton instance of the `API` struct.
+    /// The shared singleton instance of `API`.
     public static let shared = API()
 
-    private init(){}
+    private init() {
+        self.sessionConfiguration = nil
+    }
 
-    /// Performs an asynchronous network request and decodes the response into a `Codable` type.
+    /// Test-only. Builds an isolated instance whose `URLSession`s use
+    /// `configuration` — register a stub `URLProtocol` on it. Never call from
+    /// production code; `shared` state is untouched.
+    init(testConfiguration configuration: URLSessionConfiguration) {
+        self.sessionConfiguration = configuration
+    }
+
+    /// `true` when a client certificate has been supplied via ``setupCertification(certData:password:)``.
+    var hasClientCertificateConfigured: Bool { certData != nil }
+
+    /// Overrides ``persistConnectionDelay``.
+    public func setPersistConnectionDelay(_ seconds: Double) {
+        persistConnectionDelay = seconds
+    }
+    
+    /// Maximum number of extra attempts made when `persistConnection` is set and
+    /// the server keeps returning a 4xx. Bounds what was previously an unbounded
+    /// recursion on a permanent client error.
+    public static let maxPersistRetries = 3
+
+    /// Performs an asynchronous network request and decodes the JSON response.
     ///
     /// - Parameters:
-    ///   - url: The URL string for the request.
+    ///   - url: The URL string. `{name}` placeholders are filled from `pathParams`.
-    ///   - params: Optional parameters for the request. Can be `[String: Any]` for JSON/form-data, or `Data` for raw body.
+    ///   - method: The HTTP method (`.get`, `.post`, `.put`, `.delete`, `.patch`).
-    ///   - method: The HTTP method to use for the request (`.get`, `.post`, `.put`, `.delete`,`.patch` ).
+    ///   - body: Optional typed request body (``JSONBody``, ``FormURLEncodedBody``,
-    ///   - headers: Optional custom HTTP headers to be added to the request. These override default headers if there are conflicts.
+    ///     ``RawBody``, or any ``HTTPBody``). Its `Content-Type` and
-    ///   - jsonEncoding: A boolean indicating whether parameters should be JSON encoded. Defaults to `true`.
+    ///     `Content-Length` are set automatically.
-    ///   - debug: A boolean indicating whether to print debug logs for the request and response. Defaults to `true`.
+    ///   - pathParams: Values substituted into `{name}` placeholders in `url`.
-    ///   - timeoutInterval: The timeout interval in seconds for the request. Defaults to `30`.
+    ///   - headers: Custom headers, merged over the defaults (custom wins).
-    ///   - networkServiceType: The `URLRequest.NetworkServiceType` for the request. Defaults to `.default`.
+    ///   - debug: Print request/response debug logs. Defaults to `true`.
-    ///   - persistConnection: A boolean indicating whether to persist the connection on certain error codes (e.g., 4xx). Defaults to `false`.
+    ///   - timeoutInterval: Request timeout in seconds. Defaults to `30`.
-    /// - Returns: An instance of the `T` type, decoded from the response data.
+    ///   - networkServiceType: `URLRequest.NetworkServiceType`. Defaults to `.default`.
-    /// - Throws: An `Error` if the request fails, including `URLError` for network issues or `DecodingError` for JSON decoding failures.
+    ///   - persistConnection: Retry (bounded by ``maxPersistRetries``) on a 4xx.
-    public func request<T: Codable>(url: String,
+    /// - Returns: `T` decoded from the response body, or the raw string when `T == String`.
-                                    params: Any? = nil,
+    /// - Throws: `URLError` for transport failures, an `NSError` carrying the HTTP
-                                    method: httpMethod,
+    ///   status for non-2xx responses, or `DecodingError` on a malformed body.
-                                    headers: [String: String] = [:],
+    public func request<T: Decodable & Sendable>(
-                                    jsonEncoding: Bool = true,
+        url: String,
-                                    debug: Bool = true,
+        method: httpMethod,
-                                    timeoutInterval: TimeInterval = 30,
+        body: (any HTTPBody)? = nil,
-                                    networkServiceType: URLRequest.NetworkServiceType = .default,
+        pathParams: [String: String] = [:],
-                                    persistConnection: Bool = false) async throws -> T {
+        headers: [String: String] = [:],
-        
+        debug: Bool = true,
-        if let urlReq = URL(string: url.replaceURL(params as? [String: Any] ?? [:] )) {
+        timeoutInterval: TimeInterval = 30,
-            var request = URLRequest(url: urlReq, cachePolicy: .reloadIgnoringLocalCacheData, timeoutInterval: timeoutInterval)
+        networkServiceType: URLRequest.NetworkServiceType = .default,
-            if method == .post || method == .put || method == .delete || method == .patch {
+        persistConnection: Bool = false
-                if let params = params as? [String: Any],
+    ) async throws -> T {
-                   let pathFile = params["file"] as? String,
+        let resolvedURL = try makeURL(url, pathParams: pathParams)
-                   let fileURL = URL(string: pathFile) {
+        var urlRequest = buildRequest(url: resolvedURL, method: method, headers: headers,
-                    let boundary = UUID().uuidString
+                                      timeout: timeoutInterval, serviceType: networkServiceType)
-                    request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")
+        if let body {
-                    
+            try Self.attach(body: body, to: &urlRequest)
-                    var body = Data()
-                    
-                    // Add additional fields (if any)
-                    for (key, value) in params where key != "file" {
-                        let stringValue = "\(value)"
-                        body.append("--\(boundary)\r\n".data(using: .utf8)!)
-                        body.append("Content-Disposition: form-data; name=\"\(key)\"\r\n\r\n".data(using: .utf8)!)
-                        body.append("\(stringValue)\r\n".data(using: .utf8)!)
-                    }
-                    
-                    // Add the file
-                    let fileName = fileURL.lastPathComponent
-                    let mimeType = mimeTypeForPath(path: fileName)
-                    printInfo(title: "Body size before", msg: "\(body.count) bytes")
-                    
-                    let fileData: Data
-                    do {
-                        fileData = try Data(contentsOf: fileURL)
-                        printInfo(title: "Body size after", msg: "\(body.count) bytes")
-                    } catch {
-                        printError(title: "Upload File", msg: error.localizedDescription)
-                        throw error
-                    }
-                    
-                    do {
-                        body.append("--\(boundary)\r\n".data(using: .utf8)!)
-                        body.append("Content-Disposition: form-data; name=\"file\"; filename=\"\(fileName)\"\r\n".data(using: .utf8)!)
-                        body.append("Content-Type: \(mimeType)\r\n\r\n".data(using: .utf8)!)
-                        let fileDataCopy = Data(fileData)
-                        body.append(fileDataCopy)
-                        let dataUTF8 = "\r\n".data(using: .utf8)!
-                        body.append(dataUTF8)
-                        printInfo(title: "Body size after", msg: "\(body.count) bytes")
-                    }
-                    
-                    // Finalize the request body
-                    body.append("--\(boundary)--\r\n".data(using: .utf8)!)
-                    request.httpBody = body
-                    request.setValue("\(body.count)", forHTTPHeaderField: "Content-Length")
-                    // Debug logs
-                    printLog(title: "Boundary", msg: boundary)
-                    if let bodyString = String(data: body, encoding: .utf8) {
-                        printLog(title: "Body Content", msg: bodyString)
-                    }
-                } else if jsonEncoding, let params = params as? [String: Any] {
-                    let requestObject = try JSONSerialization.data(withJSONObject: params)
-                    request.httpBody = requestObject
-                } else if let params = params as? [String: Any] {
-                    var bodyComponents = URLComponents()
-                    params.forEach({ (key, value) in
-                        bodyComponents.queryItems?.append(URLQueryItem(name: key, value: value as? String))
-                    })
-                    request.httpBody = bodyComponents.query?.data(using: .utf8)
-                } else if let params = params as? Data {
-                    request.httpBody = params
-                }
-            }
-            request.httpMethod = method.rawValue
-            request.timeoutInterval = timeoutInterval
-            request.networkServiceType = networkServiceType
-            
-            // - Put Default Headers together with user defined params
-            if !headers.isEmpty {
-                // - Add it to request
-                headers.forEach { (key, value) in
-                    request.addValue(value, forHTTPHeaderField: key)
-                }
-            }else{
-                defaultHeaders.forEach { (key, value) in
-                    request.addValue(value, forHTTPHeaderField: key)
-                }
-            }
-            if debug {
-                API.requestLOG(method: method, request: request)
-            }
-            
-            // Only spin up a dedicated session (with its own @MainActor
-            // delegate hop for every TLS/auth challenge) when client
-            // certificate auth is actually configured. Creating one of
-            // these per request unconditionally — and never invalidating
-            // it — could stall the async challenge callback waiting on an
-            // already-busy MainActor, hanging the request indefinitely with
-            // no timeout or error ever surfacing. The common case (no
-            // client cert) uses the shared session, which has none of this
-            // risk and is what URLSession is designed to be reused as.
-            let usesCertSession = API.certData != nil
-            let session: URLSession = usesCertSession
-                ? URLSession(
-                    configuration: .default,
-                    delegate: URLSessionDelegateHandler(
-                        certData: API.certData,
-                        password: API.certPassword
-                    ),
-                    delegateQueue: nil
-                )
-                : URLSession.shared
-            defer {
-                if usesCertSession {
-                    session.finishTasksAndInvalidate()
-                }
-            }
-            do {
-                let (data, response) = try await session.data(for: request)
-                
-                
-                var code: Int = LCEssentials.DEFAULT_ERROR_CODE
-                let httpResponse = response as? HTTPURLResponse ?? HTTPURLResponse()
-                code = httpResponse.statusCode
-                let error = URLError(URLError.Code(rawValue: code))
-                switch code {
-                case 200..<300:
-                    // - Debug LOG
-                    if debug {
-                        API.responseLOG(method: method, request: request, data: data, statusCode: code, error: nil)
-                    }
-                    
-                    // - Check if is JSON result and try decode it
-                    if let string = data.string as? T, T.self == String.self {
-                        return string
-                    }
-                    // - Normal decoding
-                    do {
-                        return try JSONDecoder.decode(data: data)
-                    } catch {
-                        printError(title: "JSONDecoder", msg: error.localizedDescription)
-                        throw error
-                    }
-                case 400..<500:
-                    // - Debug LOG
-                    if debug {
-                        API.responseLOG(method: method, request: request, data: data, statusCode: code, error: error)
-                    }
-                    if persistConnection {
-                        printError(title: "INTERNET CONNECTION ERROR", msg: "WILL PERSIST")
-                        // Recursive call for persistence
-                        let persist: T = try await self.request(
-                            url: url,
-                            params: params,
-                            method: method,
-                            headers: headers,
-                            jsonEncoding: jsonEncoding,
-                            debug: debug,
-                            timeoutInterval: timeoutInterval,
-                            networkServiceType: networkServiceType,
-                            persistConnection: persistConnection
-                        )
-                        return persist
-                    } else {
-                        if debug {
-                            API.responseLOG(method: method, request: request, data: data, statusCode: code, error: error)
-                        }
-                        let friendlyError = NSError.createErrorWith(code: code, description: error.localizedDescription, reasonForError: data.prettyJson ?? "")
-                        throw friendlyError
-                    }
-                default:
-                    // - Debug LOG
-                    if debug {
-                        API.responseLOG(method: method, request: request, data: data, statusCode: code, error: error)
-                    }
-                    let friendlyError = NSError.createErrorWith(code: code, description: error.localizedDescription, reasonForError: data.prettyJson ?? "")
-                    throw friendlyError
-                }
-            } catch {
-                throw error
-            }
         }
-        throw API.defaultError
+        return try await send(urlRequest, method: method, debug: debug,
+                              persistConnection: persistConnection, retriesLeft: Self.maxPersistRetries)
+    }
+
+    /// Sends a fully-built request, handles the response, and applies bounded
+    /// `persistConnection` retries.
+    private func send<T: Decodable & Sendable>(
+        _ urlRequest: URLRequest,
+        method: httpMethod,
+        debug: Bool,
+        persistConnection: Bool,
+        retriesLeft: Int
+    ) async throws -> T {
+        if debug { API.requestLOG(method: method, request: urlRequest) }
+
+        let (session, mustInvalidate) = makeSession()
+        defer { if mustInvalidate { session.finishTasksAndInvalidate() } }
+
+        let (data, response) = try await session.data(for: urlRequest)
+        let code = (response as? HTTPURLResponse)?.statusCode ?? LCEssentials.DEFAULT_ERROR_CODE
+
+        switch Self.classify(code: code, data: data, method: method, request: urlRequest, debug: debug) {
+        case .success:
+            return try Self.decodeResponse(data)
+        case .clientError where persistConnection && retriesLeft > 0:
+            printError(title: "INTERNET CONNECTION ERROR", msg: "WILL PERSIST (\(retriesLeft) left)")
+            return try await send(urlRequest, method: method, debug: debug,
+                                  persistConnection: persistConnection, retriesLeft: retriesLeft - 1)
+        case .clientError, .otherError:
+            throw Self.friendlyError(code: code, data: data)
+        }
+    }
+
+    // MARK: - Request building
+
+    func makeURL(_ template: String, pathParams: [String: String]) throws -> URL {
+        guard let url = URL(string: template.replaceURL(pathParams)) else { throw API.defaultError }
+        return url
+    }
+
+    func buildRequest(url: URL,
+                              method: httpMethod,
+                              headers: [String: String],
+                              timeout: TimeInterval,
+                              serviceType: URLRequest.NetworkServiceType) -> URLRequest {
+        var request = URLRequest(url: url, cachePolicy: .reloadIgnoringLocalCacheData, timeoutInterval: timeout)
+        request.httpMethod = method.rawValue
+        request.timeoutInterval = timeout
+        request.networkServiceType = serviceType
+        defaultHeaders.merging(headers) { _, custom in custom }
+            .forEach { request.setValue($0.value, forHTTPHeaderField: $0.key) }
+        return request
+    }
+
+    /// Sets the body plus its `Content-Type` and `Content-Length`. The body's own
+    /// content type wins over any set through `headers`.
+    private static func attach(body: any HTTPBody, to request: inout URLRequest) throws {
+        let (data, contentType) = try body.encoded()
+        request.httpBody = data
+        request.setValue(contentType, forHTTPHeaderField: "Content-Type")
+        request.setValue("\(data.count)", forHTTPHeaderField: "Content-Length")
+    }
+
+    // MARK: - Response handling
+
+    enum ResponseDisposition { case success, clientError, otherError }
+
+    static func classify(code: Int, data: Data, method: httpMethod,
+                                 request: URLRequest, debug: Bool) -> ResponseDisposition {
+        let error = (200..<300).contains(code) ? nil : URLError(URLError.Code(rawValue: code))
+        if debug {
+            API.responseLOG(method: method, request: request, data: data, statusCode: code, error: error)
+        }
+        switch code {
+        case 200..<300: return .success
+        case 400..<500: return .clientError
+        default:        return .otherError
+        }
+    }
+
+    static func decodeResponse<T: Decodable & Sendable>(_ data: Data) throws -> T {
+        if T.self == String.self, let string = String(data: data, encoding: .utf8) as? T {
+            return string
+        }
+        do {
+            return try JSONDecoder.decode(data: data)
+        } catch {
+            printError(title: "JSONDecoder", msg: error.localizedDescription)
+            throw error
+        }
+    }
+
+    static func friendlyError(code: Int, data: Data) -> NSError {
+        let urlError = URLError(URLError.Code(rawValue: code))
+        return NSError.createErrorWith(code: code,
+                                       description: urlError.localizedDescription,
+                                       reasonForError: data.prettyJson ?? "")
     }
 
     /// Sets up client certificate data and an optional password for authentication.
@@ -292,21 +244,52 @@ public struct API {
     /// - Parameters:
     ///   - certData: The `Data` representation of the client certificate (e.g., a .p12 file).
     ///   - password: The password for the certificate, if required. Defaults to an empty string.
-    public func setupCertificationRequest(certData: Data, password: String = "") {
+    public func setupCertification(certData: Data, password: String = "") {
-        API.certData = certData
+        self.certData = certData
-        API.certPassword = password
+        self.certPassword = password
     }
+
+    /// Builds the `URLSession` for one request.
+    ///
+    /// - A test configuration (if injected) always wins, carrying the cert
+    ///   delegate when one is configured.
+    /// - Otherwise a dedicated, delegate-backed session is created only when a
+    ///   client certificate is configured, and must be invalidated afterwards.
+    /// - The common no-cert case reuses `URLSession.shared`.
+    ///
+    /// - Returns: the session and whether the caller must invalidate it.
+    func makeSession() -> (session: URLSession, mustInvalidate: Bool) {
+        #if canImport(Security)
+        let delegate: URLSessionDelegateHandler? = certData != nil
+            ? URLSessionDelegateHandler(certData: certData, password: certPassword)
+            : nil
+        #else
+        let delegate: URLSessionDelegate? = nil
+        #endif
+
+        if let configuration = sessionConfiguration {
+            return (URLSession(configuration: configuration, delegate: delegate, delegateQueue: nil), true)
+        }
+        if delegate != nil {
+            return (URLSession(configuration: .default, delegate: delegate, delegateQueue: nil), true)
+        }
+        return (URLSession.shared, false)
+    }
+
 }
 
 #if canImport(Security)
 /// A custom `URLSessionDelegate` handler for managing URL session challenges,
 /// particularly for client and server trust authentication.
+///
+/// Immutable after `init`, so it is safe to hand to `URLSession` and have its
+/// challenge callback invoked on any thread. The auth logic touches only the
+/// Security framework, which is thread-safe.
 @available(iOS 13.0.0, *)
-@MainActor
+private final class URLSessionDelegateHandler: NSObject, URLSessionDelegate, @unchecked Sendable {
-private class URLSessionDelegateHandler: NSObject, URLSessionDelegate {
 
-    private var certData: Data?
+    private let certData: Data?
-    private var certPass: String?
+    private let certPass: String?
 
     /// Initializes a new `URLSessionDelegateHandler` instance.
     ///
@@ -314,9 +297,9 @@ private class URLSessionDelegateHandler: NSObject, URLSessionDelegate {
     ///   - certData: Optional `Data` for the client certificate.
     ///   - password: Optional password for the client certificate.
     init(certData: Data? = nil, password: String? = nil) {
-        super.init()
         self.certData = certData
         self.certPass = password
+        super.init()
     }
 
     /// Handles URL session authentication challenges.
@@ -363,16 +346,29 @@ private class URLSessionDelegateHandler: NSObject, URLSessionDelegate {
         // Import the .p12 certificate to get the identity
         let status = SecPKCS12Import(certData as CFData, options as CFDictionary, &items)
 
-        if status == errSecSuccess,
+        guard status == errSecSuccess,
-           let item = (items as? [[String: Any]])?.first,
+              let items,
-           let identityRef = item[kSecImportItemIdentity as String] as CFTypeRef?,
+              CFArrayGetCount(items) > 0,
-           CFGetTypeID(identityRef) == SecIdentityGetTypeID() {
+              let itemPtr = CFArrayGetValueAtIndex(items, 0) else {
-            return (identityRef as! SecIdentity)
+            printError(title: "Certificate", msg: "Failed to import client identity from .p12 (status: \(status))")
-        } else {
-            print("Erro ao importar a identidade do certificado: \(status)")
             return nil
         }
 
+        // Read the identity straight out of the CF result via typed `Unmanaged`
+        // bridging — no `as!`. `SecPKCS12Import` boxes a CoreFoundation ref that
+        // Swift will not let us downcast without a force operation.
+        let itemDict = Unmanaged<CFDictionary>.fromOpaque(itemPtr).takeUnretainedValue()
+        let identityKey = Unmanaged.passUnretained(kSecImportItemIdentity).toOpaque()
+        guard let identityPtr = CFDictionaryGetValue(itemDict, identityKey) else {
+            printError(title: "Certificate", msg: "Imported .p12 contained no client identity")
+            return nil
+        }
+        let identity = Unmanaged<SecIdentity>.fromOpaque(identityPtr).takeUnretainedValue()
+        guard CFGetTypeID(identity) == SecIdentityGetTypeID() else {
+            printError(title: "Certificate", msg: "Imported .p12 entry is not a SecIdentity")
+            return nil
+        }
+        return identity
     }
     
     /// Checks if the provided data is a valid PKCS#12 (P12) certificate with the given password.
@@ -401,133 +397,4 @@ extension Error {
     }
 }
 
-@available(iOS 13.0.0, *)
-extension API {
-    
-    /// Logs details of an outgoing network request for debugging purposes.
-    ///
-    /// - Parameters:
-    ///   - method: The HTTP method of the request.
-    ///   - request: The `URLRequest` object.
-    fileprivate static func requestLOG(method: httpMethod, request: URLRequest) {
-        
-        print("\n<========================= 🟠 INTERNET CONNECTION - REQUEST =========================>")
-        printLog(title: "DATE AND TIME", msg: Date().debugDescription)
-        printLog(title: "METHOD", msg: method.rawValue)
-        printLog(title: "REQUEST", msg: String(describing: request))
-        printLog(title: "HEADERS", msg: request.allHTTPHeaderFields?.debugDescription ?? "")
-        
-        //
-        if let dataBody = request.httpBody, let prettyJson = dataBody.prettyJson {
-            printLog(title: "PARAMETERS", msg: prettyJson)
-        } else if let dataBody = request.httpBody {
-            printLog(title: "PARAMETERS", msg: String(data: dataBody, encoding: .utf8) ?? "-")
-        }
-        //
-        print("<======================================================================================>")
-   }
-    
-    /// Logs details of an incoming network response for debugging purposes.
-    ///
-    /// - Parameters:
-    ///   - method: The HTTP method of the original request.
-    ///   - request: The `URLRequest` object that generated this response.
-    ///   - data: The data received in the response.
-    ///   - statusCode: The HTTP status code of the response.
-    ///   - error: An optional `Error` object if the request failed.
-    fileprivate static func responseLOG(method: httpMethod, request: URLRequest, data: Data?, statusCode: Int, error: Error?) {
-        ///
-        let icon = error != nil ? "🔴" : "🟢"
-         print("\n<========================= \(icon) INTERNET CONNECTION - RESPONSE =========================>")
-         printLog(title: "DATE AND TIME", msg: Date().debugDescription)
-         printLog(title: "METHOD", msg: method.rawValue)
-         printLog(title: "REQUEST", msg: String(describing: request))
-         printLog(title: "HEADERS", msg: request.allHTTPHeaderFields?.debugDescription ?? "")
-         
-         //
-         if let dataBody = request.httpBody, let prettyJson = dataBody.prettyJson {
-             printLog(title: "PARAMETERS", msg: prettyJson)
-         } else if let dataBody = request.httpBody {
-             printLog(title: "PARAMETERS", msg: String(data: dataBody, encoding: .utf8) ?? "-")
-         }
-         //
-         printLog(title: "STATUS CODE", msg: String(describing: statusCode))
-         //
-         if let dataResponse = data, let prettyJson = dataResponse.prettyJson {
-             printLog(title: "RESPONSE", msg: prettyJson)
-         } else {
-             printLog(title: "RESPONSE", msg: String(data: data ?? Data(), encoding: .utf8) ?? "-")
-         }
-         //
-         if let error = error {
-             switch error.statusCode {
-             case NSURLErrorTimedOut:
-                 printError(title: "RESPONSE ERROR TIMEOUT", msg: "DESCRICAO: \(error.localizedDescription)")
-                 
-             case NSURLErrorNotConnectedToInternet:
-                 printError(title: "RESPONSE ERROR NO INTERNET", msg: "DESCRICAO: \(error.localizedDescription)")
-                 
-             case NSURLErrorNetworkConnectionLost:
-                 printError(title: "RESPONSE ERROR CONNECTION LOST", msg: "DESCRICAO: \(error.localizedDescription)")
-                 
-             case NSURLErrorCancelledReasonUserForceQuitApplication:
-                 printError(title: "RESPONSE ERROR APP QUIT", msg: "DESCRICAO: \(error.localizedDescription)")
-                 
-             case NSURLErrorCancelledReasonBackgroundUpdatesDisabled:
-                 printError(title: "RESPONSE ERROR BG DISABLED", msg: "DESCRICAO: \(error.localizedDescription)")
-                 
-             case NSURLErrorBackgroundSessionWasDisconnected:
-                 printError(title: "RESPONSE ERROR BG SESSION DISCONNECTED", msg: "DESCRICAO: \(error.localizedDescription)")
-                 
-             default:
-                 printError(title: "GENERAL", msg: error.localizedDescription)
-             }
-         }else if let data = data, statusCode != 200 {
-             // - Check if is JSON result
-             if let jsonString = String(data: data, encoding: .utf8) {
-                 printError(title: "JSON STATUS CODE \(statusCode)", msg: jsonString)
-             }else{
-                 printError(title: "DATA STATUS CODE \(statusCode)", msg: data.debugDescription)
-             }
-         }
-         //
-        print("<======================================================================================>")
-    }
-    
-    /// Determines the MIME type for a given file path based on its extension.
-    ///
-    /// - Parameter path: The file path string.
-    /// - Returns: A string representing the MIME type. Defaults to "application/octet-stream" if the type is unknown.
-    func mimeTypeForPath(path: String) -> String {
-        let url = URL(fileURLWithPath: path)
-        let pathExtension = url.pathExtension.lowercased()
-        
-        // Dictionary of common extensions and MIME types
-        let mimeTypes: [String: String] = [
-            "jpg": "image/jpeg",
-            "jpeg": "image/jpeg",
-            "png": "image/png",
-            "gif": "image/gif",
-            "pdf": "application/pdf",
-            "txt": "text/plain",
-            "html": "text/html",
-            "htm": "text/html",
-            "json": "application/json",
-            "xml": "application/xml",
-            "zip": "application/zip",
-            "mp3": "audio/mpeg",
-            "mp4": "video/mp4",
-            "mov": "video/quicktime",
-            "doc": "application/msword",
-            "docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
-            "xls": "application/vnd.ms-excel",
-            "xlsx": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
-            "ppt": "application/vnd.ms-powerpoint",
-            "pptx": "application/vnd.openxmlformats-officedocument.presentationml.presentation"
-        ]
-        
-        // Returns the corresponding MIME type for the extension, or "application/octet-stream" as default
-        return mimeTypes[pathExtension] ?? "application/octet-stream"
-    }
-}
 #endif

Sources/LCEssentials/Extensions/LCEssentials+Data.swift

@@ -112,7 +112,7 @@ public extension Data {
 #endif
     }
     
-    func object<T: Codable>() -> T? {
+    func object<T: Codable & Sendable>() -> T? {
         do {
             let outPut: T = try JSONDecoder.decode(data: self)
             return outPut

Sources/LCEssentials/Extensions/LCEssentials+Dictionary.swift

@@ -137,11 +137,10 @@ public extension Dictionary {
 
     /// - LoverdeCo: Convert Dictonary to Object
     ///
-    /// - returns: Object: Codable/Decodable
+    /// - returns: Object: Decodable & Sendable
-    func toObjetct<T: Codable>() -> T {
+    /// - throws: `DecodingError` when the dictionary does not match `T`.
-        let jsonString = self.convertToJSON
+    func toObjetct<T: Codable & Sendable>() throws -> T {
-        let output: T = try! JSONDecoder.decode(jsonString)
+        try JSONDecoder.decode(self.convertToJSON)
-        return output
     }
 
     /// Check if key exists in dictionary.

Sources/LCEssentials/Extensions/LCEssentials+EncodableDecodable.swift

@@ -44,8 +44,8 @@ extension JSONDecoder {
     /// - LoverdeCo: Decode JSON Data to Object
     ///
     /// - Parameter data: Data
-    /// - returns: Object: Codable/Decodable
+    /// - returns: Object: Decodable & Sendable
-    public static func decode<T: Codable>(data: Data) throws -> T {
+    public static func decode<T: Decodable & Sendable>(data: Data) throws -> T {
         var error = NSError(domain: "", code: 0)
         let decoder = JSONDecoder()
         decoder.keyDecodingStrategy = .useDefaultKeys
@@ -70,28 +70,24 @@ extension JSONDecoder {
     /// - LoverdeCo: Decode JSON String to Object
     ///
     /// - Parameter json: String
-    /// - returns: Object: Codable/Decodable
+    /// - returns: Object: Decodable & Sendable
-    public static func decode<T: Codable>(_ json: String, using encoding: String.Encoding = .utf8) throws -> T {
+    public static func decode<T: Decodable & Sendable>(_ json: String, using encoding: String.Encoding = .utf8) throws -> T {
-        var error = NSError()
+        guard let jsonData = json.data(using: encoding) else {
-        if let jsonData = json.data(using: .utf8) {
+            let msg = "Could not convert string to \(encoding) data for \(T.self)"
-            do {
+            throw NSError.createErrorWith(code: 0, description: msg, reasonForError: msg)
-                return try decode(data: jsonData)
-            } catch {
-                throw error
-            }
         }
-        throw error
+        return try decode(data: jsonData)
     }
 
     /// - LoverdeCo: Decode JSON URL to Object
     ///
     /// - Parameter url: URL
-    /// - returns: Object: Codable/Decodable
+    /// - returns: Object: Decodable & Sendable
-    public static func decode<T: Codable>(fromURL url: URL) throws -> T {
+    public static func decode<T: Decodable & Sendable>(fromURL url: URL) throws -> T {
-        return try decode(data: try! Data(contentsOf: url))
+        return try decode(data: Data(contentsOf: url))
     }
 
-    public static func decode<T: Codable>(dictionary: Any) throws -> T {
+    public static func decode<T: Decodable & Sendable>(dictionary: Any) throws -> T {
         do {
             let json = try JSONSerialization.data(withJSONObject: dictionary)
             let decoder = JSONDecoder()

Tests/LCEssentialsTests/APIActorTests.swift

@@ -0,0 +1,26 @@
+import XCTest
+@testable import LCEssentials
+
+final class APIActorTests: XCTestCase {
+
+    func testAPIIsAnActorNotMainActorBound() async {
+        let isActor = (API.shared as Any) is any Actor
+        XCTAssertTrue(isActor, "API must be an actor so callers are not forced onto the main thread")
+    }
+
+    func testPersistConnectionDelayRoundTrips() async {
+        let api = API(testConfiguration: .ephemeral)
+        await api.setPersistConnectionDelay(9)
+        let value = await api.persistConnectionDelay
+        XCTAssertEqual(value, 9)
+    }
+
+    func testIsolatedTestInstanceDoesNotTouchSharedCertState() async {
+        let api = API(testConfiguration: .ephemeral)
+        await api.setupCertification(certData: Data([0x01, 0x02]), password: "pw")
+        let sharedHasCert = await API.shared.hasClientCertificateConfigured
+        let instanceHasCert = await api.hasClientCertificateConfigured
+        XCTAssertFalse(sharedHasCert)
+        XCTAssertTrue(instanceHasCert)
+    }
+}

Tests/LCEssentialsTests/APIRequestTests.swift

@@ -0,0 +1,122 @@
+import XCTest
+@testable import LCEssentials
+
+private struct Echo: Decodable, Sendable, Equatable {
+    let id: Int
+    let name: String
+}
+
+private struct CreateDTO: Encodable, Sendable {
+    let name: String
+}
+
+final class APIRequestTests: XCTestCase {
+
+    private var api: API!
+
+    override func setUp() {
+        super.setUp()
+        let cfg = URLSessionConfiguration.ephemeral
+        cfg.protocolClasses = [StubURLProtocol.self]
+        api = API(testConfiguration: cfg)
+    }
+
+    override func tearDown() {
+        StubURLProtocol.reset()
+        api = nil
+        super.tearDown()
+    }
+
+    func testJSONBodyRequestSendsEncodedBodyAndDecodesResponse() async throws {
+        var stub = StubURLProtocol.Stub()
+        stub.statusCode = 200
+        stub.body = Data(#"{"id":10,"name":"x"}"#.utf8)
+        StubURLProtocol.setStub(stub)
+
+        let result: Echo = try await api.request(
+            url: "https://api.example.com/users",
+            method: .post,
+            body: jsonBody(CreateDTO(name: "x"))
+        )
+
+        XCTAssertEqual(result, Echo(id: 10, name: "x"))
+        let sent = StubURLProtocol.capturedRequests.first
+        XCTAssertEqual(sent?.httpMethod, "POST")
+        XCTAssertEqual(sent?.value(forHTTPHeaderField: "Content-Type"), "application/json; charset=UTF-8")
+        XCTAssertEqual(StubURLProtocol.lastCapturedBody, Data(#"{"name":"x"}"#.utf8))
+    }
+
+    func testCustomHeaderOverridesDefault() async throws {
+        StubURLProtocol.setStub(.init(statusCode: 200, body: Data(#"{"id":1,"name":"a"}"#.utf8)))
+
+        let _: Echo = try await api.request(
+            url: "https://api.example.com/x",
+            method: .get,
+            headers: ["Accept": "application/xml"]
+        )
+
+        XCTAssertEqual(StubURLProtocol.capturedRequests.first?.value(forHTTPHeaderField: "Accept"),
+                       "application/xml")
+    }
+
+    func testPathParamsSubstitution() async throws {
+        StubURLProtocol.setStub(.init(statusCode: 200, body: Data(#"{"id":42,"name":"a"}"#.utf8)))
+
+        let _: Echo = try await api.request(
+            url: "https://api.example.com/users/{id}/posts",
+            method: .get,
+            pathParams: ["id": "42"]
+        )
+
+        XCTAssertEqual(StubURLProtocol.capturedRequests.first?.url?.absoluteString,
+                       "https://api.example.com/users/42/posts")
+    }
+
+    func testStringResponsePassthroughSkipsJSONDecoding() async throws {
+        StubURLProtocol.setStub(.init(statusCode: 200,
+                                      headers: ["Content-Type": "text/plain"],
+                                      body: Data("plain hello".utf8)))
+
+        let text: String = try await api.request(url: "https://api.example.com/ping", method: .get)
+        XCTAssertEqual(text, "plain hello")
+    }
+
+    func testClientErrorThrowsNSErrorWithStatusAndBody() async {
+        StubURLProtocol.setStub(.init(statusCode: 422,
+                                      body: Data(#"{"error":"invalid"}"#.utf8)))
+
+        do {
+            let _: Echo = try await api.request(url: "https://api.example.com/x", method: .post,
+                                                body: jsonBody(CreateDTO(name: "")))
+            XCTFail("expected throw")
+        } catch let error as NSError {
+            XCTAssertEqual(error.code, 422)
+            XCTAssertTrue(error.localizedFailureReason?.contains("invalid") ?? false,
+                          "reason: \(error.localizedFailureReason ?? "nil")")
+        }
+    }
+
+    func testPersistConnectionRetriesButIsBoundedOnPermanentClientError() async {
+        StubURLProtocol.setStub(.init(statusCode: 400, body: Data(#"{"error":"nope"}"#.utf8)))
+
+        do {
+            let _: Echo = try await api.request(url: "https://api.example.com/x",
+                                                method: .get, persistConnection: true)
+            XCTFail("expected throw after retries exhausted")
+        } catch let error as NSError {
+            XCTAssertEqual(error.code, 400)
+        } catch {
+            XCTFail("unexpected error type: \(error)")
+        }
+
+        // retried, but did NOT loop forever
+        XCTAssertGreaterThanOrEqual(StubURLProtocol.requestCount, 2)
+        XCTAssertLessThanOrEqual(StubURLProtocol.requestCount, API.maxPersistRetries + 1)
+    }
+
+    func testNoPersistConnectionDoesNotRetry() async {
+        StubURLProtocol.setStub(.init(statusCode: 400, body: Data(#"{"error":"nope"}"#.utf8)))
+        let _: Echo? = try? await api.request(url: "https://api.example.com/x", method: .get)
+        XCTAssertEqual(StubURLProtocol.requestCount, 1)
+    }
+}

Tests/LCEssentialsTests/APIUploadTests.swift

@@ -0,0 +1,123 @@
+import XCTest
+@testable import LCEssentials
+
+private struct UploadEcho: Decodable, Sendable, Equatable {
+    let ok: Bool
+}
+
+/// Thread-safe sink for progress callbacks (invoked on an arbitrary queue).
+private final class ProgressBox: @unchecked Sendable {
+    private let lock = NSLock()
+    private var storage: [Double] = []
+    func record(_ value: Double) { lock.lock(); storage.append(value); lock.unlock() }
+    var values: [Double] { lock.lock(); defer { lock.unlock() }; return storage }
+}
+
+final class APIUploadTests: XCTestCase {
+
+    private var api: API!
+
+    override func setUp() {
+        super.setUp()
+        let cfg = URLSessionConfiguration.ephemeral
+        cfg.protocolClasses = [StubURLProtocol.self]
+        api = API(testConfiguration: cfg)
+    }
+
+    override func tearDown() {
+        StubURLProtocol.reset()
+        api = nil
+        super.tearDown()
+    }
+
+    private func tempCountInDir(_ dir: URL) -> Int {
+        (try? FileManager.default.contentsOfDirectory(atPath: dir.path).filter {
+            $0.hasPrefix("lce-multipart-")
+        }.count) ?? -1
+    }
+
+    func testUploadSendsMultipartBodyAndDecodesResponse() async throws {
+        StubURLProtocol.setStub(.init(statusCode: 200, body: Data(#"{"ok":true}"#.utf8)))
+
+        var form = MultipartForm()
+        form.field("caption", "hi")
+        form.file("photo", data: Data([0x89, 0x50, 0x4E, 0x47]), filename: "p.png")
+        let expectedBody = try Data(contentsOf: form.serialize().fileURL)
+
+        let result: UploadEcho = try await api.upload(
+            url: "https://api.example.com/media",
+            form: form
+        )
+
+        XCTAssertEqual(result, UploadEcho(ok: true))
+        let sent = StubURLProtocol.capturedRequests.first
+        XCTAssertEqual(sent?.httpMethod, "POST")
+        XCTAssertTrue(sent?.value(forHTTPHeaderField: "Content-Type")?
+            .hasPrefix("multipart/form-data; boundary=") ?? false)
+        // body framing matches a fresh serialize() (boundary differs per form
+        // instance, so compare structure, not bytes, by re-serialising the SAME form)
+        XCTAssertEqual(StubURLProtocol.lastCapturedBody?.count, expectedBody.count)
+    }
+
+    func testTempBodyFileRemovedAfterSuccess() async throws {
+        StubURLProtocol.setStub(.init(statusCode: 200, body: Data(#"{"ok":true}"#.utf8)))
+        let dir = FileManager.default.temporaryDirectory
+        let before = tempCountInDir(dir)
+
+        var form = MultipartForm()
+        form.file("f", data: Data("x".utf8), filename: "a.txt")
+        let _: UploadEcho = try await api.upload(url: "https://api.example.com/x", form: form)
+
+        XCTAssertEqual(tempCountInDir(dir), before)
+    }
+
+    func testTempBodyFileRemovedAfterThrow() async {
+        StubURLProtocol.setStub(.init(statusCode: 500, body: Data(#"{"error":"boom"}"#.utf8)))
+        let dir = FileManager.default.temporaryDirectory
+        let before = tempCountInDir(dir)
+
+        var form = MultipartForm()
+        form.file("f", data: Data("x".utf8), filename: "a.txt")
+        do {
+            let _: UploadEcho = try await api.upload(url: "https://api.example.com/x", form: form)
+            XCTFail("expected throw")
+        } catch {
+            // expected
+        }
+        XCTAssertEqual(tempCountInDir(dir), before)
+    }
+
+    func testProgressOverloadDeliversFinalCompletionAndDecodes() async throws {
+        StubURLProtocol.setStub(.init(statusCode: 200, body: Data(#"{"ok":true}"#.utf8)))
+
+        var form = MultipartForm()
+        form.file("f", data: Data(repeating: 0x41, count: 4096), filename: "a.bin")
+
+        let progressBox = ProgressBox()
+        let result: UploadEcho = try await api.upload(
+            url: "https://api.example.com/x",
+            form: form,
+            onProgress: { progressBox.record($0) }
+        )
+
+        XCTAssertEqual(result, UploadEcho(ok: true))
+        let values = progressBox.values
+        XCTAssertEqual(values.last, 1.0, "final progress must be 1.0")
+        XCTAssertTrue(values.allSatisfy { $0 >= 0 && $0 <= 1 })
+        XCTAssertEqual(values, values.sorted(), "progress must be monotonic non-decreasing")
+    }
+
+    func testUploadServerErrorThrowsWithStatus() async {
+        StubURLProtocol.setStub(.init(statusCode: 413, body: Data(#"{"error":"too big"}"#.utf8)))
+        var form = MultipartForm()
+        form.file("f", data: Data("x".utf8), filename: "a.txt")
+        do {
+            let _: UploadEcho = try await api.upload(url: "https://api.example.com/x", form: form)
+            XCTFail("expected throw")
+        } catch let error as NSError {
+            XCTAssertEqual(error.code, 413)
+        } catch {
+            XCTFail("wrong error: \(error)")
+        }
+    }
+}

Tests/LCEssentialsTests/HTTPBodyTests.swift

@@ -0,0 +1,58 @@
+import XCTest
+@testable import LCEssentials
+
+private struct SamplePayload: Encodable, Sendable {
+    let name: String
+    let age: Int
+}
+
+final class HTTPBodyTests: XCTestCase {
+
+    // MARK: - JSONBody
+
+    func testJSONBodyEncodesPayloadAndContentType() throws {
+        let payload = SamplePayload(name: "loverde", age: 3)
+        let (data, contentType) = try JSONBody(payload).encoded()
+
+        XCTAssertEqual(contentType, "application/json; charset=UTF-8")
+
+        let decoded = try JSONDecoder().decode([String: AnyDecodable].self, from: data)
+        XCTAssertEqual(decoded["name"]?.value as? String, "loverde")
+        XCTAssertEqual(decoded["age"]?.value as? Int, 3)
+    }
+
+    func testJSONBodyFactory() throws {
+        let (data, _) = try jsonBody(SamplePayload(name: "x", age: 1)).encoded()
+        XCTAssertFalse(data.isEmpty)
+    }
+
+    // MARK: - FormURLEncodedBody
+
+    func testFormURLEncodedEncodesPairsAndPercentEscapes() throws {
+        let (data, contentType) = try FormURLEncodedBody(["a": "1", "b": "two words"]).encoded()
+
+        XCTAssertEqual(contentType, "application/x-www-form-urlencoded; charset=UTF-8")
+
+        let pairs = Set(String(data: data, encoding: .utf8)!.split(separator: "&").map(String.init))
+        XCTAssertEqual(pairs, ["a=1", "b=two%20words"])
+    }
+
+    func testFormURLEncodedEscapesReservedCharactersInsteadOfDropping() throws {
+        let (data, _) = try FormURLEncodedBody(["q": "a&b=c"]).encoded()
+        let body = String(data: data, encoding: .utf8)!
+        XCTAssertEqual(body, "q=a%26b%3Dc")
+    }
+}
+
+/// Minimal type-erased decoder for asserting JSON shape in tests.
+struct AnyDecodable: Decodable {
+    let value: Any
+    init(from decoder: Decoder) throws {
+        let c = try decoder.singleValueContainer()
+        if let i = try? c.decode(Int.self) { value = i }
+        else if let s = try? c.decode(String.self) { value = s }
+        else if let b = try? c.decode(Bool.self) { value = b }
+        else if let d = try? c.decode(Double.self) { value = d }
+        else { value = "" }
+    }
+}

Tests/LCEssentialsTests/JSONDecoderDecodeTests.swift

@@ -0,0 +1,26 @@
+import XCTest
+@testable import LCEssentials
+
+private struct OnlyDecodable: Decodable, Sendable, Equatable {
+    let id: Int
+    let name: String
+}
+
+final class JSONDecoderDecodeTests: XCTestCase {
+
+    func testDecodesTypeThatIsDecodableAndSendableButNotEncodable() throws {
+        let data = Data(#"{"id":7,"name":"loverde"}"#.utf8)
+        let value: OnlyDecodable = try JSONDecoder.decode(data: data)
+        XCTAssertEqual(value, OnlyDecodable(id: 7, name: "loverde"))
+    }
+
+    func testDecodeFromStringOverload() throws {
+        let value: OnlyDecodable = try JSONDecoder.decode(#"{"id":1,"name":"a"}"#)
+        XCTAssertEqual(value, OnlyDecodable(id: 1, name: "a"))
+    }
+
+    func testDecodeFromURLThrowsInsteadOfCrashingOnMissingFile() {
+        let missing = URL(fileURLWithPath: "/tmp/does-not-exist-\(UUID().uuidString).json")
+        XCTAssertThrowsError(try JSONDecoder.decode(fromURL: missing) as OnlyDecodable)
+    }
+}

Tests/LCEssentialsTests/MultipartFormTests.swift

@@ -0,0 +1,106 @@
+import XCTest
+@testable import LCEssentials
+
+final class MultipartFormTests: XCTestCase {
+
+    private func readSerialized(_ form: MultipartForm) throws -> (body: Data, contentType: String, url: URL) {
+        let result = try form.serialize()
+        let data = try Data(contentsOf: result.fileURL)
+        return (data, result.contentType, result.fileURL)
+    }
+
+    private func addCleanup(_ url: URL) {
+        addTeardownBlock { try? FileManager.default.removeItem(at: url) }
+    }
+
+    // MARK: - Fields
+
+    func testFieldPartHasNoContentTypeLine() throws {
+        var form = MultipartForm()
+        form.field("caption", "hello world")
+
+        let (body, contentType, url) = try readSerialized(form)
+        addCleanup(url)
+        let text = String(data: body, encoding: .utf8)!
+
+        XCTAssertTrue(contentType.hasPrefix("multipart/form-data; boundary="))
+        let boundary = String(contentType.split(separator: "=", maxSplits: 1)[1])
+
+        XCTAssertEqual(text, [
+            "--\(boundary)\r\n",
+            "Content-Disposition: form-data; name=\"caption\"\r\n",
+            "\r\n",
+            "hello world\r\n",
+            "--\(boundary)--\r\n"
+        ].joined())
+    }
+
+    // MARK: - In-memory data file
+
+    func testDataFilePartCarriesFilenameAndMimeAndRawBytes() throws {
+        let png = Data([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0xFF])
+        var form = MultipartForm()
+        form.file("photo", data: png, filename: "p.png")
+
+        let (body, contentType, url) = try readSerialized(form)
+        addCleanup(url)
+        let boundary = String(contentType.split(separator: "=", maxSplits: 1)[1])
+        let text = String(data: body, encoding: .isoLatin1)!
+
+        XCTAssertTrue(text.contains("Content-Disposition: form-data; name=\"photo\"; filename=\"p.png\"\r\n"))
+        XCTAssertTrue(text.contains("Content-Type: image/png\r\n"))
+        XCTAssertTrue(text.hasSuffix("--\(boundary)--\r\n"))
+
+        // raw bytes appear verbatim between the blank line and the trailing CRLF
+        let marker = Data("\r\n\r\n".utf8)
+        let range = body.range(of: marker)!
+        let afterHeader = body[range.upperBound...]
+        XCTAssertTrue(afterHeader.starts(with: png))
+    }
+
+    func testExplicitMimeOverridesGuess() throws {
+        var form = MultipartForm()
+        form.file("f", data: Data("x".utf8), filename: "a.png", mime: "application/octet-stream")
+        let (body, _, url) = try readSerialized(form)
+        addCleanup(url)
+        XCTAssertTrue(String(data: body, encoding: .utf8)!.contains("Content-Type: application/octet-stream\r\n"))
+    }
+
+    // MARK: - Disk file, streamed
+
+    func testDiskFilePartIsStreamedAndContentMatches() throws {
+        let big = Data((0..<(2 * 1024 * 1024)).map { UInt8($0 % 251) })
+        let src = FileManager.default.temporaryDirectory.appendingPathComponent("src-\(UUID().uuidString).bin")
+        try big.write(to: src)
+        addCleanup(src)
+
+        var form = MultipartForm()
+        form.field("kind", "raw")
+        form.file("doc", url: src)
+
+        let (body, contentType, out) = try readSerialized(form)
+        addCleanup(out)
+        let boundary = String(contentType.split(separator: "=", maxSplits: 1)[1])
+
+        // header uses the source filename
+        XCTAssertTrue(String(data: body.prefix(400), encoding: .isoLatin1)!
+            .contains("filename=\"\(src.lastPathComponent)\""))
+
+        // the 2 MB payload is present verbatim
+        let marker = Data("Content-Type: application/octet-stream\r\n\r\n".utf8)
+        let r = body.range(of: marker)!
+        let payload = body[r.upperBound..<(body.index(r.upperBound, offsetBy: big.count))]
+        XCTAssertEqual(Data(payload), big)
+
+        XCTAssertTrue(String(data: body.suffix(boundary.count + 8), encoding: .utf8)!
+            .hasSuffix("--\(boundary)--\r\n"))
+    }
+
+    // MARK: - MIME lookup
+
+    func testMimeTypeLookup() {
+        XCTAssertEqual(MultipartForm.mimeType(for: "a.jpg"), "image/jpeg")
+        XCTAssertEqual(MultipartForm.mimeType(for: "a.PDF"), "application/pdf")
+        XCTAssertEqual(MultipartForm.mimeType(for: "a.unknownext"), "application/octet-stream")
+    }
+}

Tests/LCEssentialsTests/SmokeTests.swift

@@ -0,0 +1,8 @@
+import XCTest
+@testable import LCEssentials
+
+final class SmokeTests: XCTestCase {
+    func testTargetBuildsAndRuns() {
+        XCTAssertTrue(true)
+    }
+}

Tests/LCEssentialsTests/Support/StubURLProtocol.swift

@@ -0,0 +1,116 @@
+import Foundation
+
+/// Test double for `URLProtocol`. Intercepts every request on a `URLSession`
+/// configured with it, records the outgoing `URLRequest`, and replays a canned
+/// response or error supplied by the test.
+///
+/// Register via:
+/// ```
+/// let cfg = URLSessionConfiguration.ephemeral
+/// cfg.protocolClasses = [StubURLProtocol.self]
+/// let session = URLSession(configuration: cfg)
+/// ```
+final class StubURLProtocol: URLProtocol, @unchecked Sendable {
+
+    struct Stub {
+        var statusCode: Int = 200
+        var headers: [String: String] = ["Content-Type": "application/json"]
+        var body: Data = Data()
+        var error: Error?
+        /// Bytes reported through `URLSession`'s upload progress, in order.
+        var uploadProgressChunks: [Int] = []
+    }
+
+    // MARK: - Test-facing state (guarded)
+
+    private static let lock = NSLock()
+    // Access is serialised through `lock`; the unsafe opt-out is the documented
+    // pattern for lock-guarded mutable statics under strict concurrency.
+    nonisolated(unsafe) private static var _stub = Stub()
+    nonisolated(unsafe) private static var _capturedRequests: [URLRequest] = []
+    nonisolated(unsafe) private static var _capturedBodies: [Data] = []
+
+    static func setStub(_ stub: Stub) {
+        lock.lock(); defer { lock.unlock() }
+        _stub = stub
+        _capturedRequests = []
+        _capturedBodies = []
+    }
+
+    static func reset() { setStub(Stub()) }
+
+    static var capturedRequests: [URLRequest] {
+        lock.lock(); defer { lock.unlock() }
+        return _capturedRequests
+    }
+
+    /// Body of the last intercepted request. `URLProtocol` strips `httpBody` for
+    /// stream bodies, so this reads `httpBodyStream` when needed.
+    static var lastCapturedBody: Data? {
+        lock.lock(); defer { lock.unlock() }
+        return _capturedBodies.last
+    }
+
+    static var requestCount: Int {
+        lock.lock(); defer { lock.unlock() }
+        return _capturedRequests.count
+    }
+
+    private static func currentStub() -> Stub {
+        lock.lock(); defer { lock.unlock() }
+        return _stub
+    }
+
+    private static func record(_ request: URLRequest, body: Data) {
+        lock.lock(); defer { lock.unlock() }
+        _capturedRequests.append(request)
+        _capturedBodies.append(body)
+    }
+
+    // MARK: - URLProtocol
+
+    override class func canInit(with request: URLRequest) -> Bool { true }
+
+    override class func canonicalRequest(for request: URLRequest) -> URLRequest { request }
+
+    override func startLoading() {
+        let stub = Self.currentStub()
+        Self.record(request, body: Self.bodyData(from: request))
+
+        guard let client = client else { return }
+
+        if let error = stub.error {
+            client.urlProtocol(self, didFailWithError: error)
+            return
+        }
+
+        let url = request.url ?? URL(string: "https://stub.invalid")!
+        let response = HTTPURLResponse(url: url,
+                                       statusCode: stub.statusCode,
+                                       httpVersion: "HTTP/1.1",
+                                       headerFields: stub.headers)!
+        client.urlProtocol(self, didReceive: response, cacheStoragePolicy: .notAllowed)
+        client.urlProtocol(self, didLoad: stub.body)
+        client.urlProtocolDidFinishLoading(self)
+    }
+
+    override func stopLoading() {}
+
+    // MARK: - Body extraction
+
+    private static func bodyData(from request: URLRequest) -> Data {
+        if let body = request.httpBody { return body }
+        guard let stream = request.httpBodyStream else { return Data() }
+        stream.open()
+        defer { stream.close() }
+        var data = Data()
+        let bufferSize = 64 * 1024
+        var buffer = [UInt8](repeating: 0, count: bufferSize)
+        while stream.hasBytesAvailable {
+            let read = stream.read(&buffer, maxLength: bufferSize)
+            if read <= 0 { break }
+            data.append(buffer, count: read)
+        }
+        return data
+    }
+}

Tests/LCEssentialsTests/Support/StubURLProtocolTests.swift

@@ -0,0 +1,47 @@
+import XCTest
+
+final class StubURLProtocolTests: XCTestCase {
+
+    private func makeSession() -> URLSession {
+        let cfg = URLSessionConfiguration.ephemeral
+        cfg.protocolClasses = [StubURLProtocol.self]
+        return URLSession(configuration: cfg)
+    }
+
+    override func tearDown() {
+        StubURLProtocol.reset()
+        super.tearDown()
+    }
+
+    func testReplaysCannedResponseAndCapturesRequest() async throws {
+        var stub = StubURLProtocol.Stub()
+        stub.statusCode = 201
+        stub.body = Data(#"{"ok":true}"#.utf8)
+        StubURLProtocol.setStub(stub)
+
+        var request = URLRequest(url: URL(string: "https://example.com/things")!)
+        request.httpMethod = "POST"
+        request.httpBody = Data(#"{"name":"x"}"#.utf8)
+
+        let (data, response) = try await makeSession().data(for: request)
+
+        XCTAssertEqual((response as? HTTPURLResponse)?.statusCode, 201)
+        XCTAssertEqual(String(data: data, encoding: .utf8), #"{"ok":true}"#)
+        XCTAssertEqual(StubURLProtocol.requestCount, 1)
+        XCTAssertEqual(StubURLProtocol.capturedRequests.first?.httpMethod, "POST")
+        XCTAssertEqual(StubURLProtocol.lastCapturedBody, Data(#"{"name":"x"}"#.utf8))
+    }
+
+    func testReplaysError() async {
+        var stub = StubURLProtocol.Stub()
+        stub.error = URLError(.notConnectedToInternet)
+        StubURLProtocol.setStub(stub)
+
+        do {
+            _ = try await makeSession().data(for: URLRequest(url: URL(string: "https://example.com")!))
+            XCTFail("expected throw")
+        } catch {
+            XCTAssertEqual((error as? URLError)?.code, .notConnectedToInternet)
+        }
+    }
+}