diff --git a/.github/workflows/release-please.yml b/.github/workflows/release-please.yml
new file mode 100644
index 0000000..a985967
--- /dev/null
+++ b/.github/workflows/release-please.yml
@@ -0,0 +1,25 @@
+name: Release Please
+
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  release-please:
+    name: Release Please
+    runs-on: ubuntu-latest
+    outputs:
+      release_created: ${{ steps.release.outputs.release_created }}
+      tag_name: ${{ steps.release.outputs.tag_name }}
+    steps:
+      - uses: googleapis/release-please-action@v4
+        id: release
+        with:
+          config-file: release-please-config.json
+          manifest-file: .release-please-manifest.json
diff --git a/.release-please-manifest.json b/.release-please-manifest.json
new file mode 100644
index 0000000..2537c1f
--- /dev/null
+++ b/.release-please-manifest.json
@@ -0,0 +1,3 @@
+{
+  ".": "0.4.0"
+}
diff --git a/Sources/HTTPClient/Interface/Client.swift b/Sources/HTTPClient/Interface/Client.swift
index 841d3c7..f022656 100644
--- a/Sources/HTTPClient/Interface/Client.swift
+++ b/Sources/HTTPClient/Interface/Client.swift
@@ -33,14 +33,18 @@ public struct Client: Sendable {
   public var middlewares: [any ClientMiddleware]
 
   /// Creates a new client.
+  // / - Parameters:
+  ///   - serverURL: The URL of the server, used as the base URL for requests made by the client.
+  ///   - transport: A type capable of sending HTTP requests and receiving HTTP responses.
+  ///   - middlewares: The middlewares to be invoked before the transport. If not provided, a default middleware that adds default headers to requests will be used.
   public init(
     serverURL: URL,
     transport: any ClientTransport,
-    middlewares: [any ClientMiddleware] = []
+    middlewares: [any ClientMiddleware]? = nil
   ) {
     self.serverURL = serverURL
     self.transport = transport
-    self.middlewares = middlewares
+    self.middlewares = middlewares ?? [DefaultHeadersMiddleware()]
   }
 
   /// Sends the HTTP request and returns the HTTP response.
diff --git a/Sources/HTTPClient/Middlewares/DefaultHeadersMiddleware.swift b/Sources/HTTPClient/Middlewares/DefaultHeadersMiddleware.swift
new file mode 100644
index 0000000..b60ee39
--- /dev/null
+++ b/Sources/HTTPClient/Middlewares/DefaultHeadersMiddleware.swift
@@ -0,0 +1,110 @@
+import Foundation
+import HTTPTypes
+
+public struct DefaultHeadersMiddleware: ClientMiddleware {
+
+  let headers = HTTPFields([
+    HTTPField.defaultUserAgent,
+    HTTPField.defaultAcceptEncoding,
+    HTTPField.defaultAcceptLanguage,
+  ])
+
+  public func intercept(
+    _ request: HTTPRequest,
+    body: sending HTTPBody?,
+    baseURL: URL,
+    next: (HTTPRequest, sending HTTPBody?, URL) async throws -> (HTTPResponse, HTTPBody?)
+  ) async throws -> (HTTPResponse, HTTPBody?) {
+    var request = request
+    for field in headers {
+      if !request.headerFields.contains(field.name) {
+        request.headerFields[field.name] = field.value
+      }
+    }
+    return try await next(request, body, baseURL)
+  }
+}
+
+extension HTTPField {
+  /// Returns default `Accept-Encoding` header, appropriate for the encodings supported by particular OS versions.
+  ///
+  /// See the [Accept-Encoding HTTP header documentation](https://tools.ietf.org/html/rfc7230#section-4.2.3) .
+  static let defaultAcceptEncoding: HTTPField = {
+    let encodings = ["gzip", "deflate"]
+    return HTTPField(name: .acceptEncoding, value: encodings.qualityEncoded())
+  }()
+
+  /// Returns default `Accept-Language` header, generated by querying `Locale` for the user's `preferredLanguages`.
+  ///
+  /// See the [Accept-Language HTTP header documentation](https://tools.ietf.org/html/rfc7231#section-5.3.5).
+  static let defaultAcceptLanguage: HTTPField = HTTPField(
+    name: .acceptLanguage, value: Locale.preferredLanguages.prefix(6).qualityEncoded())
+
+  /// Returns default `User-Agent` header.
+  ///
+  /// See the [User-Agent header documentation](https://tools.ietf.org/html/rfc7231#section-5.5.3).
+  ///
+  /// Example: `iOS Example/1.0 (dev.grds.swift-http-client.iOS-Example; build:1; iOS 16.0.0) swift-http-client/1.0.0`
+  static let defaultUserAgent: HTTPField = {
+    let info = Bundle.main.infoDictionary
+    let executable =
+      (info?["CFBundleExecutable"] as? String)
+      ?? (ProcessInfo.processInfo.arguments.first?.split(separator: "/").last.map(String.init))
+      ?? "Unknown"
+    let bundle = info?["CFBundleIdentifier"] as? String ?? "Unknown"
+    let appVersion = info?["CFBundleShortVersionString"] as? String ?? "Unknown"
+    let appBuild = info?["CFBundleVersion"] as? String ?? "Unknown"
+
+    let osNameVersion: String = {
+      let version = ProcessInfo.processInfo.operatingSystemVersion
+      let versionString = "\(version.majorVersion).\(version.minorVersion).\(version.patchVersion)"
+      let osName: String = {
+        #if os(iOS)
+          #if targetEnvironment(macCatalyst)
+            return "macOS(Catalyst)"
+          #else
+            return "iOS"
+          #endif
+        #elseif os(watchOS)
+          return "watchOS"
+        #elseif os(tvOS)
+          return "tvOS"
+        #elseif os(macOS)
+          #if targetEnvironment(macCatalyst)
+            return "macOS(Catalyst)"
+          #else
+            return "macOS"
+          #endif
+        #elseif os(visionOS)
+          return "visionOS"
+        #elseif os(Linux)
+          return "Linux"
+        #elseif os(Windows)
+          return "Windows"
+        #elseif os(Android)
+          return "Android"
+        #elseif os(WASI)
+          return "WASI"
+        #else
+          return "Unknown"
+        #endif
+      }()
+
+      return "\(osName) \(versionString)"
+    }()
+
+    let userAgent =
+      "\(executable)/\(appVersion) (\(bundle); build:\(appBuild); \(osNameVersion)) swift-http-client/\(version)"
+
+    return HTTPField(name: .userAgent, value: userAgent)
+  }()
+}
+
+extension Collection<String> {
+  func qualityEncoded() -> String {
+    enumerated().map { index, encoding in
+      let quality = 1.0 - (Double(index) * 0.1)
+      return "\(encoding);q=\(quality)"
+    }.joined(separator: ", ")
+  }
+}
diff --git a/Sources/HTTPClient/Version.swift b/Sources/HTTPClient/Version.swift
new file mode 100644
index 0000000..d76fc65
--- /dev/null
+++ b/Sources/HTTPClient/Version.swift
@@ -0,0 +1,3 @@
+// x-release-please-start-version
+let version = "0.4.0"
+// x-release-please-end
diff --git a/Tests/HTTPClientTests/ClientTests.swift b/Tests/HTTPClientTests/ClientTests.swift
index d9a6167..746b3df 100644
--- a/Tests/HTTPClientTests/ClientTests.swift
+++ b/Tests/HTTPClientTests/ClientTests.swift
@@ -89,7 +89,9 @@ struct ClientTests {
     let client = Client(serverURL: serverURL, transport: transport)
 
     #expect(client.serverURL == serverURL)
-    #expect(client.middlewares.isEmpty)
+    #expect(
+      client.middlewares.isEmpty == false,
+      "Default middleware should be added when no middlewares are provided")
   }
 
   @Test func clientInitializationWithMiddlewares() {
diff --git a/release-please-config.json b/release-please-config.json
new file mode 100644
index 0000000..b20289d
--- /dev/null
+++ b/release-please-config.json
@@ -0,0 +1,19 @@
+{
+  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
+  "release-type": "simple",
+  "packages": {
+    ".": {
+      "release-type": "simple",
+      "package-name": "swift-http-client",
+      "changelog-path": "CHANGELOG.md",
+      "bump-minor-pre-major": true,
+      "bump-patch-for-minor-pre-major": true,
+      "extra-files": [
+        {
+          "type": "generic",
+          "path": "Sources/HTTPClient/Version.swift"
+        }
+      ]
+    }
+  }
+}