diff --git a/Package.swift b/Package.swift
index 54f8b3f..1b9a0d3 100644
--- a/Package.swift
+++ b/Package.swift
@@ -50,5 +50,10 @@ let package = Package(
             path: "Tests/ContainerComposeKitTests",
             resources: [.copy("Fixtures")]
         ),
+        .testTarget(
+            name: "container-composeTests",
+            dependencies: ["container-compose"],
+            path: "Tests/container-composeTests"
+        ),
     ]
 )
diff --git a/README.md b/README.md
index caf8b4b..bda36d0 100644
--- a/README.md
+++ b/README.md
@@ -72,6 +72,17 @@ container compose down -v       # stop+remove containers, networks, and named vo
 they run. `--profile <name>` (repeatable, merged with `COMPOSE_PROFILES`) activates
 profile-gated services. Override the CLI with `CONTAINER_CLI=/path/to/container`.
 
+### Updating
+
+```sh
+container compose update          # download + verify + install the latest release
+container compose update --check  # just report whether a newer version exists
+```
+
+`update` fetches the latest GitHub Release, downloads the signed + notarized `.pkg`,
+verifies its signature (`pkgutil --check-signature`), and installs it (prompts for
+admin, since the plugin lives under `/usr/local`). Works no matter how it was installed.
+
 ## Compatibility
 
 Supported and translated to `container run`/`build`/`network`/`volume`:
diff --git a/Sources/container-compose/ContainerCompose.swift b/Sources/container-compose/ContainerCompose.swift
index 2b7f7d9..7a08ab9 100644
--- a/Sources/container-compose/ContainerCompose.swift
+++ b/Sources/container-compose/ContainerCompose.swift
@@ -19,6 +19,7 @@ struct ContainerCompose: AsyncParsableCommand {
         subcommands: [
             Up.self, Down.self, Ps.self, Logs.self, Config.self,
             Exec.self, Pull.self, Stop.self, Start.self, Restart.self,
+            Update.self,
         ],
         defaultSubcommand: Up.self
     )
diff --git a/Sources/container-compose/Update.swift b/Sources/container-compose/Update.swift
new file mode 100644
index 0000000..85b199d
--- /dev/null
+++ b/Sources/container-compose/Update.swift
@@ -0,0 +1,171 @@
+// `container-compose update` — self-update from the latest GitHub Release.
+//
+// Checks the Releases API, downloads the signed + notarized .pkg, verifies its
+// signature, and installs it (the macOS installer places the plugin in the right
+// location and prompts for admin). Works regardless of how it was installed.
+
+import ArgumentParser
+import Foundation
+
+private let repoSlug = "flaticols/container-compose"
+
+struct Update: AsyncParsableCommand {
+    static let configuration = CommandConfiguration(
+        commandName: "update",
+        abstract: "Update container-compose to the latest release."
+    )
+
+    @Flag(name: .long, help: "Only check for a newer version; don't download or install.")
+    var check = false
+
+    @Flag(name: .long, help: "Install even if it appears up to date (or a dev build).")
+    var force = false
+
+    func run() async throws {
+        let current = containerComposeVersion
+        let release = try await fetchLatestRelease()
+        let latestTag = release.tag_name
+
+        let currentV = SemVer(current)
+        let latestV = SemVer(latestTag)
+        let isNewer = (currentV != nil && latestV != nil) ? currentV! < latestV! : true
+
+        guard isNewer || force else {
+            print("container-compose is up to date (\(current)).")
+            return
+        }
+
+        print("Current: \(current)   Latest: \(latestTag)")
+        if check {
+            print("Run `container-compose update` to install.")
+            return
+        }
+
+        guard let asset = release.assets.first(where: { $0.name.hasSuffix(".pkg") }),
+            let assetURL = URL(string: asset.browser_download_url)
+        else {
+            throw Fail("the latest release has no .pkg installer attached")
+        }
+
+        let pkg = try await download(asset.name, from: assetURL)
+        defer { try? FileManager.default.removeItem(at: pkg) }
+
+        try verifySignature(of: pkg)
+        try install(pkg)
+        print("Updated to \(latestTag). Run `container-compose --version` to confirm.")
+    }
+
+    // MARK: - Steps
+
+    private func fetchLatestRelease() async throws -> Release {
+        let url = URL(string: "https://api.github.com/repos/\(repoSlug)/releases/latest")!
+        var request = URLRequest(url: url)
+        request.setValue("application/vnd.github+json", forHTTPHeaderField: "Accept")
+        request.setValue("container-compose", forHTTPHeaderField: "User-Agent")
+        let (data, response) = try await URLSession.shared.data(for: request)
+        guard let http = response as? HTTPURLResponse, http.statusCode == 200 else {
+            let code = (response as? HTTPURLResponse)?.statusCode ?? -1
+            throw Fail("could not reach the GitHub Releases API (HTTP \(code))")
+        }
+        return try JSONDecoder().decode(Release.self, from: data)
+    }
+
+    private func download(_ name: String, from url: URL) async throws -> URL {
+        print("Downloading \(name) ...")
+        let (data, response) = try await URLSession.shared.data(from: url)
+        guard let http = response as? HTTPURLResponse, http.statusCode == 200 else {
+            throw Fail("download failed (HTTP \((response as? HTTPURLResponse)?.statusCode ?? -1))")
+        }
+        let dest = FileManager.default.temporaryDirectory.appendingPathComponent(name)
+        try? FileManager.default.removeItem(at: dest)
+        try data.write(to: dest)
+        return dest
+    }
+
+    private func verifySignature(of pkg: URL) throws {
+        // A signed, notarized .pkg makes `pkgutil --check-signature` exit 0.
+        let (status, _) = capture("/usr/sbin/pkgutil", ["--check-signature", pkg.path])
+        guard status == 0 else {
+            throw Fail("the downloaded .pkg is not signed/notarized; refusing to install")
+        }
+        print("Signature verified.")
+    }
+
+    private func install(_ pkg: URL) throws {
+        // Installing into /usr/local needs admin; `sudo installer` prompts in the
+        // terminal and places the plugin where `container` looks for it.
+        print("Installing (you may be prompted for your password) ...")
+        let status = runInheriting(
+            "/usr/bin/sudo", ["/usr/sbin/installer", "-pkg", pkg.path, "-target", "/"])
+        guard status == 0 else { throw Fail("installer exited with status \(status)") }
+    }
+}
+
+// MARK: - GitHub API model
+
+private struct Release: Decodable {
+    let tag_name: String
+    let assets: [Asset]
+}
+
+private struct Asset: Decodable {
+    let name: String
+    let browser_download_url: String
+}
+
+// MARK: - Version comparison
+
+/// A minimal semantic version: `major.minor.patch`, with a prerelease suffix
+/// (e.g. `-dev`, `-beta1`) sorting before the same release.
+struct SemVer: Comparable {
+    let parts: [Int]
+    let isPrerelease: Bool
+
+    init?(_ raw: String) {
+        var s = raw
+        if s.hasPrefix("v") { s.removeFirst() }
+        let split = s.split(separator: "-", maxSplits: 1)
+        isPrerelease = split.count > 1
+        let nums = String(split[0]).split(separator: ".").map { Int($0) }
+        guard !nums.isEmpty, nums.allSatisfy({ $0 != nil }) else { return nil }
+        var p = nums.compactMap { $0 }
+        while p.count < 3 { p.append(0) }
+        parts = Array(p.prefix(3))
+    }
+
+    static func < (lhs: SemVer, rhs: SemVer) -> Bool {
+        for i in 0..<3 where lhs.parts[i] != rhs.parts[i] { return lhs.parts[i] < rhs.parts[i] }
+        // Same x.y.z: a prerelease precedes the final release.
+        if lhs.isPrerelease != rhs.isPrerelease { return lhs.isPrerelease }
+        return false
+    }
+}
+
+// MARK: - Process helpers
+
+private struct Fail: Error, CustomStringConvertible {
+    let description: String
+    init(_ message: String) { self.description = message }
+}
+
+private func runInheriting(_ launchPath: String, _ args: [String]) -> Int32 {
+    let p = Process()
+    p.executableURL = URL(fileURLWithPath: launchPath)
+    p.arguments = args
+    do { try p.run() } catch { return -1 }
+    p.waitUntilExit()
+    return p.terminationStatus
+}
+
+private func capture(_ launchPath: String, _ args: [String]) -> (status: Int32, output: String) {
+    let p = Process()
+    p.executableURL = URL(fileURLWithPath: launchPath)
+    p.arguments = args
+    let pipe = Pipe()
+    p.standardOutput = pipe
+    p.standardError = pipe
+    do { try p.run() } catch { return (-1, "") }
+    let data = pipe.fileHandleForReading.readDataToEndOfFile()
+    p.waitUntilExit()
+    return (p.terminationStatus, String(data: data, encoding: .utf8) ?? "")
+}
diff --git a/Tests/container-composeTests/UpdateTests.swift b/Tests/container-composeTests/UpdateTests.swift
new file mode 100644
index 0000000..45b00e1
--- /dev/null
+++ b/Tests/container-composeTests/UpdateTests.swift
@@ -0,0 +1,35 @@
+import Testing
+
+@testable import container_compose
+
+@Suite("SemVer comparison")
+struct SemVerTests {
+    @Test("orders by major.minor.patch")
+    func ordering() throws {
+        #expect(try lt("0.0.2", "0.0.3"))
+        #expect(try lt("0.0.9", "0.1.0"))
+        #expect(try lt("0.9.0", "1.0.0"))
+        #expect(try !lt("0.0.3", "0.0.3"))
+        #expect(try !lt("0.1.0", "0.0.9"))
+    }
+
+    @Test("a prerelease precedes the same final release")
+    func prerelease() throws {
+        #expect(try lt("0.0.1-beta1", "0.0.1"))
+        #expect(try lt("0.0.0-dev", "0.0.6"))
+        #expect(try !lt("0.0.1", "0.0.1-beta1"))
+    }
+
+    @Test("tolerates a leading v and short forms")
+    func forms() throws {
+        #expect(try lt("v0.0.2", "v0.0.3"))
+        #expect(try !lt("v1", "v1.0.0"))  // 1 == 1.0.0
+        #expect(SemVer("not-a-version") == nil)
+    }
+
+    private func lt(_ a: String, _ b: String) throws -> Bool {
+        let x = try #require(SemVer(a))
+        let y = try #require(SemVer(b))
+        return x < y
+    }
+}