diff --git a/App/Views/StackSection.swift b/App/Views/StackSection.swift
index b866836..a221730 100644
--- a/App/Views/StackSection.swift
+++ b/App/Views/StackSection.swift
@@ -87,7 +87,9 @@ struct StackSection: View {
             stackButton("folder", "Reveal compose file") {
                 NSWorkspace.shared.activateFileViewerSelecting([file])
             }
-        } else if stack.origin == .inferred {
+        } else if appState.composeAvailable {
+            // No compose file linked yet (inferred, or labeled but launched outside Consai):
+            // let the user point at one to enable up/down.
             stackButton("link", "Link compose file…") {
                 if let file = ComposeFilePicker.pick() {
                     appState.linkComposeFile(project: stack.projectName, file: file)
diff --git a/ConsaiCore/Sources/ConsaiCore/Engines/ProjectRegistry.swift b/ConsaiCore/Sources/ConsaiCore/Engines/ProjectRegistry.swift
index 28b3c47..8c4ae46 100644
--- a/ConsaiCore/Sources/ConsaiCore/Engines/ProjectRegistry.swift
+++ b/ConsaiCore/Sources/ConsaiCore/Engines/ProjectRegistry.swift
@@ -44,6 +44,10 @@ public struct ProjectRegistry: Codable, Sendable, Equatable {
 
     // MARK: - Assembly
 
+    /// The de-facto-standard Docker Compose project label, written by compose tools (incl.
+    /// container-compose once Mcrich23/Container-Compose#110 lands).
+    public static let composeProjectLabel = "com.docker.compose.project"
+
     /// Fold containers into stacks + standalone leftovers.
     ///
     /// - Parameter inferStacks: when true, containers Consai didn't launch are grouped by
@@ -58,6 +62,24 @@ public struct ProjectRegistry: Codable, Sendable, Equatable {
         var remaining = containers
         var stacks: [Stack] = []
 
+        // 0. Reliable grouping by the `com.docker.compose.project` label (always on — no
+        //    guessing). Lets externally-launched stacks group correctly without the
+        //    name-prefix heuristic, once the compose tool labels its containers.
+        let labeled = Dictionary(grouping: remaining.filter { $0.labels[Self.composeProjectLabel] != nil }) {
+            $0.labels[Self.composeProjectLabel]!
+        }
+        for (project, members) in labeled {
+            remaining.removeAll { m in members.contains { $0.id == m.id } }
+            stacks.append(
+                Stack(
+                    projectName: project,
+                    composeFilePath: knownProjects[project]?.path,
+                    services: members,
+                    origin: .composeLabeled
+                )
+            )
+        }
+
         // 1. Known projects (authoritative), longest project name first so a more specific
         //    project wins over a shorter one that is a prefix of it.
         for project in knownProjects.keys.sorted(by: { $0.count > $1.count }) {
diff --git a/ConsaiCore/Sources/ConsaiCore/Models/Models.swift b/ConsaiCore/Sources/ConsaiCore/Models/Models.swift
index 9318748..09ad95a 100644
--- a/ConsaiCore/Sources/ConsaiCore/Models/Models.swift
+++ b/ConsaiCore/Sources/ConsaiCore/Models/Models.swift
@@ -57,10 +57,14 @@ public func formatBytes(_ bytes: UInt64) -> String {
     return "\(Int(mb.rounded())) MB"
 }
 
-/// Whether a stack was launched by Consai (authoritative, has compose file) or merely
-/// inferred from container naming (best-effort, may lack a compose file).
+/// How confident we are that a stack's grouping is real.
 public enum StackOrigin: Sendable, Equatable {
+    /// Consai launched it via compose; we hold its compose file (full up/down).
     case launchedByConsai
+    /// Grouped reliably by the `com.docker.compose.project` label (a real stack, possibly
+    /// launched outside Consai so we may not hold its compose file).
+    case composeLabeled
+    /// Best-effort grouping from the `<project>-<service>` name prefix (may mis-group).
     case inferred
 }
 
diff --git a/ConsaiCore/Tests/ConsaiCoreTests/ProjectRegistryTests.swift b/ConsaiCore/Tests/ConsaiCoreTests/ProjectRegistryTests.swift
index 2ae917e..c1f4d18 100644
--- a/ConsaiCore/Tests/ConsaiCoreTests/ProjectRegistryTests.swift
+++ b/ConsaiCore/Tests/ConsaiCoreTests/ProjectRegistryTests.swift
@@ -55,6 +55,20 @@ import Foundation
         #expect(result.standalone.map(\.name).sorted() == ["qa-cache", "qa-web"])
     }
 
+    @Test func groupsByComposeProjectLabelEvenWithInferenceOff() {
+        let lbl = ProjectRegistry.composeProjectLabel
+        let labeledApi = Container(id: "1", name: "shop-api", image: "img", status: .running, labels: [lbl: "shop"])
+        let labeledWorker = Container(id: "2", name: "shop-worker", image: "img", status: .running, labels: [lbl: "shop"])
+        let result = ProjectRegistry().assemble(containers: [labeledApi, labeledWorker, c("3", "qa-web")])
+
+        #expect(result.stacks.count == 1)
+        let stack = try! #require(result.stacks.first)
+        #expect(stack.projectName == "shop")
+        #expect(stack.origin == .composeLabeled)
+        #expect(stack.services.count == 2)
+        #expect(result.standalone.map(\.name) == ["qa-web"])   // unlabeled stays standalone
+    }
+
     @Test func singleHyphenatedContainerIsNotAStack() {
         let result = ProjectRegistry().assemble(containers: [c("1", "alone-web")])
         #expect(result.stacks.isEmpty)