COMFY_DIR alone manages ComfyUI: derive the launch command from the standard venv layout

internal/config/config.go

@@ -51,11 +51,14 @@ type Config struct {
 	LLMBusyStatus  int
 	BusyRetryAfter int
 
-	// ComfyCmd spawns and supervises a ComfyUI server on demand (empty =
-	// unmanaged, the current behavior). ComfyDir is its working directory.
-	// The managed server is stopped after ComfyIdleTimeout without
-	// requests, freeing its VRAM; ComfyStartTimeout bounds how long a
-	// request waits for it to come up.
+	// ComfyCmd spawns and supervises a ComfyUI server on demand. When
+	// ComfyCmd is empty but ComfyDir is set, management is enabled with the
+	// standard venv layout under ComfyDir (.venv + main.py or
+	// ComfyUI/main.py; --port from the COMFY_URL port) — ComfyCmd is the
+	// override for other layouts and doubles as the working directory when
+	// set explicitly. The managed server is stopped after ComfyIdleTimeout
+	// without requests, freeing its VRAM; ComfyStartTimeout bounds how long
+	// a request waits for it to come up.
 	ComfyCmd          string
 	ComfyDir          string
 	ComfyIdleTimeout  time.Duration
@@ -305,6 +308,9 @@ func Load(getenv func(string) string) (Config, error) {
 	if cfg.ComfyCmd != "" && cfg.ComfyURL == "" {
 		return cfg, fmt.Errorf("COMFY_CMD requires COMFY_URL to be set (the proxy needs somewhere to forward)")
 	}
+	if cfg.ComfyCmd == "" && cfg.ComfyDir != "" && cfg.ComfyURL == "" {
+		return cfg, fmt.Errorf("COMFY_DIR without COMFY_CMD requires COMFY_URL to be set (it enables the managed ComfyUI)")
+	}
 	if cfg.OllamaURL == "" && cfg.ComfyURL == "" {
 		return cfg, ErrNoConsumer
 	}

internal/config/config_test.go

@@ -222,3 +222,28 @@ func TestGameDetectionSettings(t *testing.T) {
 		t.Fatal("GPUIgnoreProcs default must not be empty")
 	}
 }
+
+func TestComfyDirOnlyEnablesManaged(t *testing.T) {
+	// COMFY_DIR without COMFY_CMD and without COMFY_URL is a mistake.
+	_, err := Load(func(k string) string {
+		if k == "COMFY_DIR" {
+			return `C:\ComfyUI`
+		}
+		return ""
+	})
+	if err == nil || !strings.Contains(err.Error(), "COMFY_DIR") {
+		t.Fatalf("err = %v, want COMFY_DIR/COMFY_URL validation error", err)
+	}
+	// With COMFY_URL it loads — the launch command is derived from the dir.
+	if _, err := Load(func(k string) string {
+		switch k {
+		case "COMFY_DIR":
+			return `C:\ComfyUI`
+		case "COMFY_URL":
+			return "http://127.0.0.1:8189"
+		}
+		return ""
+	}); err != nil {
+		t.Fatalf("COMFY_DIR with COMFY_URL must load: %v", err)
+	}
+}

internal/config/sample.go

@@ -28,8 +28,8 @@ func sampleEntries(logFile string) []sampleEntry {
 		{"OLLAMA_URL", "http://127.0.0.1:11434", "Ollama upstream URL; setting it enables the Ollama consumer (default: empty = disabled)", false},
 		{"COMFY_URL", "http://127.0.0.1:8188", "ComfyUI upstream URL; setting it enables the ComfyUI consumer (default: empty = disabled)", false},
 		{"WARM_MODEL", "", "Optional model to reload after an image job (default: empty = none)", false},
-		{"COMFY_CMD", `"C:\ComfyUI\.venv\Scripts\python.exe" ComfyUI\main.py --port 8188`, "Spawn and supervise ComfyUI on demand: the first request starts it, it stops after COMFY_IDLE_TIMEOUT to free VRAM (default: empty = unmanaged)", false},
-		{"COMFY_DIR", `C:\ComfyUI`, "Working directory for COMFY_CMD (default: empty = inherit)", false},
+		{"COMFY_CMD", `"C:\ComfyUI\.venv\Scripts\python.exe" ComfyUI\main.py --port 8188`, "Spawn and supervise ComfyUI on demand: the first request starts it, it stops after COMFY_IDLE_TIMEOUT to free VRAM (default: derived from COMFY_DIR; both empty = unmanaged)", false},
+		{"COMFY_DIR", `C:\ComfyUI`, "Root of a standard ComfyUI venv install (.venv + main.py): setting it alone supervises ComfyUI with the derived launch command; also the working directory for COMFY_CMD", false},
 		{"COMFY_IDLE_TIMEOUT", "5m", "Stop the managed ComfyUI after this long without requests or jobs (frees VRAM)", false},
 		{"COMFY_START_TIMEOUT", "2m", "How long a request waits for the managed ComfyUI to come up", false},
 		{"GAME_PROCS", "cyberpunk2077.exe,hl2.exe", "While a listed process runs, the GPU counts as held by it: requests wait, Ollama unloads, managed ComfyUI stops (default: empty = disabled)", false},