diff --git a/models/workflow/workflow.go b/models/workflow/workflow.go
index d83575e..57eb2a6 100644
--- a/models/workflow/workflow.go
+++ b/models/workflow/workflow.go
@@ -215,8 +215,30 @@ func (d *Workflow) ExtractFromPlantUML(plantUML multipart.File, request *tools.A
 			}
 		}
 
+		// Handle links outside the catalog loop: each link line must be processed
+		// exactly once (the catalog loop would otherwise call extractLink once per
+		// catalog entry, producing N×7 duplicate links in the graph).
+		if strings.Contains(line, "-->") {
+			if err := d.extractLink(parseLine, graphVarName, "-->", false); err != nil {
+				fmt.Println(err)
+			}
+			continue
+		}
+		if strings.Contains(line, "<--") {
+			if err := d.extractLink(parseLine, graphVarName, "<--", true); err != nil {
+				fmt.Println(err)
+			}
+			continue
+		}
+		if strings.Contains(line, "--") {
+			if err := d.extractLink(parseLine, graphVarName, "--", false); err != nil {
+				fmt.Println(err)
+			}
+			continue
+		}
+
 		for n, new := range resourceCatalog {
-			if strings.Contains(line, n+"(") && !strings.Contains(line, "!procedure") && !strings.Contains(line, "!define") { // exclude macro declarations
+			if strings.Contains(line, n+"(") && !strings.Contains(line, "!procedure") && !strings.Contains(line, "!define") {
 				newRes := new()
 				newRes.SetID(uuid.New().String())
 				varName, graphItem, err := d.extractResourcePlantUML(parseLine, newRes, n, request.PeerID)
@@ -226,31 +248,7 @@ func (d *Workflow) ExtractFromPlantUML(plantUML multipart.File, request *tools.A
 				if graphItem != nil {
 					graphVarName[varName] = *graphItem
 				}
-				continue
-			} else if strings.Contains(line, "-->") {
-				err := d.extractLink(parseLine, graphVarName, "-->", false)
-				if err != nil {
-					fmt.Println(err)
-					continue
-				}
-			} else if strings.Contains(line, "<--") {
-				err := d.extractLink(parseLine, graphVarName, "<--", true)
-				if err != nil {
-					fmt.Println(err)
-					continue
-				}
-			} else if strings.Contains(line, "--") {
-				err := d.extractLink(parseLine, graphVarName, "--", false)
-				if err != nil {
-					fmt.Println(err)
-					continue
-				}
-			} else if strings.Contains(line, "-") {
-				err := d.extractLink(parseLine, graphVarName, "-", false)
-				if err != nil {
-					fmt.Println(err)
-					continue
-				}
+				break
 			}
 		}
 	}
@@ -355,14 +353,37 @@ func (d *Workflow) extractLink(line string, graphVarName map[string]graph.GraphI
 	if len(splitted) < 2 {
 		return errors.New("links elements not found")
 	}
+
+	// Source: trim surrounding whitespace.
+	srcVar := strings.TrimSpace(splitted[0])
+
+	// Destination: trim whitespace then stop at the first space or apostrophe
+	// (the rest may be a trailing comment produced by ToPlantUML look-ahead).
+	dstTokens := strings.FieldsFunc(strings.TrimSpace(splitted[1]), func(r rune) bool {
+		return r == ' ' || r == '\t' || r == '\''
+	})
+	if len(dstTokens) == 0 {
+		return errors.New("link destination var name not found")
+	}
+	dstVar := dstTokens[0]
+
+	srcItem, srcOk := graphVarName[srcVar]
+	dstItem, dstOk := graphVarName[dstVar]
+	if !srcOk || srcItem.ID == "" {
+		return fmt.Errorf("link source %q not declared", srcVar)
+	}
+	if !dstOk || dstItem.ID == "" {
+		return fmt.Errorf("link destination %q not declared", dstVar)
+	}
+
 	link := &graph.GraphLink{
 		Source: graph.Position{
-			ID: graphVarName[splitted[0]].ID,
+			ID: srcItem.ID,
 			X:  0,
 			Y:  0,
 		},
 		Destination: graph.Position{
-			ID: graphVarName[splitted[1]].ID,
+			ID: dstItem.ID,
 			X:  0,
 			Y:  0,
 		},