diff --git a/packages/language/src/generated/ast.ts b/packages/language/src/generated/ast.ts
index 7d6a589c..527868d4 100644
--- a/packages/language/src/generated/ast.ts
+++ b/packages/language/src/generated/ast.ts
@@ -144,7 +144,7 @@ export function isMemberAccessTarget(item: unknown): item is MemberAccessTarget
     return reflection.isInstance(item, MemberAccessTarget);
 }
 
-export type ReferenceTarget = DataField | EnumField | FunctionParam;
+export type ReferenceTarget = CollectionPredicateBinding | DataField | EnumField | FunctionParam;
 
 export const ReferenceTarget = 'ReferenceTarget';
 
@@ -258,6 +258,7 @@ export function isAttributeParamType(item: unknown): item is AttributeParamType
 export interface BinaryExpr extends langium.AstNode {
     readonly $container: Argument | ArrayExpr | AttributeArg | BinaryExpr | FieldInitializer | FunctionDecl | MemberAccessExpr | ReferenceArg | UnaryExpr;
     readonly $type: 'BinaryExpr';
+    binding?: CollectionPredicateBinding;
     left: Expression;
     operator: '!' | '!=' | '&&' | '<' | '<=' | '==' | '>' | '>=' | '?' | '^' | 'in' | '||';
     right: Expression;
@@ -281,6 +282,18 @@ export function isBooleanLiteral(item: unknown): item is BooleanLiteral {
     return reflection.isInstance(item, BooleanLiteral);
 }
 
+export interface CollectionPredicateBinding extends langium.AstNode {
+    readonly $container: BinaryExpr;
+    readonly $type: 'CollectionPredicateBinding';
+    name: RegularID;
+}
+
+export const CollectionPredicateBinding = 'CollectionPredicateBinding';
+
+export function isCollectionPredicateBinding(item: unknown): item is CollectionPredicateBinding {
+    return reflection.isInstance(item, CollectionPredicateBinding);
+}
+
 export interface ConfigArrayExpr extends langium.AstNode {
     readonly $container: ConfigField;
     readonly $type: 'ConfigArrayExpr';
@@ -775,6 +788,7 @@ export type ZModelAstType = {
     AttributeParamType: AttributeParamType
     BinaryExpr: BinaryExpr
     BooleanLiteral: BooleanLiteral
+    CollectionPredicateBinding: CollectionPredicateBinding
     ConfigArrayExpr: ConfigArrayExpr
     ConfigExpr: ConfigExpr
     ConfigField: ConfigField
@@ -822,7 +836,7 @@ export type ZModelAstType = {
 export class ZModelAstReflection extends langium.AbstractAstReflection {
 
     getAllTypes(): string[] {
-        return [AbstractDeclaration, Argument, ArrayExpr, Attribute, AttributeArg, AttributeParam, AttributeParamType, BinaryExpr, BooleanLiteral, ConfigArrayExpr, ConfigExpr, ConfigField, ConfigInvocationArg, ConfigInvocationExpr, DataField, DataFieldAttribute, DataFieldType, DataModel, DataModelAttribute, DataSource, Enum, EnumField, Expression, FieldInitializer, FunctionDecl, FunctionParam, FunctionParamType, GeneratorDecl, InternalAttribute, InvocationExpr, LiteralExpr, MemberAccessExpr, MemberAccessTarget, Model, ModelImport, NullExpr, NumberLiteral, ObjectExpr, Plugin, PluginField, Procedure, ProcedureParam, ReferenceArg, ReferenceExpr, ReferenceTarget, StringLiteral, ThisExpr, TypeDeclaration, TypeDef, UnaryExpr, UnsupportedFieldType];
+        return [AbstractDeclaration, Argument, ArrayExpr, Attribute, AttributeArg, AttributeParam, AttributeParamType, BinaryExpr, BooleanLiteral, CollectionPredicateBinding, ConfigArrayExpr, ConfigExpr, ConfigField, ConfigInvocationArg, ConfigInvocationExpr, DataField, DataFieldAttribute, DataFieldType, DataModel, DataModelAttribute, DataSource, Enum, EnumField, Expression, FieldInitializer, FunctionDecl, FunctionParam, FunctionParamType, GeneratorDecl, InternalAttribute, InvocationExpr, LiteralExpr, MemberAccessExpr, MemberAccessTarget, Model, ModelImport, NullExpr, NumberLiteral, ObjectExpr, Plugin, PluginField, Procedure, ProcedureParam, ReferenceArg, ReferenceExpr, ReferenceTarget, StringLiteral, ThisExpr, TypeDeclaration, TypeDef, UnaryExpr, UnsupportedFieldType];
     }
 
     protected override computeIsSubtype(subtype: string, supertype: string): boolean {
@@ -850,6 +864,11 @@ export class ZModelAstReflection extends langium.AbstractAstReflection {
             case StringLiteral: {
                 return this.isSubtype(LiteralExpr, supertype);
             }
+            case CollectionPredicateBinding:
+            case EnumField:
+            case FunctionParam: {
+                return this.isSubtype(ReferenceTarget, supertype);
+            }
             case ConfigArrayExpr: {
                 return this.isSubtype(ConfigExpr, supertype);
             }
@@ -861,10 +880,6 @@ export class ZModelAstReflection extends langium.AbstractAstReflection {
             case TypeDef: {
                 return this.isSubtype(AbstractDeclaration, supertype) || this.isSubtype(TypeDeclaration, supertype);
             }
-            case EnumField:
-            case FunctionParam: {
-                return this.isSubtype(ReferenceTarget, supertype);
-            }
             case InvocationExpr:
             case LiteralExpr: {
                 return this.isSubtype(ConfigExpr, supertype) || this.isSubtype(Expression, supertype);
@@ -975,6 +990,7 @@ export class ZModelAstReflection extends langium.AbstractAstReflection {
                 return {
                     name: BinaryExpr,
                     properties: [
+                        { name: 'binding' },
                         { name: 'left' },
                         { name: 'operator' },
                         { name: 'right' }
@@ -989,6 +1005,14 @@ export class ZModelAstReflection extends langium.AbstractAstReflection {
                     ]
                 };
             }
+            case CollectionPredicateBinding: {
+                return {
+                    name: CollectionPredicateBinding,
+                    properties: [
+                        { name: 'name' }
+                    ]
+                };
+            }
             case ConfigArrayExpr: {
                 return {
                     name: ConfigArrayExpr,
diff --git a/packages/language/src/generated/grammar.ts b/packages/language/src/generated/grammar.ts
index 53688b82..925d4dcb 100644
--- a/packages/language/src/generated/grammar.ts
+++ b/packages/language/src/generated/grammar.ts
@@ -70,7 +70,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@69"
+                "$ref": "#/rules@70"
               },
               "arguments": []
             }
@@ -119,42 +119,42 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@37"
+              "$ref": "#/rules@38"
             },
             "arguments": []
           },
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@42"
+              "$ref": "#/rules@43"
             },
             "arguments": []
           },
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@44"
+              "$ref": "#/rules@45"
             },
             "arguments": []
           },
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@46"
+              "$ref": "#/rules@47"
             },
             "arguments": []
           },
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@53"
+              "$ref": "#/rules@54"
             },
             "arguments": []
           },
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@50"
+              "$ref": "#/rules@51"
             },
             "arguments": []
           }
@@ -176,7 +176,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@71"
+              "$ref": "#/rules@72"
             },
             "arguments": [],
             "cardinality": "*"
@@ -192,7 +192,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -236,7 +236,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@71"
+              "$ref": "#/rules@72"
             },
             "arguments": [],
             "cardinality": "*"
@@ -252,7 +252,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -296,7 +296,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@71"
+              "$ref": "#/rules@72"
             },
             "arguments": [],
             "cardinality": "*"
@@ -308,7 +308,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -347,7 +347,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@71"
+              "$ref": "#/rules@72"
             },
             "arguments": [],
             "cardinality": "*"
@@ -363,7 +363,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -407,7 +407,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@71"
+              "$ref": "#/rules@72"
             },
             "arguments": [],
             "cardinality": "*"
@@ -419,7 +419,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -474,7 +474,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
       "definition": {
         "$type": "RuleCall",
         "rule": {
-          "$ref": "#/rules@33"
+          "$ref": "#/rules@34"
         },
         "arguments": []
       },
@@ -495,7 +495,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
         "terminal": {
           "$type": "RuleCall",
           "rule": {
-            "$ref": "#/rules@70"
+            "$ref": "#/rules@71"
           },
           "arguments": []
         }
@@ -517,7 +517,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
         "terminal": {
           "$type": "RuleCall",
           "rule": {
-            "$ref": "#/rules@69"
+            "$ref": "#/rules@70"
           },
           "arguments": []
         }
@@ -539,7 +539,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
         "terminal": {
           "$type": "RuleCall",
           "rule": {
-            "$ref": "#/rules@63"
+            "$ref": "#/rules@64"
           },
           "arguments": []
         }
@@ -663,7 +663,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@68"
+                "$ref": "#/rules@69"
               },
               "arguments": []
             }
@@ -761,7 +761,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@68"
+                "$ref": "#/rules@69"
               },
               "arguments": []
             }
@@ -970,7 +970,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
               "terminal": {
                 "$type": "RuleCall",
                 "rule": {
-                  "$ref": "#/rules@52"
+                  "$ref": "#/rules@53"
                 },
                 "arguments": []
               },
@@ -1069,7 +1069,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@68"
+                "$ref": "#/rules@69"
               },
               "arguments": []
             }
@@ -1183,14 +1183,14 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@51"
+                    "$ref": "#/rules@52"
                   },
                   "arguments": []
                 },
                 {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@69"
+                    "$ref": "#/rules@70"
                   },
                   "arguments": []
                 }
@@ -1235,7 +1235,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "CrossReference",
               "type": {
-                "$ref": "#/rules@46"
+                "$ref": "#/rules@47"
               },
               "deprecatedSyntax": false
             }
@@ -1247,7 +1247,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@35"
+              "$ref": "#/rules@36"
             },
             "arguments": [],
             "cardinality": "?"
@@ -1278,7 +1278,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@34"
+              "$ref": "#/rules@35"
             },
             "arguments": []
           },
@@ -1418,6 +1418,28 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "$type": "Keyword",
                 "value": "["
               },
+              {
+                "$type": "Group",
+                "elements": [
+                  {
+                    "$type": "Assignment",
+                    "feature": "binding",
+                    "operator": "=",
+                    "terminal": {
+                      "$type": "RuleCall",
+                      "rule": {
+                        "$ref": "#/rules@30"
+                      },
+                      "arguments": []
+                    }
+                  },
+                  {
+                    "$type": "Keyword",
+                    "value": ","
+                  }
+                ],
+                "cardinality": "?"
+              },
               {
                 "$type": "Assignment",
                 "feature": "right",
@@ -1446,6 +1468,28 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
       "parameters": [],
       "wildcard": false
     },
+    {
+      "$type": "ParserRule",
+      "name": "CollectionPredicateBinding",
+      "definition": {
+        "$type": "Assignment",
+        "feature": "name",
+        "operator": "=",
+        "terminal": {
+          "$type": "RuleCall",
+          "rule": {
+            "$ref": "#/rules@52"
+          },
+          "arguments": []
+        }
+      },
+      "definesHiddenTokens": false,
+      "entry": false,
+      "fragment": false,
+      "hiddenTokens": [],
+      "parameters": [],
+      "wildcard": false
+    },
     {
       "$type": "ParserRule",
       "name": "InExpr",
@@ -1521,7 +1565,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@30"
+              "$ref": "#/rules@31"
             },
             "arguments": []
           },
@@ -1570,7 +1614,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@30"
+                    "$ref": "#/rules@31"
                   },
                   "arguments": []
                 }
@@ -1600,7 +1644,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@31"
+              "$ref": "#/rules@32"
             },
             "arguments": []
           },
@@ -1641,7 +1685,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@31"
+                    "$ref": "#/rules@32"
                   },
                   "arguments": []
                 }
@@ -1671,7 +1715,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@32"
+              "$ref": "#/rules@33"
             },
             "arguments": []
           },
@@ -1712,7 +1756,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@32"
+                    "$ref": "#/rules@33"
                   },
                   "arguments": []
                 }
@@ -1838,7 +1882,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@36"
+                "$ref": "#/rules@37"
               },
               "arguments": []
             }
@@ -1857,7 +1901,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@36"
+                    "$ref": "#/rules@37"
                   },
                   "arguments": []
                 }
@@ -1908,7 +1952,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@71"
+                "$ref": "#/rules@72"
               },
               "arguments": []
             },
@@ -1931,7 +1975,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                     "terminal": {
                       "$type": "RuleCall",
                       "rule": {
-                        "$ref": "#/rules@51"
+                        "$ref": "#/rules@52"
                       },
                       "arguments": []
                     }
@@ -1942,14 +1986,14 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                       {
                         "$type": "RuleCall",
                         "rule": {
-                          "$ref": "#/rules@38"
+                          "$ref": "#/rules@39"
                         },
                         "arguments": []
                       },
                       {
                         "$type": "RuleCall",
                         "rule": {
-                          "$ref": "#/rules@39"
+                          "$ref": "#/rules@40"
                         },
                         "arguments": []
                       },
@@ -1959,14 +2003,14 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                           {
                             "$type": "RuleCall",
                             "rule": {
-                              "$ref": "#/rules@39"
+                              "$ref": "#/rules@40"
                             },
                             "arguments": []
                           },
                           {
                             "$type": "RuleCall",
                             "rule": {
-                              "$ref": "#/rules@38"
+                              "$ref": "#/rules@39"
                             },
                             "arguments": []
                           }
@@ -1978,14 +2022,14 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                           {
                             "$type": "RuleCall",
                             "rule": {
-                              "$ref": "#/rules@38"
+                              "$ref": "#/rules@39"
                             },
                             "arguments": []
                           },
                           {
                             "$type": "RuleCall",
                             "rule": {
-                              "$ref": "#/rules@39"
+                              "$ref": "#/rules@40"
                             },
                             "arguments": []
                           }
@@ -2015,7 +2059,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                     "terminal": {
                       "$type": "RuleCall",
                       "rule": {
-                        "$ref": "#/rules@51"
+                        "$ref": "#/rules@52"
                       },
                       "arguments": []
                     }
@@ -2038,7 +2082,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@40"
+                    "$ref": "#/rules@41"
                   },
                   "arguments": []
                 }
@@ -2050,7 +2094,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@57"
+                    "$ref": "#/rules@58"
                   },
                   "arguments": []
                 }
@@ -2089,7 +2133,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "CrossReference",
               "type": {
-                "$ref": "#/rules@42"
+                "$ref": "#/rules@43"
               },
               "deprecatedSyntax": false
             }
@@ -2109,7 +2153,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "CrossReference",
                   "type": {
-                    "$ref": "#/rules@42"
+                    "$ref": "#/rules@43"
                   },
                   "deprecatedSyntax": false
                 }
@@ -2143,7 +2187,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "CrossReference",
               "type": {
-                "$ref": "#/rules@37"
+                "$ref": "#/rules@38"
               },
               "deprecatedSyntax": false
             }
@@ -2169,7 +2213,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@71"
+                "$ref": "#/rules@72"
               },
               "arguments": []
             },
@@ -2182,7 +2226,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@52"
+                "$ref": "#/rules@53"
               },
               "arguments": []
             }
@@ -2194,7 +2238,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@41"
+                "$ref": "#/rules@42"
               },
               "arguments": []
             }
@@ -2206,7 +2250,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@56"
+                "$ref": "#/rules@57"
               },
               "arguments": []
             },
@@ -2237,7 +2281,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@62"
+                    "$ref": "#/rules@63"
                   },
                   "arguments": []
                 }
@@ -2249,7 +2293,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@43"
+                    "$ref": "#/rules@44"
                   },
                   "arguments": []
                 }
@@ -2266,7 +2310,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                   "terminal": {
                     "$type": "RuleCall",
                     "rule": {
-                      "$ref": "#/rules@51"
+                      "$ref": "#/rules@52"
                     },
                     "arguments": []
                   },
@@ -2326,7 +2370,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@71"
+                "$ref": "#/rules@72"
               },
               "arguments": []
             },
@@ -2343,7 +2387,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -2351,7 +2395,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@38"
+              "$ref": "#/rules@39"
             },
             "arguments": [],
             "cardinality": "?"
@@ -2370,7 +2414,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@40"
+                    "$ref": "#/rules@41"
                   },
                   "arguments": []
                 }
@@ -2382,7 +2426,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@57"
+                    "$ref": "#/rules@58"
                   },
                   "arguments": []
                 }
@@ -2455,7 +2499,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@71"
+                "$ref": "#/rules@72"
               },
               "arguments": []
             },
@@ -2472,7 +2516,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -2491,7 +2535,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@45"
+                    "$ref": "#/rules@46"
                   },
                   "arguments": []
                 }
@@ -2503,7 +2547,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@57"
+                    "$ref": "#/rules@58"
                   },
                   "arguments": []
                 }
@@ -2537,7 +2581,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@71"
+                "$ref": "#/rules@72"
               },
               "arguments": []
             },
@@ -2550,7 +2594,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@52"
+                "$ref": "#/rules@53"
               },
               "arguments": []
             }
@@ -2562,7 +2606,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@56"
+                "$ref": "#/rules@57"
               },
               "arguments": []
             },
@@ -2586,7 +2630,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@71"
+              "$ref": "#/rules@72"
             },
             "arguments": [],
             "cardinality": "*"
@@ -2602,7 +2646,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -2621,7 +2665,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@47"
+                    "$ref": "#/rules@48"
                   },
                   "arguments": []
                 }
@@ -2640,7 +2684,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                     "terminal": {
                       "$type": "RuleCall",
                       "rule": {
-                        "$ref": "#/rules@47"
+                        "$ref": "#/rules@48"
                       },
                       "arguments": []
                     }
@@ -2666,7 +2710,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@48"
+                "$ref": "#/rules@49"
               },
               "arguments": []
             }
@@ -2699,7 +2743,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@58"
+                "$ref": "#/rules@59"
               },
               "arguments": []
             },
@@ -2723,7 +2767,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@71"
+              "$ref": "#/rules@72"
             },
             "arguments": [],
             "cardinality": "*"
@@ -2735,7 +2779,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -2751,7 +2795,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@48"
+                "$ref": "#/rules@49"
               },
               "arguments": []
             }
@@ -2791,7 +2835,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@61"
+                    "$ref": "#/rules@62"
                   },
                   "arguments": []
                 }
@@ -2808,7 +2852,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                   "terminal": {
                     "$type": "RuleCall",
                     "rule": {
-                      "$ref": "#/rules@51"
+                      "$ref": "#/rules@52"
                     },
                     "arguments": []
                   },
@@ -2854,7 +2898,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@71"
+              "$ref": "#/rules@72"
             },
             "arguments": [],
             "cardinality": "*"
@@ -2866,7 +2910,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -2882,7 +2926,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@48"
+                "$ref": "#/rules@49"
               },
               "arguments": []
             }
@@ -2915,7 +2959,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@71"
+              "$ref": "#/rules@72"
             },
             "arguments": [],
             "cardinality": "*"
@@ -2941,7 +2985,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -2960,7 +3004,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@49"
+                    "$ref": "#/rules@50"
                   },
                   "arguments": []
                 }
@@ -2979,7 +3023,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                     "terminal": {
                       "$type": "RuleCall",
                       "rule": {
-                        "$ref": "#/rules@49"
+                        "$ref": "#/rules@50"
                       },
                       "arguments": []
                     }
@@ -3005,7 +3049,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@48"
+                "$ref": "#/rules@49"
               },
               "arguments": []
             }
@@ -3017,7 +3061,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@58"
+                "$ref": "#/rules@59"
               },
               "arguments": []
             },
@@ -3042,7 +3086,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@68"
+              "$ref": "#/rules@69"
             },
             "arguments": []
           },
@@ -3105,7 +3149,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@51"
+              "$ref": "#/rules@52"
             },
             "arguments": []
           },
@@ -3187,7 +3231,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@71"
+                "$ref": "#/rules@72"
               },
               "arguments": []
             },
@@ -3207,21 +3251,21 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@65"
+                    "$ref": "#/rules@66"
                   },
                   "arguments": []
                 },
                 {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@66"
+                    "$ref": "#/rules@67"
                   },
                   "arguments": []
                 },
                 {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@67"
+                    "$ref": "#/rules@68"
                   },
                   "arguments": []
                 }
@@ -3242,7 +3286,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@54"
+                    "$ref": "#/rules@55"
                   },
                   "arguments": []
                 }
@@ -3261,7 +3305,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                     "terminal": {
                       "$type": "RuleCall",
                       "rule": {
-                        "$ref": "#/rules@54"
+                        "$ref": "#/rules@55"
                       },
                       "arguments": []
                     }
@@ -3283,7 +3327,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@58"
+                "$ref": "#/rules@59"
               },
               "arguments": []
             },
@@ -3311,7 +3355,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@71"
+                "$ref": "#/rules@72"
               },
               "arguments": []
             },
@@ -3334,7 +3378,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@51"
+                "$ref": "#/rules@52"
               },
               "arguments": []
             }
@@ -3350,7 +3394,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@55"
+                "$ref": "#/rules@56"
               },
               "arguments": []
             }
@@ -3362,7 +3406,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@58"
+                "$ref": "#/rules@59"
               },
               "arguments": []
             },
@@ -3396,7 +3440,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                     {
                       "$type": "RuleCall",
                       "rule": {
-                        "$ref": "#/rules@61"
+                        "$ref": "#/rules@62"
                       },
                       "arguments": []
                     },
@@ -3427,7 +3471,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                   "terminal": {
                     "$type": "RuleCall",
                     "rule": {
-                      "$ref": "#/rules@51"
+                      "$ref": "#/rules@52"
                     },
                     "arguments": []
                   },
@@ -3487,12 +3531,12 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "CrossReference",
               "type": {
-                "$ref": "#/rules@53"
+                "$ref": "#/rules@54"
               },
               "terminal": {
                 "$type": "RuleCall",
                 "rule": {
-                  "$ref": "#/rules@67"
+                  "$ref": "#/rules@68"
                 },
                 "arguments": []
               },
@@ -3509,7 +3553,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
               {
                 "$type": "RuleCall",
                 "rule": {
-                  "$ref": "#/rules@59"
+                  "$ref": "#/rules@60"
                 },
                 "arguments": [],
                 "cardinality": "?"
@@ -3539,7 +3583,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "RuleCall",
             "rule": {
-              "$ref": "#/rules@71"
+              "$ref": "#/rules@72"
             },
             "arguments": [],
             "cardinality": "*"
@@ -3551,12 +3595,12 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "CrossReference",
               "type": {
-                "$ref": "#/rules@53"
+                "$ref": "#/rules@54"
               },
               "terminal": {
                 "$type": "RuleCall",
                 "rule": {
-                  "$ref": "#/rules@66"
+                  "$ref": "#/rules@67"
                 },
                 "arguments": []
               },
@@ -3573,7 +3617,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
               {
                 "$type": "RuleCall",
                 "rule": {
-                  "$ref": "#/rules@59"
+                  "$ref": "#/rules@60"
                 },
                 "arguments": [],
                 "cardinality": "?"
@@ -3607,12 +3651,12 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "CrossReference",
               "type": {
-                "$ref": "#/rules@53"
+                "$ref": "#/rules@54"
               },
               "terminal": {
                 "$type": "RuleCall",
                 "rule": {
-                  "$ref": "#/rules@65"
+                  "$ref": "#/rules@66"
                 },
                 "arguments": []
               },
@@ -3629,7 +3673,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
               {
                 "$type": "RuleCall",
                 "rule": {
-                  "$ref": "#/rules@59"
+                  "$ref": "#/rules@60"
                 },
                 "arguments": [],
                 "cardinality": "?"
@@ -3664,7 +3708,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
             "terminal": {
               "$type": "RuleCall",
               "rule": {
-                "$ref": "#/rules@60"
+                "$ref": "#/rules@61"
               },
               "arguments": []
             }
@@ -3683,7 +3727,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@60"
+                    "$ref": "#/rules@61"
                   },
                   "arguments": []
                 }
@@ -3715,7 +3759,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
                 "terminal": {
                   "$type": "RuleCall",
                   "rule": {
-                    "$ref": "#/rules@51"
+                    "$ref": "#/rules@52"
                   },
                   "arguments": []
                 }
@@ -4011,19 +4055,25 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "SimpleType",
             "typeRef": {
-              "$ref": "#/rules@47"
+              "$ref": "#/rules@48"
             }
           },
           {
             "$type": "SimpleType",
             "typeRef": {
-              "$ref": "#/rules@40"
+              "$ref": "#/rules@41"
             }
           },
           {
             "$type": "SimpleType",
             "typeRef": {
-              "$ref": "#/rules@45"
+              "$ref": "#/rules@46"
+            }
+          },
+          {
+            "$type": "SimpleType",
+            "typeRef": {
+              "$ref": "#/rules@30"
             }
           }
         ]
@@ -4035,7 +4085,7 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
       "type": {
         "$type": "SimpleType",
         "typeRef": {
-          "$ref": "#/rules@40"
+          "$ref": "#/rules@41"
         }
       }
     },
@@ -4048,19 +4098,19 @@ export const ZModelGrammar = (): Grammar => loadedZModelGrammar ?? (loadedZModel
           {
             "$type": "SimpleType",
             "typeRef": {
-              "$ref": "#/rules@37"
+              "$ref": "#/rules@38"
             }
           },
           {
             "$type": "SimpleType",
             "typeRef": {
-              "$ref": "#/rules@42"
+              "$ref": "#/rules@43"
             }
           },
           {
             "$type": "SimpleType",
             "typeRef": {
-              "$ref": "#/rules@44"
+              "$ref": "#/rules@45"
             }
           }
         ]
diff --git a/packages/language/src/validators/attribute-application-validator.ts b/packages/language/src/validators/attribute-application-validator.ts
index 79db61cc..28983e82 100644
--- a/packages/language/src/validators/attribute-application-validator.ts
+++ b/packages/language/src/validators/attribute-application-validator.ts
@@ -11,7 +11,6 @@ import {
     DataFieldAttribute,
     DataModelAttribute,
     InternalAttribute,
-    ReferenceExpr,
     isArrayExpr,
     isAttribute,
     isConfigArrayExpr,
@@ -554,9 +553,16 @@ function isValidAttributeTarget(attrDecl: Attribute, targetDecl: DataField) {
         return true;
     }
 
-    const fieldTypes = (targetField.args[0].value as ArrayExpr).items.map(
-        (item) => (item as ReferenceExpr).target.ref?.name,
-    );
+    const fieldTypes = (targetField.args[0].value as ArrayExpr).items
+        .map((item) => {
+            if (!isReferenceExpr(item)) {
+                return undefined;
+            }
+
+            const ref = item.target.ref;
+            return ref && 'name' in ref && typeof ref.name === 'string' ? ref.name : undefined;
+        })
+        .filter((name): name is string => !!name);
 
     let allowed = false;
     for (const allowedType of fieldTypes) {
diff --git a/packages/language/src/validators/expression-validator.ts b/packages/language/src/validators/expression-validator.ts
index c2848c14..3efe6d91 100644
--- a/packages/language/src/validators/expression-validator.ts
+++ b/packages/language/src/validators/expression-validator.ts
@@ -3,6 +3,7 @@ import {
     BinaryExpr,
     Expression,
     isArrayExpr,
+    isCollectionPredicateBinding,
     isDataModel,
     isDataModelAttribute,
     isEnum,
@@ -12,6 +13,7 @@ import {
     isReferenceExpr,
     isThisExpr,
     MemberAccessExpr,
+    ReferenceExpr,
     UnaryExpr,
     type ExpressionType,
 } from '../generated/ast';
@@ -51,7 +53,7 @@ export default class ExpressionValidator implements AstValidator<Expression> {
                     }
                     return false;
                 });
-                if (!hasReferenceResolutionError) {
+                if (hasReferenceResolutionError) {
                     // report silent errors not involving linker errors
                     accept('error', 'Expression cannot be resolved', {
                         node: expr,
@@ -62,6 +64,9 @@ export default class ExpressionValidator implements AstValidator<Expression> {
 
         // extra validations by expression type
         switch (expr.$type) {
+            case 'ReferenceExpr':
+                this.validateReferenceExpr(expr, accept);
+                break;
             case 'MemberAccessExpr':
                 this.validateMemberAccessExpr(expr, accept);
                 break;
@@ -74,6 +79,16 @@ export default class ExpressionValidator implements AstValidator<Expression> {
         }
     }
 
+    private validateReferenceExpr(expr: ReferenceExpr, accept: ValidationAcceptor) {
+        // reference to collection predicate's binding can't be used standalone like:
+        //   `items?[e, e]`, `items?[e, e != null]`, etc.
+        if (isCollectionPredicateBinding(expr.target.ref) && !isMemberAccessExpr(expr.$container)) {
+            accept('error', 'Collection predicate binding cannot be used without a member access', {
+                node: expr,
+            });
+        }
+    }
+
     private validateMemberAccessExpr(expr: MemberAccessExpr, accept: ValidationAcceptor) {
         if (isBeforeInvocation(expr.operand) && isDataModel(expr.$resolvedType?.decl)) {
             accept('error', 'relation fields cannot be accessed from `before()`', { node: expr });
diff --git a/packages/language/src/zmodel-code-generator.ts b/packages/language/src/zmodel-code-generator.ts
index 55efb5fc..1e0366ed 100644
--- a/packages/language/src/zmodel-code-generator.ts
+++ b/packages/language/src/zmodel-code-generator.ts
@@ -252,13 +252,15 @@ ${ast.fields.map((x) => this.indent + this.generate(x)).join('\n')}${
 
         const { left: isLeftParenthesis, right: isRightParenthesis } = this.isParenthesesNeededForBinaryExpr(ast);
 
+        const collectionPredicate = isCollectionPredicate
+            ? `[${ast.binding ? `${ast.binding}, ${rightExpr}` : rightExpr}]`
+            : rightExpr;
+
         return `${isLeftParenthesis ? '(' : ''}${this.generate(ast.left)}${
             isLeftParenthesis ? ')' : ''
         }${isCollectionPredicate ? '' : this.binaryExprSpace}${operator}${
             isCollectionPredicate ? '' : this.binaryExprSpace
-        }${isRightParenthesis ? '(' : ''}${
-            isCollectionPredicate ? `[${rightExpr}]` : rightExpr
-        }${isRightParenthesis ? ')' : ''}`;
+        }${isRightParenthesis ? '(' : ''}${collectionPredicate}${isRightParenthesis ? ')' : ''}`;
     }
 
     @gen(ReferenceExpr)
diff --git a/packages/language/src/zmodel-linker.ts b/packages/language/src/zmodel-linker.ts
index 3bb45134..fc3a7f0d 100644
--- a/packages/language/src/zmodel-linker.ts
+++ b/packages/language/src/zmodel-linker.ts
@@ -24,10 +24,8 @@ import {
     DataFieldType,
     DataModel,
     Enum,
-    EnumField,
     type ExpressionType,
     FunctionDecl,
-    FunctionParam,
     FunctionParamType,
     InvocationExpr,
     LiteralExpr,
@@ -43,10 +41,13 @@ import {
     UnaryExpr,
     isArrayExpr,
     isBooleanLiteral,
+    isCollectionPredicateBinding,
     isDataField,
     isDataFieldType,
     isDataModel,
     isEnum,
+    isEnumField,
+    isFunctionParam,
     isNumberLiteral,
     isReferenceExpr,
     isStringLiteral,
@@ -249,13 +250,21 @@ export class ZModelLinker extends DefaultLinker {
 
     private resolveReference(node: ReferenceExpr, document: LangiumDocument<AstNode>, extraScopes: ScopeProvider[]) {
         this.resolveDefault(node, document, extraScopes);
-
-        if (node.target.ref) {
-            // resolve type
-            if (node.target.ref.$type === EnumField) {
-                this.resolveToBuiltinTypeOrDecl(node, node.target.ref.$container);
-            } else {
-                this.resolveToDeclaredType(node, (node.target.ref as DataField | FunctionParam).type);
+        const target = node.target.ref;
+
+        if (target) {
+            if (isCollectionPredicateBinding(target)) {
+                // collection predicate's binding is resolved to the element type of the collection
+                const collectionType = target.$container.left.$resolvedType;
+                if (collectionType) {
+                    node.$resolvedType = { ...collectionType, array: false };
+                }
+            } else if (isEnumField(target)) {
+                // enum field is resolved to its containing enum
+                this.resolveToBuiltinTypeOrDecl(node, target.$container);
+            } else if (isDataField(target) || isFunctionParam(target)) {
+                // other references are resolved to their declared type
+                this.resolveToDeclaredType(node, target.type);
             }
         }
     }
@@ -506,6 +515,9 @@ export class ZModelLinker extends DefaultLinker {
     //#region Utils
 
     private resolveToDeclaredType(node: AstNode, type: FunctionParamType | DataFieldType) {
+        if (!type) {
+            return;
+        }
         let nullable = false;
         if (isDataFieldType(type)) {
             nullable = type.optional;
diff --git a/packages/language/src/zmodel-scope.ts b/packages/language/src/zmodel-scope.ts
index 6fd866f0..30b77e29 100644
--- a/packages/language/src/zmodel-scope.ts
+++ b/packages/language/src/zmodel-scope.ts
@@ -18,7 +18,9 @@ import {
 import { match } from 'ts-pattern';
 import {
     BinaryExpr,
+    Expression,
     MemberAccessExpr,
+    isCollectionPredicateBinding,
     isDataField,
     isDataModel,
     isEnumField,
@@ -124,7 +126,7 @@ export class ZModelScopeProvider extends DefaultScopeProvider {
             // when reference expression is resolved inside a collection predicate, the scope is the collection
             const containerCollectionPredicate = getCollectionPredicateContext(context.container);
             if (containerCollectionPredicate) {
-                return this.getCollectionPredicateScope(context, containerCollectionPredicate as BinaryExpr);
+                return this.getCollectionPredicateScope(context, containerCollectionPredicate);
             }
         }
 
@@ -145,10 +147,20 @@ export class ZModelScopeProvider extends DefaultScopeProvider {
             .when(isReferenceExpr, (operand) => {
                 // operand is a reference, it can only be a model/type-def field
                 const ref = operand.target.ref;
-                if (isDataField(ref)) {
-                    return this.createScopeForContainer(ref.type.reference?.ref, globalScope, allowTypeDefScope);
-                }
-                return EMPTY_SCOPE;
+                return match(ref)
+                    .when(isDataField, (r) =>
+                        // build a scope with model/typedef members
+                        this.createScopeForContainer(r.type.reference?.ref, globalScope, allowTypeDefScope),
+                    )
+                    .when(isCollectionPredicateBinding, (r) =>
+                        // build a scope from the collection predicate's collection
+                        this.createScopeForCollectionPredicateCollection(
+                            r.$container.left,
+                            globalScope,
+                            allowTypeDefScope,
+                        ),
+                    )
+                    .otherwise(() => EMPTY_SCOPE);
             })
             .when(isMemberAccessExpr, (operand) => {
                 // operand is a member access, it must be resolved to a non-array model/typedef type
@@ -179,15 +191,44 @@ export class ZModelScopeProvider extends DefaultScopeProvider {
             .otherwise(() => EMPTY_SCOPE);
     }
 
-    private getCollectionPredicateScope(context: ReferenceInfo, collectionPredicate: BinaryExpr) {
-        const referenceType = this.reflection.getReferenceType(context);
-        const globalScope = this.getGlobalScope(referenceType, context);
+    private getCollectionPredicateScope(context: ReferenceInfo, collectionPredicate: BinaryExpr): Scope {
+        // walk up to collect all collection predicate bindings, which are all available in the scope
+        let currPredicate: BinaryExpr | undefined = collectionPredicate;
+        const bindingStack: AstNode[] = [];
+        while (currPredicate) {
+            if (currPredicate.binding) {
+                bindingStack.unshift(currPredicate.binding);
+            }
+            currPredicate = AstUtils.getContainerOfType(currPredicate.$container, isCollectionPredicate);
+        }
+
+        // build a scope chain: global scope -> bindings' scope -> collection scope
+        const globalScope = this.getGlobalScope(this.reflection.getReferenceType(context), context);
+        const parentScope = bindingStack.reduce(
+            (scope, binding) => this.createScopeForNodes([binding], scope),
+            globalScope,
+        );
+
         const collection = collectionPredicate.left;
 
         // TODO: full support of typedef member access
-        // // typedef's fields are only added to the scope if the access starts with `auth().`
+        // typedef's fields are only added to the scope if the access starts with `auth().`
         const allowTypeDefScope = isAuthOrAuthMemberAccess(collection);
 
+        const collectionScope = this.createScopeForCollectionPredicateCollection(
+            collection,
+            parentScope,
+            allowTypeDefScope,
+        );
+
+        return collectionScope;
+    }
+
+    private createScopeForCollectionPredicateCollection(
+        collection: Expression,
+        globalScope: Scope,
+        allowTypeDefScope: boolean,
+    ) {
         return match(collection)
             .when(isReferenceExpr, (expr) => {
                 // collection is a reference - model or typedef field
diff --git a/packages/language/src/zmodel.langium b/packages/language/src/zmodel.langium
index 9f09dbf8..e7c33ad2 100644
--- a/packages/language/src/zmodel.langium
+++ b/packages/language/src/zmodel.langium
@@ -66,7 +66,7 @@ ConfigArrayExpr:
 ConfigExpr:
     LiteralExpr | InvocationExpr | ConfigArrayExpr;
 
-type ReferenceTarget = FunctionParam | DataField | EnumField;
+type ReferenceTarget = FunctionParam | DataField | EnumField | CollectionPredicateBinding;
 
 ThisExpr:
     value='this';
@@ -109,13 +109,17 @@ UnaryExpr:
 // binary operator precedence follow Javascript's rules:
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence#table
 
+// TODO: promote CollectionPredicateExpr to a first-class expression type
 CollectionPredicateExpr infers Expression:
     MemberAccessExpr (
         {infer BinaryExpr.left=current}
         operator=('?'|'!'|'^')
-        '[' right=Expression ']'
+        '[' (binding=CollectionPredicateBinding ',')? right=Expression ']'
     )*;
 
+CollectionPredicateBinding:
+    name=RegularID;
+
 InExpr infers Expression:
     CollectionPredicateExpr (
         {infer BinaryExpr.left=current}
diff --git a/packages/language/test/expression-validation.test.ts b/packages/language/test/expression-validation.test.ts
index 100f02b2..40bad771 100644
--- a/packages/language/test/expression-validation.test.ts
+++ b/packages/language/test/expression-validation.test.ts
@@ -2,9 +2,10 @@ import { describe, it } from 'vitest';
 import { loadSchema, loadSchemaWithError } from './utils';
 
 describe('Expression Validation Tests', () => {
-    it('should reject model comparison1', async () => {
-        await loadSchemaWithError(
-            `
+    describe('Model Comparison Tests', () => {
+        it('should reject model comparison1', async () => {
+            await loadSchemaWithError(
+                `
             model User {
                 id Int @id
                 name String
@@ -19,13 +20,13 @@ describe('Expression Validation Tests', () => {
                 @@allow('all', author == this)
             }
         `,
-            'comparison between models is not supported',
-        );
-    });
+                'comparison between models is not supported',
+            );
+        });
 
-    it('should reject model comparison2', async () => {
-        await loadSchemaWithError(
-            `
+        it('should reject model comparison2', async () => {
+            await loadSchemaWithError(
+                `
             model User {
                 id Int @id
                 name String
@@ -48,13 +49,13 @@ describe('Expression Validation Tests', () => {
                 userId Int @unique
             }
         `,
-            'comparison between models is not supported',
-        );
-    });
+                'comparison between models is not supported',
+            );
+        });
 
-    it('should allow auth comparison with auth type', async () => {
-        await loadSchema(
-            `
+        it('should allow auth comparison with auth type', async () => {
+            await loadSchema(
+                `
             datasource db {
                 provider = 'sqlite'
                 url      = 'file:./dev.db'
@@ -75,12 +76,12 @@ describe('Expression Validation Tests', () => {
                 @@allow('read', auth() == user)
             }
         `,
-        );
-    });
+            );
+        });
 
-    it('should reject auth comparison with non-auth type', async () => {
-        await loadSchemaWithError(
-            `
+        it('should reject auth comparison with non-auth type', async () => {
+            await loadSchemaWithError(
+                `
             model User {
                 id Int @id
                 name String
@@ -95,7 +96,265 @@ describe('Expression Validation Tests', () => {
                 @@allow('read', auth() == this)
             }
         `,
-            'incompatible operand types',
-        );
+                'incompatible operand types',
+            );
+        });
+    });
+
+    describe('Collection Predicate Tests', () => {
+        it('should reject standalone binding access', async () => {
+            await loadSchemaWithError(
+                `
+            datasource db {
+                provider = 'sqlite'
+                url      = 'file:./dev.db'
+            }
+
+            model User {
+                id Int @id
+                memberships Membership[]
+                @@allow('read', memberships?[m, m != null])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+            }
+        `,
+                'binding cannot be used without a member access',
+            );
+        });
+
+        it('should allow referencing binding', async () => {
+            await loadSchema(`
+            datasource db {
+                provider = 'sqlite'
+                url      = 'file:./dev.db'
+            }
+
+            model User {
+                id Int @id
+                memberships Membership[]
+                @@allow('read', memberships?[m, m.tenantId == id])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+            }
+        `);
+        });
+
+        it('should keep supporting unbound collection predicate syntax', async () => {
+            await loadSchema(`
+            datasource db {
+                provider = 'sqlite'
+                url      = 'file:./dev.db'
+            }
+
+            model User {
+                id Int @id
+                memberships Membership[]
+                @@allow('read', memberships?[tenantId == id])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+            }
+        `);
+        });
+
+        it('should support mixing bound and unbound syntax', async () => {
+            await loadSchema(`
+            datasource db {
+                provider = 'sqlite'
+                url      = 'file:./dev.db'
+            }
+
+            model User {
+                id Int @id
+                memberships Membership[]
+                @@allow('read', memberships?[m, m.tenantId == id && tenantId == id])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+            }
+        `);
+        });
+
+        it('should allow disambiguation with this', async () => {
+            await loadSchema(`
+                datasource db {
+                    provider = 'sqlite'
+                    url      = 'file:./dev.db'
+                }
+
+                model User {
+                    id Int @id
+                    memberships Membership[]
+                    value Int
+                    @@allow('read', memberships?[m, m.value == this.value])
+                }
+
+                model Membership {
+                    id Int @id
+                    tenantId Int
+                    user User @relation(fields: [userId], references: [id])
+                    userId Int
+                    value Int
+                }
+            `);
+
+            await loadSchemaWithError(
+                `
+            datasource db {
+                provider = 'sqlite'
+                url      = 'file:./dev.db'
+            }
+
+            model User {
+                id Int @id
+                memberships Membership[]
+                value String
+                @@allow('read', memberships?[m, m.value == this.value])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                value Int
+            }
+        `,
+                'incompatible operand types',
+            );
+
+            await loadSchemaWithError(
+                `
+            datasource db {
+                provider = 'sqlite'
+                url      = 'file:./dev.db'
+            }
+
+            model User {
+                id Int @id
+                memberships Membership[]
+                value String
+                @@allow('read', memberships?[value == this.value])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                value Int
+            }
+        `,
+                'incompatible operand types',
+            );
+        });
+
+        it('should support accessing binding from deep context', async () => {
+            await loadSchema(`
+            datasource db {
+                provider = 'sqlite'
+                url      = 'file:./dev.db'
+            }
+
+            model User {
+                id Int @id
+                memberships Membership[]
+                @@allow('read', memberships?[m, roles?[value == m.value]])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                value  Int
+                roles Role[]
+            }
+
+            model Role {
+                id Int @id
+                membership Membership @relation(fields: [membershipId], references: [id])
+                membershipId Int
+                value Int
+            }
+        `);
+
+            await loadSchema(`
+            datasource db {
+                provider = 'sqlite'
+                url      = 'file:./dev.db'
+            }
+
+            model User {
+                id Int @id
+                memberships Membership[]
+                @@allow('read', memberships?[m, roles?[r, r.value == m.value]])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                value  Int
+                roles Role[]
+            }
+
+            model Role {
+                id Int @id
+                membership Membership @relation(fields: [membershipId], references: [id])
+                membershipId Int
+                value Int
+            }
+        `);
+
+            await loadSchema(`
+            datasource db {
+                provider = 'sqlite'
+                url      = 'file:./dev.db'
+            }
+
+            model User {
+                id Int @id
+                memberships Membership[]
+                x Int
+                @@allow('read', memberships?[m, roles?[this.x == m.value]])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                value  Int
+                roles Role[]
+            }
+
+            model Role {
+                id Int @id
+                membership Membership @relation(fields: [membershipId], references: [id])
+                membershipId Int
+                value Int
+            }
+        `);
+        });
     });
 });
diff --git a/packages/orm/src/client/crud/validator/utils.ts b/packages/orm/src/client/crud/validator/utils.ts
index bbd35900..c9909a70 100644
--- a/packages/orm/src/client/crud/validator/utils.ts
+++ b/packages/orm/src/client/crud/validator/utils.ts
@@ -310,6 +310,9 @@ function evalExpression(data: any, expr: Expression): unknown {
         .with({ kind: 'call' }, (e) => evalCall(data, e))
         .with({ kind: 'this' }, () => data ?? null)
         .with({ kind: 'null' }, () => null)
+        .with({ kind: 'binding' }, () => {
+            throw new Error('Binding expression is not supported in validation expressions');
+        })
         .exhaustive();
 }
 
diff --git a/packages/orm/src/utils/schema-utils.ts b/packages/orm/src/utils/schema-utils.ts
index b928b078..17fb3149 100644
--- a/packages/orm/src/utils/schema-utils.ts
+++ b/packages/orm/src/utils/schema-utils.ts
@@ -2,6 +2,7 @@ import { match } from 'ts-pattern';
 import type {
     ArrayExpression,
     BinaryExpression,
+    BindingExpression,
     CallExpression,
     Expression,
     FieldExpression,
@@ -24,6 +25,7 @@ export class ExpressionVisitor {
             .with({ kind: 'binary' }, (e) => this.visitBinary(e))
             .with({ kind: 'unary' }, (e) => this.visitUnary(e))
             .with({ kind: 'call' }, (e) => this.visitCall(e))
+            .with({ kind: 'binding' }, (e) => this.visitBinding(e))
             .with({ kind: 'this' }, (e) => this.visitThis(e))
             .with({ kind: 'null' }, (e) => this.visitNull(e))
             .exhaustive();
@@ -68,6 +70,8 @@ export class ExpressionVisitor {
         }
     }
 
+    protected visitBinding(_e: BindingExpression): VisitResult {}
+
     protected visitThis(_e: ThisExpression): VisitResult {}
 
     protected visitNull(_e: NullExpression): VisitResult {}
diff --git a/packages/plugins/policy/src/expression-evaluator.ts b/packages/plugins/policy/src/expression-evaluator.ts
index 45c7b855..85e97a03 100644
--- a/packages/plugins/policy/src/expression-evaluator.ts
+++ b/packages/plugins/policy/src/expression-evaluator.ts
@@ -1,9 +1,9 @@
 import { invariant } from '@zenstackhq/common-helpers';
-import { match } from 'ts-pattern';
 import {
     ExpressionUtils,
     type ArrayExpression,
     type BinaryExpression,
+    type BindingExpression,
     type CallExpression,
     type Expression,
     type FieldExpression,
@@ -11,10 +11,13 @@ import {
     type MemberExpression,
     type UnaryExpression,
 } from '@zenstackhq/orm/schema';
+import { match } from 'ts-pattern';
 
 type ExpressionEvaluatorContext = {
     auth?: any;
     thisValue?: any;
+    // scope for resolving references to collection predicate bindings
+    bindingScope?: Record<string, any>;
 };
 
 /**
@@ -30,6 +33,7 @@ export class ExpressionEvaluator {
             .when(ExpressionUtils.isMember, (expr) => this.evaluateMember(expr, context))
             .when(ExpressionUtils.isUnary, (expr) => this.evaluateUnary(expr, context))
             .when(ExpressionUtils.isCall, (expr) => this.evaluateCall(expr, context))
+            .when(ExpressionUtils.isBinding, (expr) => this.evaluateBinding(expr, context))
             .when(ExpressionUtils.isThis, () => context.thisValue)
             .when(ExpressionUtils.isNull, () => null)
             .exhaustive();
@@ -64,6 +68,9 @@ export class ExpressionEvaluator {
     }
 
     private evaluateField(expr: FieldExpression, context: ExpressionEvaluatorContext): any {
+        if (context.bindingScope && expr.field in context.bindingScope) {
+            return context.bindingScope[expr.field];
+        }
         return context.thisValue?.[expr.field];
     }
 
@@ -113,8 +120,28 @@ export class ExpressionEvaluator {
         invariant(Array.isArray(left), 'expected array');
 
         return match(op)
-            .with('?', () => left.some((item: any) => this.evaluate(expr.right, { ...context, thisValue: item })))
-            .with('!', () => left.every((item: any) => this.evaluate(expr.right, { ...context, thisValue: item })))
+            .with('?', () =>
+                left.some((item: any) =>
+                    this.evaluate(expr.right, {
+                        ...context,
+                        thisValue: item,
+                        bindingScope: expr.binding
+                            ? { ...(context.bindingScope ?? {}), [expr.binding]: item }
+                            : context.bindingScope,
+                    }),
+                ),
+            )
+            .with('!', () =>
+                left.every((item: any) =>
+                    this.evaluate(expr.right, {
+                        ...context,
+                        thisValue: item,
+                        bindingScope: expr.binding
+                            ? { ...(context.bindingScope ?? {}), [expr.binding]: item }
+                            : context.bindingScope,
+                    }),
+                ),
+            )
             .with(
                 '^',
                 () =>
@@ -122,9 +149,19 @@ export class ExpressionEvaluator {
                         this.evaluate(expr.right, {
                             ...context,
                             thisValue: item,
+                            bindingScope: expr.binding
+                                ? { ...(context.bindingScope ?? {}), [expr.binding]: item }
+                                : context.bindingScope,
                         }),
                     ),
             )
             .exhaustive();
     }
+
+    private evaluateBinding(expr: BindingExpression, context: ExpressionEvaluatorContext): any {
+        if (!context.bindingScope || !(expr.name in context.bindingScope)) {
+            throw new Error(`Unresolved binding: ${expr.name}`);
+        }
+        return context.bindingScope[expr.name];
+    }
 }
diff --git a/packages/plugins/policy/src/expression-transformer.ts b/packages/plugins/policy/src/expression-transformer.ts
index 18320c69..7977ccb2 100644
--- a/packages/plugins/policy/src/expression-transformer.ts
+++ b/packages/plugins/policy/src/expression-transformer.ts
@@ -11,6 +11,7 @@ import {
 import type {
     BinaryExpression,
     BinaryOperator,
+    BindingExpression,
     BuiltinType,
     FieldDef,
     GetModels,
@@ -59,6 +60,8 @@ import {
     trueNode,
 } from './utils';
 
+type BindingScope = Record<string, { type: string; alias: string; value?: any }>;
+
 /**
  * Context for transforming a policy expression
  */
@@ -93,6 +96,11 @@ export type ExpressionTransformerContext = {
      */
     contextValue?: Record<string, any>;
 
+    /**
+     * Additional named collection predicate bindings available during transformation
+     */
+    bindingScope?: BindingScope;
+
     /**
      * The model or type name that `this` keyword refers to
      */
@@ -311,7 +319,11 @@ export class ExpressionTransformer<Schema extends SchemaDef> {
 
             // LHS of the expression is evaluated as a value
             const evaluator = new ExpressionEvaluator();
-            const receiver = evaluator.evaluate(expr.left, { thisValue: context.contextValue, auth: this.auth });
+            const receiver = evaluator.evaluate(expr.left, {
+                thisValue: context.contextValue,
+                auth: this.auth,
+                bindingScope: this.getEvaluationBindingScope(context.bindingScope),
+            });
 
             // get LHS's type
             const baseType = this.isAuthMember(expr.left) ? this.authType : context.modelOrType;
@@ -335,21 +347,38 @@ export class ExpressionTransformer<Schema extends SchemaDef> {
             newContextModel = fieldDef.type;
         } else {
             invariant(
-                ExpressionUtils.isMember(expr.left) && ExpressionUtils.isField(expr.left.receiver),
+                ExpressionUtils.isMember(expr.left) &&
+                    (ExpressionUtils.isField(expr.left.receiver) || ExpressionUtils.isBinding(expr.left.receiver)),
                 'left operand must be member access with field receiver',
             );
-            const fieldDef = QueryUtils.requireField(this.schema, context.modelOrType, expr.left.receiver.field);
-            newContextModel = fieldDef.type;
+            if (ExpressionUtils.isField(expr.left.receiver)) {
+                // collection is a field access, context model is the field's type
+                const fieldDef = QueryUtils.requireField(this.schema, context.modelOrType, expr.left.receiver.field);
+                newContextModel = fieldDef.type;
+            } else {
+                // collection is a binding reference, get type from binding scope
+                const binding = this.requireBindingScope(expr.left.receiver, context);
+                newContextModel = binding.type;
+            }
+
             for (const member of expr.left.members) {
                 const memberDef = QueryUtils.requireField(this.schema, newContextModel, member);
                 newContextModel = memberDef.type;
             }
         }
 
+        const bindingScope = expr.binding
+            ? {
+                  ...(context.bindingScope ?? {}),
+                  [expr.binding]: { type: newContextModel, alias: newContextModel },
+              }
+            : context.bindingScope;
+
         let predicateFilter = this.transform(expr.right, {
             ...context,
             modelOrType: newContextModel,
             alias: undefined,
+            bindingScope: bindingScope,
         });
 
         if (expr.op === '!') {
@@ -392,6 +421,7 @@ export class ExpressionTransformer<Schema extends SchemaDef> {
             const value = new ExpressionEvaluator().evaluate(expr, {
                 auth: this.auth,
                 thisValue: context.contextValue,
+                bindingScope: this.getEvaluationBindingScope(context.bindingScope),
             });
             return this.transformValue(value, 'Boolean');
         } else {
@@ -403,15 +433,27 @@ export class ExpressionTransformer<Schema extends SchemaDef> {
             // e.g.: `auth().profiles[age == this.age]`, each `auth().profiles` element (which is a value)
             // is used to build an expression for the RHS `age == this.age`
             // the transformation happens recursively for nested collection predicates
-            const components = receiver.map((item) =>
-                this.transform(expr.right, {
+            const components = receiver.map((item) => {
+                const bindingScope = expr.binding
+                    ? {
+                          ...(context.bindingScope ?? {}),
+                          [expr.binding]: {
+                              type: context.modelOrType,
+                              alias: context.thisAlias ?? context.modelOrType,
+                              value: item,
+                          },
+                      }
+                    : context.bindingScope;
+
+                return this.transform(expr.right, {
                     operation: context.operation,
                     thisType: context.thisType,
                     thisAlias: context.thisAlias,
                     modelOrType: context.modelOrType,
                     contextValue: item,
-                }),
-            );
+                    bindingScope: bindingScope,
+                });
+            });
 
             // compose the components based on the operator
             return (
@@ -601,6 +643,14 @@ export class ExpressionTransformer<Schema extends SchemaDef> {
     @expr('member')
     // @ts-ignore
     private _member(expr: MemberExpression, context: ExpressionTransformerContext) {
+        if (ExpressionUtils.isBinding(expr.receiver)) {
+            // if the binding has a plain value in the scope, evaluate directly
+            const scope = this.requireBindingScope(expr.receiver, context);
+            if (scope.value !== undefined) {
+                return this.valueMemberAccess(scope.value, expr, scope.type);
+            }
+        }
+
         // `auth()` member access
         if (this.isAuthCall(expr.receiver)) {
             return this.valueMemberAccess(this.auth, expr, this.authType);
@@ -616,12 +666,15 @@ export class ExpressionTransformer<Schema extends SchemaDef> {
         }
 
         invariant(
-            ExpressionUtils.isField(expr.receiver) || ExpressionUtils.isThis(expr.receiver),
-            'expect receiver to be field expression or "this"',
+            ExpressionUtils.isField(expr.receiver) ||
+                ExpressionUtils.isThis(expr.receiver) ||
+                ExpressionUtils.isBinding(expr.receiver),
+            'expect receiver to be field expression, collection predicate binding, or "this"',
         );
 
         let members = expr.members;
         let receiver: OperationNode;
+        let startType: string | undefined;
         const { memberFilter, memberSelect, ...restContext } = context;
 
         if (ExpressionUtils.isThis(expr.receiver)) {
@@ -639,6 +692,32 @@ export class ExpressionTransformer<Schema extends SchemaDef> {
                 const firstMemberFieldDef = QueryUtils.requireField(this.schema, context.thisType, expr.members[0]!);
                 receiver = this.transformRelationAccess(expr.members[0]!, firstMemberFieldDef.type, restContext);
                 members = expr.members.slice(1);
+                // startType should be the type of the relation access
+                startType = firstMemberFieldDef.type;
+            }
+        } else if (ExpressionUtils.isBinding(expr.receiver)) {
+            if (expr.members.length === 1) {
+                const bindingScope = this.requireBindingScope(expr.receiver, context);
+                // `binding.relation` case, equivalent to field access
+                return this._field(ExpressionUtils.field(expr.members[0]!), {
+                    ...context,
+                    modelOrType: bindingScope.type,
+                    alias: bindingScope.alias,
+                    thisType: context.thisType,
+                    contextValue: undefined,
+                });
+            } else {
+                // transform the first segment into a relation access, then continue with the rest of the members
+                const bindingScope = this.requireBindingScope(expr.receiver, context);
+                const firstMemberFieldDef = QueryUtils.requireField(this.schema, bindingScope.type, expr.members[0]!);
+                receiver = this.transformRelationAccess(expr.members[0]!, firstMemberFieldDef.type, {
+                    ...restContext,
+                    modelOrType: bindingScope.type,
+                    alias: bindingScope.alias,
+                });
+                members = expr.members.slice(1);
+                // startType should be the type of the relation access
+                startType = firstMemberFieldDef.type;
             }
         } else {
             receiver = this.transform(expr.receiver, restContext);
@@ -646,13 +725,14 @@ export class ExpressionTransformer<Schema extends SchemaDef> {
 
         invariant(SelectQueryNode.is(receiver), 'expected receiver to be select query');
 
-        let startType: string;
-        if (ExpressionUtils.isField(expr.receiver)) {
-            const receiverField = QueryUtils.requireField(this.schema, context.modelOrType, expr.receiver.field);
-            startType = receiverField.type;
-        } else {
-            // "this." case
-            startType = context.thisType;
+        if (startType === undefined) {
+            if (ExpressionUtils.isField(expr.receiver)) {
+                const receiverField = QueryUtils.requireField(this.schema, context.modelOrType, expr.receiver.field);
+                startType = receiverField.type;
+            } else {
+                // "this." case - already handled above if members were sliced
+                startType = context.thisType;
+            }
         }
 
         // traverse forward to collect member types
@@ -706,6 +786,12 @@ export class ExpressionTransformer<Schema extends SchemaDef> {
         };
     }
 
+    private requireBindingScope(expr: BindingExpression, context: ExpressionTransformerContext) {
+        const binding = context.bindingScope?.[expr.name];
+        invariant(binding, `binding not found: ${expr.name}`);
+        return binding;
+    }
+
     private valueMemberAccess(receiver: any, expr: MemberExpression, receiverType: string) {
         if (!receiver) {
             return ValueNode.createImmediate(null);
@@ -834,6 +920,22 @@ export class ExpressionTransformer<Schema extends SchemaDef> {
         return this.buildDelegateBaseFieldSelect(context.modelOrType, tableName, column, fieldDef.originModel);
     }
 
+    // convert transformer's binding scope to equivalent expression evaluator binding scope
+    private getEvaluationBindingScope(scope?: BindingScope) {
+        if (!scope) {
+            return undefined;
+        }
+
+        const result: Record<string, any> = {};
+        for (const [key, value] of Object.entries(scope)) {
+            if (value.value !== undefined) {
+                result[key] = value.value;
+            }
+        }
+
+        return Object.keys(result).length > 0 ? result : undefined;
+    }
+
     private buildDelegateBaseFieldSelect(model: string, modelAlias: string, field: string, baseModel: string) {
         const idFields = QueryUtils.requireIdFields(this.client.$schema, model);
         return {
diff --git a/packages/schema/src/expression-utils.ts b/packages/schema/src/expression-utils.ts
index ee48aecc..07ee1c11 100644
--- a/packages/schema/src/expression-utils.ts
+++ b/packages/schema/src/expression-utils.ts
@@ -2,6 +2,7 @@ import type {
     ArrayExpression,
     BinaryExpression,
     BinaryOperator,
+    BindingExpression,
     CallExpression,
     Expression,
     FieldExpression,
@@ -39,12 +40,13 @@ export const ExpressionUtils = {
         };
     },
 
-    binary: (left: Expression, op: BinaryOperator, right: Expression): BinaryExpression => {
+    binary: (left: Expression, op: BinaryOperator, right: Expression, binding?: string): BinaryExpression => {
         return {
             kind: 'binary',
             op,
             left,
             right,
+            binding,
         };
     },
 
@@ -71,6 +73,13 @@ export const ExpressionUtils = {
         };
     },
 
+    binding: (name: string): BindingExpression => {
+        return {
+            kind: 'binding',
+            name,
+        };
+    },
+
     _this: (): ThisExpression => {
         return {
             kind: 'this',
@@ -117,6 +126,8 @@ export const ExpressionUtils = {
 
     isMember: (value: unknown): value is MemberExpression => ExpressionUtils.is(value, 'member'),
 
+    isBinding: (value: unknown): value is BindingExpression => ExpressionUtils.is(value, 'binding'),
+
     getLiteralValue: (expr: Expression): string | number | boolean | undefined => {
         return ExpressionUtils.isLiteral(expr) ? expr.value : undefined;
     },
diff --git a/packages/schema/src/expression.ts b/packages/schema/src/expression.ts
index 3ce3c2d1..1828b9cc 100644
--- a/packages/schema/src/expression.ts
+++ b/packages/schema/src/expression.ts
@@ -6,6 +6,7 @@ export type Expression =
     | CallExpression
     | UnaryExpression
     | BinaryExpression
+    | BindingExpression
     | ThisExpression
     | NullExpression;
 
@@ -30,6 +31,11 @@ export type MemberExpression = {
     members: string[];
 };
 
+export type BindingExpression = {
+    kind: 'binding';
+    name: string;
+};
+
 export type UnaryExpression = {
     kind: 'unary';
     op: UnaryOperator;
@@ -41,6 +47,7 @@ export type BinaryExpression = {
     op: BinaryOperator;
     left: Expression;
     right: Expression;
+    binding?: string;
 };
 
 export type CallExpression = {
diff --git a/packages/sdk/src/ts-schema-generator.ts b/packages/sdk/src/ts-schema-generator.ts
index 6baeff42..4a5e0a54 100644
--- a/packages/sdk/src/ts-schema-generator.ts
+++ b/packages/sdk/src/ts-schema-generator.ts
@@ -13,6 +13,7 @@ import {
     InvocationExpr,
     isArrayExpr,
     isBinaryExpr,
+    isCollectionPredicateBinding,
     isDataField,
     isDataModel,
     isDataSource,
@@ -1257,11 +1258,17 @@ export class TsSchemaGenerator {
     }
 
     private createBinaryExpression(expr: BinaryExpr) {
-        return this.createExpressionUtilsCall('binary', [
+        const args = [
             this.createExpression(expr.left),
             this.createLiteralNode(expr.operator),
             this.createExpression(expr.right),
-        ]);
+        ];
+
+        if (expr.binding) {
+            args.push(this.createLiteralNode(expr.binding.name));
+        }
+
+        return this.createExpressionUtilsCall('binary', args);
     }
 
     private createUnaryExpression(expr: UnaryExpr) {
@@ -1278,13 +1285,18 @@ export class TsSchemaGenerator {
     }
 
     private createRefExpression(expr: ReferenceExpr): any {
-        if (isDataField(expr.target.ref)) {
-            return this.createExpressionUtilsCall('field', [this.createLiteralNode(expr.target.$refText)]);
-        } else if (isEnumField(expr.target.ref)) {
-            return this.createLiteralExpression('StringLiteral', expr.target.$refText);
-        } else {
-            throw new Error(`Unsupported reference type: ${expr.target.$refText}`);
-        }
+        const target = expr.target.ref;
+        return match(target)
+            .when(isDataField, () =>
+                this.createExpressionUtilsCall('field', [this.createLiteralNode(expr.target.$refText)]),
+            )
+            .when(isEnumField, () => this.createLiteralExpression('StringLiteral', expr.target.$refText))
+            .when(isCollectionPredicateBinding, () =>
+                this.createExpressionUtilsCall('binding', [this.createLiteralNode(expr.target.$refText)]),
+            )
+            .otherwise(() => {
+                throw Error(`Unsupported reference type: ${expr.target.$refText}`);
+            });
     }
 
     private createCallExpression(expr: InvocationExpr) {
diff --git a/tests/e2e/orm/policy/auth-access.test.ts b/tests/e2e/orm/policy/auth-access.test.ts
index b994324f..56942de4 100644
--- a/tests/e2e/orm/policy/auth-access.test.ts
+++ b/tests/e2e/orm/policy/auth-access.test.ts
@@ -130,6 +130,48 @@ model Foo {
         await expect(db.$setAuth({ profiles: [{ age: 15 }, { age: 20 }] }).foo.findFirst()).toResolveTruthy();
     });
 
+    it('uses iterator binding inside collection predicate for auth model', async () => {
+        const db = await createPolicyTestClient(
+            `
+model User {
+    id Int @id
+    tenantId Int
+    memberships Membership[] @relation("UserMemberships")
+}
+
+model Membership {
+    id Int @id
+    tenantId Int
+    userId Int
+    user User @relation("UserMemberships", fields: [userId], references: [id])
+}
+
+model Foo {
+    id Int @id
+    tenantId Int
+    @@allow('read', auth().memberships?[m, m.tenantId == auth().tenantId])
+}
+`,
+        );
+
+        await db.$unuseAll().foo.createMany({
+            data: [
+                { id: 1, tenantId: 1 },
+                { id: 2, tenantId: 2 },
+            ],
+        });
+
+        // allowed because iterator binding matches tenantId = 1
+        await expect(
+            db.$setAuth({ tenantId: 1, memberships: [{ id: 10, tenantId: 1 }] }).foo.findMany(),
+        ).toResolveWithLength(2);
+
+        // denied because membership tenantId doesn't match
+        await expect(
+            db.$setAuth({ tenantId: 1, memberships: [{ id: 20, tenantId: 3 }] }).foo.findMany(),
+        ).toResolveWithLength(0);
+    });
+
     it('works with shallow auth model collection predicates involving fields - some', async () => {
         const db = await createPolicyTestClient(
             `
diff --git a/tests/e2e/orm/policy/collection-predicate.test.ts b/tests/e2e/orm/policy/collection-predicate.test.ts
new file mode 100644
index 00000000..09e22228
--- /dev/null
+++ b/tests/e2e/orm/policy/collection-predicate.test.ts
@@ -0,0 +1,447 @@
+import { createPolicyTestClient } from '@zenstackhq/testtools';
+import { describe, expect, it } from 'vitest';
+
+describe('Collection Predicate Tests', () => {
+    it('should support collection predicates without binding', async () => {
+        const db = await createPolicyTestClient(
+            `
+            model User {
+                id Int @id
+                memberships Membership[]
+                @@allow('create', true)
+                @@allow('read', memberships?[tenantId == id])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                @@allow('all', true)
+            }
+`,
+        );
+        await db.$unuseAll().user.create({
+            data: { id: 1, memberships: { create: [{ id: 1, tenantId: 1 }] } },
+        });
+        await db.$unuseAll().user.create({
+            data: { id: 2, memberships: { create: [{ id: 2, tenantId: 1 }] } },
+        });
+        await expect(db.user.findUnique({ where: { id: 1 } })).toResolveTruthy();
+        await expect(db.user.findUnique({ where: { id: 2 } })).toResolveNull();
+    });
+
+    it('should support referencing binding', async () => {
+        const db = await createPolicyTestClient(
+            `
+            model User {
+                id Int @id
+                memberships Membership[]
+                @@allow('create', true)
+                @@allow('read', memberships?[m, m.tenantId == id])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                @@allow('all', true)
+            }
+`,
+        );
+        await db.$unuseAll().user.create({
+            data: { id: 1, memberships: { create: [{ id: 1, tenantId: 1 }] } },
+        });
+        await db.$unuseAll().user.create({
+            data: { id: 2, memberships: { create: [{ id: 2, tenantId: 1 }] } },
+        });
+        await expect(db.user.findUnique({ where: { id: 1 } })).toResolveTruthy();
+        await expect(db.user.findUnique({ where: { id: 2 } })).toResolveNull();
+    });
+
+    it('should support mixing bound and unbound syntax', async () => {
+        const db = await createPolicyTestClient(
+            `
+            model User {
+                id Int @id
+                memberships Membership[]
+                @@allow('create', true)
+                @@allow('read', memberships?[m, m.tenantId == id && tenantId == id])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                @@allow('all', true)
+            }
+`,
+        );
+        await db.$unuseAll().user.create({
+            data: { id: 1, memberships: { create: [{ id: 1, tenantId: 1 }] } },
+        });
+        await db.$unuseAll().user.create({
+            data: { id: 2, memberships: { create: [{ id: 2, tenantId: 1 }] } },
+        });
+        await expect(db.user.findUnique({ where: { id: 1 } })).toResolveTruthy();
+        await expect(db.user.findUnique({ where: { id: 2 } })).toResolveNull();
+    });
+
+    it('should allow disambiguation with this', async () => {
+        const db = await createPolicyTestClient(
+            `
+            model User {
+                id Int @id
+                memberships Membership[]
+                tenantId Int
+                @@allow('create', true)
+                @@allow('read', memberships?[m, m.tenantId == this.tenantId])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                @@allow('all', true)
+            }
+`,
+        );
+        await db.$unuseAll().user.create({
+            data: { id: 1, tenantId: 1, memberships: { create: [{ id: 1, tenantId: 1 }] } },
+        });
+        await db.$unuseAll().user.create({
+            data: { id: 2, tenantId: 2, memberships: { create: [{ id: 2, tenantId: 1 }] } },
+        });
+        await expect(db.user.findUnique({ where: { id: 1 } })).toResolveTruthy();
+        await expect(db.user.findUnique({ where: { id: 2 } })).toResolveNull();
+    });
+
+    it('should support accessing binding from deep context - case 1', async () => {
+        const db = await createPolicyTestClient(
+            `
+            model User {
+                id Int @id
+                memberships Membership[]
+                @@allow('create', true)
+                @@allow('read', memberships?[m, roles?[tenantId == m.tenantId]])
+            }
+
+            model Membership {
+                id Int @id
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                tenantId Int
+                roles Role[]
+                @@allow('all', true)
+            }
+
+            model Role {
+                id Int @id
+                membership Membership @relation(fields: [membershipId], references: [id])
+                membershipId Int
+                tenantId Int
+                @@allow('all', true)
+            }
+`,
+        );
+        await db.$unuseAll().user.create({
+            data: {
+                id: 1,
+                memberships: { create: [{ id: 1, tenantId: 1, roles: { create: { id: 1, tenantId: 1 } } }] },
+            },
+        });
+        await db.$unuseAll().user.create({
+            data: {
+                id: 2,
+                memberships: { create: [{ id: 2, tenantId: 2, roles: { create: { id: 2, tenantId: 1 } } }] },
+            },
+        });
+        await expect(db.user.findUnique({ where: { id: 1 } })).toResolveTruthy();
+        await expect(db.user.findUnique({ where: { id: 2 } })).toResolveNull();
+    });
+
+    it('should support accessing binding from deep context - case 2', async () => {
+        const db = await createPolicyTestClient(
+            `
+            model User {
+                id Int @id
+                memberships Membership[]
+                tenantId Int
+                @@allow('create', true)
+                @@allow('read', memberships?[m, roles?[this.tenantId == m.tenantId]])
+            }
+
+            model Membership {
+                id Int @id
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                tenantId Int
+                roles Role[]
+                @@allow('all', true)
+            }
+
+            model Role {
+                id Int @id
+                membership Membership @relation(fields: [membershipId], references: [id])
+                membershipId Int
+                @@allow('all', true)
+            }
+`,
+        );
+        await db.$unuseAll().user.create({
+            data: {
+                id: 1,
+                tenantId: 1,
+                memberships: { create: [{ id: 1, tenantId: 1, roles: { create: { id: 1 } } }] },
+            },
+        });
+        await db.$unuseAll().user.create({
+            data: {
+                id: 2,
+                tenantId: 2,
+                memberships: { create: [{ id: 2, tenantId: 1, roles: { create: { id: 2 } } }] },
+            },
+        });
+        await expect(db.user.findUnique({ where: { id: 1 } })).toResolveTruthy();
+        await expect(db.user.findUnique({ where: { id: 2 } })).toResolveNull();
+    });
+
+    it('should support accessing to-one relation from binding', async () => {
+        const db = await createPolicyTestClient(
+            `
+            model User {
+                id Int @id
+                memberships Membership[]
+                tenants Tenant[]
+                @@allow('create', true)
+                @@allow('read', memberships?[m, m.tenant.ownerId == id])
+            }
+
+            model Tenant {
+                id Int @id
+                ownerId Int
+                owner User @relation(fields: [ownerId], references: [id])
+                memberships Membership[]
+                @@allow('all', true)
+            }
+
+            model Membership {
+                id Int @id
+                tenant Tenant @relation(fields: [tenantId], references: [id])
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                @@allow('all', true)
+            }
+`,
+        );
+        await db.$unuseAll().user.create({
+            data: {
+                id: 1,
+                memberships: {
+                    create: [{ id: 1, tenant: { create: { id: 1, ownerId: 1 } } }],
+                },
+            },
+        });
+        await db.$unuseAll().user.create({
+            data: {
+                id: 2,
+                memberships: {
+                    create: [{ id: 2, tenant: { create: { id: 2, ownerId: 1 } } }],
+                },
+            },
+        });
+        await expect(db.user.findUnique({ where: { id: 1 } })).toResolveTruthy();
+        await expect(db.user.findUnique({ where: { id: 2 } })).toResolveNull();
+    });
+
+    it('should support multiple bindings in nested predicates', async () => {
+        const db = await createPolicyTestClient(
+            `
+            model User {
+                id Int @id
+                memberships Membership[]
+                @@allow('create', true)
+                @@allow('read', memberships?[m, m.roles?[r, r.tenantId == m.tenantId]])
+            }
+
+            model Membership {
+                id Int @id
+                tenantId Int
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                roles Role[]
+                @@allow('all', true)
+            }
+
+            model Role {
+                id Int @id
+                tenantId Int
+                membership Membership @relation(fields: [membershipId], references: [id])
+                membershipId Int
+                @@allow('all', true)
+            }
+`,
+        );
+        await db.$unuseAll().user.create({
+            data: {
+                id: 1,
+                memberships: {
+                    create: [{ id: 1, tenantId: 1, roles: { create: { id: 1, tenantId: 1 } } }],
+                },
+            },
+        });
+        await db.$unuseAll().user.create({
+            data: {
+                id: 2,
+                memberships: {
+                    create: [{ id: 2, tenantId: 2, roles: { create: { id: 2, tenantId: 1 } } }],
+                },
+            },
+        });
+        await expect(db.user.findUnique({ where: { id: 1 } })).toResolveTruthy();
+        await expect(db.user.findUnique({ where: { id: 2 } })).toResolveNull();
+    });
+
+    it('should work with inner binding masking outer binding names', async () => {
+        const db = await createPolicyTestClient(
+            `
+            model User {
+                id Int @id
+                memberships Membership[]
+                tenantId Int
+                @@allow('create', true)
+                @@allow('read', memberships?[m, m.roles?[m, m.tenantId == this.tenantId]])
+            }
+
+            model Membership {
+                id Int @id
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+                roles Role[]
+                @@allow('all', true)
+            }
+
+            model Role {
+                id Int @id
+                tenantId Int
+                membership Membership @relation(fields: [membershipId], references: [id])
+                membershipId Int
+                @@allow('all', true)
+            }
+`,
+        );
+        await db.$unuseAll().user.create({
+            data: {
+                id: 1,
+                tenantId: 1,
+                memberships: { create: [{ id: 1, roles: { create: { id: 1, tenantId: 1 } } }] },
+            },
+        });
+        await db.$unuseAll().user.create({
+            data: {
+                id: 2,
+                tenantId: 2,
+                memberships: { create: [{ id: 2, roles: { create: { id: 2, tenantId: 1 } } }] },
+            },
+        });
+        await expect(db.user.findUnique({ where: { id: 1 } })).toResolveTruthy();
+        await expect(db.user.findUnique({ where: { id: 2 } })).toResolveNull();
+    });
+
+    it('should work with bindings with auth collection predicates', async () => {
+        const db = await createPolicyTestClient(
+            `
+            model User {
+                id Int @id
+                companies Company[]
+                test Int
+
+                @@allow('read', auth().companies?[c, c.staff?[s, s.companyId == this.test]])
+            }
+
+            model Company {
+                id Int @id
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+
+                staff Staff[]
+                @@allow('read', true)
+            }
+
+            model Staff {
+                id Int @id
+
+                company Company @relation(fields: [companyId], references: [id])
+                companyId Int
+
+                @@allow('read', true)
+              }
+            `,
+        );
+        await db.$unuseAll().user.create({
+            data: {
+                id: 1,
+                test: 1,
+                companies: { create: { id: 1, staff: { create: { id: 1 } } } },
+            },
+        });
+
+        await expect(
+            db
+                .$setAuth({ id: 1, companies: [{ id: 1, staff: [{ id: 1, companyId: 1 }] }], test: 1 })
+                .user.findUnique({ where: { id: 1 } }),
+        ).toResolveTruthy();
+    });
+
+    it('should work with bindings with auth collection predicates - pure value', async () => {
+        const db = await createPolicyTestClient(
+            `
+            model User {
+                id Int @id
+                companies Company[]
+
+                @@allow('read', auth().companies?[c, c.staff?[s, s.companyId == c.id]])
+            }
+
+            model Company {
+                id Int @id
+                user User @relation(fields: [userId], references: [id])
+                userId Int
+
+                staff Staff[]
+                @@allow('read', true)
+            }
+
+            model Staff {
+                id Int @id
+
+                company Company @relation(fields: [companyId], references: [id])
+                companyId Int
+
+                @@allow('read', true)
+              }
+            `,
+        );
+        await db.$unuseAll().user.create({
+            data: {
+                id: 1,
+                companies: { create: { id: 1, staff: { create: { id: 1 } } } },
+            },
+        });
+
+        await expect(
+            db
+                .$setAuth({ id: 1, companies: [{ id: 1, staff: [{ id: 1, companyId: 1 }] }] })
+                .user.findUnique({ where: { id: 1 } }),
+        ).toResolveTruthy();
+        await expect(
+            db
+                .$setAuth({ id: 1, companies: [{ id: 1, staff: [{ id: 1, companyId: 2 }] }] })
+                .user.findUnique({ where: { id: 1 } }),
+        ).toResolveNull();
+    });
+});