diff --git a/src/entity-aspect.ts b/src/entity-aspect.ts
index 4cae4d9..14708aa 100644
--- a/src/entity-aspect.ts
+++ b/src/entity-aspect.ts
@@ -14,9 +14,9 @@ import { EntityQuery } from './entity-query';
 export interface Entity {
   entityAspect: EntityAspect;
   entityType: EntityType;
-  /** @internal */
+  /** Get the property with the given name */
   getProperty?(prop: string): any;
-  /** @internal */
+  /** Set the property with the given name */
   setProperty?(prop: any, value: any): void;
   /** @hidden @internal */
   prototype?: { _$typeName: string };
@@ -77,7 +77,7 @@ export class EntityAspect {
   isBeingSaved: boolean;
   /** The 'original values' of this entity where they are different from the 'current values'.
   This is a map where the key is a property name and the value is the 'original value' of the property. */
-  originalValues: {};
+  originalValues: Record<string, any>;
   /**  Whether this entity has any validation errors. __Read Only__ */
   hasValidationErrors: boolean;
   /** Whether this entity has a temporary [[EntityKey]]. */
@@ -900,7 +900,7 @@ export class ComplexAspect {
   /** The 'original values' of this complex object where they are different from the 'current values'.
   This is a map where the key is a property name and the value is the 'original value' of the property.
   __Read Only__ */
-  originalValues: {};
+  originalValues: Record<string, any>;
   /** The parent object that to which this aspect belongs; this will either be an entity or another complex object. __Read Only__ */
   parent?: StructuralObject;
   /** The [[DataProperty]] on the 'parent' that contains this complex object. __Read Only__ */
diff --git a/src/entity-manager.ts b/src/entity-manager.ts
index 3d27ac1..ac3c09a 100644
--- a/src/entity-manager.ts
+++ b/src/entity-manager.ts
@@ -2396,7 +2396,7 @@ function unwrapOriginalValues(target: StructuralObject, metadataStore: MetadataS
   let stype = EntityAspect.isEntity(target) ? target.entityType : target.complexType;
   let aspect = EntityAspect.isEntity(target) ? target.entityAspect : target.complexAspect;
   let fn = metadataStore.namingConvention.clientPropertyNameToServer;
-  let result = {};
+  let result = {} as Record<string, any>;
   core.objectForEach(aspect.originalValues, function (propName, val) {
     let prop = stype.getProperty(propName) as DataProperty;
     val = transformFn ? transformFn(prop, val) : val;
@@ -2425,7 +2425,7 @@ function unwrapChangedValues(entity: Entity, metadataStore: MetadataStore, trans
   let stype = entity.entityType;
   let serializerFn = getSerializerFn(stype);
   let fn = metadataStore.namingConvention.clientPropertyNameToServer;
-  let result = {};
+  let result = {} as Record<string, any>;
   core.objectForEach(entity.entityAspect.originalValues, function (propName, value) {
     let prop = stype.getProperty(propName) as DataProperty;
     let val = entity.getProperty(propName);
diff --git a/src/entity-metadata.ts b/src/entity-metadata.ts
index e92b6ca..e075aec 100644
--- a/src/entity-metadata.ts
+++ b/src/entity-metadata.ts
@@ -20,6 +20,12 @@ export type StructuralType = EntityType | ComplexType;
 export interface IStructuralTypeMap {
   [index: string]: StructuralType;
 }
+/** Keep track of constructors and initializers for StructuralTypes */
+interface CtorRecord { 
+  ctor: { new (): StructuralObject };
+  initFn?: Function | string; 
+  noTrackingFn?: Function;
+}
 
 // TODO: consider exposing later
 /** @hidden @internal */
@@ -91,21 +97,21 @@ export class MetadataStore {
   **/
   metadataFetched: BreezeEvent<MetadataFetchedEventArgs>;
   /** @hidden @internal */
-  _resourceEntityTypeMap: {};
-  /** @hidden @internal */
-  _entityTypeResourceMap: {};
+  _resourceEntityTypeMap: Record<string, string>;
   /** @hidden @internal */
-  _structuralTypeMap: IStructuralTypeMap; // key is qualified structuraltype name - value is structuralType. ( structural = entityType or complexType).
-  /** @hidden @internal **/
-  _shortNameMap: {}; // key is shortName, value is qualified name - does not need to be serialized.
-  /** @hidden @internal **/
-  _ctorRegistry: {}; // key is either short or qual type name - value is ctor;
-  /** @hidden @internal **/
-  _incompleteTypeMap: {}; // key is entityTypeName; value is array of nav props
-  /** @hidden @internal **/
-  _incompleteComplexTypeMap: {}; //
+  _entityTypeResourceMap: Record<string, string>;
+  /** @hidden @internal key is qualified structuraltype name - value is structuralType. ( structural = entityType or complexType). */
+  _structuralTypeMap: IStructuralTypeMap;
+  /** @hidden @internal key is shortName, value is qualified name - does not need to be serialized. **/
+  _shortNameMap: Record<string, string>;
+  /** @hidden @internal key is either short or qual type name - value is ctor; **/
+  _ctorRegistry: Record<string, CtorRecord>;
+  /** @hidden @internal key is entityTypeName; value is array of nav props **/
+  _incompleteTypeMap: Record<string, NavigationProperty[]>;
   /** @hidden @internal **/
-  _deferredTypes: {};
+  _incompleteComplexTypeMap: Record<string, DataProperty[]>;
+  /** @hidden @internal { json: any, stype: StructuralType }[] | { entityType: EntityType, csdlEntityType: any }[] **/
+  _deferredTypes: Record<string, any>;
   /** @hidden @internal **/
   _id: number;
 
@@ -866,7 +872,7 @@ export interface EntityTypeConfig {
   dataProperties?: DataProperty[] | Object[] | Object;  // TODO: see if we can't qualify Object[] a little better.
   navigationProperties?: NavigationProperty[] | Object[] | Object;
   serializerFn?: (prop: EntityProperty, val: any) => any;
-  custom?: Object;
+  custom?: any;
 }
 
 /** Configuration info to be passed to the [[EntityType.setProperties]] method */
@@ -874,7 +880,7 @@ export interface EntityTypeSetConfig {
   autoGeneratedKeyType?: AutoGeneratedKeyType;
   defaultResourceName?: string;
   serializerFn?: (prop: EntityProperty, val: any) => any;
-  custom?: Object;
+  custom?: any;
 }
 
 /** Container for all of the metadata about a specific type of Entity.
@@ -936,7 +942,7 @@ export class EntityType {
   /** A function that is used to customize the serialization of any EntityProperties of this type. */
   serializerFn?: (prop: EntityProperty, val: any) => any;
   /**  A free form object that can be used to define any custom metadata for this EntityType. __Read Only__  **/
-  custom?: Object;
+  custom?: any;
   /** The entity level validators associated with this EntityType. Validators can be added and
   removed from this collection. __Read Only__.   **/
   validators: Validator[];
@@ -1263,7 +1269,7 @@ export class EntityType {
     if (this._ctor && !forceRefresh) return this._ctor;
 
     let ctorRegistry = this.metadataStore._ctorRegistry;
-    let r = ctorRegistry[this.name] || ctorRegistry[this.shortName] || {};
+    let r = ctorRegistry[this.name] || ctorRegistry[this.shortName] || {} as CtorRecord;
     let aCtor = r.ctor || this._ctor;
 
     let ctorType = aCtor && aCtor.prototype && (aCtor.prototype.entityType || aCtor.prototype.complexType);
@@ -1810,7 +1816,7 @@ export interface ComplexTypeConfig {
   namespace?: string;
   dataProperties?: DataProperty[] | Object[] | Object;
   isComplexType?: boolean;  // needed because this ctor can get called from the addEntityType method which needs the isComplexType prop
-  custom?: Object;
+  custom?: any;
 }
 
 /**  Container for all of the metadata about a specific type of Complex object.
@@ -1929,7 +1935,7 @@ export class ComplexType {
   @param config - Custom config object
   @param config.custom - {Object}
   **/
-  setProperties(config: { custom?: Object }) {
+  setProperties(config: { custom?: any }) {
     assertConfig(config)
       .whereParam("custom").isOptional()
       .applyAll(this);
@@ -1993,7 +1999,7 @@ export interface DataPropertyConfig {
   displayName?: string;
   enumType?: string;
   rawTypeName?: string;  // occurs with undefined datatypes
-  custom?: Object;
+  custom?: any;
 }
 
 /**
@@ -2047,7 +2053,7 @@ export class DataProperty {
   /** The raw type name of this property. will only be defined for properties with a DataType of 'Undefined' */
   declare rawTypeName?: string;  // occurs with undefined datatypes
   /**  A free form object that can be used to define any custom metadata for this DataProperty. __Read Only__ */
-  declare custom?: Object;
+  declare custom?: any;
   // TODO: doc this
   declare inverseNavigationProperty?: NavigationProperty;
   /**
@@ -2140,7 +2146,7 @@ export class DataProperty {
 
   }
 
-  static getRawValueFromServer(rawEntity: Object, dp: DataProperty) {
+  static getRawValueFromServer(rawEntity: Object & Record<string, any>, dp: DataProperty) {
     if (dp.isUnmapped) {
       return rawEntity[dp.nameOnServer || dp.name];
     } else {
@@ -2149,7 +2155,7 @@ export class DataProperty {
     }
   }
 
-  static getRawValueFromClient(rawEntity: Object, dp: DataProperty) {
+  static getRawValueFromClient(rawEntity: Object & Record<string, any>, dp: DataProperty) {
     let val = rawEntity[dp.name];
     return val !== undefined ? val : dp.defaultValue;
   }
@@ -2248,7 +2254,7 @@ export interface NavigationPropertyConfig {
   invForeignKeyNamesOnServer?: string[];
   validators?: Validator[];
   displayName?: string;
-  custom?: Object;
+  custom?: any;
 }
 
 /**   A NavigationProperty describes the metadata for a single property of an [[EntityType]] that return instances of other EntityTypes.
@@ -2313,7 +2319,7 @@ export class NavigationProperty {
   declare displayName: string;
   declare isUnmapped: boolean;
   /** A free form object that can be used to define any custom metadata for this NavigationProperty.   **/
-  declare custom: Object;
+  declare custom: any;
 
   /** NavigationProperty constructor
   >      let homeAddressProp = new NavigationProperty( {
@@ -2369,7 +2375,7 @@ export class NavigationProperty {
     foreignKeyNames?: string[],
     invForeignKeyNames?: string[],
     inverse?: NavigationProperty | string,
-    custom?: Object
+    custom?: any
   }) {
     if (!this.parentType) {
       throw new Error("Cannot call NavigationProperty.setProperties until the parent EntityType of the NavigationProperty has been set.");
diff --git a/src/entity-state.ts b/src/entity-state.ts
index ba6bc95..aafb474 100644
--- a/src/entity-state.ts
+++ b/src/entity-state.ts
@@ -78,6 +78,11 @@ export class EntityState extends BreezeEnum {
     return this === EntityState.Detached;
   }
 
+  /** Return true if EntityState is Deleted or Detached */
+  isDeletedOrDetached() {
+    return this === EntityState.Detached || this === EntityState.Detached;
+  }
+
   /**
   Returns whether an entityState instance is EntityState.Unchanged or EntityState.Modified.
   >     var es = anEntity.entityAspect.entityState;
@@ -90,6 +95,11 @@ export class EntityState extends BreezeEnum {
     return this === EntityState.Unchanged || this === EntityState.Modified;
   }
 
+  /** Return true if EntityStatis is Added or Modified */
+  isAddedOrModified() {
+    return this === EntityState.Added || this === EntityState.Modified;
+  }
+
   /** Returns whether an entityState instance is EntityState.Added or EntityState.Modified or EntityState.Deleted.
   >     var es = anEntity.entityAspect.entityState;
   >     return es.isAddedModifiedOrDeleted();
diff --git a/src/key-generator.ts b/src/key-generator.ts
index ebd8c51..ff534fe 100644
--- a/src/key-generator.ts
+++ b/src/key-generator.ts
@@ -5,7 +5,7 @@ import { config } from './config';
 interface IPropEntry {
   entityType: EntityType;
   propertyName: string;
-  keyMap: Object;
+  keyMap: Record<string, any>;
 }
 
 interface ITempIdMap {
diff --git a/src/mapping-context.ts b/src/mapping-context.ts
index 1c8c077..a347c25 100644
--- a/src/mapping-context.ts
+++ b/src/mapping-context.ts
@@ -47,7 +47,7 @@ export class MappingContext {
   mergeOptions: MergeOptions;
   adapter: DataServiceAdapter;  // assigned in the AbstractDataServiceAdapter.
 
-  refMap: Object; // TODO
+  refMap: Record<string, any>; // TODO
   deferredFns: Function[]; // TODO
   jsonResultsAdapter: JsonResultsAdapter;
   metadataStore: MetadataStore;
@@ -165,7 +165,7 @@ function processMeta(mc: MappingContext, node: any, meta: NodeMeta, assignFn?: (
 }
 
 function processNoMerge(mc: MappingContext, stype: StructuralType, node: any) {
-  let result = {};
+  let result = {} as Record<string, any>;
 
   stype.dataProperties.forEach(function (dp) {
     if (dp.isComplexProperty) {
@@ -198,7 +198,7 @@ function processAnonType(mc: MappingContext, node: any) {
   return result;
 }
 
-function visitNode(node: any, mc: MappingContext, nodeContext: NodeContext, result: Object, key: string) {
+function visitNode(node: any, mc: MappingContext, nodeContext: NodeContext, result: Record<string, any>, key: string) {
   let jra = mc.jsonResultsAdapter;
   let meta = jra.visitNode(node, mc, nodeContext) || {};
   // allows visitNode to change the value;