diff --git a/src/models/clone-plain.ts b/src/models/clone-plain.ts
new file mode 100644
index 0000000..4346e63
--- /dev/null
+++ b/src/models/clone-plain.ts
@@ -0,0 +1,27 @@
+import { isProxy, toRaw } from 'vue';
+
+function normalizeCloneable<T>(value: T): T {
+    if (value === null || value === undefined) {
+        return value;
+    }
+
+    if (typeof value !== 'object') {
+        return value;
+    }
+
+    const rawValue = isProxy(value) ? toRaw(value) : value;
+
+    if (Array.isArray(rawValue)) {
+        return rawValue.map(item => normalizeCloneable(item)) as T;
+    }
+
+    const plainObject = Object.fromEntries(
+        Object.entries(rawValue).map(([key, nestedValue]) => [key, normalizeCloneable(nestedValue)])
+    );
+
+    return plainObject as T;
+}
+
+export function clonePlain<T>(value: T): T {
+    return structuredClone(normalizeCloneable(value));
+}
diff --git a/src/models/collection.ts b/src/models/collection.ts
index ef9b089..c56e85c 100644
--- a/src/models/collection.ts
+++ b/src/models/collection.ts
@@ -1,47 +1,52 @@
 /**
- * Class model for Collection Interface
+ * Class models for Collection interfaces
  */
 
-import type { CollectionContentTypes, CollectionInterface, CollectionPropertiesInterface } from "@/types/collection";
+import type {
+    CollectionContentTypes,
+    CollectionInterface,
+    CollectionModelInterface,
+    CollectionPropertiesInterface,
+    CollectionPropertiesModelInterface
+} from '@/types/collection';
+import type {
+    CollectionIdentifier,
+    ServiceIdentifier
+} from '@/types/common';
+import { clonePlain } from './clone-plain';
 
-export class CollectionObject implements CollectionInterface {
+export class CollectionObject implements CollectionModelInterface {
 
-    _data!: CollectionInterface;
+    private _data: CollectionInterface<CollectionPropertiesInterface>;
+    private _properties: CollectionPropertiesObject | undefined = undefined;
 
     constructor() {
         this._data = {
+            '@type': 'people:collection',
+            version: 1,
             provider: '',
-            service: '',
-            collection: null,
-            identifier: '',
-            signature: null,
-            created: null,
-            modified: null,
-            properties: new CollectionPropertiesObject(),
+            service: '' as ServiceIdentifier,
+            collection: null as CollectionIdentifier | null,
+            identifier: '' as CollectionIdentifier,
+            properties: new CollectionPropertiesObject().toJson(),
         };
     }
 
     fromJson(data: CollectionInterface): CollectionObject {
-        this._data = data;
-        if (data.properties) {
-            this._data.properties = new CollectionPropertiesObject().fromJson(data.properties as CollectionPropertiesInterface);
-        }
+        this._data = clonePlain(data);
+        this._properties = undefined;
         return this;
     }
 
     toJson(): CollectionInterface {
-        const json = { ...this._data };
-        if (this._data.properties instanceof CollectionPropertiesObject) {
-            json.properties = this._data.properties.toJson();
-        }
-        return json;
+        const json = this._properties
+            ? { ...this._data, properties: this._properties.toJson() }
+            : this._data;
+        return clonePlain(json);
     }
 
     clone(): CollectionObject {
-        const cloned = new CollectionObject();
-        cloned._data = { ...this._data };
-        cloned._data.properties = this.properties.clone();
-        return cloned;
+        return new CollectionObject().fromJson(this.toJson());
     }
 
     /** Immutable Properties */
@@ -50,16 +55,16 @@ export class CollectionObject implements CollectionInterface {
         return this._data.provider;
     }
 
-    get service(): string | number {
-        return this._data.service;
+    get service(): ServiceIdentifier {
+        return this._data.service as ServiceIdentifier;
     }
 
-    get collection(): string | number | null {
-        return this._data.collection;
+    get collection(): CollectionIdentifier | null {
+        return this._data.collection as CollectionIdentifier | null;
     }
 
-    get identifier(): string | number {
-        return this._data.identifier;
+    get identifier(): CollectionIdentifier {
+        return this._data.identifier as CollectionIdentifier;
     }
 
     get signature(): string | null | undefined {
@@ -74,37 +79,33 @@ export class CollectionObject implements CollectionInterface {
         return this._data.modified;
     }
 
+    /** Mutable Properties */
+
     get properties(): CollectionPropertiesObject {
-        if (this._data.properties instanceof CollectionPropertiesObject) {
-            return this._data.properties;
+        if (this._properties) {
+            return this._properties;
+        }
+        else if (this._data.properties) {
+            const properties = new CollectionPropertiesObject().fromJson(this._data.properties as CollectionPropertiesInterface);
+            this._properties = properties;
+            return properties;
         }
 
-        if (this._data.properties) {
-            const hydrated = new CollectionPropertiesObject().fromJson(this._data.properties as CollectionPropertiesInterface);
-            this._data.properties = hydrated;
-            return hydrated;
-        }
-        
         return new CollectionPropertiesObject();
     }
 
     set properties(value: CollectionPropertiesObject) {
-        if (value instanceof CollectionPropertiesObject) {
-            this._data.properties = value as any;
-        } else {
-            this._data.properties = value;
-        }
+        this._properties = value;
     }
 }
 
-export class CollectionPropertiesObject implements CollectionPropertiesInterface {
-
-    _data!: CollectionPropertiesInterface;
+export class CollectionPropertiesObject implements CollectionPropertiesModelInterface {
+    
+    private _data: CollectionPropertiesInterface;
 
     constructor() {
         this._data = {
-            '@type': 'chrono:collection',
-            version: 1,
+            '@type': 'chrono:calendar',
             content: [],
             label: '',
             description: null,
@@ -115,32 +116,22 @@ export class CollectionPropertiesObject implements CollectionPropertiesInterface
     }
 
     fromJson(data: CollectionPropertiesInterface): CollectionPropertiesObject {
-        this._data = data;
+        this._data = clonePlain(data);
         return this;
     }
 
     toJson(): CollectionPropertiesInterface {
-        return this._data;
+        return clonePlain(this._data);
     }
 
     clone(): CollectionPropertiesObject {
-        const cloned = new CollectionPropertiesObject();
-        cloned._data = { ...this._data };
-        return cloned;
+        return new CollectionPropertiesObject().fromJson(this.toJson());
     }
 
     /** Immutable Properties */
 
-    get '@type'(): string {
-        return this._data['@type'];
-    }
-
-    get version(): number {
-        return this._data.version;
-    }
-
     get content(): CollectionContentTypes[] {
-        return this._data.content || [];
+        return this._data.content ?? [];
     }
 
     /** Mutable Properties */
@@ -185,4 +176,4 @@ export class CollectionPropertiesObject implements CollectionPropertiesInterface
         this._data.color = value;
     }
 
-}
\ No newline at end of file
+}
diff --git a/src/models/entity.ts b/src/models/entity.ts
index 069766a..a8c5d86 100644
--- a/src/models/entity.ts
+++ b/src/models/entity.ts
@@ -1,106 +1,102 @@
 /**
  * Class model for Entity Interface
  */
-import type { EntityInterface } from "@/types/entity";
-import type { EventInterface } from "@/types/event";
-import type { TaskInterface } from "@/types/task";
-import type { JournalInterface } from "@/types/journal";
-import { EventObject } from "./event";
-import { TaskObject } from "./task";
-import { JournalObject } from "./journal";
 
-export class EntityObject implements EntityInterface {
+import type { CollectionIdentifier, EntityIdentifier } from '@/types/common';
+import type { EntityInterface, EntityModelInterface, EntityPropertiesInterface } from '@/types/entity';
+import type { EventInterface } from '@/types/event';
+import type { JournalInterface } from '@/types/journal';
+import type { TaskInterface } from '@/types/task';
+import { EventObject } from './event';
+import { JournalObject } from './journal';
+import { TaskObject } from './task';
+import { clonePlain } from './clone-plain';
 
-    _data!: EntityInterface;
+export type EntityPropertiesObject = EventObject | TaskObject | JournalObject;
+
+export class EntityObject implements EntityModelInterface {
+    private _data: EntityInterface<EntityPropertiesInterface>;
+    private _properties: EntityPropertiesObject | undefined;
 
     constructor() {
         this._data = {
+            '@type': 'chrono:entity',
+            version: 1,
             provider: '',
             service: '',
-            collection: '',
-            identifier: '',
+            collection: '' as CollectionIdentifier,
+            identifier: '' as EntityIdentifier,
             signature: null,
             created: null,
             modified: null,
-            properties: new EventObject(),
+            properties: new EventObject().toJson(),
         };
     }
 
     fromJson(data: EntityInterface): EntityObject {
-        this._data = data
-        if (data.properties) {
-            const type = data.properties.type
-            if (type === 'task') {
-                this._data.properties = new TaskObject().fromJson(data.properties as TaskInterface);
-            } else if (type === 'journal') {
-                this._data.properties = new JournalObject().fromJson(data.properties as JournalInterface);
-            } else {
-                this._data.properties = new EventObject().fromJson(data.properties as EventInterface);
-            }
-        }
+        this._data = clonePlain(data);
+        this._properties = undefined;
         return this;
     }
 
     toJson(): EntityInterface {
-        const json = { ...this._data }
-        if (this._data.properties instanceof EventObject ||
-            this._data.properties instanceof TaskObject ||
-            this._data.properties instanceof JournalObject) {
-            json.properties = this._data.properties.toJson();
-        }
-        return json as EntityInterface
+        const json = this._properties
+            ? { ...this._data, properties: this._properties.toJson() }
+            : this._data;
+        return clonePlain(json);
     }
 
     clone(): EntityObject {
-        const cloned = new EntityObject()
-        cloned._data = { ...this._data }
-        return cloned
+        return new EntityObject().fromJson(this.toJson());
     }
 
-    /** Immutable Properties */
+    /** Metadata Properties */
 
     get provider(): string {
-        return this._data.provider
+        return this._data.provider;
     }
 
     get service(): string {
-        return this._data.service
+        return this._data.service;
     }
 
-    get collection(): string | number {
-        return this._data.collection
+    get collection(): CollectionIdentifier {
+        return this._data.collection;
     }
 
-    get identifier(): string | number {
-        return this._data.identifier
+    get identifier(): EntityIdentifier {
+        return this._data.identifier;
     }
 
     get signature(): string | null {
-        return this._data.signature
+        return this._data.signature;
     }
 
     get created(): string | null {
-        return this._data.created
+        return this._data.created;
     }
 
     get modified(): string | null {
-        return this._data.modified
+        return this._data.modified;
     }
 
-    get properties(): EventObject | TaskObject | JournalObject {
-        if (this._data.properties instanceof EventObject ||
-            this._data.properties instanceof TaskObject ||
-            this._data.properties instanceof JournalObject) {
-            return this._data.properties
+    /** Entity Properties (individual | organization | group) */
+
+    get properties(): EntityPropertiesObject {
+        if (this._properties) return this._properties;
+
+        const raw = this._data.properties;
+        if (raw.type === 'task') {
+            this._properties = new TaskObject().fromJson(raw as TaskInterface);
+        } else if (raw.type === 'journal') {
+            this._properties = new JournalObject().fromJson(raw as JournalInterface);
+        } else {
+            this._properties = new EventObject().fromJson(raw as EventInterface);
         }
-
-        const defaultProperties = new EventObject();
-        this._data.properties = defaultProperties;
-        return defaultProperties
+        return this._properties;
     }
 
-    set properties(value: EventObject | TaskObject | JournalObject) {
-        this._data.properties = value
+    set properties(value: EntityPropertiesObject) {
+        this._properties = value;
     }
-
 }
diff --git a/src/models/identity.ts b/src/models/identity.ts
index 3291090..ec9360f 100644
--- a/src/models/identity.ts
+++ b/src/models/identity.ts
@@ -1,196 +1,124 @@
 /**
- * Identity implementation classes for Mail Manager services
+ * Identity models for Chrono Manager services
  */
 
 import type {
-  ServiceIdentity,
-  ServiceIdentityNone,
-  ServiceIdentityBasic,
-  ServiceIdentityToken,
-  ServiceIdentityOAuth,
-  ServiceIdentityCertificate
+    ServiceIdentity,
+    ServiceIdentityBasic,
+    ServiceIdentityCertificate,
+    ServiceIdentityNone,
+    ServiceIdentityOAuth,
+    ServiceIdentityToken
 } from '@/types/service';
+import { clonePlain } from './clone-plain';
+import { MutationProxy } from './mutation-proxy';
 
-/**
- * Base Identity class
- */
-export abstract class Identity {
-  abstract toJson(): ServiceIdentity;
-  
-  static fromJson(data: ServiceIdentity): Identity {
-    switch (data.type) {
-      case 'NA':
-        return IdentityNone.fromJson(data);
-      case 'BA':
-        return IdentityBasic.fromJson(data);
-      case 'TA':
-        return IdentityToken.fromJson(data);
-      case 'OA':
-        return IdentityOAuth.fromJson(data);
-      case 'CC':
-        return IdentityCertificate.fromJson(data);
-      default:
-        throw new Error(`Unknown identity type: ${(data as any).type}`);
+export abstract class Identity<T extends ServiceIdentity = ServiceIdentity> {
+    protected _original: T;
+    protected _mutated: Partial<T>;
+    protected _mutationProxy: MutationProxy<T>;
+    protected _data: T;
+
+    protected constructor(initial: T) {
+        this._original = clonePlain(initial);
+        this._mutated = {};
+        this._mutationProxy = new MutationProxy<T>(() => this._original, () => this._mutated);
+        this._data = this._mutationProxy.create();
+    }
+
+    protected load(data: T): this {
+        this._original = clonePlain(data);
+        this._mutated = {};
+        this._data = this._mutationProxy.create();
+        return this;
+    }
+
+    toJSON(): ServiceIdentity { return this.toJson(); }
+    toJson(): T;
+    toJson(delta: true): Partial<T>;
+    toJson(delta?: boolean): T | Partial<T> {
+        return delta
+            ? clonePlain(this._mutated)
+            : { ...clonePlain(this._original), ...clonePlain(this._mutated) };
+    }
+
+    abstract clone(): Identity;
+    mutated(): boolean { return Reflect.ownKeys(this._mutated).length > 0; }
+
+    static fromJson(data: ServiceIdentity): Identity {
+        switch (data.type) {
+            case 'NA': return IdentityNone.fromJson(data);
+            case 'BA': return IdentityBasic.fromJson(data);
+            case 'TA': return IdentityToken.fromJson(data);
+            case 'OA': return IdentityOAuth.fromJson(data);
+            case 'CC': return IdentityCertificate.fromJson(data);
+            default: throw new Error(`Unknown identity type: ${(data as any).type}`);
+        }
     }
-  }
 }
 
-/**
- * No authentication
- */
-export class IdentityNone extends Identity {
-  readonly type = 'NA' as const;
-
-  static fromJson(_data: ServiceIdentityNone): IdentityNone {
-    return new IdentityNone();
-  }
-
-  toJson(): ServiceIdentityNone {
-    return {
-      type: this.type
-    };
-  }
+export class IdentityNone extends Identity<ServiceIdentityNone> {
+    constructor() { super({ type: 'NA' }); }
+    static fromJson(_data: ServiceIdentityNone): IdentityNone { return new IdentityNone(); }
+    clone(): IdentityNone { return IdentityNone.fromJson(this.toJson()); }
+    get type(): 'NA' { return this._data.type; }
 }
 
-/**
- * Basic authentication (username/password)
- */
-export class IdentityBasic extends Identity {
-  readonly type = 'BA' as const;
-  identity: string;
-  secret: string;
-
-  constructor(identity: string = '', secret: string = '') {
-    super();
-    this.identity = identity;
-    this.secret = secret;
-  }
-
-  static fromJson(data: ServiceIdentityBasic): IdentityBasic {
-    return new IdentityBasic(data.identity, data.secret);
-  }
-
-  toJson(): ServiceIdentityBasic {
-    return {
-      type: this.type,
-      identity: this.identity,
-      secret: this.secret
-    };
-  }
+export class IdentityBasic extends Identity<ServiceIdentityBasic> {
+    constructor(identity: string = '', secret: string = '') { super({ type: 'BA', identity, secret }); }
+    static fromJson(data: ServiceIdentityBasic): IdentityBasic { return new IdentityBasic().load(data); }
+    clone(): IdentityBasic { return IdentityBasic.fromJson(this.toJson()); }
+    get type(): 'BA' { return this._data.type; }
+    get identity(): string { return this._data.identity; }
+    set identity(value: string) { this._data.identity = value; }
+    get secret(): string { return this._data.secret; }
+    set secret(value: string) { this._data.secret = value; }
 }
 
-/**
- * Token authentication (API key, static token)
- */
-export class IdentityToken extends Identity {
-  readonly type = 'TA' as const;
-  token: string;
-
-  constructor(token: string = '') {
-    super();
-    this.token = token;
-  }
-
-  static fromJson(data: ServiceIdentityToken): IdentityToken {
-    return new IdentityToken(data.token);
-  }
-
-  toJson(): ServiceIdentityToken {
-    return {
-      type: this.type,
-      token: this.token
-    };
-  }
+export class IdentityToken extends Identity<ServiceIdentityToken> {
+    constructor(token: string = '') { super({ type: 'TA', token }); }
+    static fromJson(data: ServiceIdentityToken): IdentityToken { return new IdentityToken().load(data); }
+    clone(): IdentityToken { return IdentityToken.fromJson(this.toJson()); }
+    get type(): 'TA' { return this._data.type; }
+    get token(): string { return this._data.token; }
+    set token(value: string) { this._data.token = value; }
 }
 
-/**
- * OAuth authentication
- */
-export class IdentityOAuth extends Identity {
-  readonly type = 'OA' as const;
-  accessToken: string;
-  accessScope?: string[];
-  accessExpiry?: number;
-  refreshToken?: string;
-  refreshLocation?: string;
+export class IdentityOAuth extends Identity<ServiceIdentityOAuth> {
+    constructor(accessToken: string = '', accessScope?: string[], accessExpiry?: number, refreshToken?: string, refreshLocation?: string) {
+        super({ type: 'OA', accessToken, accessScope, accessExpiry, refreshToken, refreshLocation });
+    }
 
-  constructor(
-    accessToken: string = '',
-    accessScope?: string[],
-    accessExpiry?: number,
-    refreshToken?: string,
-    refreshLocation?: string
-  ) {
-    super();
-    this.accessToken = accessToken;
-    this.accessScope = accessScope;
-    this.accessExpiry = accessExpiry;
-    this.refreshToken = refreshToken;
-    this.refreshLocation = refreshLocation;
-  }
+    static fromJson(data: ServiceIdentityOAuth): IdentityOAuth { return new IdentityOAuth().load(data); }
+    clone(): IdentityOAuth { return IdentityOAuth.fromJson(this.toJson()); }
+    isExpired(): boolean { return this.accessExpiry ? Date.now() / 1000 >= this.accessExpiry : false; }
+    expiresIn(): number { return this.accessExpiry ? Math.max(0, this.accessExpiry - Date.now() / 1000) : Infinity; }
 
-  static fromJson(data: ServiceIdentityOAuth): IdentityOAuth {
-    return new IdentityOAuth(
-      data.accessToken,
-      data.accessScope,
-      data.accessExpiry,
-      data.refreshToken,
-      data.refreshLocation
-    );
-  }
-
-  toJson(): ServiceIdentityOAuth {
-    return {
-      type: this.type,
-      accessToken: this.accessToken,
-      ...(this.accessScope && { accessScope: this.accessScope }),
-      ...(this.accessExpiry && { accessExpiry: this.accessExpiry }),
-      ...(this.refreshToken && { refreshToken: this.refreshToken }),
-      ...(this.refreshLocation && { refreshLocation: this.refreshLocation })
-    };
-  }
-
-  isExpired(): boolean {
-    if (!this.accessExpiry) return false;
-    return Date.now() / 1000 >= this.accessExpiry;
-  }
-
-  expiresIn(): number {
-    if (!this.accessExpiry) return Infinity;
-    return Math.max(0, this.accessExpiry - Date.now() / 1000);
-  }
+    get type(): 'OA' { return this._data.type; }
+    get accessToken(): string { return this._data.accessToken; }
+    set accessToken(value: string) { this._data.accessToken = value; }
+    get accessScope(): string[] | undefined { return this._data.accessScope ? [...this._data.accessScope] : undefined; }
+    set accessScope(value: string[] | undefined) { this._data.accessScope = value ? [...value] : undefined; }
+    get accessExpiry(): number | undefined { return this._data.accessExpiry; }
+    set accessExpiry(value: number | undefined) { this._data.accessExpiry = value; }
+    get refreshToken(): string | undefined { return this._data.refreshToken; }
+    set refreshToken(value: string | undefined) { this._data.refreshToken = value; }
+    get refreshLocation(): string | undefined { return this._data.refreshLocation; }
+    set refreshLocation(value: string | undefined) { this._data.refreshLocation = value; }
 }
 
-/**
- * Client certificate authentication (mTLS)
- */
-export class IdentityCertificate extends Identity {
-  readonly type = 'CC' as const;
-  certificate: string;
-  privateKey: string;
-  passphrase?: string;
+export class IdentityCertificate extends Identity<ServiceIdentityCertificate> {
+    constructor(certificate: string = '', privateKey: string = '', passphrase?: string) {
+        super({ type: 'CC', certificate, privateKey, passphrase });
+    }
 
-  constructor(certificate: string = '', privateKey: string = '', passphrase?: string) {
-    super();
-    this.certificate = certificate;
-    this.privateKey = privateKey;
-    this.passphrase = passphrase;
-  }
-
-  static fromJson(data: ServiceIdentityCertificate): IdentityCertificate {
-    return new IdentityCertificate(
-      data.certificate,
-      data.privateKey,
-      data.passphrase
-    );
-  }
-
-  toJson(): ServiceIdentityCertificate {
-    return {
-      type: this.type,
-      certificate: this.certificate,
-      privateKey: this.privateKey,
-      ...(this.passphrase && { passphrase: this.passphrase })
-    };
-  }
+    static fromJson(data: ServiceIdentityCertificate): IdentityCertificate { return new IdentityCertificate().load(data); }
+    clone(): IdentityCertificate { return IdentityCertificate.fromJson(this.toJson()); }
+    get type(): 'CC' { return this._data.type; }
+    get certificate(): string { return this._data.certificate; }
+    set certificate(value: string) { this._data.certificate = value; }
+    get privateKey(): string { return this._data.privateKey; }
+    set privateKey(value: string) { this._data.privateKey = value; }
+    get passphrase(): string | undefined { return this._data.passphrase; }
+    set passphrase(value: string | undefined) { this._data.passphrase = value; }
 }
diff --git a/src/models/index.ts b/src/models/index.ts
index ededa2d..85e1e87 100644
--- a/src/models/index.ts
+++ b/src/models/index.ts
@@ -1,6 +1,6 @@
 export { ProviderObject } from './provider';
 export { ServiceObject } from './service';
-export { CollectionObject } from './collection';
+export { CollectionObject, CollectionPropertiesObject } from './collection';
 export { EntityObject } from './entity';
 export { EventObject } from './event';
 export { TaskObject } from './task';
@@ -16,7 +16,6 @@ export {
 export {
   Location,
   LocationUri,
-  LocationSocketSole,
-  LocationSocketSplit,
   LocationFile
 } from './location';
+export { MutationProxy } from './mutation-proxy';
diff --git a/src/models/location.ts b/src/models/location.ts
index 7e19cce..80a87ab 100644
--- a/src/models/location.ts
+++ b/src/models/location.ts
@@ -1,240 +1,91 @@
 /**
- * Location implementation classes for Mail Manager services
+ * Location models for Chrono Manager services
  */
 
-import type {
-  ServiceLocation,
-  ServiceLocationUri,
-  ServiceLocationSocketSole,
-  ServiceLocationSocketSplit,
-  ServiceLocationFile
-} from '@/types/service';
+import type { ServiceLocation, ServiceLocationFile, ServiceLocationUri } from '@/types/service';
+import { clonePlain } from './clone-plain';
+import { MutationProxy } from './mutation-proxy';
 
-/**
- * Base Location class
- */
-export abstract class Location {
-  abstract toJson(): ServiceLocation;
-  
-  static fromJson(data: ServiceLocation): Location {
-    switch (data.type) {
-      case 'URI':
-        return LocationUri.fromJson(data);
-      case 'SOCKET_SOLE':
-        return LocationSocketSole.fromJson(data);
-      case 'SOCKET_SPLIT':
-        return LocationSocketSplit.fromJson(data);
-      case 'FILE':
-        return LocationFile.fromJson(data);
-      default:
-        throw new Error(`Unknown location type: ${(data as any).type}`);
+export abstract class Location<T extends ServiceLocation = ServiceLocation> {
+    protected _original: T;
+    protected _mutated: Partial<T>;
+    protected _mutationProxy: MutationProxy<T>;
+    protected _data: T;
+
+    protected constructor(initial: T) {
+        this._original = clonePlain(initial);
+        this._mutated = {};
+        this._mutationProxy = new MutationProxy<T>(() => this._original, () => this._mutated);
+        this._data = this._mutationProxy.create();
+    }
+
+    protected load(data: T): this {
+        this._original = clonePlain(data);
+        this._mutated = {};
+        this._data = this._mutationProxy.create();
+        return this;
+    }
+
+    toJson(): T;
+    toJson(delta: true): Partial<T>;
+    toJson(delta?: boolean): T | Partial<T> {
+        return delta
+            ? clonePlain(this._mutated)
+            : { ...clonePlain(this._original), ...clonePlain(this._mutated) };
+    }
+
+    abstract clone(): Location;
+
+    mutated(): boolean {
+        return Reflect.ownKeys(this._mutated).length > 0;
+    }
+
+    static fromJson(data: ServiceLocation): Location {
+        switch (data.type) {
+            case 'URI': return LocationUri.fromJson(data);
+            case 'FILE': return LocationFile.fromJson(data);
+            default: throw new Error(`Unknown location type: ${(data as any).type}`);
+        }
     }
-  }
 }
 
-/**
- * URI-based service location for API and web services
- * Used by: JMAP, Gmail API, etc.
- */
-export class LocationUri extends Location {
-  readonly type = 'URI' as const;
-  scheme: string;
-  host: string;
-  port: number;
-  path?: string;
-  verifyPeer: boolean;
-  verifyHost: boolean;
+export class LocationUri extends Location<ServiceLocationUri> {
+    constructor(
+        scheme: string = 'https',
+        host: string = '',
+        port: number = 443,
+        path?: string,
+        verifyPeer: boolean = true,
+        verifyHost: boolean = true
+    ) {
+        super({ type: 'URI', scheme, host, port, ...(path !== undefined && { path }), verifyPeer, verifyHost });
+    }
 
-  constructor(
-    scheme: string = 'https',
-    host: string = '',
-    port: number = 443,
-    path?: string,
-    verifyPeer: boolean = true,
-    verifyHost: boolean = true
-  ) {
-    super();
-    this.scheme = scheme;
-    this.host = host;
-    this.port = port;
-    this.path = path;
-    this.verifyPeer = verifyPeer;
-    this.verifyHost = verifyHost;
-  }
+    static fromJson(data: ServiceLocationUri): LocationUri { return new LocationUri().load(data); }
+    clone(): LocationUri { return LocationUri.fromJson(this.toJson()); }
+    getUrl(): string { return `${this.scheme}://${this.host}:${this.port}${this.path || ''}`; }
 
-  static fromJson(data: ServiceLocationUri): LocationUri {
-    return new LocationUri(
-      data.scheme,
-      data.host,
-      data.port,
-      data.path,
-      data.verifyPeer ?? true,
-      data.verifyHost ?? true
-    );
-  }
-
-  toJson(): ServiceLocationUri {
-    return {
-      type: this.type,
-      scheme: this.scheme,
-      host: this.host,
-      port: this.port,
-      ...(this.path && { path: this.path }),
-      ...(this.verifyPeer !== undefined && { verifyPeer: this.verifyPeer }),
-      ...(this.verifyHost !== undefined && { verifyHost: this.verifyHost })
-    };
-  }
-
-  getUrl(): string {
-    const path = this.path || '';
-    return `${this.scheme}://${this.host}:${this.port}${path}`;
-  }
+    get type(): 'URI' { return this._data.type; }
+    get scheme(): string { return this._data.scheme; }
+    set scheme(value: string) { this._data.scheme = value; }
+    get host(): string { return this._data.host; }
+    set host(value: string) { this._data.host = value; }
+    get port(): number { return this._data.port; }
+    set port(value: number) { this._data.port = value; }
+    get path(): string | undefined { return this._data.path; }
+    set path(value: string | undefined) { this._data.path = value; }
+    get verifyPeer(): boolean { return this._data.verifyPeer ?? true; }
+    set verifyPeer(value: boolean) { this._data.verifyPeer = value; }
+    get verifyHost(): boolean { return this._data.verifyHost ?? true; }
+    set verifyHost(value: boolean) { this._data.verifyHost = value; }
 }
 
-/**
- * Single socket-based service location
- * Used by: services using a single host/port combination
- */
-export class LocationSocketSole extends Location {
-  readonly type = 'SOCKET_SOLE' as const;
-  host: string;
-  port: number;
-  encryption: 'none' | 'ssl' | 'tls' | 'starttls';
-  verifyPeer: boolean;
-  verifyHost: boolean;
+export class LocationFile extends Location<ServiceLocationFile> {
+    constructor(path: string = '') { super({ type: 'FILE', path }); }
+    static fromJson(data: ServiceLocationFile): LocationFile { return new LocationFile().load(data); }
+    clone(): LocationFile { return LocationFile.fromJson(this.toJson()); }
 
-  constructor(
-    host: string = '',
-    port: number = 993,
-    encryption: 'none' | 'ssl' | 'tls' | 'starttls' = 'ssl',
-    verifyPeer: boolean = true,
-    verifyHost: boolean = true
-  ) {
-    super();
-    this.host = host;
-    this.port = port;
-    this.encryption = encryption;
-    this.verifyPeer = verifyPeer;
-    this.verifyHost = verifyHost;
-  }
-
-  static fromJson(data: ServiceLocationSocketSole): LocationSocketSole {
-    return new LocationSocketSole(
-      data.host,
-      data.port,
-      data.encryption,
-      data.verifyPeer ?? true,
-      data.verifyHost ?? true
-    );
-  }
-
-  toJson(): ServiceLocationSocketSole {
-    return {
-      type: this.type,
-      host: this.host,
-      port: this.port,
-      encryption: this.encryption,
-      ...(this.verifyPeer !== undefined && { verifyPeer: this.verifyPeer }),
-      ...(this.verifyHost !== undefined && { verifyHost: this.verifyHost })
-    };
-  }
-}
-
-/**
- * Split socket-based service location
- * Used by: traditional IMAP/SMTP configurations
- */
-export class LocationSocketSplit extends Location {
-  readonly type = 'SOCKET_SPLIT' as const;
-  inboundHost: string;
-  inboundPort: number;
-  inboundEncryption: 'none' | 'ssl' | 'tls' | 'starttls';
-  outboundHost: string;
-  outboundPort: number;
-  outboundEncryption: 'none' | 'ssl' | 'tls' | 'starttls';
-  inboundVerifyPeer: boolean;
-  inboundVerifyHost: boolean;
-  outboundVerifyPeer: boolean;
-  outboundVerifyHost: boolean;
-
-  constructor(
-    inboundHost: string = '',
-    inboundPort: number = 993,
-    inboundEncryption: 'none' | 'ssl' | 'tls' | 'starttls' = 'ssl',
-    outboundHost: string = '',
-    outboundPort: number = 465,
-    outboundEncryption: 'none' | 'ssl' | 'tls' | 'starttls' = 'ssl',
-    inboundVerifyPeer: boolean = true,
-    inboundVerifyHost: boolean = true,
-    outboundVerifyPeer: boolean = true,
-    outboundVerifyHost: boolean = true
-  ) {
-    super();
-    this.inboundHost = inboundHost;
-    this.inboundPort = inboundPort;
-    this.inboundEncryption = inboundEncryption;
-    this.outboundHost = outboundHost;
-    this.outboundPort = outboundPort;
-    this.outboundEncryption = outboundEncryption;
-    this.inboundVerifyPeer = inboundVerifyPeer;
-    this.inboundVerifyHost = inboundVerifyHost;
-    this.outboundVerifyPeer = outboundVerifyPeer;
-    this.outboundVerifyHost = outboundVerifyHost;
-  }
-
-  static fromJson(data: ServiceLocationSocketSplit): LocationSocketSplit {
-    return new LocationSocketSplit(
-      data.inboundHost,
-      data.inboundPort,
-      data.inboundEncryption,
-      data.outboundHost,
-      data.outboundPort,
-      data.outboundEncryption,
-      data.inboundVerifyPeer ?? true,
-      data.inboundVerifyHost ?? true,
-      data.outboundVerifyPeer ?? true,
-      data.outboundVerifyHost ?? true
-    );
-  }
-
-  toJson(): ServiceLocationSocketSplit {
-    return {
-      type: this.type,
-      inboundHost: this.inboundHost,
-      inboundPort: this.inboundPort,
-      inboundEncryption: this.inboundEncryption,
-      outboundHost: this.outboundHost,
-      outboundPort: this.outboundPort,
-      outboundEncryption: this.outboundEncryption,
-      ...(this.inboundVerifyPeer !== undefined && { inboundVerifyPeer: this.inboundVerifyPeer }),
-      ...(this.inboundVerifyHost !== undefined && { inboundVerifyHost: this.inboundVerifyHost }),
-      ...(this.outboundVerifyPeer !== undefined && { outboundVerifyPeer: this.outboundVerifyPeer }),
-      ...(this.outboundVerifyHost !== undefined && { outboundVerifyHost: this.outboundVerifyHost })
-    };
-  }
-}
-
-/**
- * File-based service location
- * Used by: local file system providers
- */
-export class LocationFile extends Location {
-  readonly type = 'FILE' as const;
-  path: string;
-
-  constructor(path: string = '') {
-    super();
-    this.path = path;
-  }
-
-  static fromJson(data: ServiceLocationFile): LocationFile {
-    return new LocationFile(data.path);
-  }
-
-  toJson(): ServiceLocationFile {
-    return {
-      type: this.type,
-      path: this.path
-    };
-  }
+    get type(): 'FILE' { return this._data.type; }
+    get path(): string { return this._data.path; }
+    set path(value: string) { this._data.path = value; }
 }
diff --git a/src/models/mutation-proxy.ts b/src/models/mutation-proxy.ts
new file mode 100644
index 0000000..a91fb8c
--- /dev/null
+++ b/src/models/mutation-proxy.ts
@@ -0,0 +1,36 @@
+import { clonePlain } from './clone-plain';
+
+export class MutationProxy<T extends object> {
+    constructor(
+        private readonly getOriginal: () => T,
+        private readonly getMutated: () => Partial<T>,
+    ) {}
+
+    create(): T {
+        return new Proxy({} as T, {
+            get: (_target, prop: string | symbol) => {
+                if (typeof prop !== 'string') return undefined;
+
+                const key = prop as keyof T;
+                const mutated = this.getMutated();
+                return key in mutated ? mutated[key] : this.getOriginal()[key];
+            },
+            set: (_target, prop: string | symbol, value: unknown) => {
+                if (typeof prop === 'string') {
+                    const key = prop as keyof T;
+                    (this.getMutated() as Record<keyof T, unknown>)[key] = clonePlain(value);
+                }
+                return true;
+            },
+            has: (_target, prop: string | symbol) => {
+                if (typeof prop !== 'string') return false;
+                return prop in this.getMutated() || prop in this.getOriginal();
+            },
+            ownKeys: () => Array.from(new Set([
+                ...Reflect.ownKeys(this.getOriginal()),
+                ...Reflect.ownKeys(this.getMutated()),
+            ])),
+            getOwnPropertyDescriptor: () => ({ enumerable: true, configurable: true }),
+        });
+    }
+}
diff --git a/src/models/provider.ts b/src/models/provider.ts
index 0b223f8..85579d4 100644
--- a/src/models/provider.ts
+++ b/src/models/provider.ts
@@ -4,10 +4,12 @@
 
 import type { 
     ProviderInterface,
-    ProviderCapabilitiesInterface
+    ProviderCapabilitiesInterface,
+    ProviderModelInterface
 } from "@/types/provider";
+import { clonePlain } from './clone-plain';
 
-export class ProviderObject implements ProviderInterface {
+export class ProviderObject implements ProviderModelInterface {
 
     _data!: ProviderInterface;
 
@@ -21,12 +23,16 @@ export class ProviderObject implements ProviderInterface {
     }
 
     fromJson(data: ProviderInterface): ProviderObject {
-        this._data = data;
+        this._data = clonePlain(data);
         return this;
     }
 
     toJson(): ProviderInterface {
-        return this._data;
+        return clonePlain(this._data);
+    }
+
+    clone(): ProviderObject {
+        return new ProviderObject().fromJson(this.toJson());
     }
 
     capable(capability: keyof ProviderCapabilitiesInterface): boolean {
@@ -43,10 +49,6 @@ export class ProviderObject implements ProviderInterface {
 
     /** Immutable Properties */
 
-    get '@type'(): string {
-        return this._data['@type'];
-    }
-
     get identifier(): string {
         return this._data.identifier;
     }
@@ -56,7 +58,7 @@ export class ProviderObject implements ProviderInterface {
     }
 
     get capabilities(): ProviderCapabilitiesInterface {
-        return this._data.capabilities;
+        return clonePlain(this._data.capabilities);
     }
 
 }
diff --git a/src/models/service.ts b/src/models/service.ts
index e6e2609..af265cb 100644
--- a/src/models/service.ts
+++ b/src/models/service.ts
@@ -5,18 +5,26 @@
 import type {
     ServiceInterface,
     ServiceCapabilitiesInterface,
-    ServiceIdentity,
-    ServiceLocation
+    ServiceLocation,
+    ServiceModelInterface
 } from "@/types/service";
 import { Identity } from './identity';
 import { Location } from './location';
+import { MutationProxy } from './mutation-proxy';
+import { clonePlain } from './clone-plain';
 
-export class ServiceObject implements ServiceInterface {
-
+export class ServiceObject implements ServiceModelInterface {
+    private _original: ServiceInterface;
+    private _mutated: Partial<ServiceInterface>;
+    private _mutationProxy = new MutationProxy<ServiceInterface>(() => this._original, () => this._mutated);
     _data!: ServiceInterface;
+    private _location: Location | null | undefined = undefined;
+    private _identity: Identity | null | undefined = undefined;
+    private _locationAssigned = false;
+    private _identityAssigned = false;
 
     constructor() {
-        this._data = {
+        this._original = {
             '@type': 'chrono:service',
             provider: '',
             identifier: null,
@@ -24,15 +32,59 @@ export class ServiceObject implements ServiceInterface {
             enabled: false,
             capabilities: {}
         };
+        this._mutated = {};
+        this._data = this._mutationProxy.create();
     }
 
     fromJson(data: ServiceInterface): ServiceObject {
-        this._data = data;
+        this._original = clonePlain(data);
+        this._mutated = {};
+        this._data = this._mutationProxy.create();
+        this._location = undefined;
+        this._identity = undefined;
+        this._locationAssigned = false;
+        this._identityAssigned = false;
         return this;
     }
 
-    toJson(): ServiceInterface {
-        return this._data;
+    toJson(): ServiceInterface;
+    toJson(delta: true): Partial<ServiceInterface>;
+    toJson(delta?: boolean): ServiceInterface | Partial<ServiceInterface> {
+        if (delta) {
+            const json = clonePlain(this._mutated);
+            if (this._locationAssigned) {
+                json.location = this._location ? this._location.toJson() : null;
+            } else if (this._location?.mutated()) {
+                json.location = this._location.toJson(true) as ServiceInterface['location'];
+            }
+
+            if (this._identityAssigned) {
+                json.identity = this._identity ? this._identity.toJson() : null;
+            } else if (this._identity?.mutated()) {
+                json.identity = this._identity.toJson(true) as ServiceInterface['identity'];
+            }
+            return json;
+        }
+
+        const json: ServiceInterface = {
+            ...clonePlain(this._original),
+            ...clonePlain(this._mutated),
+        };
+        if (this._location !== undefined) json.location = this._location ? this._location.toJson() : null;
+        if (this._identity !== undefined) json.identity = this._identity ? this._identity.toJson() : null;
+        return json;
+    }
+
+    clone(): ServiceObject {
+        return new ServiceObject().fromJson(this.toJson());
+    }
+
+    mutated(): boolean {
+        return Reflect.ownKeys(this._mutated).length > 0
+            || this._locationAssigned
+            || this._identityAssigned
+            || (this._location?.mutated() ?? false)
+            || (this._identity?.mutated() ?? false);
     }
 
     capable(capability: keyof ServiceCapabilitiesInterface): boolean {
@@ -41,88 +93,41 @@ export class ServiceObject implements ServiceInterface {
     }
 
     capability(capability: keyof ServiceCapabilitiesInterface): any | null {
-        if (this._data.capabilities) {
-            return this._data.capabilities[capability];
-        }
-        return null;
+        return this._data.capabilities?.[capability] ?? null;
     }
 
-    /** Immutable Properties */
+    get provider(): string { return this._data.provider; }
+    get identifier(): string | number | null { return this._data.identifier; }
+    get capabilities(): ServiceCapabilitiesInterface { return this._data.capabilities ?? {}; }
 
-    get '@type'(): string {
-        return this._data['@type'];
+    get label(): string | null { return this._data.label; }
+    set label(value: string | null) { this._data.label = value; }
+
+    get enabled(): boolean { return this._data.enabled; }
+    set enabled(value: boolean) { this._data.enabled = value; }
+
+    get location(): Location | null {
+        if (this._location !== undefined) return this._location;
+        this._location = this._data.location ? Location.fromJson(this._data.location as ServiceLocation) : null;
+        return this._location;
     }
 
-    get provider(): string {
-        return this._data.provider;
+    set location(value: Location | null) {
+        this._location = value;
+        this._locationAssigned = true;
     }
 
-    get identifier(): string | number | null {
-        return this._data.identifier;
+    get identity(): Identity | null {
+        if (this._identity !== undefined) return this._identity;
+        this._identity = this._data.identity ? Identity.fromJson(this._data.identity) : null;
+        return this._identity;
     }
 
-    get capabilities(): ServiceCapabilitiesInterface | undefined {
-        return this._data.capabilities;
-    }
-
-    /** Mutable Properties */
-
-    get label(): string | null {
-        return this._data.label;
-    }
-
-    set label(value: string | null) {
-        this._data.label = value;
-    }
-
-    get enabled(): boolean {
-        return this._data.enabled;
-    }
-
-    set enabled(value: boolean) {
-        this._data.enabled = value;
-    }
-
-    get location(): ServiceLocation | null {
-        return this._data.location ?? null;
-    }
-
-    set location(value: ServiceLocation | null) {
-        this._data.location = value;
-    }
-
-    get identity(): ServiceIdentity | null {
-        return this._data.identity ?? null;
-    }
-
-    set identity(value: ServiceIdentity | null) {
-        this._data.identity = value;
-    }
-
-    get auxiliary(): Record<string, any> {
-        return this._data.auxiliary ?? {};
-    }
-    
-    set auxiliary(value: Record<string, any>) {
-        this._data.auxiliary = value;
-    }
-
-    /** Helper Methods */
-
-    /**
-     * Get identity as a class instance for easier manipulation
-     */
-    getIdentity(): Identity | null {
-        if (!this._data.identity) return null;
-        return Identity.fromJson(this._data.identity);
-    }
-
-    /**
-     * Get location as a class instance for easier manipulation
-     */
-    getLocation(): Location | null {
-        if (!this._data.location) return null;
-        return Location.fromJson(this._data.location);
+    set identity(value: Identity | null) {
+        this._identity = value;
+        this._identityAssigned = true;
     }
 
+    get auxiliary(): Record<string, any> { return this._data.auxiliary ?? {}; }
+    set auxiliary(value: Record<string, any>) { this._data.auxiliary = value; }
 }
diff --git a/src/services/collectionService.ts b/src/services/collectionService.ts
index c91f5c0..817c020 100644
--- a/src/services/collectionService.ts
+++ b/src/services/collectionService.ts
@@ -70,9 +70,15 @@ export const collectionService = {
    * 
    * @returns Promise with collection object
    */
-  async fetch(request: CollectionFetchRequest): Promise<CollectionObject> {
+  async fetch(request: CollectionFetchRequest): Promise<Record<string, CollectionObject>> {
     const response = await transceivePost<CollectionFetchRequest, CollectionFetchResponse>('collection.fetch', request);
-    return createCollectionObject(response);
+
+    const list: Record<string, CollectionObject> = {};
+    Object.entries(response).forEach(([, collection]) => {
+      list[collection.identifier] = createCollectionObject(collection);
+    });
+
+    return list;
   },
 
   /**
@@ -123,8 +129,14 @@ export const collectionService = {
    * 
    * @returns Promise with deletion result
    */
-  async delete(request: CollectionDeleteRequest): Promise<CollectionDeleteResponse> {
-    return await transceivePost<CollectionDeleteRequest, CollectionDeleteResponse>('collection.delete', request);
+  async delete(request: CollectionDeleteRequest): Promise<boolean | CollectionObject> {
+    const response = await transceivePost<CollectionDeleteRequest, CollectionDeleteResponse>('collection.delete', request);
+
+    if (response.disposition === 'moved' && response.mutation) {
+      return createCollectionObject(response.mutation);
+    }
+
+    return true;
   },
 };
 
diff --git a/src/services/entityService.ts b/src/services/entityService.ts
index f69051b..3518696 100644
--- a/src/services/entityService.ts
+++ b/src/services/entityService.ts
@@ -2,10 +2,12 @@
  * Entity management service
  */
 
-import { transceivePost } from './transceive';
+import { transceivePost, transceiveStream } from './transceive';
 import type {
-  EntityListRequest,
-  EntityListResponse,
+  EntityListBulkRequest,
+  EntityListBulkResponse,
+  EntityListStreamRequest,
+  EntityListStreamResponse,
   EntityFetchRequest,
   EntityFetchResponse,
   EntityExtantRequest,
@@ -18,6 +20,8 @@ import type {
   EntityDeleteResponse,
   EntityDeltaRequest,
   EntityDeltaResponse,
+  EntityMoveRequest,
+  EntityMoveResponse,
   EntityInterface,
 } from '../types/entity';
 import { useIntegrationStore } from '@KTXC/stores/integrationStore';
@@ -31,7 +35,7 @@ function createEntityObject(data: EntityInterface): EntityObject {
   const integrationStore = useIntegrationStore();
   const factoryItem = integrationStore.getItemById('chrono_entity_factory', data.provider) as any;
   const factory = factoryItem?.factory;
-  
+
   // Use provider factory if available, otherwise base class
   return factory ? factory(data) : new EntityObject().fromJson(data);
 }
@@ -39,16 +43,11 @@ function createEntityObject(data: EntityInterface): EntityObject {
 export const entityService = {
 
   /**
-   * Retrieve list of entities, optionally filtered by source selector
-   * 
-   * @param request - list request parameters
-   * 
-   * @returns Promise with entity object list grouped by provider, service, collection, and entity identifier
+   * Retrieve list of entities, optionally filtered by source collection identifiers
    */
-  async list(request: EntityListRequest = {}): Promise<Record<string, Record<string, Record<string, Record<string, EntityObject>>>>> {
-    const response = await transceivePost<EntityListRequest, EntityListResponse>('entity.list', request);
-    
-    // Convert nested response to EntityObject instances
+  async listBulk(request: EntityListBulkRequest = {}): Promise<Record<string, Record<string, Record<string, Record<string, EntityObject>>>>> {
+    const response = await transceivePost<EntityListBulkRequest, EntityListBulkResponse>('entity.listBulk', request);
+
     const providerList: Record<string, Record<string, Record<string, Record<string, EntityObject>>>> = {};
     Object.entries(response).forEach(([providerId, providerServices]) => {
       const serviceList: Record<string, Record<string, Record<string, EntityObject>>> = {};
@@ -65,35 +64,39 @@ export const entityService = {
       });
       providerList[providerId] = serviceList;
     });
-    
+
     return providerList;
   },
 
   /**
-   * Retrieve a specific entity by provider and identifier
-   * 
-   * @param request - fetch request parameters
-   * 
-   * @returns Promise with entity objects keyed by identifier
+   * Stream entities as NDJSON, invoking onEntity for each entity as it arrives.
+   */
+  async listStream(request: EntityListStreamRequest, onEntity: (entity: EntityObject) => void): Promise<{ total: number }> {
+    return await transceiveStream<EntityListStreamRequest, EntityListStreamResponse>(
+      'entity.listStream',
+      request,
+      (entity) => {
+        onEntity(createEntityObject(entity));
+      }
+    );
+  },
+
+  /**
+   * Retrieve specific entities by their identifiers
    */
   async fetch(request: EntityFetchRequest): Promise<Record<string, EntityObject>> {
     const response = await transceivePost<EntityFetchRequest, EntityFetchResponse>('entity.fetch', request);
-    
-    // Convert response to EntityObject instances
+
     const list: Record<string, EntityObject> = {};
-    Object.entries(response).forEach(([identifier, entityData]) => {
-      list[identifier] = createEntityObject(entityData);
+    Object.entries(response).forEach(([, entity]) => {
+      list[entity.identifier] = createEntityObject(entity);
     });
-    
+
     return list;
   },
 
   /**
-   * Retrieve entity availability status for a given source selector
-   * 
-   * @param request - extant request parameters
-   * 
-   * @returns Promise with entity availability status
+   * Retrieve entity availability status for a given set of entity identifiers
    */
   async extant(request: EntityExtantRequest): Promise<EntityExtantResponse> {
     return await transceivePost<EntityExtantRequest, EntityExtantResponse>('entity.extant', request);
@@ -101,10 +104,6 @@ export const entityService = {
 
   /**
    * Create a new entity
-   * 
-   * @param request - create request parameters
-   * 
-   * @returns Promise with created entity object
    */
   async create(request: EntityCreateRequest): Promise<EntityObject> {
     const response = await transceivePost<EntityCreateRequest, EntityCreateResponse>('entity.create', request);
@@ -113,10 +112,6 @@ export const entityService = {
 
   /**
    * Update an existing entity
-   * 
-   * @param request - update request parameters
-   * 
-   * @returns Promise with updated entity object
    */
   async update(request: EntityUpdateRequest): Promise<EntityObject> {
     const response = await transceivePost<EntityUpdateRequest, EntityUpdateResponse>('entity.update', request);
@@ -124,11 +119,7 @@ export const entityService = {
   },
 
   /**
-   * Delete an entity
-   * 
-   * @param request - delete request parameters
-   * 
-   * @returns Promise with deletion result
+   * Delete entities by their identifiers
    */
   async delete(request: EntityDeleteRequest): Promise<EntityDeleteResponse> {
     return await transceivePost<EntityDeleteRequest, EntityDeleteResponse>('entity.delete', request);
@@ -136,15 +127,18 @@ export const entityService = {
 
   /**
    * Retrieve delta changes for entities
-   * 
-   * @param request - delta request parameters
-   * 
-   * @returns Promise with delta changes (created, modified, deleted)
    */
   async delta(request: EntityDeltaRequest): Promise<EntityDeltaResponse> {
     return await transceivePost<EntityDeltaRequest, EntityDeltaResponse>('entity.delta', request);
   },
 
+  /**
+   * Move entities to a target collection
+   */
+  async move(request: EntityMoveRequest): Promise<EntityMoveResponse> {
+    return await transceivePost<EntityMoveRequest, EntityMoveResponse>('entity.move', request);
+  },
+
 };
 
 export default entityService;
diff --git a/src/services/transceive.ts b/src/services/transceive.ts
index 98d3f67..bde52a3 100644
--- a/src/services/transceive.ts
+++ b/src/services/transceive.ts
@@ -4,7 +4,7 @@
  */
 
 import { createFetchWrapper } from '@KTXC';
-import type { ApiRequest, ApiResponse } from '../types/common';
+import type { ApiRequest, ApiResponse, ApiStreamResponse } from '../types/common';
 
 const fetchWrapper = createFetchWrapper();
 const API_URL = '/m/chrono_manager/v1';
@@ -48,3 +48,82 @@ export async function transceivePost<TRequest, TResponse>(
   
   return response.data;
 }
+
+/**
+ * Stream an NDJSON API response, unwrapping data frames for the caller.
+ *
+ * @param operation - Operation name, e.g. 'entity.listStream'
+ * @param data      - Operation-specific request data
+ * @param onData    - Synchronous callback invoked for every unwrapped data payload.
+ * @param options   - Optional `user` override and an `onStart` hook.
+ * @returns Promise resolving to the final stream total from the control/end frame
+ */
+export async function transceiveStream<TRequest, TData>(
+  operation: string,
+  data: TRequest,
+  onData: (data: TData) => void,
+  options?: { user?: string; onStart?: (expected?: number) => void }
+): Promise<{ total: number }> {
+  const request: ApiRequest<TRequest> = {
+    version: API_VERSION,
+    transaction: generateTransactionId(),
+    operation,
+    data,
+    user: options?.user,
+  };
+
+  let total = 0;
+
+  const dispatch = (line: string): void => {
+    const message = JSON.parse(line) as ApiStreamResponse<TData>;
+
+    if (message.type === 'control') {
+      if (message.status === 'start') {
+        options?.onStart?.(message.total);
+      } else if (message.status === 'end') {
+        total = message.total;
+      }
+      return;
+    }
+
+    if (message.type === 'error') {
+      throw new Error(`[${operation}] ${message.message}`);
+    }
+
+    onData(message.data);
+  };
+
+  await fetchWrapper.post(API_URL, request, {
+    headers: { 'Accept': 'application/json' },
+    onStream: async (response: Response) => {
+      if (!response.body) {
+        throw new Error(`[${operation}] Response body is not readable`);
+      }
+
+      const reader = response.body.getReader();
+      const decoder = new TextDecoder();
+      let buffer = '';
+
+      try {
+        while (true) {
+          const { done, value } = await reader.read();
+          if (done) break;
+
+          buffer += decoder.decode(value, { stream: true });
+          const lines = buffer.split('\n');
+          buffer = lines.pop()!;
+
+          for (const line of lines) {
+            if (line.trim()) dispatch(line);
+          }
+        }
+
+        if (buffer.trim()) dispatch(buffer);
+      } finally {
+        reader.releaseLock();
+      }
+    },
+  });
+
+  return { total };
+}
diff --git a/src/stores/collectionsStore.ts b/src/stores/collectionsStore.ts
index 6835f53..9b6b517 100644
--- a/src/stores/collectionsStore.ts
+++ b/src/stores/collectionsStore.ts
@@ -4,9 +4,14 @@
 
 import { ref, computed, readonly } from 'vue'
 import { defineStore } from 'pinia'
+import {
+  type ServiceIdentifier,
+  type CollectionIdentifier,
+  type ListFilter,
+  type ListSort,
+} from '../types'
 import { collectionService } from '../services'
 import { CollectionObject, CollectionPropertiesObject } from '../models/collection'
-import type { SourceSelector, ListFilter, ListSort } from '../types'
 
 export const useCollectionsStore = defineStore('chronoCollectionsStore', () => {
   // State
@@ -33,101 +38,61 @@ export const useCollectionsStore = defineStore('chronoCollectionsStore', () => {
    */
   const collectionsByService = computed(() => {
     const groups: Record<string, CollectionObject[]> = {}
-    
+
     Object.values(_collections.value).forEach((collection) => {
       const serviceKey = `${collection.provider}:${collection.service}`
-      if (!groups[serviceKey]) {
-        groups[serviceKey] = []
-      }
-      groups[serviceKey].push(collection)
+      const serviceCollections = (groups[serviceKey] ??= [])
+      serviceCollections.push(collection)
     })
-    
+
     return groups
   })
 
   /**
    * Get a specific collection from store, with optional retrieval
-   * 
-   * @param provider - provider identifier
-   * @param service - service identifier
-   * @param identifier - collection identifier
-   * @param retrieve - Retrieve behavior: true = fetch if missing or refresh, false = cache only
-   * 
-   * @returns Collection object or null
    */
-  function collection(provider: string, service: string | number, identifier: string | number, retrieve: boolean = false): CollectionObject | null {
-    const key = identifierKey(provider, service, identifier)
-    if (retrieve === true && !_collections.value[key]) {
-      console.debug(`[Chrono Manager][Store] - Force fetching collection "${key}"`)
-      fetch(provider, service, identifier)
+  function collection(target: CollectionIdentifier, retrieve: boolean = false): CollectionObject | null {
+    if (retrieve === true && !_collections.value[target]) {
+      console.debug(`[Chrono Manager][Store] - Force fetching collection "${target}"`)
+      fetch([target])
     }
-    
-    return _collections.value[key] || null
+
+    return _collections.value[target] || null
   }
 
   /**
    * Get all collections for a specific service
-   * 
-   * @param provider - provider identifier
-   * @param service - service identifier
-   * @param retrieve - Retrieve behavior: true = fetch if missing or refresh, false = cache only
-   * 
-   * @returns Array of collection objects
    */
   function collectionsForService(provider: string, service: string | number, retrieve: boolean = false): CollectionObject[] {
-    const serviceKeyPrefix = `${provider}:${service}:`
-    const serviceCollections = Object.entries(_collections.value)
-      .filter(([key]) => key.startsWith(serviceKeyPrefix))
-      .map(([_, collection]) => collection)
-    
+    const serviceIdentifier = `${provider}:${service}` as ServiceIdentifier
+    const serviceCollections = Object.values(_collections.value)
+      .filter(collection => `${collection.provider}:${collection.service}` === serviceIdentifier)
+
     if (retrieve === true && serviceCollections.length === 0) {
-      console.debug(`[Chrono Manager][Store] - Force fetching collections for service "${provider}:${service}"`)
-      const sources: SourceSelector = {
-        [provider]: {
-          [String(service)]: true
-        }
-      }
-      list(sources)
+      console.debug(`[Chrono Manager][Store] - Force fetching collections for service "${serviceIdentifier}"`)
+      list([serviceIdentifier])
     }
-    
+
     return serviceCollections
   }
 
   /**
-   * Create unique key for a collection
+   * Retrieve all or specific collections, optionally filtered by service/collection identifiers
    */
-  function identifierKey(provider: string, service: string | number | null, identifier: string | number | null): string {
-    return `${provider}:${service ?? ''}:${identifier ?? ''}`
-  }
-
-  // Actions
-  
-  /**
-   * Retrieve all or specific collections, optionally filtered by source selector
-   * 
-   * @param sources - optional source selector
-   * @param filter - optional list filter
-   * @param sort - optional list sort
-   * 
-   * @returns Promise with collection object list keyed by provider, service, and collection identifier
-   */
-  async function list(sources?: SourceSelector, filter?: ListFilter, sort?: ListSort): Promise<Record<string, CollectionObject>> {
+  async function list(sources?: ServiceIdentifier[] | CollectionIdentifier[], filter?: ListFilter, sort?: ListSort): Promise<Record<string, CollectionObject>> {
     transceiving.value = true
     try {
       const response = await collectionService.list({ sources, filter, sort })
 
-      // Flatten nested structure: provider:service:collection -> "provider:service:collection": object
       const collections: Record<string, CollectionObject> = {}
       Object.entries(response).forEach(([_providerId, providerServices]) => {
         Object.entries(providerServices).forEach(([_serviceId, serviceCollections]) => {
           Object.entries(serviceCollections).forEach(([_collectionId, collectionObj]) => {
-            const key = identifierKey(collectionObj.provider, collectionObj.service, collectionObj.identifier)
-            collections[key] = collectionObj
+            collections[collectionObj.identifier] = collectionObj
           })
         })
       })
 
-      // Merge retrieved collections into state
       _collections.value = { ..._collections.value, ...collections }
 
       console.debug('[Chrono Manager][Store] - Successfully retrieved', Object.keys(collections).length, 'collections')
@@ -139,29 +104,23 @@ export const useCollectionsStore = defineStore('chronoCollectionsStore', () => {
       transceiving.value = false
     }
   }
-  
+
   /**
-   * Retrieve a specific collection by provider, service, and identifier
-   * 
-   * @param provider - provider identifier
-   * @param service - service identifier
-   * @param identifier - collection identifier
-   * 
-   * @returns Promise with collection object
+   * Retrieve specific collections by their identifiers
    */
-  async function fetch(provider: string, service: string | number, identifier: string | number): Promise<CollectionObject> {
+  async function fetch(targets: CollectionIdentifier[]): Promise<Record<string, CollectionObject>> {
     transceiving.value = true
     try {
-      const response = await collectionService.fetch({ provider, service, collection: identifier })
-      
-      // Merge fetched collection into state
-      const key = identifierKey(response.provider, response.service, response.identifier)
-      _collections.value[key] = response
+      const response = await collectionService.fetch({ targets })
 
-      console.debug('[Chrono Manager][Store] - Successfully fetched collection:', key)
+      Object.values(response).forEach(collectionObj => {
+        _collections.value[collectionObj.identifier] = collectionObj
+      })
+
+      console.debug('[Chrono Manager][Store] - Successfully fetched collections:', Object.keys(response).join(', '))
       return response
     } catch (error: any) {
-      console.error('[Chrono Manager][Store] - Failed to fetch collection:', error)
+      console.error('[Chrono Manager][Store] - Failed to fetch collections:', error)
       throw error
     } finally {
       transceiving.value = false
@@ -169,18 +128,14 @@ export const useCollectionsStore = defineStore('chronoCollectionsStore', () => {
   }
 
   /**
-   * Retrieve collection availability status for a given source selector
-   * 
-   * @param sources - source selector to check availability for
-   * 
-   * @returns Promise with collection availability status
+   * Retrieve collection availability status for the given collection identifiers
    */
-  async function extant(sources: SourceSelector) {
+  async function extant(targets: CollectionIdentifier[]): Promise<Record<string, Record<string, Record<string, boolean>>>> {
     transceiving.value = true
     try {
-      const response = await collectionService.extant({ sources })
-      
-      console.debug('[Chrono Manager][Store] - Successfully checked', sources ? Object.keys(sources).length : 0, 'collections')
+      const response = await collectionService.extant({ targets })
+
+      console.debug('[Chrono Manager][Store] - Successfully checked', targets ? targets.length : 0, 'collections')
       return response
     } catch (error: any) {
       console.error('[Chrono Manager][Store] - Failed to check collections:', error)
@@ -191,30 +146,20 @@ export const useCollectionsStore = defineStore('chronoCollectionsStore', () => {
   }
 
   /**
-   * Create a new collection with given provider, service, and data
-   * 
-   * @param provider - provider identifier for the new collection
-   * @param service - service identifier for the new collection
-   * @param collection - optional parent collection identifier
-   * @param data - collection properties for creation
-   * 
-   * @returns Promise with created collection object
+   * Create a new collection with given provider, service, and properties
    */
-  async function create(provider: string, service: string | number, collection: string | number | null, data: CollectionPropertiesObject): Promise<CollectionObject> {
+  async function create(provider: string, service: string | number, properties: CollectionPropertiesObject): Promise<CollectionObject> {
     transceiving.value = true
     try {
-      const response = await collectionService.create({ 
-        provider, 
-        service, 
-        collection, 
-        properties: data
+      const response = await collectionService.create({
+        provider,
+        service,
+        properties: properties.toJson(),
       })
-      
-      // Merge created collection into state
-      const key = identifierKey(response.provider, response.service, response.identifier)
-      _collections.value[key] = response
-      
-      console.debug('[Chrono Manager][Store] - Successfully created collection:', key)
+
+      _collections.value[response.identifier] = response
+
+      console.debug('[Chrono Manager][Store] - Successfully created collection:', response.identifier)
       return response
     } catch (error: any) {
       console.error('[Chrono Manager][Store] - Failed to create collection:', error)
@@ -225,30 +170,19 @@ export const useCollectionsStore = defineStore('chronoCollectionsStore', () => {
   }
 
   /**
-   * Update an existing collection with given provider, service, identifier, and data
-   * 
-   * @param provider - provider identifier for the collection to update
-   * @param service - service identifier for the collection to update
-   * @param identifier - collection identifier for the collection to update
-   * @param data - collection properties for update
-   * 
-   * @returns Promise with updated collection object
+   * Update an existing collection with given target and properties
    */
-  async function update(provider: string, service: string | number, identifier: string | number, data: CollectionPropertiesObject): Promise<CollectionObject> {
+  async function update(target: CollectionIdentifier, properties: CollectionPropertiesObject): Promise<CollectionObject> {
     transceiving.value = true
     try {
-      const response = await collectionService.update({ 
-        provider, 
-        service, 
-        identifier, 
-        properties: data
+      const response = await collectionService.update({
+        target,
+        properties: properties.toJson(),
       })
-      
-      // Merge updated collection into state
-      const key = identifierKey(response.provider, response.service, response.identifier)
-      _collections.value[key] = response
-      
-      console.debug('[Chrono Manager][Store] - Successfully updated collection:', key)
+
+      _collections.value[response.identifier] = response
+
+      console.debug('[Chrono Manager][Store] - Successfully updated collection:', response.identifier)
       return response
     } catch (error: any) {
       console.error('[Chrono Manager][Store] - Failed to update collection:', error)
@@ -259,24 +193,28 @@ export const useCollectionsStore = defineStore('chronoCollectionsStore', () => {
   }
 
   /**
-   * Delete a collection by provider, service, and identifier
-   * 
-   * @param provider - provider identifier for the collection to delete
-   * @param service - service identifier for the collection to delete
-   * @param identifier - collection identifier for the collection to delete
-   * 
-   * @returns Promise with deletion result
+   * Delete a collection by identifier.
    */
-  async function remove(provider: string, service: string | number, identifier: string | number): Promise<any> {
+  async function remove(target: CollectionIdentifier, force?: boolean): Promise<CollectionObject | boolean> {
     transceiving.value = true
     try {
-      await collectionService.delete({ provider, service, identifier })
-      
-      // Remove deleted collection from state
-      const key = identifierKey(provider, service, identifier)
-      delete _collections.value[key]
+      const response = await collectionService.delete({ target, options: { force } })
 
-      console.debug('[Chrono Manager][Store] - Successfully deleted collection:', key)
+      if (response !== true && !(response instanceof CollectionObject)) {
+        console.warn('[Chrono Manager][Store] - Delete failed. Received unexpected response from delete operation:', response)
+        return false
+      }
+
+      delete _collections.value[target]
+
+      if (response instanceof CollectionObject) {
+        _collections.value[response.identifier] = response
+        console.debug('[Chrono Manager][Store] - Successfully moved collection', target, '->', response.identifier)
+        return response
+      }
+
+      console.debug('[Chrono Manager][Store] - Successfully deleted collection:', target)
+      return response
     } catch (error: any) {
       console.error('[Chrono Manager][Store] - Failed to delete collection:', error)
       throw error
@@ -285,17 +223,13 @@ export const useCollectionsStore = defineStore('chronoCollectionsStore', () => {
     }
   }
 
-  // Return public API
   return {
-    // State (readonly)
     transceiving: readonly(transceiving),
-    // Getters
     count,
     has,
     collections,
     collectionsByService,
     collectionsForService,
-    // Actions
     collection,
     list,
     fetch,
diff --git a/src/stores/entitiesStore.ts b/src/stores/entitiesStore.ts
index 7a4a501..8b86fba 100644
--- a/src/stores/entitiesStore.ts
+++ b/src/stores/entitiesStore.ts
@@ -6,7 +6,14 @@ import { ref, computed, readonly } from 'vue'
 import { defineStore } from 'pinia'
 import { entityService } from '../services'
 import { EntityObject } from '../models'
-import type { SourceSelector, ListFilter, ListSort, ListRange } from '../types/common'
+import type {
+  CollectionIdentifier,
+  EntityIdentifier,
+  ListFilter,
+  ListRange,
+  ListSort,
+} from '../types/common'
+import type { EntityPropertiesInterface } from '@/types/entity'
 
 export const useEntitiesStore = defineStore('chronoEntitiesStore', () => {
   // State
@@ -30,95 +37,44 @@ export const useEntitiesStore = defineStore('chronoEntitiesStore', () => {
 
   /**
    * Get a specific entity from store, with optional retrieval
-   * 
-   * @param provider - provider identifier
-   * @param service - service identifier
-   * @param collection - collection identifier
-   * @param identifier - entity identifier
-   * @param retrieve - Retrieve behavior: true = fetch if missing or refresh, false = cache only
-   * 
-   * @returns Entity object or null
    */
-  function entity(provider: string, service: string | number, collection: string | number, identifier: string | number, retrieve: boolean = false): EntityObject | null {
-    const key = identifierKey(provider, service, collection, identifier)
-    if (retrieve === true && !_entities.value[key]) {
-      console.debug(`[Chrono Manager][Store] - Force fetching entity "${key}"`)
-      fetch(provider, service, collection, [identifier])
+  function entity(target: EntityIdentifier, retrieve: boolean = false): EntityObject | null {
+    if (retrieve === true && !_entities.value[target]) {
+      console.debug(`[Chrono Manager][Store] - Force fetching entity "${target}"`)
+      fetch([target])
     }
-    
-    return _entities.value[key] || null
+
+    return _entities.value[target] || null
   }
 
   /**
    * Get all entities for a specific collection
-   * 
-   * @param provider - provider identifier
-   * @param service - service identifier
-   * @param collection - collection identifier
-   * @param retrieve - Retrieve behavior: true = fetch if missing or refresh, false = cache only
-   * 
-   * @returns Array of entity objects
    */
-  function entitiesForCollection(provider: string, service: string | number, collection: string | number, retrieve: boolean = false): EntityObject[] {
-    const collectionKeyPrefix = `${provider}:${service}:${collection}:`
+  function entitiesForCollection(target: CollectionIdentifier, retrieve: boolean = false): EntityObject[] {
     const collectionEntities = Object.entries(_entities.value)
-      .filter(([key]) => key.startsWith(collectionKeyPrefix))
+      .filter(([key]) => key.startsWith(`${target}:`))
       .map(([_, entity]) => entity)
-    
+
     if (retrieve === true && collectionEntities.length === 0) {
-      console.debug(`[Chrono Manager][Store] - Force fetching entities for collection "${provider}:${service}:${collection}"`)
-      const sources: SourceSelector = {
-        [provider]: {
-          [String(service)]: {
-            [String(collection)]: true
-          }
-        }
-      }
-      list(sources)
+      console.debug(`[Chrono Manager][Store] - Force fetching entities for collection "${target}"`)
+      list([target])
     }
-    
+
     return collectionEntities
   }
 
   /**
-   * Create unique key for an entity
+   * Retrieve all or specific entities, optionally filtered by source collection identifiers
    */
-  function identifierKey(provider: string, service: string | number, collection: string | number, identifier: string | number): string {
-    return `${provider}:${service}:${collection}:${identifier}`
-  }
-
-  // Actions
-  
-  /**
-   * Retrieve all or specific entities, optionally filtered by source selector
-   * 
-   * @param sources - optional source selector
-   * @param filter - optional list filter
-   * @param sort - optional list sort
-   * @param range - optional list range
-   * 
-   * @returns Promise with entity object list keyed by identifier
-   */
-  async function list(sources?: SourceSelector, filter?: ListFilter, sort?: ListSort, range?: ListRange): Promise<Record<string, EntityObject>> {
+  async function list(sources: CollectionIdentifier[], filter?: ListFilter, sort?: ListSort, range?: ListRange): Promise<Record<string, EntityObject>> {
     transceiving.value = true
     try {
-      const response = await entityService.list({ sources, filter, sort, range })
-
-      // Flatten nested structure: provider:service:collection:entity -> "provider:service:collection:entity": object
       const entities: Record<string, EntityObject> = {}
-      Object.entries(response).forEach(([providerId, providerServices]) => {
-        Object.entries(providerServices).forEach(([serviceId, serviceCollections]) => {
-          Object.entries(serviceCollections).forEach(([collectionId, collectionEntities]) => {
-            Object.entries(collectionEntities).forEach(([entityId, entityData]) => {
-              const key = identifierKey(providerId, serviceId, collectionId, entityId)
-              entities[key] = entityData
-            })
-          })
-        })
-      })
 
-      // Merge retrieved entities into state
-      _entities.value = { ..._entities.value, ...entities }
+      await entityService.listStream({ sources, filter, sort, range }, (entity: EntityObject) => {
+        _entities.value[entity.identifier] = entity
+        entities[entity.identifier] = entity
+      })
 
       console.debug('[Chrono Manager][Store] - Successfully retrieved', Object.keys(entities).length, 'entities')
       return entities
@@ -129,28 +85,19 @@ export const useEntitiesStore = defineStore('chronoEntitiesStore', () => {
       transceiving.value = false
     }
   }
-  
+
   /**
-   * Retrieve specific entities by provider, service, collection, and identifiers
-   * 
-   * @param provider - provider identifier
-   * @param service - service identifier
-   * @param collection - collection identifier
-   * @param identifiers - array of entity identifiers to fetch
-   * 
-   * @returns Promise with entity objects keyed by identifier
+   * Retrieve specific entities by their identifiers
    */
-  async function fetch(provider: string, service: string | number, collection: string | number, identifiers: (string | number)[]): Promise<Record<string, EntityObject>> {
+  async function fetch(targets: EntityIdentifier[]): Promise<Record<string, EntityObject>> {
     transceiving.value = true
     try {
-      const response = await entityService.fetch({ provider, service, collection, identifiers })
-      
-      // Merge fetched entities into state
+      const response = await entityService.fetch({ targets })
+
       const entities: Record<string, EntityObject> = {}
-      Object.entries(response).forEach(([identifier, entityData]) => {
-        const key = identifierKey(provider, service, collection, identifier)
-        entities[key] = entityData
-        _entities.value[key] = entityData
+      Object.entries(response).forEach(([identifier, entity]) => {
+        entities[identifier] = entity
+        _entities.value[identifier] = entity
       })
 
       console.debug('[Chrono Manager][Store] - Successfully fetched', Object.keys(entities).length, 'entities')
@@ -164,16 +111,12 @@ export const useEntitiesStore = defineStore('chronoEntitiesStore', () => {
   }
 
   /**
-   * Retrieve entity availability status for a given source selector
-   * 
-   * @param sources - source selector to check availability for
-   * 
-   * @returns Promise with entity availability status
+   * Retrieve entity availability status for a given set of entity identifiers
    */
-  async function extant(sources: SourceSelector) {
+  async function extant(targets: EntityIdentifier[]) {
     transceiving.value = true
     try {
-      const response = await entityService.extant({ sources })
+      const response = await entityService.extant({ targets })
       console.debug('[Chrono Manager][Store] - Successfully checked entity availability')
       return response
     } catch (error: any) {
@@ -184,132 +127,28 @@ export const useEntitiesStore = defineStore('chronoEntitiesStore', () => {
     }
   }
 
-  /**
-   * Create a new entity with given provider, service, collection, and data
-   * 
-   * @param provider - provider identifier for the new entity
-   * @param service - service identifier for the new entity
-   * @param collection - collection identifier for the new entity
-   * @param data - entity properties for creation
-   * 
-   * @returns Promise with created entity object
-   */
-  async function create(provider: string, service: string | number, collection: string | number, data: any): Promise<EntityObject> {
-    transceiving.value = true
-    try {
-      const response = await entityService.create({ provider, service, collection, properties: data })
-      
-      // Add created entity to state
-      const key = identifierKey(response.provider, response.service, response.collection, response.identifier)
-      _entities.value[key] = response
-
-      console.debug('[Chrono Manager][Store] - Successfully created entity:', key)
-      return response
-    } catch (error: any) {
-      console.error('[Chrono Manager][Store] - Failed to create entity:', error)
-      throw error
-    } finally {
-      transceiving.value = false
-    }
-  }
-
-  /**
-   * Update an existing entity with given provider, service, collection, identifier, and data
-   * 
-   * @param provider - provider identifier for the entity to update
-   * @param service - service identifier for the entity to update
-   * @param collection - collection identifier for the entity to update
-   * @param identifier - entity identifier for the entity to update
-   * @param data - entity properties for update
-   * 
-   * @returns Promise with updated entity object
-   */
-  async function update(provider: string, service: string | number, collection: string | number, identifier: string | number, data: any): Promise<EntityObject> {
-    transceiving.value = true
-    try {
-      const response = await entityService.update({ provider, service, collection, identifier, properties: data })
-      
-      // Update entity in state
-      const key = identifierKey(response.provider, response.service, response.collection, response.identifier)
-      _entities.value[key] = response
-
-      console.debug('[Chrono Manager][Store] - Successfully updated entity:', key)
-      return response
-    } catch (error: any) {
-      console.error('[Chrono Manager][Store] - Failed to update entity:', error)
-      throw error
-    } finally {
-      transceiving.value = false
-    }
-  }
-
-  /**
-   * Delete an entity by provider, service, collection, and identifier
-   * 
-   * @param provider - provider identifier for the entity to delete
-   * @param service - service identifier for the entity to delete
-   * @param collection - collection identifier for the entity to delete
-   * @param identifier - entity identifier for the entity to delete
-   * 
-   * @returns Promise with deletion result
-   */
-  async function remove(provider: string, service: string | number, collection: string | number, identifier: string | number): Promise<any> {
-    transceiving.value = true
-    try {
-      const response = await entityService.delete({ provider, service, collection, identifier })
-      
-      // Remove entity from state
-      const key = identifierKey(provider, service, collection, identifier)
-      delete _entities.value[key]
-
-      console.debug('[Chrono Manager][Store] - Successfully deleted entity:', key)
-      return response
-    } catch (error: any) {
-      console.error('[Chrono Manager][Store] - Failed to delete entity:', error)
-      throw error
-    } finally {
-      transceiving.value = false
-    }
-  }
-
   /**
    * Retrieve delta changes for entities
-   * 
-   * @param sources - source selector for delta check
-   * 
-   * @returns Promise with delta changes (additions, modifications, deletions)
-   * 
-   * Note: Delta returns only identifiers, not full entities.
-   * Caller should fetch full entities for additions/modifications separately.
    */
-  async function delta(sources: SourceSelector) {
+  async function delta(targets: (CollectionIdentifier | EntityIdentifier)[]) {
     transceiving.value = true
     try {
-      const response = await entityService.delta({ sources })
-      
-      // Process delta and update store
-      Object.entries(response).forEach(([provider, providerData]) => {
-        // Skip if no changes for provider
+      const response = await entityService.delta({ targets })
+
+      Object.entries(response).forEach(([, providerData]) => {
         if (providerData === false) return
-        
-        Object.entries(providerData).forEach(([service, serviceData]) => {
-          // Skip if no changes for service
+
+        Object.entries(providerData).forEach(([, serviceData]) => {
           if (serviceData === false) return
-          
-          Object.entries(serviceData).forEach(([collection, collectionData]) => {
-            // Skip if no changes for collection
+
+          Object.entries(serviceData).forEach(([, collectionData]) => {
             if (collectionData === false) return
-            
-            // Process deletions (remove from store)
+
             if (collectionData.deletions && collectionData.deletions.length > 0) {
               collectionData.deletions.forEach((identifier) => {
-                const key = identifierKey(provider, service, collection, identifier)
-                delete _entities.value[key]
+                delete _entities.value[identifier]
               })
             }
-            
-            // Note: additions and modifications contain only identifiers
-            // The caller should fetch full entities using the fetch() method
           })
         })
       })
@@ -324,16 +163,156 @@ export const useEntitiesStore = defineStore('chronoEntitiesStore', () => {
     }
   }
 
-  // Return public API
+  /**
+   * Create a new empty entity object
+   */
+  function fresh(): EntityObject {
+    return new EntityObject()
+  }
+
+  /**
+   * Create a new entity with given collection identifier and properties
+   */
+  async function create(target: CollectionIdentifier, properties: EntityPropertiesInterface): Promise<EntityObject> {
+    transceiving.value = true
+    try {
+      const response = await entityService.create({ target, properties })
+
+      _entities.value[response.identifier] = response
+
+      console.debug('[Chrono Manager][Store] - Successfully created entity:', response.identifier)
+      return response
+    } catch (error: any) {
+      console.error('[Chrono Manager][Store] - Failed to create entity:', error)
+      throw error
+    } finally {
+      transceiving.value = false
+    }
+  }
+
+  /**
+   * Update an existing entity with given entity identifier and properties
+   */
+  async function update(target: EntityIdentifier, properties: EntityPropertiesInterface): Promise<EntityObject> {
+    transceiving.value = true
+    try {
+      const response = await entityService.update({ target, properties })
+
+      _entities.value[response.identifier] = response
+
+      console.debug('[Chrono Manager][Store] - Successfully updated entity:', response.identifier)
+      return response
+    } catch (error: any) {
+      console.error('[Chrono Manager][Store] - Failed to update entity:', error)
+      throw error
+    } finally {
+      transceiving.value = false
+    }
+  }
+
+  /**
+   * Delete entities by their identifiers.
+   */
+  async function remove(targets: EntityIdentifier[]): Promise<{ successes: EntityIdentifier[], failures: EntityIdentifier[] }> {
+    transceiving.value = true
+    try {
+      const response = await entityService.delete({ targets })
+      const successes: EntityIdentifier[] = []
+      const failures: EntityIdentifier[] = []
+
+      Object.entries(response).forEach(([targetIdentifier, result]) => {
+        const originalIdentifier = targetIdentifier as EntityIdentifier
+        if (!result.disposition || result.disposition === 'error') {
+          console.warn(`[Chrono Manager][Store] - Entity delete on "${originalIdentifier}" returned an error: ${result.error})`)
+          failures.push(originalIdentifier)
+          return
+        }
+
+        if (result.disposition !== 'moved' && result.disposition !== 'deleted') {
+          console.warn(`[Chrono Manager][Store] - Entity delete on "${originalIdentifier}" returned invalid disposition: ${result.disposition})`)
+          failures.push(originalIdentifier)
+          return
+        }
+
+        const cachedEntity = _entities.value[originalIdentifier]
+
+        if (result.disposition === 'moved' && cachedEntity && result.mutation) {
+          const movedEntity = cachedEntity.clone().fromJson({
+            ...cachedEntity.toJson(),
+            collection: result.destination,
+            identifier: result.mutation,
+          })
+          _entities.value[result.mutation] = movedEntity
+        }
+
+        delete _entities.value[originalIdentifier]
+        successes.push(originalIdentifier)
+      })
+
+      console.debug('[Chrono Manager][Store] - Successfully deleted', successes.length, 'entities')
+      return { successes, failures }
+    } catch (error: any) {
+      console.error('[Chrono Manager][Store] - Failed to delete entities:', error)
+      throw error
+    } finally {
+      transceiving.value = false
+    }
+  }
+
+  /**
+   * Move entities to another collection.
+   */
+  async function move(target: CollectionIdentifier, sources: EntityIdentifier[]): Promise<{ successes: EntityIdentifier[], failures: EntityIdentifier[] }> {
+    transceiving.value = true
+    try {
+      const response = await entityService.move({ target, sources })
+      const successes: EntityIdentifier[] = []
+      const failures: EntityIdentifier[] = []
+
+      Object.entries(response).forEach(([sourceIdentifier, result]) => {
+        const originalIdentifier = sourceIdentifier as EntityIdentifier
+        if (!result.disposition || result.disposition === 'error') {
+          console.warn(`[Chrono Manager][Store] - Entity move on "${originalIdentifier}" returned an error: ${result.error})`)
+          failures.push(originalIdentifier)
+          return
+        }
+
+        if (result.disposition !== 'moved') {
+          console.warn(`[Chrono Manager][Store] - Entity move on "${originalIdentifier}" returned invalid disposition: ${result.disposition})`)
+          failures.push(originalIdentifier)
+          return
+        }
+
+        const cachedEntity = _entities.value[originalIdentifier]
+        if (cachedEntity && result.mutation) {
+          const movedEntity = cachedEntity.clone().fromJson({
+            ...cachedEntity.toJson(),
+            collection: result.destination,
+            identifier: result.mutation,
+          })
+          _entities.value[result.mutation] = movedEntity
+          delete _entities.value[originalIdentifier]
+        }
+
+        successes.push(originalIdentifier)
+      })
+
+      console.debug('[Chrono Manager][Store] - Successfully moved', successes.length, 'entities')
+      return { successes, failures }
+    } catch (error: any) {
+      console.error('[Chrono Manager][Store] - Failed to move entities:', error)
+      throw error
+    } finally {
+      transceiving.value = false
+    }
+  }
+
   return {
-    // State (readonly)
     transceiving: readonly(transceiving),
-    // Getters
     count,
     has,
     entities,
     entitiesForCollection,
-    // Actions
     entity,
     list,
     fetch,
@@ -342,5 +321,7 @@ export const useEntitiesStore = defineStore('chronoEntitiesStore', () => {
     update,
     delete: remove,
     delta,
+    fresh,
+    move,
   }
 })
diff --git a/src/stores/providersStore.ts b/src/stores/providersStore.ts
index a7141b6..a41a8c8 100644
--- a/src/stores/providersStore.ts
+++ b/src/stores/providersStore.ts
@@ -6,7 +6,7 @@ import { ref, computed, readonly } from 'vue'
 import { defineStore } from 'pinia'
 import { providerService } from '../services'
 import { ProviderObject } from '../models/provider'
-import type { SourceSelector } from '../types'
+import type { ProviderIdentifier } from '../types'
 
 export const useProvidersStore = defineStore('chronoProvidersStore', () => {
   // State
@@ -54,10 +54,10 @@ export const useProvidersStore = defineStore('chronoProvidersStore', () => {
    * 
    * @returns Promise with provider object list keyed by provider identifier
    */
-  async function list(sources?: SourceSelector): Promise<Record<string, ProviderObject>> {
+  async function list(targets?: ProviderIdentifier[]): Promise<Record<string, ProviderObject>> {
     transceiving.value = true
     try {
-      const providers = await providerService.list({ sources })
+      const providers = await providerService.list({ targets })
 
       // Merge retrieved providers into state
       _providers.value = { ..._providers.value, ...providers }
@@ -82,7 +82,7 @@ export const useProvidersStore = defineStore('chronoProvidersStore', () => {
   async function fetch(identifier: string): Promise<ProviderObject> {
     transceiving.value = true
     try {
-      const provider = await providerService.fetch({ identifier })
+      const provider = await providerService.fetch({ target: identifier })
 
       // Merge fetched provider into state
       _providers.value[provider.identifier] = provider
@@ -104,10 +104,10 @@ export const useProvidersStore = defineStore('chronoProvidersStore', () => {
    * 
    * @returns Promise with provider availability status
    */
-  async function extant(sources: SourceSelector) {
+  async function extant(targets: ProviderIdentifier[]) {
     transceiving.value = true
     try {
-      const response = await providerService.extant({ sources })
+      const response = await providerService.extant({ targets })
 
       Object.entries(response).forEach(([providerId, providerStatus]) => {
         if (providerStatus === false) {
@@ -115,7 +115,7 @@ export const useProvidersStore = defineStore('chronoProvidersStore', () => {
         }
       })
 
-      console.debug('[Chrono Manager][Store] - Successfully checked', sources ? Object.keys(sources).length : 0, 'providers')
+      console.debug('[Chrono Manager][Store] - Successfully checked', targets ? targets.length : 0, 'providers')
       return response
     } catch (error: any) {
       console.error('[Chrono Manager][Store] - Failed to check providers:', error)
diff --git a/src/stores/servicesStore.ts b/src/stores/servicesStore.ts
index 23e2ae4..2d73f72 100644
--- a/src/stores/servicesStore.ts
+++ b/src/stores/servicesStore.ts
@@ -7,7 +7,8 @@ import { defineStore } from 'pinia'
 import { serviceService } from '../services'
 import { ServiceObject } from '../models/service'
 import type {
-  SourceSelector,
+  CollectionIdentifier,
+  ServiceIdentifier,
   ServiceInterface,
 } from '../types'
 
@@ -55,20 +56,30 @@ export const useServicesStore = defineStore('chronoServicesStore', () => {
    * @returns Service object or null
    */
   function service(provider: string, identifier: string | number, retrieve: boolean = false): ServiceObject | null {
-    const key = identifierKey(provider, identifier)
-    if (retrieve === true && !_services.value[key]) {
-      console.debug(`[Chrono Manager][Store] - Force fetching service "${key}"`)
-      fetch(provider, identifier)
+    return serviceByIdentifier(identifierKey(provider, identifier), retrieve)
+  }
+
+  /**
+   * Get a service from store by its unique identifier, with optional retrieval
+   */
+  function serviceByIdentifier(identifier: ServiceIdentifier, retrieve: boolean = false): ServiceObject | null {
+    if (retrieve === true && !_services.value[identifier]) {
+      console.debug(`[Chrono Manager][Store] - Force fetching service "${identifier}"`)
+      const separatorIndex = identifier.indexOf(':')
+      const provider = identifier.slice(0, separatorIndex)
+      const serviceIdentifier = identifier.slice(separatorIndex + 1)
+
+      void fetch(provider, serviceIdentifier)
     }
-    
-    return _services.value[key] || null
+
+    return _services.value[identifier] ?? null
   }
 
   /**
    * Unique key for a service
    */
-  function identifierKey(provider: string, identifier: string | number | null): string {
-    return `${provider}:${identifier ?? ''}`
+  function identifierKey(provider: string, identifier: string | number | null): ServiceIdentifier {
+    return `${provider}:${identifier ?? ''}` as ServiceIdentifier
   }
 
   // Actions
@@ -80,10 +91,10 @@ export const useServicesStore = defineStore('chronoServicesStore', () => {
    * 
    * @returns Promise with service object list keyed by provider and service identifier
    */
-  async function list(sources?: SourceSelector): Promise<Record<string, ServiceObject>> {
+  async function list(targets?: ServiceIdentifier[] | CollectionIdentifier[]): Promise<Record<string, ServiceObject>> {
     transceiving.value = true
     try {
-      const response = await serviceService.list({ sources })
+      const response = await serviceService.list({ targets })
 
       // Flatten nested structure: provider-id: { service-id: object } -> "provider-id:service-id": object
       const services: Record<string, ServiceObject> = {}
@@ -141,12 +152,12 @@ export const useServicesStore = defineStore('chronoServicesStore', () => {
    * 
    * @returns Promise with service availability status
    */
-  async function extant(sources: SourceSelector) {
+  async function extant(targets: ServiceIdentifier[]) {
     transceiving.value = true
     try {
-      const response = await serviceService.extant({ sources })
+      const response = await serviceService.extant({ targets })
       
-      console.debug('[Chrono Manager][Store] - Successfully checked', sources ? Object.keys(sources).length : 0, 'services')
+      console.debug('[Chrono Manager][Store] - Successfully checked', targets?.length ?? 0, 'services')
       return response
     } catch (error: any) {
       console.error('[Chrono Manager][Store] - Failed to check services:', error)
@@ -192,10 +203,14 @@ export const useServicesStore = defineStore('chronoServicesStore', () => {
    * 
    * @returns Promise with updated service object
    */
-  async function update(provider: string, identifier: string | number, data: Partial<ServiceInterface>): Promise<ServiceObject> {
+  async function update(provider: string, identifier: string | number, delta: boolean, data: ServiceObject | Partial<ServiceInterface>): Promise<ServiceObject> {
     transceiving.value = true
     try {
-      const service = await serviceService.update({ provider, identifier, data })
+      const payload: Partial<ServiceInterface> = data instanceof ServiceObject
+        ? (delta ? data.toJson(true) : data.toJson())
+        : data
+
+      const service = await serviceService.update({ provider, identifier, delta, data: payload })
       
       // Merge updated service into state
       const key = identifierKey(service.provider, service.identifier)
@@ -249,6 +264,7 @@ export const useServicesStore = defineStore('chronoServicesStore', () => {
     
     // Actions
     service,
+    serviceByIdentifier,
     list,
     fetch,
     extant,
diff --git a/src/types/collection.ts b/src/types/collection.ts
index 24f2896..9ce8a93 100644
--- a/src/types/collection.ts
+++ b/src/types/collection.ts
@@ -1,27 +1,37 @@
 /**
  * Collection type definitions
  */
-import type { ListFilter, ListSort, SourceSelector } from './common';
+import type {
+  ServiceIdentifier,
+  CollectionIdentifier,
+  ListFilter,
+  ListSort
+} from './common';
 
 /**
  * Collection information
  */
-export interface CollectionInterface {
+export interface CollectionInterface<T = CollectionPropertiesInterface> {
+  '@type': string;
+  version: number;
   provider: string;
   service: string | number;
-  collection: string | number | null;
-  identifier: string | number;
+  collection: CollectionIdentifier | null;
+  identifier: CollectionIdentifier;
   signature?: string | null;
   created?: string | null;
   modified?: string | null;
-  properties: CollectionPropertiesInterface;
+  properties: T;
+}
+
+export interface CollectionModelInterface extends Omit<CollectionInterface<CollectionPropertiesInterface>, '@type' | 'version' | 'properties'> {
+  properties: CollectionPropertiesModelInterface;
 }
 
 export type CollectionContentTypes = 'event' | 'task' | 'journal';
 
 export interface CollectionBaseProperties {
   '@type': string;
-  version: number;
 }
 
 export interface CollectionImmutableProperties extends CollectionBaseProperties {
@@ -38,11 +48,13 @@ export interface CollectionMutableProperties extends CollectionBaseProperties {
 
 export interface CollectionPropertiesInterface extends CollectionMutableProperties, CollectionImmutableProperties {}
 
+export interface CollectionPropertiesModelInterface extends Omit<CollectionPropertiesInterface, '@type'> {}
+
 /**
  * Collection list
  */
 export interface CollectionListRequest {
-  sources?: SourceSelector;
+  sources?: ServiceIdentifier[] | CollectionIdentifier[];
   filter?: ListFilter;
   sort?: ListSort;
 }
@@ -59,18 +71,18 @@ export interface CollectionListResponse {
  * Collection fetch
  */
 export interface CollectionFetchRequest {
-  provider: string;
-  service: string | number;
-  collection: string | number;
+  targets: CollectionIdentifier[];
 }
 
-export interface CollectionFetchResponse extends CollectionInterface {}
+export interface CollectionFetchResponse {
+  [identifier: CollectionIdentifier]: CollectionInterface;
+}
 
 /**
  * Collection extant
  */
 export interface CollectionExtantRequest {
-  sources: SourceSelector;
+  targets: CollectionIdentifier[];
 }
 
 export interface CollectionExtantResponse {
@@ -87,7 +99,6 @@ export interface CollectionExtantResponse {
 export interface CollectionCreateRequest {
   provider: string;
   service: string | number;
-  collection?: string | number | null; // Parent Collection Identifier
   properties: CollectionMutableProperties;
 }
 
@@ -97,9 +108,7 @@ export interface CollectionCreateResponse extends CollectionInterface {}
  * Collection modify
  */
 export interface CollectionUpdateRequest {
-  provider: string;
-  service: string | number;
-  identifier: string | number;
+  target: CollectionIdentifier;
   properties: CollectionMutableProperties;
 }
 
@@ -109,14 +118,13 @@ export interface CollectionUpdateResponse extends CollectionInterface {}
  * Collection delete
  */
 export interface CollectionDeleteRequest {
-  provider: string;
-  service: string | number;
-  identifier: string | number;
+  target: CollectionIdentifier;
   options?: {
     force?: boolean; // Whether to force delete even if collection is not empty
   };
 }
 
 export interface CollectionDeleteResponse {
-  success: boolean;
+  disposition: 'deleted' | 'moved';
+  mutation?: CollectionInterface | null; // If moved, the new location of the collection
 }
diff --git a/src/types/common.ts b/src/types/common.ts
index ab912d4..210c391 100644
--- a/src/types/common.ts
+++ b/src/types/common.ts
@@ -44,34 +44,57 @@ export interface ApiErrorResponse {
 export type ApiResponse<T = any> = ApiSuccessResponse<T> | ApiErrorResponse;
 
 /**
- * Selector for targeting specific providers, services, collections, or entities in list or extant operations.
- * 
- * Example usage:
- * {
- *   "provider1": true, // Select all services/collections/entities under provider1
- *   "provider2": {
- *     "serviceA": true, // Select all collections/entities under serviceA of provider2
- *     "serviceB": {
- *       "collectionX": true, // Select all entities under collectionX of serviceB of provider2
- *       "collectionY": [1, 2, 3] // Select entities with identifiers 1, 2, and 3 under collectionY of serviceB of provider2
- *     }
- *   }
- * }
+ * Stream control start line.
  */
-export type SourceSelector = {
-  [provider: string]: boolean | ServiceSelector;
-};
+export interface ApiStreamStartResponse {
+  type: 'control';
+  status: 'start';
+  version: number;
+  transaction: string;
+  total?: number;
+}
 
-export type ServiceSelector = {
-  [service: string]: boolean | CollectionSelector;
-};
+/**
+ * Stream control end line
+ */
+export interface ApiStreamEndResponse {
+  type: 'control';
+  status: 'end';
+  total: number;
+}
 
-export type CollectionSelector = {
-  [collection: string | number]: boolean | EntitySelector;
-};
+/**
+ * Stream error line
+ */
+export interface ApiStreamErrorResponse {
+  type: 'error';
+  message: string;
+}
 
-export type EntitySelector = (string | number)[];
+export interface ApiStreamDataResponse<T = any> {
+  type: 'data';
+  data: T;
+}
 
+/**
+ * Shared stream control lines
+ */
+export type ApiStreamResponse<T = any> =
+  | ApiStreamStartResponse
+  | ApiStreamEndResponse
+  | ApiStreamErrorResponse
+  | ApiStreamDataResponse<T>;
+
+/**
+ * Identifiers for targeting specific providers, services, collections, or entities in list or extant operations.
+ *
+ * Operations accept flat arrays of colon-separated identifier strings, e.g.
+ * ["caldav:account1:calendar", "caldav:account1:calendar:1001"].
+ */
+export type ProviderIdentifier = `${string}`;
+export type ServiceIdentifier = `${string}:${string}`;
+export type CollectionIdentifier = `${string}:${string}:${string | number}`;
+export type EntityIdentifier = `${string}:${string}:${string}:${string | number}`;
 
 /**
  * Filter comparison for list operations
diff --git a/src/types/entity.ts b/src/types/entity.ts
index c113cfa..317ac1a 100644
--- a/src/types/entity.ts
+++ b/src/types/entity.ts
@@ -1,64 +1,85 @@
 /**
  * Entity type definitions
  */
-import type { ListFilter, ListRange, ListSort, SourceSelector } from './common';
+import type {
+  CollectionIdentifier,
+  EntityIdentifier,
+  ListFilter,
+  ListRange,
+  ListSort,
+} from './common';
 import type { EventInterface } from './event';
 import type { TaskInterface } from './task';
 import type { JournalInterface } from './journal';
 
+export type EntityPropertiesInterface = EventInterface | TaskInterface | JournalInterface;
+
 /**
  * Entity definition
  */
-export interface EntityInterface<T = EventInterface | TaskInterface | JournalInterface> {
+export interface EntityInterface<T = EntityPropertiesInterface> {
+  '@type': string;
+  version: number;
   provider: string;
   service: string;
-  collection: string | number;
-  identifier: string | number;
+  collection: CollectionIdentifier;
+  identifier: EntityIdentifier;
   signature: string | null;
   created: string | null;
   modified: string | null;
   properties: T;
 }
 
+export interface EntityModelInterface extends Omit<EntityInterface<EntityPropertiesInterface>, '@type' | 'version'> {}
+
 /**
- * Entity list
+ * Entity list bulk
  */
-export interface EntityListRequest {
-  sources?: SourceSelector;
+export interface EntityListBulkRequest {
+  sources?: CollectionIdentifier[];
   filter?: ListFilter;
   sort?: ListSort;
   range?: ListRange;
 }
 
-export interface EntityListResponse {
+export interface EntityListBulkResponse {
   [providerId: string]: {
     [serviceId: string]: {
       [collectionId: string]: {
-        [identifier: string]: EntityInterface<EventInterface | TaskInterface | JournalInterface>;
+        [identifier: string]: EntityInterface;
       };
     };
   };
 }
 
+/**
+ * Entity list stream
+ */
+export interface EntityListStreamRequest {
+  sources?: CollectionIdentifier[];
+  filter?: ListFilter;
+  sort?: ListSort;
+  range?: ListRange;
+}
+
+export interface EntityListStreamResponse extends EntityInterface {}
+
 /**
  * Entity fetch
  */
 export interface EntityFetchRequest {
-  provider: string;
-  service: string | number;
-  collection: string | number;
-  identifiers: (string | number)[];
+  targets: EntityIdentifier[];
 }
 
 export interface EntityFetchResponse {
-  [identifier: string]: EntityInterface<EventInterface | TaskInterface | JournalInterface>;
+  [identifier: string]: EntityInterface;
 }
 
 /**
  * Entity extant
  */
 export interface EntityExtantRequest {
-  sources: SourceSelector;
+  targets: EntityIdentifier[];
 }
 
 export interface EntityExtantResponse {
@@ -71,50 +92,13 @@ export interface EntityExtantResponse {
   };
 }
 
-/**
- * Entity create
- */
-export interface EntityCreateRequest<T = EventInterface | TaskInterface | JournalInterface> {
-  provider: string;
-  service: string | number;
-  collection: string | number;
-  properties: T;
-}
-
-export interface EntityCreateResponse<T = EventInterface | TaskInterface | JournalInterface> extends EntityInterface<T> {}
-
-/**
- * Entity update
- */
-export interface EntityUpdateRequest<T = EventInterface | TaskInterface | JournalInterface> {
-  provider: string;
-  service: string | number;
-  collection: string | number;
-  identifier: string | number;
-  properties: T;
-}
-
-export interface EntityUpdateResponse<T = EventInterface | TaskInterface | JournalInterface> extends EntityInterface<T> {}
-
-/**
- * Entity delete
- */
-export interface EntityDeleteRequest {
-  provider: string;
-  service: string | number;
-  collection: string | number;
-  identifier: string | number;
-}
-
-export interface EntityDeleteResponse {
-  success: boolean;
-}
-
 /**
  * Entity delta
  */
 export interface EntityDeltaRequest {
-  sources: SourceSelector;
+  // Each target is provider:service:collection, or provider:service:collection:signature
+  // to request a delta relative to a known signature (the signature is the entity slot).
+  targets: (CollectionIdentifier | EntityIdentifier)[];
 }
 
 export interface EntityDeltaResponse {
@@ -128,4 +112,58 @@ export interface EntityDeltaResponse {
       };
     };
   };
-}
\ No newline at end of file
+}
+
+/**
+ * Entity create
+ */
+export interface EntityCreateRequest<T = EntityPropertiesInterface> {
+  target: CollectionIdentifier;
+  properties: T;
+  options?: Record<string, any>;
+}
+
+export interface EntityCreateResponse<T = EntityPropertiesInterface> extends EntityInterface<T> {}
+
+/**
+ * Entity update
+ */
+export interface EntityUpdateRequest<T = EntityPropertiesInterface> {
+  target: EntityIdentifier;
+  properties: T;
+}
+
+export interface EntityUpdateResponse<T = EntityPropertiesInterface> extends EntityInterface<T> {}
+
+/**
+ * Entity delete
+ */
+export interface EntityDeleteRequest {
+  targets: EntityIdentifier[];
+}
+
+export interface EntityDeleteResponse {
+  [targetIdentifier: EntityIdentifier]: {
+    disposition: 'deleted' | 'moved' | 'error';
+    destination: CollectionIdentifier | null;
+    mutation: EntityIdentifier | null;
+    error?: string;
+  };
+}
+
+/**
+ * Entity move
+ */
+export interface EntityMoveRequest {
+  target: CollectionIdentifier;
+  sources: EntityIdentifier[];
+}
+
+export interface EntityMoveResponse {
+  [sourceIdentifier: EntityIdentifier]: {
+    disposition: 'moved' | 'error';
+    destination: CollectionIdentifier | null;
+    mutation: EntityIdentifier | null;
+    error?: string;
+  };
+}
diff --git a/src/types/provider.ts b/src/types/provider.ts
index b9632c8..1b39b6d 100644
--- a/src/types/provider.ts
+++ b/src/types/provider.ts
@@ -1,7 +1,7 @@
 /**
  * Provider type definitions
  */
-import type { SourceSelector } from "./common";
+import type { ProviderIdentifier } from './common';
 
 /**
  * Provider capabilities
@@ -28,22 +28,24 @@ export interface ProviderInterface {
   capabilities: ProviderCapabilitiesInterface;
 }
 
+export interface ProviderModelInterface extends Omit<ProviderInterface, '@type'> {}
+
 /**
  * Provider list
  */
 export interface ProviderListRequest {
-  sources?: SourceSelector;
+  targets?: ProviderIdentifier[];
 }
 
 export interface ProviderListResponse {
-  [identifier: string]: ProviderInterface;
+  [identifier: ProviderIdentifier]: ProviderInterface;
 }
 
 /**
  * Provider fetch 
  */
 export interface ProviderFetchRequest {
-  identifier: string;
+  target: ProviderIdentifier;
 }
 
 export interface ProviderFetchResponse extends ProviderInterface {}
@@ -52,9 +54,9 @@ export interface ProviderFetchResponse extends ProviderInterface {}
  * Provider extant 
  */
 export interface ProviderExtantRequest {
-  sources: SourceSelector;
+  targets: ProviderIdentifier[];
 }
 
 export interface ProviderExtantResponse {
-  [identifier: string]: boolean;
+  [identifier: ProviderIdentifier]: boolean;
 }
diff --git a/src/types/service.ts b/src/types/service.ts
index ce47898..3c791e9 100644
--- a/src/types/service.ts
+++ b/src/types/service.ts
@@ -1,7 +1,13 @@
 /**
  * Service type definitions
  */
-import type { SourceSelector, ListFilterComparisonOperator } from './common';
+import type {
+  ServiceIdentifier,
+  CollectionIdentifier,
+  ListFilterComparisonOperator,
+} from './common';
+import type { Identity } from '@/models/identity';
+import type { Location } from '@/models/location';
 
 /**
  * Service capabilities
@@ -47,11 +53,18 @@ export interface ServiceInterface {
   auxiliary?: Record<string, any>;  // Provider-specific extension data
 }
 
+export interface ServiceModelInterface extends Omit<{
+  [K in keyof ServiceInterface]-?: Exclude<ServiceInterface[K], undefined>;
+}, '@type' | 'location' | 'identity'> {
+  location: Location | null;
+  identity: Identity | null;
+}
+
 /**
  * Service list
  */
 export interface ServiceListRequest {
-  sources?: SourceSelector;
+  targets?: ServiceIdentifier[] | CollectionIdentifier[];
 }
 
 export interface ServiceListResponse {
@@ -74,7 +87,7 @@ export interface ServiceFetchResponse extends ServiceInterface {}
  * Service extant
  */
 export interface ServiceExtantRequest {
-  sources: SourceSelector;
+  targets: ServiceIdentifier[];
 }
 
 export interface ServiceExtantResponse {
@@ -99,6 +112,7 @@ export interface ServiceCreateResponse extends ServiceInterface {}
 export interface ServiceUpdateRequest {
   provider: string;
   identifier: string | number;
+  delta?: boolean;
   data: Partial<ServiceInterface>;
 }