OData V4 Feature Matrix

A structured inventory of everything the OData V4 (4.0 / 4.01) protocol defines — independent of any implementation. This document describes the specification only; it makes no statement about any client or server library.

The companion document odata-v1-v3.md does the same for OData 1.0, 2.0 and 3.0 — those three share one normative specification and one continuous lineage, so they are covered together, with the break placed where it actually is: between 3.0 and 4.0. Coverage of a concrete implementation is tracked separately — for odata2ts itself see feature support.

Scope

• Covers the complete protocol: not only what a client sends and receives, but also the data model (CSDL), service obligations, conformance levels and security considerations.
• JSON is the payload format described here. Atom/XML is a defined but rarely used alternative format and is not broken down; CSDL is covered in both its XML and JSON representation.
• The OData Protocol specification (Part 1) provides the backbone of this document; URL syntax, payload shapes and schema details are pulled in from Parts 2, the JSON Format and the CSDL specification.

Sources

Prefix	Document
Protocol	OData V4.01 Part 1: Protocol
Url	OData V4.01 Part 2: URL Conventions
Json	OData JSON Format V4.01
Csdl	OData CSDL XML Representation V4.01
Agg	OData Data Aggregation Extension V4.0

Legend

Symbol	Meaning
4.0	Present since OData 4.0
4.01	Added in OData 4.01

Required vs. optional — the Role, Conformance and Requirement columns

OData has no flat required/optional split. It defines three conformance levels plus an orthogonal Updatable qualifier, and grades each rule as MUST / SHOULD / MAY. Those are independent axes, so the matrix carries them in three columns.

Role — on whom the obligation falls:

Value	Meaning
Server	The service has to provide or honour it
Client	The consumer has to send, follow or tolerate it
Both	Obligations on both sides
–	Not an obligation: a modelling construct or a definition

The conformance levels are defined for services, so most rows are Server. Client marks the places where the protocol puts the duty on the consumer — following a nextLink or a delta link, polling an async status monitor, composing batch dependencies. For header rows the value follows the Direction column.

Conformance — at which level the feature is demanded, i.e. the weakest level that requires it:

Value	Meaning
Core	Part of the core protocol or data model, not gated by a conformance level at all
Min	Minimal conformance level — every conformant service
Int	Intermediate conformance level and upwards
Adv	Advanced conformance level and upwards
Upd	A service that supports modification (Updatable OData Service)
–	No level demands it; support is entirely at the service's discretion

Requirement — how hard the demand is, in the sense of RFC 2119:

Value	Meaning
MUST	Mandatory at the stated conformance level
SHOULD	Recommended; a service may omit it, so a client cannot rely on it
MAY	Entirely optional
–	Not applicable — the row describes a Core construct, which is not phrased as a service obligation

The two columns combine: Min + MUST is the hard floor every service meets, while – + MAY is never guaranteed. Two combinations never occur, by construction: SHOULD alongside a conformance level, since a recommendation is not a level requirement; and a graded requirement on a Core row, since those describe what the protocol is rather than what a service has to do. A client that must work against arbitrary services can rely on Core and Min alone.

Values are derived from Protocol §13.1 (4.0) and §13.2 (4.01); where the two versions differ, the stricter one is shown.

How to read this document

The matrix is multi-level. The Overview summarizes the protocol into coarse areas. Each area then has its own section listing its features, and the genuinely complex ones — nested $expand, the $filter expression language, $apply transformations, the schema elements — are broken down one level further into their own subsections.

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Overview

#	Area	What it covers	Spec
1	Data model & schema	Types, properties, relationships, containers, annotations	Protocol - Data Model
2	Service model	Entity-ids, read/edit URLs, transient entities, namespaces	Protocol - Service Model
3	Versioning & extensibility	Protocol/model versioning, extension points	Protocol - Versioning
4	Formats & JSON payloads	Format negotiation, control information, payload shapes	Json - Format Design
5	Header fields & preferences	Request/response headers, Prefer and Preference-Applied	Protocol - Header Fields
6	Status codes & errors	Success/error codes, error body, in-stream errors	Protocol - Status Codes
7	Context URL	@odata.context per payload kind	Protocol - Context URL
8	Resource addressing	Service root, key predicates, path segments, casts	Url - Resource Path
9	Querying data	$select/$expand, $filter, ordering, paging, counting	Protocol - Requesting Data
10	Change tracking (delta)	track-changes, delta links, delta payloads	Protocol - Requesting Changes
11	Data modification	Create/update/delete, relationships, streams, collections	Protocol - Data Modification
12	Operations	Functions and actions, binding, overload resolution	Protocol - Operations
13	Asynchronous requests	respond-async, status monitor, result retrieval	Protocol - Asynchronous Requests
14	Batch requests	Multipart and JSON batch, change sets, dependencies	Protocol - Batch Requests
15	Aggregation ($apply)	Transformation pipeline, aggregate methods, grouping	Agg
16	Security & conformance	Authentication, conformance levels, interoperable clients	Protocol - Conformance

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1. Data Model & Schema

The model is described in CSDL and consumed by clients through $metadata. Everything a service exposes is declared here.

Feature	Description	Since	Role	Conformance	Requirement	Spec
Entity type	Structured type with an identity (key)	4.0	–	Core	–	Csdl - Entity Type
Complex type	Structured type without identity, used as a property value	4.0	–	Core	–	Csdl - Complex Type
Enumeration type	Named primitive constants, optionally flags	4.0	–	Core	–	Csdl - Enumeration Type
Type definition	Named alias/specialization of a primitive type	4.0	–	Core	–	Csdl - Type Definition
Structural property	Primitive, complex, enum or collection-valued property	4.0	–	Core	–	Csdl - Structural Property
Navigation property	Typed relationship to another entity type	4.0	–	Core	–	Csdl - Navigation Property
Entity container	Declares the exposed entity sets, singletons and imports	4.0	–	Core	–	Csdl - Entity Container
Action & function declaration	Signature, binding, return type, overloads	4.0	–	Core	–	Csdl - Action and Function
Annotations & vocabularies	Terms applied to model elements	4.0	–	Core	–	Csdl - Vocabulary and Annotation
CSDL XML representation	$metadata as XML	4.0	Server	Adv	MUST	Csdl - XML Representation
CSDL JSON representation	$metadata as JSON	4.01	Server	–	SHOULD	Csdl - CSDL Document
Schema versioning	Model evolution, $schemaversion	4.01	Server	–	MAY	Protocol - Model Versioning

1.1 Keys & Identity

Feature	Description	Since	Role	Conformance	Requirement	Spec
Simple key	Single key property	4.0	–	Core	–	Csdl - Entity Type
Composite key	Several properties forming the key	4.0	–	Core	–	Csdl - Entity Type
Alternate keys	Additional unique identifiers besides the canonical key	4.0	Server	–	MAY	Url - Addressing Entities
Entity-id	Durable, globally unique identity of an entity	4.0	–	Core	–	Protocol - Entity-Ids and Entity References

1.2 Relationships

Feature	Description	Since	Role	Conformance	Requirement	Spec
Single-valued navigation	To-one relationship	4.0	–	Core	–	Csdl - Navigation Property
Collection-valued navigation	To-many relationship	4.0	–	Core	–	Csdl - Navigation Property
Partner navigation	Bidirectional relationship declaration	4.0	–	Core	–	Csdl - Navigation Property
Referential constraint	Dependent/principal property pairs	4.0	–	Core	–	Csdl - Navigation Property
Containment navigation	Child entities addressed only through the parent	4.0	–	Core	–	Csdl - Navigation Property
Navigation property binding	Maps a navigation to a concrete target set	4.0	–	Core	–	Csdl - Entity Container
Integrity constraints on modification	Behavior when a constraint would be violated	4.0	–	Core	–	Protocol - Handling of Integrity Constraints

1.3 Inheritance & Open Types

Feature	Description	Since	Role	Conformance	Requirement	Spec
Type inheritance	Derived entity and complex types	4.0	–	Core	–	Csdl - Entity Type
Abstract types	Types that cannot be instantiated	4.0	–	Core	–	Csdl - Entity Type
Open types	Instances may carry undeclared (dynamic) properties	4.0	–	Core	–	Protocol - Properties Not Advertised in Metadata
Untyped values	Values without a declared EDM type	4.01	–	Core	–	Json - Untyped Value

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2. Service Model

Feature	Description	Since	Role	Conformance	Requirement	Spec
Service root & service document	Entry point listing entity sets, singletons, imports	4.0	Server	Min	MUST	Protocol - Service Document Request
Metadata document	$metadata, the CSDL of the service	4.0	Server	Adv	MUST	Protocol - Metadata Document Request
Entity references	Referring to an entity by its id instead of its value	4.0	–	Core	–	Protocol - Entity-Ids and Entity References
Read URLs & edit URLs	Distinct URLs for reading and modifying an entity	4.0	Server	Upd	MUST	Protocol - Read URLs and Edit URLs
Transient entities	Entities without a durable id (e.g. operation results)	4.01	–	Core	–	Protocol - Transient Entities
Default namespaces	Omitting the namespace when unambiguous	4.01	Server	Min	MUST	Protocol - Default Namespaces

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3. Versioning & Extensibility

Feature	Description	Since	Role	Conformance	Requirement	Spec
Protocol versioning	OData-Version / OData-MaxVersion negotiation	4.0	Both	Min	MUST	Protocol - Protocol Versioning
Model versioning	Evolving the schema without breaking clients	4.0	Server	–	MAY	Protocol - Model Versioning
Custom query options	Service-specific options without $ prefix	4.0	Server	–	MAY	Url - Custom Query Options
Query option extensibility	Rules for extending the option space	4.0	Both	Min	MUST	Protocol - Query Option Extensibility
Payload extensibility	Additional content in payloads	4.0	Both	Min	MUST	Protocol - Payload Extensibility
Action/function extensibility	Adding operations without breaking clients	4.0	Both	Min	MUST	Protocol - Action/Function Extensibility
Vocabulary extensibility	Defining and applying custom terms	4.0	Both	Min	MUST	Protocol - Vocabulary Extensibility
Header field extensibility	Custom headers	4.0	Both	Min	MUST	Protocol - Header Field Extensibility
Format extensibility	Additional payload formats	4.0	Both	Min	MUST	Protocol - Format Extensibility

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4. Formats & JSON Payloads

Feature	Description	Since	Role	Conformance	Requirement	Spec
Format negotiation	Accept header and $format query option	4.0	Both	Min	MUST	Protocol - Formats
$format	Format as a query option instead of a header	4.0	Server	–	MAY	Protocol - $format
Metadata level	odata.metadata=full / minimal / none	4.0	Both	–	MAY	Json - Amount of Control Information
Number representation	IEEE754Compatible for Edm.Int64 / Edm.Decimal	4.0	Server	–	MAY	Json - Representation of Numbers
Relative URLs	Shortened URLs resolved against the context	4.0	–	Core	–	Json - Relative URLs
Payload ordering constraints	Required ordering of control information	4.0	Server	Min	MUST	Json - Payload Ordering Constraints
Instance annotations	@ns.term on objects, arrays and primitives	4.0	Server	–	MAY	Json - Instance Annotations

4.1 Control Information

Metadata carried inside the payload. In 4.0 every name is prefixed (@odata.context); 4.01 allows the short form (@context), and consumers must accept both.

Control information	Meaning	Since	Role	Conformance	Requirement	Spec
@odata.context	Describes the shape of the payload	4.0	Server	Min	MUST	Protocol - Context URL
@odata.metadataEtag	ETag of the metadata document	4.0	Server	–	MAY	Json - Control Information
@odata.type	Type of the instance, for derived/ambiguous types	4.0	Server	Min	MUST	Json - Control Information
@odata.count	Total count of a collection	4.0	Server	Min	MUST	Json - Control Information
@odata.nextLink	Link to the next page (server-driven paging)	4.0	Server	Min	MUST	Json - Control Information
@odata.deltaLink	Link for subsequent change tracking	4.0	Server	–	MAY	Json - Delta Payload
@odata.id	Entity-id of the instance	4.0	Server	–	MAY	Json - Control Information
@odata.editLink / @odata.readLink	Edit and read URL of the instance	4.0	Server	Upd	MUST	Json - Control Information
@odata.etag	Concurrency token of the instance	4.0	Server	–	MAY	Json - Control Information
@odata.navigationLink / @odata.associationLink	Links to a related entity and its reference	4.0	Server	–	MAY	Json - Navigation Link
@odata.mediaEditLink, @odata.mediaReadLink, @odata.mediaContentType, @odata.mediaEtag	Media stream links and metadata	4.0	Server	–	MAY	Json - Media Entity
@odata.bind	Binds a navigation property to an existing entity	4.0	Server	–	MAY	Json - Bind Operation
@odata.removed	Marks a deleted entity in a delta payload	4.0	Server	–	MAY	Json - Delta Payload
Prefix-less form (@context, @count, …)	Short spelling of all control information	4.01	Server	Min	MUST	Json - Control Information

4.2 Payload Shapes

Payload	Description	Since	Role	Conformance	Requirement	Spec
Service document	List of exposed resources	4.0	Server	Min	MUST	Json - Service Document
Entity	Single entity	4.0	Server	Min	MUST	Json - Entity
Collection of entities	Entity set or navigation collection	4.0	Server	Min	MUST	Json - Collection of Entities
Structural property	Primitive, complex, and collections thereof	4.0	Server	Min	MUST	Json - Structural Property
Entity reference	$ref payload carrying only the entity-id	4.0	Server	–	MAY	Json - Entity Reference
Expanded navigation property	Related entities inlined	4.0	Server	Adv	MUST	Json - Expanded Navigation Property
Stream property & media entity	Binary content and its links	4.0	Server	–	MAY	Json - Stream Property
Operation response	Result of a function or action	4.0	Server	–	MAY	Json - Individual Property or Operation Response
Collection of operation responses	Results of several operations	4.01	Server	–	MAY	Json - Collection of Operation Responses
Delta payload	Changes since a delta link	4.0	Server	–	MAY	Json - Delta Payload
Collection ETag	ETag covering a whole collection	4.01	Server	–	MAY	Json - Collection ETag

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5. Header Fields & Preferences

Header	Direction	Description	Since	Role	Conformance	Requirement	Spec
Content-Type	both	Payload format incl. parameters	4.0	Both	Min	MUST	Protocol - Content-Type
Content-Encoding	both	Compression	4.0	Both	–	MAY	Protocol - Content-Encoding
Content-Language	both	Natural language of the payload	4.0	Both	–	MAY	Protocol - Content-Language
Content-Length	both	Payload size	4.0	Both	–	MAY	Protocol - Content-Length
OData-Version	both	Version of the payload	4.0	Both	Min	MUST	Protocol - OData-Version
Accept	request	Requested format	4.0	Client	Min	MUST	Protocol - Accept
Accept-Charset	request	Requested charset	4.0	Client	–	MAY	Protocol - Accept-Charset
Accept-Language	request	Requested language	4.0	Client	–	MAY	Protocol - Accept-Language
If-Match	request	Optimistic concurrency for update/delete	4.0	Client	Upd	MUST	Protocol - If-Match
If-None-Match	request	Conditional read, upsert protection	4.0	Client	–	MAY	Protocol - If-None-Match
OData-Isolation	request	snapshot isolation across requests	4.0	Client	–	MAY	Protocol - Isolation
OData-MaxVersion	request	Highest version the client understands	4.0	Client	Min	MUST	Protocol - OData-MaxVersion
Prefer	request	Behavioral hints, see 5.1	4.0	Client	–	MAY	Protocol - Prefer
ETag	response	Concurrency token	4.0	Server	–	MAY	Protocol - ETag
Location	response	URL of a created or async resource	4.0	Server	Upd	MUST	Protocol - Location
OData-EntityId	response	Entity-id when no body is returned	4.0	Server	Upd	MUST	Protocol - OData-EntityId
OData-Error	response	Signals an in-stream error	4.01	Server	–	MAY	Protocol - OData-Error
Preference-Applied	response	Which preferences were honored	4.0	Server	–	MAY	Protocol - Preference-Applied
Retry-After	response	Delay before polling again	4.0	Server	–	MAY	Protocol - Retry-After
AsyncResult	response	Status of an asynchronous request	4.0	Server	–	MAY	Protocol - AsyncResult
Vary	response	Cache-relevant request headers	4.0	Server	–	MAY	Protocol - Vary

5.1 Preferences

All preferences are hints: a service may ignore them, and reports what it applied via Preference-Applied.

Preference	Effect	Since	Role	Conformance	Requirement	Spec
allow-entityreferences	Service may return entity references instead of entities	4.0	Both	–	MAY	Protocol - allow-entityreferences
callback	Asynchronous notification via a callback URL	4.0	Both	–	MAY	Protocol - callback
continue-on-error	Batch continues after a failing request	4.0	Both	–	MAY	Protocol - continue-on-error
include-annotations	Which instance annotations to include	4.0	Both	–	MAY	Protocol - include-annotations
maxpagesize	Hint for the server-driven page size	4.0	Both	–	MAY	Protocol - maxpagesize
omit-values=nulls|defaults	Omit null/default values from the payload	4.01	Both	–	MAY	Protocol - omit-values
return=representation|minimal	Whether modifications return the full entity	4.0	Both	–	MAY	Protocol - return
respond-async	Process the request asynchronously	4.0	Both	–	MAY	Protocol - respond-async
track-changes	Request a delta link for change tracking	4.0	Both	–	MAY	Protocol - track-changes
wait	How long the client will wait for a response	4.0	Both	–	MAY	Protocol - wait

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6. Status Codes & Error Handling

Feature	Description	Since	Role	Conformance	Requirement	Spec
200 OK	Request succeeded with a body	4.0	Server	Min	MUST	Protocol - 200 OK
201 Created	Entity created	4.0	Server	Upd	MUST	Protocol - 201 Created
202 Accepted	Asynchronous processing started	4.0	Server	–	MAY	Protocol - 202 Accepted
204 No Content	Success without a body	4.0	Server	Min	MUST	Protocol - 204 No Content
3xx / 304 Not Modified	Redirection and conditional-read result	4.0	Server	–	MAY	Protocol - 3xx Redirection
404, 405, 406, 410, 412, 424	Client error responses	4.0	Server	Min	MUST	Protocol - Client Error Responses
501 Not Implemented	Unsupported feature	4.0	Server	Min	MUST	Protocol - 501 Not Implemented
Error response body	code, message, target, details, innererror	4.0	Server	Min	MUST	Protocol - Error Response Body
In-stream errors	Failure after the response body has started	4.0	Server	–	MAY	Protocol - In-Stream Errors
Error in a success payload	Error information alongside partial results	4.01	Server	–	MAY	Json - Error Information in a Success Payload

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7. Context URL

@odata.context tells the consumer how to interpret the payload. The specification defines a distinct form per payload kind.

Context for	Since	Role	Conformance	Requirement	Spec
Service document	4.0	Server	Min	MUST	Protocol - Service Document
Collection of entities / single entity	4.0	Server	Min	MUST	Protocol - Collection of Entities
Singleton	4.0	Server	Min	MUST	Protocol - Singleton
Derived entities (collection and single)	4.0	Server	–	MAY	Protocol - Collection of Derived Entities
Projected entities ($select)	4.0	Server	Int	MUST	Protocol - Collection of Projected Entities
Expanded entities ($expand)	4.0	Server	Adv	MUST	Protocol - Collection of Expanded Entities
Entity references ($ref)	4.0	Server	–	MAY	Protocol - Collection of Entity References
Property value	4.0	Server	Int	MUST	Protocol - Property Value
Complex or primitive type (and collections)	4.0	Server	Min	MUST	Protocol - Complex or Primitive Type
Operation result	4.0	Server	–	MAY	Protocol - Operation Result
Delta payload and its items	4.0	Server	–	MAY	Protocol - Delta Payload Response
$all / $crossjoin responses	4.0	Server	–	MAY	Protocol - $all Response

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8. Resource Addressing

How a URL identifies a resource. Query options are covered in section 9.

Feature	Syntax	Since	Role	Conformance	Requirement	Spec
Service root	https://host/service/	4.0	Server	Min	MUST	Url - Service Root URL
Metadata endpoint	/$metadata	4.0	Server	Adv	MUST	Url - Addressing the Model
Batch endpoint	/$batch	4.0	Server	Adv	MUST	Url - Addressing the Batch Endpoint
Entity set & singleton	/Products, /Me	4.0	Server	Min	MUST	Url - Addressing Entities
Canonical key predicate	/Products(1), /Products('abc')	4.0	Server	Min	MUST	Url - Addressing Entities
Composite key	/OrderItems(OrderID=1,ItemNo=2)	4.0	Server	Min	MUST	Url - Addressing Entities
Key-as-segment	/Products/1	4.0	Server	–	MAY	Url - Addressing Entities
Navigation path	/Orders(1)/Items	4.0	Server	Min	MUST	Url - Addressing Entities
Property access	/Products(1)/Name	4.0	Server	Int	MUST	Url - Addressing a Property
Raw value	/Products(1)/Name/$value	4.0	Server	Int	MUST	Url - Addressing a Property Value
Media stream	/Products(1)/$value	4.0	Server	Int	MUST	Url - Addressing the Media Stream
Entity references	/Orders(1)/Items/$ref	4.0	Server	Upd	MUST	Url - Addressing References
Count of a collection	/Products/$count	4.0	Server	Adv	MUST	Url - Addressing the Count
Type cast segment	/Products/Namespace.DiscountedProduct	4.0	Server	Int	MUST	Url - Addressing Derived Types
Member of a collection	/Products(1)/Tags addressed by value	4.01	Server	–	MAY	Url - Addressing a Member
Member of an ordered collection	/Tags/$index(2)	4.01	Server	–	MAY	Url - Addressing a Member of an Ordered Collection
Subset of a collection	/Items/$filter(@expr)	4.01	Server	–	MAY	Url - Addressing a Subset
Each member	/Products/$each	4.01	Server	–	MAY	Url - Addressing Each Member
Cross join	/$crossjoin(Products,Categories)	4.0	Server	–	MAY	Url - Cross Join
All entities	/$all	4.0	Server	–	MAY	Url - Addressing All Entities
Resolve an entity-id	/$entity?$id=…	4.0	Server	–	MAY	Protocol - Resolving an Entity-Id
Operation invocation	/Products(1)/Namespace.Rate	4.0	Server	–	MAY	Url - Addressing Operations
Query options in the body	POST /Products/$query with text/plain body	4.01	Server	–	MAY	Url - Passing Query Options in the Request Body

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9. Querying Data

Feature	Description	Since	Role	Conformance	Requirement	Spec
Shaping the result	$select and $expand, see 9.1	4.0	Server	Int	MUST	Protocol - Specifying Properties to Return
Filtering	$filter, see 9.2	4.0	Server	Int	MUST	Protocol - $filter
Sorting, paging, counting	$orderby, $top, $skip, $count, see 9.3	4.0	Server	Adv	MUST	Protocol - Querying Collections
Free-text search	$search with its own expression grammar	4.0	Server	Adv	MUST	Protocol - $search
Computed properties	$compute adds derived properties to the result	4.01	Server	–	SHOULD	Protocol - $compute
Aggregation	$apply, see section 15	4.0	Server	–	MAY	Agg
Parameter aliases	@name placeholders reused across options	4.0	Server	Int	MUST	Url - Parameter Aliases
Custom query options	Service-defined, without $ prefix	4.0	Server	–	MAY	Url - Custom Query Options
Individual entities & properties	Reading a single entity, property or raw value	4.0	Server	Min	MUST	Protocol - Requesting Individual Entities
Related entities	Reading across a navigation property	4.0	Server	Min	MUST	Protocol - Requesting Related Entities
Entity references	Reading $ref instead of entities	4.0	Server	–	MAY	Protocol - Requesting Entity References
Schema version selection	$schemaversion	4.01	Server	–	MAY	Protocol - $schemaversion

9.1 $select & $expand

$select narrows the properties returned; $expand inlines related entities. Both accept paths, and $expand additionally carries nested query options, which is what makes it the most complex option in the protocol.

Feature	Syntax	Since	Role	Conformance	Requirement	Spec
Select properties	$select=Name,Price	4.0	Server	Int	MUST	Protocol - $select
Select all	$select=*	4.0	Server	Int	MUST	Protocol - $select
Select with type cast	$select=Namespace.SubType/Prop	4.0	Server	Int	MUST	Protocol - $select
Select an operation	$select=Namespace.Action advertises it	4.0	Server	–	MAY	Protocol - $select
Expand a navigation property	$expand=Category	4.0	Server	Adv	MUST	Protocol - $expand
Expand all	$expand=*	4.0	Server	–	MAY	Protocol - $expand
Expand references	$expand=Items/$ref	4.0	Server	Adv	MUST	Protocol - $expand
Expand a count	$expand=Items/$count	4.0	Server	–	MAY	Protocol - $expand
Expand with type cast	$expand=Namespace.SubType/Nav	4.0	Server	Adv	MUST	Protocol - $expand

9.1.1 Nested Expand Options

Options applied inside an $expand, in parentheses and separated by ; — e.g. $expand=Items($select=Name;$filter=Price gt 10;$top=5). They apply to the related collection, not the parent.

Nested option	Applies to	Since	Role	Conformance	Requirement	Spec
$select	Related entities	4.0	Server	–	SHOULD	Protocol - Expand Options
$expand	Further nesting, recursively	4.0	Server	–	MAY	Protocol - Expand Options
$filter	Collection-valued navigation only	4.0	Server	Adv	MUST	Protocol - Expand Options
$orderby	Collection-valued navigation only	4.0	Server	–	SHOULD	Protocol - Expand Options
$top / $skip	Collection-valued navigation only	4.0	Server	–	SHOULD	Protocol - Expand Options
$count	Collection-valued navigation only	4.0	Server	–	SHOULD	Protocol - Expand Options
$search	Collection-valued navigation only	4.0	Server	–	SHOULD	Protocol - Expand Options
$compute	Related entities	4.01	Server	–	MAY	Protocol - Expand Options
$apply	Collection-valued navigation only	4.0	Server	–	MAY	Agg
$levels	Recursive expansion depth ($levels=3, $levels=max)	4.0	Server	–	SHOULD	Protocol - Expand Option $levels

9.2 $filter Expression Language

A boolean expression evaluated per item. Operands are property paths, literals, parameter aliases and function calls; $it, $this and lambda range variables provide access to the current instance.

9.2.1 Operators

Group	Operators	Since	Role	Conformance	Requirement	Spec
Comparison	eq, ne, gt, ge, lt, le	4.0	Server	Int	MUST	Protocol - Built-in Filter Operations
Logical	and, or, not	4.0	Server	–	SHOULD	Protocol - Built-in Filter Operations
Arithmetic	add, sub, mul, div, mod	4.0	Server	–	SHOULD	Protocol - Built-in Filter Operations
Integer division	divby	4.01	Server	–	SHOULD	Protocol - Built-in Filter Operations
Grouping	( … )	4.0	Server	Int	MUST	Protocol - Built-in Filter Operations
Membership	in — value against a list	4.01	Server	Int	MUST	Protocol - Built-in Filter Operations
Enum/flag test	has	4.0	Server	–	SHOULD	Protocol - Built-in Filter Operations

9.2.2 Built-in Functions

Group	Functions	Since	Role	Conformance	Requirement	Spec
String	concat, contains, endswith, startswith, indexof, length, substring, tolower, toupper, trim	4.0	Server	–	SHOULD	Protocol - Built-in Query Functions
String (4.01)	matchesPattern, substring with two arguments	4.01	Server	–	SHOULD	Protocol - Built-in Query Functions
Collection	hassubset, hassubsequence	4.01	Server	–	SHOULD	Protocol - Built-in Query Functions
Date & time	year, month, day, hour, minute, second, fractionalseconds, date, time, totaloffsetminutes, totalseconds, now, mindatetime, maxdatetime	4.0	Server	–	SHOULD	Protocol - Built-in Query Functions
Arithmetic	round, floor, ceiling	4.0	Server	–	SHOULD	Protocol - Built-in Query Functions
Type	cast, isof	4.0	Server	–	SHOULD	Protocol - Built-in Query Functions
Conditional	case	4.0	Server	–	SHOULD	Protocol - Built-in Query Functions
Geo	geo.distance, geo.intersects, geo.length	4.0	Server	–	MAY	Protocol - Built-in Query Functions

9.2.3 Lambda Operators & Path Expressions

Feature	Syntax	Since	Role	Conformance	Requirement	Spec
any	Items/any(i: i/Price gt 10)	4.0	Server	Adv	MUST	Protocol - Built-in Filter Operations
all	Items/all(i: i/InStock)	4.0	Server	Adv	MUST	Protocol - Built-in Filter Operations
any without a predicate	Items/any() — collection is non-empty	4.0	Server	Adv	MUST	Protocol - Built-in Filter Operations
$it	The current instance	4.0	Server	–	MAY	Protocol - Built-in Filter Operations
$this	The current instance inside a lambda	4.01	Server	–	MAY	Protocol - Built-in Filter Operations
$root	Absolute reference to the service root	4.0	Server	–	MAY	Protocol - Built-in Filter Operations
Parameter alias	$filter=Name eq @n&@n='X'	4.0	Server	Int	MUST	Protocol - Parameter Aliases

9.3 Ordering, Paging & Counting

Feature	Syntax	Since	Role	Conformance	Requirement	Spec
Sorting	$orderby=Name desc,Price asc	4.0	Server	Adv	MUST	Protocol - $orderby
Client-driven paging	$top=10&$skip=20	4.0	Server	Int	MUST	Protocol - $top
Inline count	$count=true	4.0	Server	Adv	MUST	Protocol - $count
Count of a collection	/Products/$count as a raw value	4.0	Server	Adv	MUST	Protocol - Requesting the Number of Items
Server-driven paging	@odata.nextLink, maxpagesize preference	4.0	Server	Min	MUST	Protocol - Server-Driven Paging
Skip token	Opaque continuation inside nextLink	4.0	Server	Min	MUST	Protocol - Server-Driven Paging
Member of an ordered collection	$index	4.01	Server	–	MAY	Protocol - Requesting an Individual Member

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10. Change Tracking (Delta)

Feature	Description	Since	Role	Conformance	Requirement	Spec
Request change tracking	Prefer: track-changes	4.0	Both	–	MAY	Protocol - track-changes
Delta link	@odata.deltaLink returned with the result	4.0	Server	–	MAY	Protocol - Delta Links
Using a delta link	Fetching changes since the previous response	4.0	Client	–	MAY	Protocol - Using Delta Links
Delta payload	Added/changed entities, deletions, link changes	4.0	Server	–	MAY	Protocol - Delta Payloads
Deleted entity	@removed with a reason	4.0	Server	–	MAY	Json - Delta Payload
Added / deleted link	Relationship changes as their own entries	4.0	Server	–	MAY	Json - Added Link
Nested delta in expanded properties	Delta inside $expand	4.01	Server	–	MAY	Json - Delta Responses

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11. Data Modification

Feature	Method	Since	Role	Conformance	Requirement	Spec
Create an entity	POST to an entity set	4.0	Server	Upd	MUST	Protocol - Create an Entity
Update an entity	PATCH (merge)	4.0	Server	Upd	MUST	Protocol - Update an Entity
Replace an entity	PUT (full replace)	4.0	Server	–	SHOULD	Protocol - Update an Entity
Upsert	PATCH/PUT on a non-existing key	4.0	Server	Upd	MUST	Protocol - Upsert an Entity
Delete an entity	DELETE	4.0	Server	Upd	MUST	Protocol - Delete an Entity
Optimistic concurrency	If-Match / If-None-Match with ETags	4.0	Server	Upd	MUST	Protocol - Use of ETags
Returning results	Prefer: return=representation|minimal	4.0	Server	–	MAY	Protocol - Returning Results
DateTimeOffset handling	Normalization rules on modification	4.0	Server	Min	MUST	Protocol - Handling of DateTimeOffset
Undeclared properties	Behavior for open/dynamic properties	4.0	Server	–	MAY	Protocol - Properties Not Advertised

11.1 Related Entities & Relationships

Feature	Description	Since	Role	Conformance	Requirement	Spec
Deep insert	Create an entity together with related ones	4.0	Server	–	SHOULD	Protocol - Create Related Entities
Bind on create	@odata.bind / @id to link existing entities	4.0	Server	–	MAY	Protocol - Link to Related Entities
Deep update	Nested changes inside PATCH	4.01	Server	–	SHOULD	Protocol - Update Related Entities
Add a reference	POST to …/Nav/$ref	4.0	Server	Upd	MUST	Protocol - Add a Reference
Remove a reference	DELETE on …/Nav/$ref	4.0	Server	Upd	MUST	Protocol - Remove a Reference
Change a single-valued reference	PUT on …/Nav/$ref	4.0	Server	Upd	MUST	Protocol - Change the Reference
Replace all references	PUT on a collection-valued …/Nav/$ref	4.0	Server	–	SHOULD	Protocol - Replace all References

11.2 Properties, Values & Collections

Feature	Description	Since	Role	Conformance	Requirement	Spec
Update a primitive property	PUT on the property URL	4.0	Server	–	SHOULD	Protocol - Update a Primitive Property
Set a value to null	DELETE on the property URL	4.0	Server	–	SHOULD	Protocol - Set a Value to Null
Update a complex property	PATCH/PUT on the property URL	4.0	Server	–	SHOULD	Protocol - Update a Complex Property
Update a collection property	Replace the whole collection	4.0	Server	–	MAY	Protocol - Update a Collection Property
Update a collection of entities	Delta-style collection update	4.01	Server	–	MAY	Protocol - Update a Collection of Entities
Update members of a collection	PATCH via $each	4.01	Server	–	MAY	Protocol - Update Members of a Collection
Delete members of a collection	DELETE via $each	4.01	Server	–	MAY	Protocol - Delete Members of a Collection
Ordered collections	Managing members by position	4.01	Server	–	MAY	Protocol - Managing Members of an Ordered Collection
Positional insert	$index on insert	4.01	Server	–	MAY	Protocol - Positional Inserts

11.3 Media Entities & Streams

Feature	Description	Since	Role	Conformance	Requirement	Spec
Create a media entity	POST the stream, then patch the properties	4.0	Server	–	MAY	Protocol - Create a Media Entity
Update a media stream	PUT on /$value	4.0	Server	–	MAY	Protocol - Update a Media Entity Stream
Delete a media entity	DELETE on the entity	4.0	Server	–	MAY	Protocol - Delete a Media Entity
Update a stream property	PUT on the stream property	4.0	Server	–	MAY	Protocol - Update Stream Values
Delete a stream property	DELETE on the stream property	4.0	Server	–	MAY	Protocol - Delete Stream Values

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12. Operations (Functions & Actions)

Feature	Description	Since	Role	Conformance	Requirement	Spec
Function	Side-effect free, GET, composable	4.0	Server	–	MAY	Protocol - Functions
Action	May have side effects, POST, not composable	4.0	Server	–	MAY	Protocol - Actions
Unbound operation	Invoked via an import at the service root	4.0	Server	–	MAY	Protocol - Operations
Bound operation	Bound to an entity, collection or complex type	4.0	Server	–	MAY	Protocol - Binding an Operation
Function parameters in the URL	/Rate(value=4)	4.0	Server	–	MAY	Protocol - Invoking a Function
Inline parameter syntax	Parameters as query options	4.01	Server	–	MAY	Protocol - Inline Parameter Syntax
Action parameters in the body	JSON object with named parameters	4.0	Server	–	MAY	Protocol - Invoking an Action
Overload resolution	Selecting among overloads by parameter names	4.0	Server	–	MAY	Protocol - Function overload resolution
Composable functions	Further path segments and options on the result	4.0	Server	–	MAY	Protocol - Functions
Operation advertisement	Available operations announced in the payload	4.0	Server	–	MAY	Protocol - Advertising Available Operations

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13. Asynchronous Requests

Feature	Description	Since	Role	Conformance	Requirement	Spec
Request async processing	Prefer: respond-async	4.0	Both	–	SHOULD	Protocol - respond-async
Status monitor	202 Accepted plus Location for polling	4.0	Server	–	MAY	Protocol - Asynchronous Requests
Polling interval	Retry-After	4.0	Client	–	MAY	Protocol - Retry-After
Fetching the result	Final response once processing finished	4.0	Client	–	MAY	Protocol - Asynchronous Requests
Cancellation	DELETE on the status monitor	4.0	Client	–	MAY	Protocol - Asynchronous Requests
Callback	Prefer: callback instead of polling	4.0	Both	–	MAY	Protocol - callback
Asynchronous batch	Async processing of a batch request	4.0	Server	–	MAY	Protocol - Asynchronous Batch Requests

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14. Batch Requests

Feature	Description	Since	Role	Conformance	Requirement	Spec
Multipart batch	multipart/mixed body	4.0	Both	Adv	MUST	Protocol - Multipart Batch Format
JSON batch	Batch as a JSON document	4.01	Both	–	MAY	Json - Batch Requests and Responses
Change sets	Group of modifications treated atomically	4.0	Server	Adv	MUST	Protocol - Multipart Batch Request Body
Request identification	id per request	4.01	Client	–	MAY	Protocol - Identifying Individual Requests
Request dependencies	dependsOn between requests	4.01	Client	–	MAY	Protocol - Request Dependencies
Referencing new entities	$<id> referring to a previous result	4.0	Client	Adv	MUST	Protocol - Referencing New Entities
Referencing an ETag	Using an ETag from an earlier response	4.0	Client	–	MAY	Protocol - Referencing an ETag
Referencing response values	Using values from earlier response bodies	4.01	Client	–	MAY	Protocol - Referencing Values from Response Bodies
Continue on error	Prefer: continue-on-error	4.0	Client	–	MAY	Protocol - continue-on-error
Batch headers	Headers applying to the batch as a whole	4.0	Both	Adv	MUST	Protocol - Batch Request Headers

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15. Aggregation ($apply)

Defined by the Data Aggregation Extension, not by the core protocol. $apply is a pipeline: each transformation consumes the previous result set.

Transformation	Description	Role	Conformance	Requirement	Spec
aggregate	Aggregate values with sum, min, max, average, countdistinct, $count	Server	–	MAY	Agg - aggregate
groupby	Group by properties, optionally with a nested transformation	Server	–	MAY	Agg - groupby
filter	Filter within the pipeline	Server	–	MAY	Agg - filter
compute	Add computed properties	Server	–	MAY	Agg - compute
expand	Expand within the pipeline	Server	–	MAY	Agg - groupby with navigation
concat	Concatenate several result sets	Server	–	MAY	Agg - concat
identity	Neutral transformation	Server	–	MAY	Agg - identity
orderby	Order within the pipeline	Server	–	MAY	Agg - orderby
skip / top	Paging within the pipeline	Server	–	MAY	Agg - top
topcount / bottomcount	Top or bottom N by an expression	Server	–	MAY	Agg - topcount/bottomcount
toppercent / bottompercent	Top or bottom N percent	Server	–	MAY	Agg - toppercent/bottompercent
topsum / bottomsum	Members contributing to a share of a sum	Server	–	MAY	Agg - topsum/bottomsum
search	Free-text search within the pipeline	Server	–	MAY	Agg - search
join / outerjoin	Join across navigation properties	Server	–	MAY	Agg - join/outerjoin
traverse	Traverse a recursive hierarchy	Server	–	MAY	Agg - traverse
ancestors / descendants	Hierarchy navigation	Server	–	MAY	Agg - ancestors/descendants
Custom aggregates	Service-defined aggregation methods	Server	–	MAY	Agg - Custom Aggregates

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16. Security & Conformance

Feature	Description	Since	Role	Conformance	Requirement	Spec
Authentication	Not prescribed; delegated to HTTP mechanisms	4.0	–	Core	–	Protocol - Authentication
Security considerations	Injection, information disclosure, resource exhaustion	4.0	–	Core	–	Protocol - Security Considerations
4.0 conformance levels	Minimal, Intermediate, Advanced	4.0	–	Core	–	Protocol - OData 4.0 Conformance Levels
4.01 conformance levels	Revised level definitions	4.01	–	Core	–	Protocol - OData 4.01 Conformance Levels
Interoperable clients	What a client must tolerate to be interoperable	4.0	–	Core	–	Protocol - Interoperable OData Clients