VALIDATORS.md

Validator Compatibility Matrix

Cross-language API surface comparison for all schemata-validator-* implementations. The reference implementation is @nostrwatch/schemata-js-ajv.

Core Functions

Function	JS (ref)	Rust	Kotlin	Go	Swift	Dart	Python	Java	PHP	Ruby	C#	C++	C
validate	yes	yes	yes	yes	—	yes	yes	yes	yes	yes	yes	yes	yes
validateNote	yes	yes	yes	yes	yes	yes	yes	yes	yes	yes	yes	yes	yes
validateNip11	yes	yes	yes	yes	yes	yes	yes	yes	yes	yes	—	yes	yes
validateMessage	yes	yes	yes	yes	yes	yes	yes	yes	—	—	—	yes	yes
getSchema	—	yes	yes	yes	yes	yes	yes	yes	yes	yes	yes	yes	yes

Types

Type	JS (ref)	Rust	Kotlin	Go	Swift	Dart	Python	Java	PHP	Ruby	C#	C++	C
ValidationResult	yes	yes	yes	yes	yes	yes	yes	yes (record)	yes	yes (Struct)	yes (record)	yes	yes (struct)
ValidationError	AJV ErrorObject	yes	yes	yes	yes	yes	yes (dataclass)	yes (record)	yes	yes (Struct)	yes (record)	yes	yes (struct)
Subject enum	string literal	yes	yes	yes (int)	yes	yes	yes (Enum)	yes	—	—	yes	yes	yes (enum)

Internal Features

Feature	JS (ref)	Rust	Kotlin	Go	Swift	Dart	Python	Java	PHP	Ruby	C#	C++	C
Strip nested $id	—	yes	yes	yes	yes	yes	yes	yes	yes	yes	—	yes	yes
Strip nested $schema	—	—	—	—	yes	yes	—	yes	yes	yes	—	yes	yes
Additional props warnings	yes	yes	yes	yes	yes	yes	yes	—	—	—	—	—	yes
errorMessage enrichment	yes	yes	yes	yes*	—	—	yes	—	—	—	—	—	yes

* Go has the code but enrichMessage is never called (dead code).

Input Types

Language	Schema input	Data input
JS (ref)	internal (AJV compiled)	any / NostrEvent
Rust	&serde_json::Value	&serde_json::Value
Kotlin	JsonElement (kotlinx)	JsonElement (kotlinx)
Go	json.RawMessage	json.RawMessage
Swift	[String: Any]	[String: Any] / Any
Dart	Map<String, dynamic>	dynamic
Python	dict	Any
Java	String (JSON)	String (JSON)
PHP	array	mixed
Ruby	Hash	Object
C#	string (JSON)	string (JSON)
C++	const std::string& (JSON)	const std::string& (JSON)
C	const char* (JSON)	const char* (JSON)

JSON Schema Library & Draft

Language	Library	Draft
JS (ref)	AJV	7
Rust	jsonschema 0.45	7
Kotlin	networknt json-schema-validator 1.5.6	7
Go	santhosh-tekuri/jsonschema v6	7
Swift	kylef/JSONSchema.swift	7
Dart	Workiva json_schema 5.2	7
Python	jsonschema >=4.0	7
Java	networknt json-schema-validator 1.5.6	7
PHP	opis/json-schema 2.0	7
Ruby	json_schemer 2.0	7
C#	JsonSchema.Net 7.*	7
C++	valijson 1.0.3	7
C	jsonc-daccord (nostrability fork)	7

Gaps

Gap	Affected repos	Severity
Missing validateMessage	PHP, Ruby, C#	Medium — can't validate relay/client protocol messages
Missing validateNip11	C#	Medium — can't validate relay info documents
Missing validate (low-level)	Swift	Low — users can't validate against arbitrary schemas
No Subject enum	PHP, Ruby	Low — follows from missing validateMessage
No additional-props warnings	Java, PHP, Ruby, C#, C++	Medium — warnings array always empty, reduces signal
No errorMessage enrichment	Swift, Dart, Java, PHP, Ruby, C#, C++	Low — uses default validator error strings instead
Dead enrichMessage code	Go	Trivial — defined but never wired into Validate()
getSchema missing from JS ref	JS	Intentional — JS uses internal AJV compiled schemas
No nested $id stripping	JS, C#	Low — may cause resolution issues with certain schemas