Actions

The ballerinax/confluent.cregistry package exposes the following clients:

Client	Purpose
Client	Registers and retrieves schemas from Confluent Schema Registry.

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Client

Registers and retrieves schemas from Confluent Schema Registry.

Configuration

Field	Type	Default	Description
baseUrl	string	Required	The base URL of the Schema Registry endpoint (e.g., https://psrc-xxxxx.us-east-2.aws.confluent.cloud).
identityMapCapacity	int	1000	Capacity of the schema ID map for a particular subject.
originals	map<anydata>?	()	Connection configurations for authentication and SSL (e.g., basic auth credentials, truststore settings).
headers	map<string>?	()	Custom HTTP headers to include in requests to the Schema Registry.

Initializing the client

import ballerinax/confluent.cregistry;

configurable string baseUrl = ?;
configurable string apiKey = ?;
configurable string apiSecret = ?;

cregistry:Client schemaRegistryClient = check new (
    baseUrl = baseUrl,
    originals = {
        "basic.auth.credentials.source": "USER_INFO",
        "basic.auth.user.info": string `${apiKey}:${apiSecret}`
    }
);

Operations

Schema operations

register

Registers a schema under the specified subject in the Schema Registry. Returns the unique schema ID assigned by the registry.

Parameters:

Name	Type	Required	Description
subject	string	Yes	The subject name under which to register the schema (e.g., "my-topic-value").
schema	string	Yes	The schema definition as a JSON string (e.g., an Avro schema).

Returns: int|cregistry:Error

Sample code:

string schema = string `
    {
        "namespace": "example.avro",
        "type": "record",
        "name": "Student",
        "fields": [
            {"name": "name", "type": "string"},
            {"name": "favorite_color", "type": ["string", "null"]}
        ]
    }`;

int registerId = check schemaRegistryClient->register("student-topic-value", schema);

Sample response:

1

getSchemaById

Retrieves a schema from the Schema Registry by its unique schema ID. Returns the schema definition as a string.

Parameters:

Name	Type	Required	Description
id	int	Yes	The unique ID of the schema to retrieve.

Returns: string|cregistry:Error

Sample code:

string schema = check schemaRegistryClient->getSchemaById(1);

Sample response:

{"type":"record","name":"Student","namespace":"example.avro","fields":[{"name":"name","type":"string"},{"name":"favorite_color","type":["string","null"]}]}

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Errors

Both operations return a cregistry:Error on failure. Its detail record, cregistry:ErrorDetails, contains the following optional fields:

Field	Type	Description
status	int	The HTTP status code returned by the Schema Registry.
errorCode	int	The error code returned by the Schema Registry.

string|cregistry:Error result = schemaRegistryClient->getSchemaById(1);
if result is cregistry:Error {
    cregistry:ErrorDetails details = result.detail();
    int? status = details?.status;
    int? errorCode = details?.errorCode;
}