# Platform Event Schema by Schema ID Gets the definition of a platform event in JSON format for a schema ID. This resource is available in REST API version 40.0 and later. | 400 Bad Request | Description | | ------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------- | | In API version 43.0 and later | The request was formatted incorrectly—an invalid value was passed for the `payloadFormat` parameter in the URI. | | In API version 42.0 and earlier | The request was formatted incorrectly—the `payloadFormat` parameter was passed in the URI but this API version doesn’t support this parameter. | ## Syntax **URI:** `/services/data/vXX.X/event/eventSchema/schemaId` **Formats:** JSON **HTTP methods:** GET **Authentication:** `Authorization: Bearer token` **Parameters** | Parameter | Description | | --------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------- | | `payloadFormat` | (Optional query parameter. Available in API version 43.0 and later.) The format of the returned event schema. Valid values are `EXPANDED` and `COMPACT`. | `payloadFormat` values: - `EXPANDED`—The JSON representation of the event schema, which is the default format when `payloadFormat` isn’t specified in API version 43.0 and later. The expanded event schema is in the open-source Apache Avro format but doesn’t strictly adhere to the record complex type. For more information about the schema fields, see [Apache Avro Format](#apache-avro-format). - `COMPACT`—The JSON representation of the event schema that adheres to the open-source Apache Avro specification for the record complex type. For more information about the schema fields, see [Apache Avro Format](#apache-avro-format). Subscribers use the compact schema format to deserialize compact events received in binary form. ## Examples for API Version 43.0 and Later This URI gets the schema of a platform event whose schema ID is `5E5OtZj5_Gm6Vax9XMXH9A`. This schema ID is a sample ID. Replace it with a valid schema ID for your event. ```nolang /services/data/v68.0/event/eventSchema/5E5OtZj5_Gm6Vax9XMXH9A ``` Or: ```nolang /services/data/v68.0/event/eventSchema/5E5OtZj5_Gm6Vax9XMXH9A?payloadFormat=EXPANDED ``` In API version 43.0 and later, the response format is the JSON representation of the event schema by default. The returned response looks like the following in API version 68.0. ```nolang { "name": "Low_Ink__e", "namespace": "com.sforce.eventbus", "type": "expanded-record", "fields": [ { "name": "data", "type": { "type": "record", "name": "Data", "namespace": "", "fields": [ { "name": "schema", "type": "string" }, { "name": "payload", "type": { "type": "record", "name": "Payload", "doc": "", "fields": [ { "name": "CreatedDate", "type": "string", "doc": "CreatedDate:DateTime" }, { "name": "CreatedById", "type": "string", "doc": "CreatedBy:EntityId" }, { "name": "Printer_Model__c", "type": [ "null", "string" ], "doc": "Data:Text:00NRM000001krnv", "default": null }, { "name": "Serial_Number__c", "type": [ "null", "string" ], "doc": "Data:Text:00NRM000001kro0", "default": null }, { "name": "Ink_Percentage__c", "type": [ "null", "double" ], "doc": "Data:Double:00NRM000001kro5", "default": null } ] } }, { "name": "event", "type": { "type": "record", "name": "Event", "fields": [ { "name": "replayId", "type": "long" } ] } } ] } }, { "name": "channel", "type": "string" } ] } ``` To get the compact (Apache Avro) format, use the following URI. ```nolang /services/data/v68.0/event/eventSchema/5E5OtZj5_Gm6Vax9XMXH9A?payloadFormat=COMPACT ``` The returned response for the compact format looks like the following in API version 68.0. ```nolang { "name": "Low_Ink__e", "namespace": "com.sforce.eventbus", "type": "record", "fields": [ { "name": "CreatedDate", "type": "long", "doc": "CreatedDate:DateTime" }, { "name": "CreatedById", "type": "string", "doc": "CreatedBy:EntityId" }, { "name": "Printer_Model__c", "type": [ "null", "string" ], "doc": "Data:Text:00NRM000001krnv", "default": null }, { "name": "Serial_Number__c", "type": [ "null", "string" ], "doc": "Data:Text:00NRM000001kro0", "default": null }, { "name": "Ink_Percentage__c", "type": [ "null", "double" ], "doc": "Data:Double:00NRM000001kro5", "default": null } ], "uuid": "5E5OtZj5_Gm6Vax9XMXH9A" } ``` :::note The compact schema doesn’t include the `replayId` or `channel` fields because these fields aren’t necessary for deserializing the compact event received. Custom formula fields contained within Change Data Capture events include a doc tag in the format `"doc" : "Formula:Text:00NSB00004I3D4L","`. ::: ## Example for API Version 42.0 and Earlier In API version 42.0 and earlier, the response format adheres to the open-source Apache Avro specification for the record complex type. :::note This format is what the API returns in API version 43.0 and later when appending the `?payloadFormat=COMPACT` parameter. ::: This URI gets the schema of a platform event whose schema ID is `5E5OtZj5_Gm6Vax9XMXH9A`. This schema ID is a sample ID. Replace it with a valid schema ID for your event. ```nolang /services/data/v42.0/event/eventSchema/5E5OtZj5_Gm6Vax9XMXH9A ``` The returned response looks like the following in API version 42.0. ```nolang { "name": "Low_Ink__e", "namespace": "com.sforce.eventbus", "type": "record", "fields": [ { "name": "CreatedDate", "type": "long", "doc": "CreatedDate:DateTime" }, { "name": "CreatedById", "type": "string", "doc": "CreatedBy:EntityId" }, { "name": "Printer_Model__c", "type": [ "null", "string" ], "doc": "Data:Text:00NRM000001krnv", "default": null }, { "name": "Serial_Number__c", "type": [ "null", "string" ], "doc": "Data:Text:00NRM000001kro0", "default": null }, { "name": "Ink_Percentage__c", "type": [ "null", "double" ], "doc": "Data:Double:00NRM000001kro5", "default": null } ], "uuid": "5E5OtZj5_Gm6Vax9XMXH9A" } ``` :::note When you change the definition of a platform event, the schema ID for this platform event changes. ::: If you don’t have the schema ID, you can get the schema by supplying the platform event name. Make a GET request to `/services/data/vXX.X/sobjects/eventName/eventSchema`. See [Platform Event Schema by Event Name](/docs/platform/api-rest/guide/resources-sobject-eventschema.md). ## Apache Avro Format The fields in the returned response adhere to the open-source Apache Avro specification for the record complex type (see [Avro Records](https://avro.apache.org/docs/1.8.1/spec.html#schema_record) in the Apache Avro specification). Note the following: - `name` is the name of the platform event. - `namespace` corresponds to `com.sforce.eventbus`. - `type` is the Avro complex type. - `fields` is a JSON array containing the fields of the platform event. For each field: - `type` indicates that the field can be either null or have a value of the specified type. When the field isn’t present, the value is `default`. - `doc` describes the field data type and includes the field ID for custom fields. This field is intended for internal use. For example, Salesforce uses the data type information to convert DateTime fields from long to DateTime. We recommend that you don't rely on this field's value because it might change in the future. The response also includes the `uuid` field, which contains the schema’s ID. The ID is the MD5 fingerprint of the normalized Avro schema encoded as a base-64 URL variant. You can append this ID to the `/vXX.X/event/eventSchema/` URI to retrieve the schema.