Classifications

Classification fields in Ango Annotation Format exports.

The classifications object is part of the task object in the Ango Annotation Format. It contains all annotation data pertaining to labels created with classifications, e.g. not tools, relations, or brushes.

General Structure

"classifications" : [
    {
        answer // object OR list, classification answers
        objectId // string, ID of the classification
        schemaId, // string, ID of the classification class in the project
        classifications, // list, nested classifications
        title // string, title of the classification
        page // int, optional, if asset is multi-page, page where the classification takes place
        tool // string, name of the tool (radio, dropdown, etc.)
        metadata // dict, optional, metadata regarding the annotation (creation date, etc.)
        interpolationStopped // bool, optional, whether in multi-frame assets the classification disappears from this frame on
    },
    { ... }
]

Common Properties

Property	Type	Description
objectId	String	Object ID of the classification. Unique in the asset. "objectId": "6b8a4338d299c63b5ee7825"
schemaId	String	ID of the class to which the classification belongs. "schemaId": "4460fa700ef030c4e575604"
tool	String	Type of classification.
title	String	Name of the class. "title": "Image Projection Type"
metadata	Dict	Only appears if the Annotation Metadata toggle has been turned on before export. createdAt: int, Time of creation in Unix epoch time in milliseconds. GMT. createdBy: string, email of user creating the classification createdIn: string, ID of the stage in which the classification was first answered. updatedAt: int, optional. Time of last classification update in Unix millisecond epoch time. GMT. Only appears if answer has been updated. updatedBy: string, optional. email of user last updating the classification. Only appears if answer has been updated. updatedIn: string, optional. ID of the stage in which the classification was last updated. Only appears if answer has been updated.
classifications	List	List of nested classifications (if any). May contain further nested classifications in its own classifications property. "classifications": [ { "objectId": "78d263ed59db8dd1dcb4666", "schemaId": "4460fa700ef030c4e575604", "tool": "radio", "title": "Nested Radio", "answer": "1", "metadata": { "createdAt": "2023-09-05T10:28:18.667Z", "createdBy": "[e-mail]", "createdIn": "Complete" }, "classifications": [] } ]

Radio

{
    "objectId": "a390f9434a330d14cf16759",
    "schemaId": "4460fa700ef030c4e575604",
    "tool": "radio",
    "title": "Image Projection Type",
    "answer": "Orthogonal",
    "metadata": {
        "createdAt": "2023-09-05T10:32:57.760Z",
        "createdBy": "[e-mail]",
        "createdIn": "194e870c-5255-4ec9-9e6d-392321e504c3"
    },
    "classifications": []
}

Property	Type	Description
answer	String	The answer picked by the annotator. "answer": "Red"

See also

Radio

Checkbox

{
    "objectId": "5ad8ed43d4c036e799fd617",
    "schemaId": "1ea7a275ce5c9cf30a6f148",
    "tool": "checkbox",
    "title": "Vehicle Color(s)",
    "answer": [
        "Red",
        "Yellow"
    ],
    "metadata": {
        "createdAt": "2023-09-06T07:34:23.618Z",
        "createdBy": "[e-mail]",
        "createdIn": "Complete",
        "updatedAt": "2023-09-06T07:34:24.877Z",
        "updatedBy": "[e-mail]",
        "updatedIn": "Complete"
    },
    "classifications": []
}

Property	Type	Description
answer	List	The answer(s) picked. Always a list, even if only one item was selected. "answer": [ "Red", "Yellow" ]

See also

Checkbox

Single-Select Dropdown

{
    "objectId": "9bca9ffa05869a4b60d9751",
    "schemaId": "a2b4a50bb90eb6523b88376",
    "tool": "single-dropdown",
    "title": "Image Projection Type",
    "answer": "Orthogonal",
    "metadata": {
        "createdAt": "2023-09-06T07:34:29.751Z",
        "createdBy": "[e-mail]",
        "createdIn": "Complete"
    },
    "classifications": []
}

Property	Type	Description
answer	String	The answer picked by the annotator. "answer": "Orthogonal"

See also

Single-Select Dropdown

Multi-Select Dropdown

{
    "objectId": "23d2beed0c3958e02d9c315",
    "schemaId": "11f6ed8e4ac4852d3422341",
    "tool": "multi-dropdown",
    "title": "Vehicle Colors",
    "answer": [
        "Red",
        "Yellow"
    ],
    "metadata": {
        "createdAt": "2023-09-06T07:34:32.316Z",
        "createdBy": "[e-mail]",
        "createdIn": "Complete",
        "updatedAt": "2023-09-06T07:34:32.599Z",
        "updatedBy": "[e-mail]",
        "updatedIn": "Complete"
    },
    "classifications": []
}

Property	Type	Description
answer	List	The answer(s) picked. Always a list, even if only one item was selected. "answer": [ "Red", "Yellow" ]

See also

Multi-Select Dropdown

Tree Dropdown

{
    "objectId": "2c786a2d76113b135f7a680",
    "schemaId": "c2b5eb27e55b186f84f3898",
    "tool": "tree-dropdown",
    "title": "Vehicle Color",
    "answer": [
        "Red",
        "Yellows / Dark Yellow"
    ],
    "metadata": {
        "createdAt": "2023-09-06T07:34:36.681Z",
        "createdBy": "[e-mail]",
        "createdIn": "Complete",
        "updatedAt": "2023-09-06T07:34:39.489Z",
        "updatedBy": "[e-mail]",
        "updatedIn": "Complete"
    },
    "classifications": []
}

Property	Type	Description
answer	List	The answer(s) picked. Always a list, even if only one item was selected. "answer": [ "Reds", "Yellows / Dark Yellows / Ochre" ] Answers nested within another are displayed after a /. For example, to get the sample above, the annotator selected the following answers in the UI:

See also

Tree Dropdown

Text

{
    "objectId": "4ff3710fd7cdc644b7dd283",
    "schemaId": "6590a72d09f1760a4578032",
    "tool": "text",
    "title": "txt",
    "answer": "Answer Text Here",
    "metadata": {
        "createdAt": "2023-09-06T07:34:41.283Z",
        "createdBy": "[e-mail]",
        "createdIn": "Complete",
        "updatedAt": "2023-09-06T07:34:42.430Z",
        "updatedBy": "[e-mail]",
        "updatedIn": "Complete"
    },
    "classifications": []
}

Property	Type	Description
answer	String	The answer written by the annotator. "answer": "6 Chained Street, Military Academy District, Ankara, Turkey"

See also

Text

Slider

{
    "objectId": "7a73c6f6d4c74450b3b4c090",
    "schemaId": "8fd54b348e85cfbbdc40326",
    "tool": "slider",
    "title": "Quality Score",
    "answer": 7,
    "metadata": {
        "createdAt": "2026-06-16T10:32:57.760Z",
        "createdBy": "[e-mail]",
        "createdIn": "194e870c-5255-4ec9-9e6d-392321e504c3"
    },
    "classifications": []
}

Property	Type	Description
answer	Number	The numeric value selected by the annotator. "answer": 7

See also

Slider

File Upload Box

{
    "objectId": "b0f7f4c7f7e14d2a8b3fcb42",
    "schemaId": "58af1b9c7f334a939afbbf89",
    "tool": "upload-box",
    "title": "Upload supporting file",
    "answer": "https://example-bucket.s3.amazonaws.com/project-id/upload-box/task-id/evidence.pdf?X-Amz-Algorithm=AWS4-HMAC-SHA256...",
    "metadata": {
        "createdAt": "2026-04-29T10:32:57.760Z",
        "createdBy": "[e-mail]",
        "createdIn": "194e870c-5255-4ec9-9e6d-392321e504c3"
    },
    "classifications": []
}

Property	Type	Description
answer	String	A signed URL to the file uploaded through the upload box. The URL is generated during export and may expire.

See also

File Upload Box