Identity

CurrentUser

CurrentUser is a frozen dataclass with this constructor:

CurrentUser(subject: str, username: Optional[str], claims: Mapping[str, Any])

Field	Value
subject	Non-empty sub claim
username	Non-empty cognito:username, otherwise non-empty username, otherwise None
claims	Read-only MappingProxyType copy returned by current_user

CurrentUserError

CurrentUserError(ValueError) is raised by current_user when the event does not contain a supported, structurally valid identity.

current_user

Signature: current_user(event: Mapping[str, Any]) -> CurrentUser

Example:

from lambda_api_decorators import current_user

def handler(event, context):
    user = current_user(event)
    return {"statusCode": 200, "body": user.subject}

Extract claims from an already-authorized API Gateway event. REST-style events use event["requestContext"]["authorizer"]["claims"]; HTTP API JWT events use event["requestContext"]["authorizer"]["jwt"]["claims"]. The event, requestContext, authorizer, JWT object (when present), and claims must be mappings. Claims must contain a non-empty string sub, otherwise CurrentUserError is raised.

The helper does not authenticate tokens, validate them, or authorize an action. It returns a copy of claims exposed through a read-only mapping.