> ## Documentation Index > Fetch the complete documentation index at: https://docs.prefect.io/llms.txt > Use this file to discover all available pages before exploring further. # block_schemas # `prefect.server.models.block_schemas` Functions for interacting with block schema ORM objects. Intended for internal use by the Prefect REST API. ## Functions ### `create_block_schema` ```python theme={null} create_block_schema(db: PrefectDBInterface, session: AsyncSession, block_schema: Union[schemas.actions.BlockSchemaCreate, schemas.core.BlockSchema, 'ClientBlockSchemaCreate', 'ClientBlockSchema'], override: bool = False, definitions: Optional[dict[str, Any]] = None) -> Union[BlockSchema, orm_models.BlockSchema] ``` Create a new block schema. **Args:** * `session`: A database session * `block_schema`: a block schema object * `definitions`: Definitions of fields from block schema fields attribute. Used when recursively creating nested block schemas **Returns:** * an ORM block schema model ### `delete_block_schema` ```python theme={null} delete_block_schema(db: PrefectDBInterface, session: AsyncSession, block_schema_id: UUID) -> bool ``` Delete a block schema by id. **Args:** * `session`: A database session * `block_schema_id`: a block schema id **Returns:** * whether or not the block schema was deleted ### `read_block_schema` ```python theme={null} read_block_schema(db: PrefectDBInterface, session: AsyncSession, block_schema_id: UUID) -> Union[BlockSchema, None] ``` Reads a block schema by id. Will reconstruct the block schema's fields attribute to include block schema references. **Args:** * `session`: A database session * `block_schema_id`: a block\_schema id **Returns:** * orm\_models..BlockSchema: the block\_schema ### `read_block_schemas` ```python theme={null} read_block_schemas(db: PrefectDBInterface, session: AsyncSession, block_schema_filter: Optional[schemas.filters.BlockSchemaFilter] = None, limit: Optional[int] = None, offset: Optional[int] = None) -> List[BlockSchema] ``` Reads block schemas, optionally filtered by type or name. **Args:** * `session`: A database session * `block_schema_filter`: a block schema filter object * `limit`: query limit * `offset`: query offset **Returns:** * List\[orm\_models.BlockSchema]: the block\_schemas ### `read_block_schema_by_checksum` ```python theme={null} read_block_schema_by_checksum(db: PrefectDBInterface, session: AsyncSession, checksum: str, version: Optional[str] = None) -> Optional[BlockSchema] ``` Reads a block\_schema by checksum. Will reconstruct the block schema's fields attribute to include block schema references. **Args:** * `session`: A database session * `checksum`: a block\_schema checksum * `version`: A block\_schema version **Returns:** * orm\_models.BlockSchema: the block\_schema ### `read_available_block_capabilities` ```python theme={null} read_available_block_capabilities(db: PrefectDBInterface, session: AsyncSession) -> List[str] ``` Retrieves a list of all available block capabilities. **Args:** * `session`: A database session. **Returns:** * List\[str]: List of all available block capabilities. ### `create_block_schema_reference` ```python theme={null} create_block_schema_reference(db: PrefectDBInterface, session: AsyncSession, block_schema_reference: schemas.core.BlockSchemaReference) -> Union[orm_models.BlockSchemaReference, None] ``` Retrieves a list of all available block capabilities. **Args:** * `session`: A database session. * `block_schema_reference`: A block schema reference object. **Returns:** * orm\_models.BlockSchemaReference: The created BlockSchemaReference ## Classes ### `MissingBlockTypeException` Raised when the block type corresponding to a block schema cannot be found Built with [Mintlify](https://mintlify.com).