How passing parameters between operations (Ops)

[alexasha66]

I'm new to dagster and need help understanding how to pass parameters (like a dictionary) between operations (Ops)

The example below works, and passing input parameters between
prn_op(sub_op_1()) passes, but

from dagster import  Out, In, op, job, get_dagster_logger, Config

class MyOpConfig(Config):
    main_param: dict



@op(out=Out(dict))
def sub_op_1() -> dict:
    return {"key1": 1, "key2": 2}

@op(out=Out(dict))
def sub_op2(ins={"op_cfg": In(MyOpConfig)} ) -> dict:
    op_cfg.main_param["key4"] = 4
    return op_cfg.main_param


@op(ins={"tst_dict": In(dict)})
def prn_op(tst_dict: dict):
    tst_dict['key3'] = 3
    print(tst_dict)



@job
def main_elt():

    prn_op(sub_op_1())

    # main_param = sub_op2(MyOpConfig(main_param={}))
    # print(main_param)

if __name__ == "__main__":
    # Call a flow function for a local flow run!
    main_elt()

If you remove the comment from the code below prn_op(sub_op_1()) , an error occurs:

dagster._core.errors.DagsterInvalidDefinitionError: In @job main_elt, received invalid type <class 'test.MyOpConfig'> for input "ins" (at position 0) in op invocation "sub_op2". Must pass the output from previous node invocations or inputs to the composition function as inputs when invoking nodes during composition.