sap_rfc_connector

sap_rfc_connector is a C++17 + pybind11 wrapper around the SAP NetWeaver RFC SDK. It exposes a small Python API for opening a SAP connection, calling RFC functions, and reading metadata.

What this package provides

• Python extension module: sap_rfc_connector
• C++ connector class: SapRfcConnector
• C++ function caller: sap_rfc::SapFunctionCaller
• Python bindings for:
  • SapRfcConnector
  • SapFunctionCaller

All RFC payload values are currently exchanged as strings (dict[str, str] style), including table rows.

Requirements

• Python >=3.7
• C++ compiler with C++17 support
• SAP NetWeaver RFC SDK (headers + libraries)
• Environment variable SAPNWRFC_HOME pointing to the SDK root

Expected SDK layout:

• ${SAPNWRFC_HOME}/include
• ${SAPNWRFC_HOME}/lib

Build / Install

From this directory:

python -m pip install --upgrade pip setuptools wheel pybind11
python -m pip install .

For local development build:

python setup.py build_ext --inplace

Quick start (Python)

from sap_rfc_connector import SapRfcConnector, SapFunctionCaller

conn = SapRfcConnector(
    user="YOUR_USER",
    passwd="YOUR_PASSWORD",
    ashost="YOUR_ASHOST",
    sysnr="00",
)

caller = SapFunctionCaller(conn)

result = caller.call(
    "STFC_CONNECTION",
    REQUTEXT="Hello SAP",
)

print(result)

Example with table parameters:

result = caller.call(
    "BBP_RFC_READ_TABLE",
    QUERY_TABLE="KONP",
    DELIMITER="|",
    ROWCOUNT=1000,
    FIELDS=["KNUMH", "KOPOS", "KAPPL", "KSCHL", "KBETR"],
    OPTIONS=[{"TEXT": "KAPPL = 'KA'"}],
)

Python binding behavior

SapRfcConnector(**kwargs) validation

The kwargs constructor requires:

• user
• passwd
• ashost
• sysnr

If one is missing, it raises ValueError. If connection fails, it raises RuntimeError.

SapFunctionCaller.call(func, **kwargs)

Binding-side parsing rules:

• Non-list kwargs are treated as scalar RFC params.
• List kwargs are treated as table params.
• Special-case FIELDS=["COL1", "COL2"] is converted to:
  • [{"FIELDNAME": "COL1"}, {"FIELDNAME": "COL2"}]
• Table row dict values are normalized to string via Python str(...).
  • None becomes empty string.
  • bytes are decoded as Python bytes-to-str cast result.

C++ design notes

• SapRfcConnector is intentionally non-copyable and non-movable to avoid handle ownership bugs.
• RFC function handles are wrapped with RAII (RfcFunctionHandle).
• Input table field write errors now fail fast with an exception (no silent partial row writes).
• Output field extraction uses a safe fallback marker when SAP field read fails:
  • "<unreadable:RFCTYPE_...>"

Encoding behavior

utils::fromSAPUC attempts UTF conversion first. If conversion fails, it returns escaped code units (\uXXXX) instead of replacing data with spaces.

Public API summary

SapRfcConnector

• connect(user, passwd, ashost, sysnr) -> bool
• check_connection() -> bool
• close_connection()
• get_library_info() -> dict[str, int]

sap_rfc::SapFunctionCaller

• get_function_description(function_name) -> list[dict[str, str]]
• call(func, params, tables) -> dict[str, list[dict[str, str]]]
• get_table_metadata(table_name) -> list[dict[str, str]]

Notes for high-volume workloads

Current API materializes output tables in memory as nested Python/C++ maps of strings. For very large result sets, plan calls in chunks at the query/source level where possible.