Invoking FunctionGraph Functions¶

Following pages demonstrate how to call a FunctionGraph implemented in Node.js:

For details on function invocation, see

Function Invocation

in FunctionGraph API reference.

Prerequisites¶

Environment Variables¶

Following environment variables need to be set:

Environment Variables¶
Name	Description
OTC_SDK_PROJECTID	Project ID
OTC_SDK_REGION	Region, e.g. “eu-de”
OTC_SDK_AK	Access Key (*)
OTC_SDK_SK	Secret Key
OTC_USER_NAME	User name (*)
OTC_USER_PASSWORD	User password
OTC_DOMAIN_NAME	Domain name
OTC_IAM_ENDPOINT	IAM Endpoint, e.g. https://iam.eu-de.otc.t-systems.com/v3

(* User needs to have permission to invoke FunctionGraph)

Deployed FunctionGraph Event Function¶

Use following settings to create the FunctionGraph event function using the FunctionGraph console:

Project : as specified in the environment variable OTC_SDK_PROJECT_ID
Region: as specified in the environment variable OTC_SDK_REGION
Name: nodejs-sample-invoke-function
Runtime: Node.js 20.15
Version: latest
Application: default

Function code: Use the following sample code for the function code.

samples-doc/invoke-fg/src-fg/index.js¶

// filename: index.js
"use strict";

// Sample event structure
class SampleEvent {
  constructor(event) {
    this._event = event || {};
  }

  getKey() {
    return this._event.key || "";
  }
}

// initializer name: index.initializer (optional)
exports.initializer = function (context, callback) {
  const logger = context.getLogger();
  logger.info("initializing :", context.getFunctionName());

  callback(null, "");
};

// handler name:  index.handler
exports.handler = function (event, context, callback) {
  const logger = context.getLogger();

  logger.info("Function name:", context.getFunctionName());

  const sampleEvent = new SampleEvent(event);

  logger.info("Key value from event:", sampleEvent.getKey());

  const output = {
    statusCode: 200,
    headers: {
      "Content-Type": "application/json",
    },
    isBase64Encoded: false,
    body: JSON.stringify(event),
  };
  callback(null, output);
};

Handler name: index.handler

Permissions¶

Make sure that your user has the necessary permissions to invoke the function.

last updated: 2026-05-07 12:49:22 UTC - commit: b33b3f65aa4809f3bbb42c38e0f31e3067f81d22