@sayak17  so this looks doable as I described above.  Not sure what program you are using in your screenshots as it does not show the full rest-api call structure. But your process would be as as follows: 1. Get bearer token 2. Extract bearer token from response body and place in FlowFile attribute 3. Format flowfile attribute as needed for use by the rest of the api-calls 4. Using bearer token make get request to the ../sites rest-api endpoint 5. Use ExtractText to extract the site id to a new FlowFile Attribute 6. Use bearer token again and use NiFi Expression Language to dynamically create the rest-api url to include the site id. 7. From response, extract the Drive id to another new FlowFile Attribute as above. 8. Use bearer token again and use NiFi Expression Language to dynamically create the rest-api url to include the drive id. 9 finally do whatever you need to do with the response json you get from that final rest-api call. Matt ... View more

@sayak17  If you are simply looking to GET from a REST API endpoint and take the response and write to a local file on the server where your NiFi service is running, you'll want to use the InvokeHTTP processor and feed that to your putFile processor.   If you found this response assisted with your query, please take a moment to login and click on "Accept as Solution" below this post. Thank you, Matt ... View more

Thanks. Using examples from that cookbook, I could make it work. Here is my code which works:   from org.apache.commons.io import IOUtils from java.nio.charset import StandardCharsets from org.apache.nifi.processor.io import OutputStreamCallback class PyOutputStreamCallback(OutputStreamCallback): def __init__(self): pass def process(self, outputStream): with open("D:\\Work\\nifi test\\custom processor input\\random_json.json") as f: file_content = f.read() outputStream.write(bytearray(file_content.encode('utf-8'))) flowFile = session.create() if(flowFile != None): flowFile = session.write(flowFile, PyOutputStreamCallback()) flowFile = session.putAttribute(flowFile, "filename", 'input_file.json') session.transfer(flowFile, REL_SUCCESS) session.commit()   Next, I will figure out if I can add the local directory path as a property and read that, instead of hardcoding it in the script. ... View more