Camunda start REST API not accepting JSON payload

Camunda start REST API not accepting JSON payload.
It only accepts the format below
“variables”: {
“aVariable” : {
“value” : “slfkjsdlfkjsdlfkj”
“businessKey” : “payment-retrieval”

Camunda will not accept this json doc
“address”: {
“address1”: “3388 Einstein Square”,
“address2”: “Heinz Weigenzhul Lane”,
“city”: “Pforzheim”,
“postalcode”: 55555,
“state”: “Germany”,

See the docs and forum on using json in the rest api.

You need to set the Variable type to json and then pass a escaped json string as the value

Hi @shkrish,

can you give more information on what you try to achieve?

You can find the documentation for the “Start Process Instance” endpoint here:
There you will find examples on how to attach variables to the process instance.


I have a json payload as given. I want to call a Camunda process that I created, with just one service node. The service node will call another rest end point passing it the payload or the service node will use a java class to extract the payload from the REST call and say print out the json If I can accomplish this, I can do anything with the payload. No need to get into my real business use case.

@shkrish did you attempt the modification to your REST call to camunda as i described above?

“person” : {
“value” : “\n {\n “address”: {\n “address1”: “3388 Einstein Square”,\n “address2”: “Heinz Weigenzhul Lane”,\n “city”: “Pforzheim”,\n “postalcode”: 55555,\n “state”: “Germany”,\n “country”:“Comal Germany”,\n “id”:2\n },\n “age”: 69,\n “email”: "”,\n “first_name”: “Marco”,\n “last_name”: “Bunte”,\n “phone”: “333-222-8888”,\n “person_id”: 199\n }\n",
“type”: “json”


“businessKey” : “myBusinessKey”,
“withVariablesInReturn”: true

The above syntax works. Thank you.

yes. it is shown above

OK. I think I found the problem. Many thanks for your pointer.

Hi @shkrish. I am still struggling to make this work. I have used the above syntax, but still getting errors from my spring boot REST endpoint saying that the payload is missing. Could you please email me at to help me out? I am literally struggling to make this work and the lack of proper documentation doesnt help at all. Thanks in advance!!