Unable to execute GraphQL mutation using cURL

Question

I have deployed a Mutation in a MicroProfile container (WildFly) and I'm able to execute it in the GraphQL UI:

mutation Add {
  createOrder(order: {
      id: 1,
      type: "car"
      model: "Ferrari"
      price: 500
    }
  )
  {
    type
    model
    price
  }
}

However, when I try to execute the same mutation using cURL:

curl \
  -X POST \
  -H "Content-Type: application/json" \
  --data '{ "query": "mutation Add {
  createOrder(order: {
      id: 1,
      type: \"car\"
      model: \"Ferrari\"
      price: 500
    }
  )
  {
    type
    model
    price
  }
}
" }' http://localhost:8080/demo/graphql

However it fails with:

javax.json.stream.JsonParsingException: Unexpected char 10 at (line no=1, column no=27, offset=26)

I haven't found many examples of running Mutation with command line tools like cURL and don't know where the error is. Any help? Thanks

Could it be as simple as the shell eating your backslashes? Try logging the exact payload that arrives at your server. — Sebastian Redl, Sep 27 '20 at 08:07

score 1 · Answer 1 · answered Sep 28 '20 at 22:42

You are sending json data through curl, and Json specs do not allow line breaks. They need to be replaced by a '\n' character.

curl \
  -X POST \
  -H "Content-Type: application/json" \
  --data '{ "query": "mutation Add { createOrder(order: {id: 1, type: \"car\", model: \"Ferrari\", price: 500}){type\n model\n price\n}}" }' http://localhost:8080/demo/graphql

See this question for other suggestions: Correct format for multiline '--data' in curl query to graphql endpoint?

score 0 · Answer 2 · answered Jan 22 '21 at 00:06

Here I have a working mutation using curl, newline quote escape and indention. It sure doesn't look fancy but somewhat more maintainable than a oneliner: https://stackoverflow.com/a/65837497/835098

I've reformatted your curl invocation and it should work now. Notice the input and output parameters nicely indented for your mutation. You only have to worry about adding a backslash at the end of each line and escaping the backslashes and quotes in the "query" string.

Oh, and don't forget to add commas after every input argument. I think those were missing in your original request.

curl \
  -X POST \
  -H "Content-Type: application/json" \
  --data \
"{ \
    \"query\": \"mutation Add { \
        createOrder(order: { \
            id: 1, \
            type: \\\"car\\\", \
            model: \\\"Ferrari\\\", \
            price: 500 \
        }){ \
            type \
            model \
            price \
        } \
    } \
} \
" http://localhost:8080/demo/graphql

Unable to execute GraphQL mutation using cURL

2 Answers2