Creating ticket via REST API - markdown description. hidden meta data field

[Nikhil Jain]

Aim it to store some JSON snippet while creating the ticket while using JIRA REST API . I am using this library - https://github.com/lesstif/php-jira-rest-client

We have another tool that will get pending tickets, use this JSON and run some automations

Where can this be done ?

1. Is there a way to add 'metadata' to a ticket , while creating it ? Ideally hidden, not visible to someone viewing the ticket ? idk if custom fields are appropriate for it.

2. Add the JSON to the description. This is not ideal obviously. More because I am not able to add it in a code block.

For having markdown I tried adding 4 spaces before a line :

{
  "fields": {
    "description": "Website \nFor debugging:\n    {\"summary\": \"Fix website.com\"}"
  }
}

Also tried enclosing in backticks 

\n\n```some text```\n

Ideas please ?

Thanks!