I am using Jira cloud and thus I couldn't get the REST API Browser add on to develop my query.
I had created another question, but it was flagged as SPAM because I tried to insert the original answer I found here to bestow credit where credit is due.
I have found on google the following very nice jql that returns all the epics from a given project.
/jira/rest/api/2/search?jql=project%3D%22Project%20Name%22%20AND%20issuetype%3D%22Epic%22&fields=summary,duedate,priority,issuetype,key,timeoriginalestimate,customfield_11000,customfield_10100,customfield_10002,customfield_10014,assignee,components,fixVersions,versions,resolution,customfield_10011,labels,reporter,status,customfield_10015,time estimate
I'm doing a trial and error approach to get something like the JSON structure bellow, my current iteration is:
/search?jql=project%3D%22<project-name>%22%20AND%20issuetype%3D%22Epic%22&fields=summary,customfield_11000,customfield_10100,customfield_10014
{[
epics: [
epic: [
name: epicName,
epicId: epicID,
url: epicURL,
sprints: [
sprint: [
name: sprintName,
sprintId: sprintID,
url: sprintURL.
stories: [
story: [
name: storyName,
storyId: storyID,
url: storyURL,
issues : [
id: issueId,
url: issueUrl,
type: issueType,
name: issueName,
status: issueStatus
]
]
]
]
]
]}
Thanks in advance