how to create master branch on empty repo by bitbucket api v2

[Huy_Tran]

Hi, I tried to use 

POST https://api.bitbucket.org/2.0/repositories/user/my_repo/refs/branches

{
  "name" : "master",
  "target" : {
    "hash" : "default"
  }
}

but I got 

{
"type": "error",
"error": {
"fields": {
"target.hash": "Commit not found: default"
},
"message": "Bad request"
}
}

I knew we need a commit, but in the new empty repo, there is no commit

[Daniil Penkin · Accepted solution]

Hello @Huy_Tran,

Welcome to the Community!

You need to use this endpoint, specifically note branch parameter:

When a branch name is specified and the repo is empty, the new commit will become the repo's root commit and also define the repo's main branch going forward.

Hope this helps.

Cheers,
Daniil

[Huy_Tran]

okay thanks @Daniil Penkin , got it

I solved by this src

request({

    url: `https://api.bitbucket.org/2.0/repositories/${user_name}/${repo_name}/src`,

    method: 'post',

    headers: { 'User-Agent': 'Request-Promise', 'content-type': 'application/x-www-form-urlencoded', Authorization: `Bearer ${access_token}` },

    form: { author: 'NewsBie <support@newbee.cccc>', message: 'empty commit' }

});

Then it auto created `master` branch.

[Ajay Chandra]

@Daniil Penkin I am trying to create a branch in an empty repository 
the solution given by @Huy_Tran  is working but I want my branch name as mainline instead master ..! 

is there a way to change?

Thanks, 
Ajay.