services resource might help you.
Create a POST service example:
curl -u tutorials:8798987 -X POST https://api.bitbucket.org/1.0/repositories/tutorials/testrepo/services/ -d "type=POST&URL=https%3A%2F%2Fbitbucket.org/post"
This will create a new POST hook with https://bitbucket.org/post
as URL:
{
"id": 5,
"service": {
"fields": [
{
"name": "URL",
"value": "https://bitbucket.org/post"
}
],
"type": "POST"
}
}