Authentication

Authentication on Heroku uses one of three mechanisms, depending on the situation:

• Email and password
• API token
• SSH key

The email address and password are used by the heroku command to obtain an API token. This token is used for authentication in all other Heroku API requests, and can be regenerated at will by the user, in the heroku.com web interface. Regenerating an API token invalidates the current token and creates a new one.

The SSH key is used for git push authentication. When heroku login first runs, it will register the user's existing SSH public key with Heroku. If no SSH key exists, heroku login will create one automatically and registers the new key.

API token storage

The Heroku command-line tool stores API tokens in the standard Unix file ~/.netrc.

The netrc format is well-established and well-supported by various network tools on unix. With Heroku credentials stored in this file, other tools such as curl can access the Heroku API with little or no extra work.

Usage examples

Running heroku login (or any other heroku command that requires authentication) will create or update your~/.netrc:

:::term
$ ls .netrc
ls: .netrc: No such file or directory
$ heroku login
Enter your Heroku credentials.
Email: [email protected]
Password:
$ cat .netrc
machine api.heroku.com
  login [email protected]
  password c4cd94da15ea0544802c2cfd5ec4ead324327430
machine code.heroku.com
  login [email protected]
  password c4cd94da15ea0544802c2cfd5ec4ead324327430
$

Authenticating with the API token

Having logged in, you can use curl to access the Heroku API:

:::term
$ curl -H "Accept: application/json" -n https://api.heroku.com/apps

You can also create a file ~/.curlrc, containing extra command-line options for curl:

~/.curlrc

--netrc
--header "Accept: application/json"

With this file, the command is simply:

:::term
$ curl https://api.heroku.com/apps

File format

The file contains a list of free-form records and comments. Comments start with a # (hash) symbol and continue to the end of the line. Each record is of the form:

machine api.heroku.com
  login [email protected]
  password ABC123

One other type of record, macdef, can appear in .netrc files, but it is not commonly used and is ignored by the heroku command.