title: API: Structure of an access token
role: manual
tags: #api #manual #reference #zettelstore
syntax: zmk
back: 00001012050600
backward: 00001012050200 00001012050400 00001012050600
box-number: 1
copyright: (c) 2020-present by Detlef Stern <ds@zettelstore.de>
created: 20210126175322
forward: 00001012050200 00001012050400 00001012930000 00001012930500
lang: en
license: EUPL-1.2-or-later
modified: 20230807165915
published: 20230807165915
visibility: public

If the [[authentication process|00001012050200]] was successful, an access token with some additional data is returned.
The same is true, if the access token was [[renewed|00001012050400]].
The response is structured as a [[symbolic expression|00001012930000]] list, with the following elements:
# The type of the token, always set to ''"Bearer"'', as described in [[RFC 6750|https://tools.ietf.org/html/rfc6750]]
# The token itself, which is technically the string representation of a [[symbolic expression|00001012930500]] containing relevant data, plus a check sum.
#* The symbolic expression has the form ''(KIND USERNAME NOW EXPIRE Z-ID)''
#* ''KIND'' is ''0'' for an API access, ''1'' if it created for the Web user interface.
#* ''USERNAME'' is the user name of the user.
#* ''NOW'' is a timestamp of the current time.
#* ''EXPIRE'' is the timestamp when the access token expires.
#* ''Z-ID'' is the zettel identifier of the user zettel.
  The symbolic expression is encoded via ""base64"".
  Based on this encoding, a checksum is calculated, also encoded via ""base64"".
  Both encoded values are concatenated, with a period (''"."'') as a delimiter.