How to get an access_token for Element / Riot / Matrix?

Question

In the Matrix instant messaging protocol, when using the reference implementation of the Matrix server (called synapse), there is an admin API with functions like resetting a password for a user etc..

Accessing this requires an access_token "API key" of a server admin user.

How do I get one?

Answer 1

Solution to find your access token:

1. Log in to the account you want to get the access token for. Click on the name in the top left corner, then "Settings".
2. Click the "Help & About" tab (left side of the dialog).
3. Scroll to the bottom and click on <click to reveal> part of Access Token.
4. Copy your access token to a safe place.

Answer 2

These access_token API keys were listed in the Riot web application until not too long ago, somewhere under the account settings. In the newest version, I could no longer find them there.

So instead, I use a technique I found here, which is basically a login procedure done with curl. The server's answer will contain the access_token.

1. Find out the Matrix user ID and password of a server admin user. The username has to be in the fully qualified form, for example @user:example.com.

2. Execute the following command on a Linux-based system that has curl installed. Of course, supply the address of you Matrix server for example.com, and also your Matrix user ID and password.

   curl -XPOST \
     -d '{"type":"m.login.password", "user":"<userid>", "password":"<password>"}' \
     "https://example.com:8448/_matrix/client/r0/login"
   

Answer 3

With the current version of the Matrix protocol, getting an access_token programmatically works slightly different:

To find out the endpoint, e.g., for matrix.org, you need to check a .well-known file for the API URL (Documentation): https://matrix.org/.well-known/matrix/client:

$ curl https://matrix.org/.well-known/matrix/client
{
    "m.homeserver": {
        "base_url": "https://matrix-client.matrix.org"
    },
    "m.identity_server": {
        "base_url": "https://vector.im"
    }
}

Afterwards, the homeserver base url can be used for the curl call (See Documentation for the /login endpoint):

$ curl '{"type":"m.login.password", "user":"'$username'", "password":"'$password'"} \ 
"https://$base_url/_matrix/client/v3/login"

{
  "user_id":"@username:matrix.org",
  "access_token":"token",
  "home_server":"matrix.org",
  "device_id":"ID",
  "well_known": { 
    "m.homeserver": {
      "base_url":"https://matrix-client.matrix.org/"
    }
  }
}