Legacy Mojang Authentication
Minecraft 1.6 introduced a new authentication scheme called Yggdrasil which completely replaces the previous authentication system. Mojang's other game, Scrolls, uses this method of authentication as well.
Contents
Request format
All requests to Yggdrasil are made to the following server:
https://authserver.mojang.com
Further, they are expected to fulfill the following rules:
- Are
POST
requests - Have the
Content-Type
header set toapplication/json
- Contain a JSON-encoded dictionary as payload
If a request was successful the server will respond with:
- Status code
200
- A JSON-encoded dictionary according to the specifications below
If however a request fails, the server will respond with:
- An appropriate, non-200 HTTP status code
- A JSON-encoded dictionary following this format:
{
"error": "Short description of the error",
"errorMessage": "Longer description which can be shown to the user",
"cause": "Cause of the error" // optional
}
Errors
These are some of the errors that can be encountered:
Error | Cause | Error message | Notes |
---|---|---|---|
Method Not Allowed
|
The method specified in the request is not allowed for the resource identified by the request URI | Something other than a POST request was received. | |
Not Found
|
The server has not found anything matching the request URI | Non-existing endpoint was called. | |
ForbiddenOperationException
|
UserMigratedException
|
Invalid credentials. Account migrated, use e-mail as username. | |
ForbiddenOperationException
|
Invalid credentials. Invalid username or password. | ||
ForbiddenOperationException
|
Invalid token. | accessToken was invalid.
| |
IllegalArgumentException
|
Access token already has a profile assigned. | Selecting profiles isn't implemented yet. | |
Unsupported Media Type
|
The server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method | Data was not submitted as application/json |
Authenticate
Authenticates a user using his password.
Endpoint
/authenticate
Payload
{
"agent": { // defaults to Minecraft
"name": "Minecraft", // For Mojang's other game Scrolls, "Scrolls" should be used
"version": 1 // This number might be increased
// by the vanilla client in the future
},
"username": "mojang account name", // Can be an email address or player name for
// unmigrated accounts
"password": "mojang account password",
"clientToken": "client identifier" // optional
}
The clientToken
should be a randomly generated identifier and must be identical for each request.
In case it is omitted the server will generate a random token based on Java's UUID.toString() which should then be stored by the client. This will however also invalidate all previously acquired accessToken
s for this user across all clients.
Response
{
"accessToken": "random access token", // hexadecimal
"clientToken": "client identifier", // identical to the one received
"availableProfiles": [ // only present if the agent field was received
{
"id": "profile identifier", // hexadecimal
"name": "player name"
}
],
"selectedProfile": { // only present if the agent field was received
"id": "profile identifier",
"name": "player name"
}
}
Note: If a user wishes to stay logged in on his computer you are strongly advised to store the received accessToken
instead of the password itself.
Currently each account will only have one single profile, multiple profiles per account are however planned in the future. If a user attempts to log into a valid Mojang account with no attached Minecraft license, the authentication will be successful, but the response will not contain a "selectedProfile" field, and the "availableProfiles" array will be empty.
Refresh
Refreshes a valid accessToken
. It can be uses to keep a user logged in between gaming sessions and is preferred over storing the user's password in a file (see lastlogin).
Endpoint
/refresh
Payload
{
"accessToken": "valid accessToken",
"clientToken": "client identifier" // This needs to be identical to the one used
// to obtain the accessToken in the first place
"selectedProfile": { // optional; sending it will result in an error
"id": "profile identifier", // hexadecimal
"name": "player name"
}
}
Note: The provided accessToken
gets invalidated.
Response
{
"accessToken": "random access token", // hexadecimal
"clientToken": "client identifier", // identical to the one received
"selectedProfile": {
"id": "profile identifier", // hexadecimal
"name": "player name"
}
}
Validate
Checks if an accessToken
is a valid session token with a currently-active session. Note: this method will not respond successfully to all currently-logged-in sessions, just the most recently-logged-in for each user. It is intended to be used by servers to validate that a user should be connecting (and reject users who have logged in elsewhere since starting Minecraft), NOT to auth that a particular session token is valid for authentication purposes. To authenticate a user by session token, use the refresh verb and catch resulting errors.
Endpoint
/validate
Payload
{
"accessToken": "valid accessToken",
}
Response
Returns an empty payload if successful.
Signout
Invalidates accessToken
s using an account's username and password.
Endpoint
/signout
Payload
{
"username": "mojang account name",
"password": "mojang account password",
}
Response
Returns an empty payload if successful.
Invalidate
Invalidates accessToken
s using a client/access token pair.
Endpoint
/invalidate
Payload
{
"accessToken": "valid accessToken",
"clientToken": "client identifier" // This needs to be identical to the one used
// to obtain the accessToken in the first place
}
Response
Returns an empty payload if successful.