Summary

MultiYggdrasil is a Forge | Fabric | NeoForge mod.
It allows you to set multiple Yggdrasil API sources, including the official and other external authentication servers.
Config design is inspired by MultiLogin, and some codes are borrowed from authlib-injector under the AGPL-3.0 license.
patchwork

Deploy

Same as other mods, there are only three steps:

1. Download mod from CurseForge | Modrinth
2. Throw it into /mods
3. Launch the server

Configuration

A template:

# This config is located at config/multi-yggdrasil.ini
[SomeRandomMirror]                     # The name, can be set freely, has no impacts.
type = OFFICIAL                        # The type, now has 2 types, "OFFICIAL" and "BLESSING_SKIN".
authHost = https://a.random.mirror     # |- The specific value of "OFFICIAL" type.
accountsHost = https://a.random.mirror # |  Requirements in below.
sessionHost = https://a.random.mirror  # |
servicesHost = https://a.random.mirror # |
profilesHost = https://a.random.mirror # |
ordinal = 0                            # The ordinal, decided the order of use for this source

[MojangOfficial]
type = OFFICIAL                        # When using "OFFICIAL" type, there can be no host-like property,
ordinal = 1                            # and it will use the official API.

[LittleSkin]
type = BLESSING_SKIN                   # ↙ The specific value of "BLESSING_SKIN" type.
apiRoot = https://littleskin.cn/api/yggdrasil/
ordinal = 2

The requirements of these host-like specific values for “OFFICIAL” type are depending on the MC version, see the table below:

authlib	Minecraft	authHost	accountsHost	sessionHost	servicesHost	profilesHost
1.5.25~1.6.25	1.14.4~1.16.3	✅	✅	✅	❌	❌
2.1.28~4.0.43	1.16.4~1.20.1	✅	✅	✅	✅	❌
5.0.47	1.20.2	❌	✅	✅	✅	❌
6.0.52~6.0.58	1.20.3~1.21.8	❌	❌	✅	✅	❌
7.0.61	1.21.9~1.21.11	❌	❌	✅	✅	✅

Version Supporting

Minecraft	Forge	Fabric	NeoForge
1.14.4-	❌	❌	❌
1.14.4~1.20.1	✅	✅	❌
1.20.1~1.20.6	✅	✅	✅
1.21.1~1.21.11	❌	✅	✅