Sai Server – The backend for your game

Three steps to connect your game

01
Create a studio and a game
In the web admin, create a studio, a team and a game, then copy the Game ID. Invite teammates by User ID.
02
Add the SDK to your game
Import the SDK and connect it with the Game ID. In Unity it is one SaiServer prefab, with auth, items, quests, battle and more already wired inside.
03
Configure and test
Set up content in the web admin and test it right away in your game, with no backend of your own to host.

Available SDKs

More game engines are planned.

Unity SDK →

The SaiServer component in the Unity Inspector with the server endpoint and game ID, and the Console showing the player signed in and their data loaded — The SaiServer component in Unity: set the endpoint and Game ID, press Play, and the Console shows the player signed in and their data loaded.

One platform for the whole LiveOps lifecycle

Everything is built on one idea, the Item Definition. Weapons, currencies, characters, chests and gacha keys are all items, so every system fits together from day one.

Players & data

Accounts & sign-in: Register, log in, refresh tokens and Google login. One account across every game.
Cross-platform cloud save: Progress lives on the server, so players continue on another device. Free-form JSON data with delta updates.
Mailbox: Send gifts, compensation and event rewards with item attachments. Claiming stays safe even when the inventory is full.
Two-factor sign-in: Google Authenticator with one-time recovery codes protects studio and player accounts.

Economy & items

Grid inventory & containers: Main inventory, vaults and custom chests up to 1,000 cells. Move, split, merge and swap, every action validated by the server.
Gacha / lootbox: Weighted pools, min/max quantities and key requirements. Every open is an atomic transaction.
Shops: Permanent or event shops, any item as currency, per-player or global purchase limits, and restocks.
Crafting & generators: Recipes with consumed or kept materials and bonus rates, plus resources produced over time for idle mechanics.

Retention & insight

Quests: One-time and daily quests, branching quest chains on a story graph, and daily pools by weight or weekly schedule.
Seasonal leaderboards: Sum, max, min or latest scoring, automatic daily, weekly or monthly resets, and archived seasons.
Analytics & journeys: Send events from your game and map them into player journeys to see funnels, drop-off points and economy flow.
Equipment, squads & decks: Equipment slots with item restrictions, presets for squads, parties and decks, and tags to group items.

Your game's own logic, running on the server

When your game needs something that is not built in, such as a combat system, special rewards or a damage formula, your team writes it in Lua. Scripts work directly with the player's items, gacha, presets, equipment and battle sessions.

A template library, from Hello World to a complete battle.

Runs in a sandbox limited to 500 ms per execution, keeping the server safe.

Called from your game with one component; the script name is the trigger keyword.

Built for a serious in-game economy

The server decides

Full bags, occupied cells, missing materials, expired shops: the server rejects the request with a clear error. The client never edits data on its own.

No double transactions

Purchases, crafting and gacha opens use idempotency keys. Resend the same request and the server returns the original result instead of running it again.

Transparent odds

Probability is weight divided by total weight, applied the same way to gacha, quest pools and enemy pools.

Run it from the web admin

Your LiveOps team views player profiles, sends gifts, opens seasons and edits shops without rebuilding the game.

Every game on Sai Server gets a home on Sai Play

Sai Play is the player site shared by every game on Sai Server. Players use the same Sai account, see their games, progress and items, buy from the shops you choose to show there, and keep one sGem balance.

Discover Sai Play

Wooden bookshelves packed with colored books, flowers blooming above each sorted compartment, and a magic wand cursor picking up a yellow book

Built on Sai Server

Infinite Book Shelf

A 3D puzzle for browser, PC and Android. Sign-in and cloud saves run on Sai Server, so every book, shelf and flower is kept across devices.

See the tech showcase

Start free. Add capacity when your game grows.

Every game starts on a free base. When it needs more, socket Materia into it from the web admin: each stack adds capacity on top of the base for one month, paid in sCoin.

	Free baseFreeincluded in every game	Uncommon$1/ stack · month100 sCoinUp to 7 stacks per game	Rare$70/ stack · month7,000 sCoinUp to 3 stacks per game	Epic$150/ stack · month15,000 sCoinUp to 3 stacks per game	Legendary$1,500/ stack · month150,000 sCoinUp to 3 stacks per game
	Included	Per stack	Per stack	Per stack	Per stack
CCU	20	+60	+4K	+10K	+100K
Player profiles	100	+1K	+20K	+200K	+5M
Items	100	+100	+4K	+10K	+100K
Shops	2	+2	+100	+1K	+7K
Quests	30	+30	+300	+3K	+30K
Journey nodes	100	—	+100	+1K	+10K
Event types	100	—	+100	+1K	+10K
Leaderboards	2	—	+10	+50	+200
Scripts	10	—	+100	+1K	+10K
Entity defs	—	—	+100	+1K	+10K