Jason Larabie 7acce2ce4b Additive schedule registration for TypeScript for file-splitting (#5435)
Closes: https://github.com/clockworklabs/SpacetimeDB/issues/4571 - The
secondary issue specifically

# Description of Changes
- Added new `onSchedule` optional parameter for `reducers` and
`procedures` as suggested by @cloutiertyler to move towards reactive
reducers
- Enforced at most one scheduled `reducer`/`procedure` per schedule
table
- Kept the existing `table({ scheduled })` path working
- Moved `ScheduleAt` column tracking onto table metadata
- Lets the new schedule API resolve schedule-at columns without relying
on legacy table options
    - Kept `schedule.scheduleAtCol` for compatibility

# Other Options Considered
- Add new additive API `.schedule()` 
- Was the first implementation of this branch but was the wrong
direction for the future
- Rust-inspired schedule token/name handle
- Closest conceptual match to Rust: table stores a schedule
descriptor/name and the reducer binds the implementation separately
- Avoids importing reducers from table definitions and could preserve
type checking if the token carries the row type
- Adds more API surface and abstraction, and needs careful design to
avoid users managing fragile names manually
- `scheduled: 'reducerName'` string/name in `table(...)`
    - Very simple and closest to the raw module-def storage model
    - Fully breaks the runtime import cycle
- Loses compile-time signature checking unless paired with another
checker/registration API, and typos become runtime/module validation
errors
    - This basically is what we had before 2.0
  
# API and ABI breaking changes
- Adds new TypeScript options to `.reducer()` and `.procedure()` for
`onSchedule`
- No intended breaking changes to existing `table({ scheduled })`
behavior

# Expected complexity level and risk
3 - Preserving legacy scheduled table behavior while changing how
schedule metadata is assembled

# Testing
- [x] Added new tests to cover the legacy schedule and new registration
- [x] Updated module-test-ts coverage to show both legacy and new
reducer scheduling
- [x] Ran a local throwaway test project to test before and after for
both legacy + new api
2026-07-16 20:03:10 +00:00
2026-06-10 19:07:22 +00:00
2023-08-02 17:17:04 +02:00
2026-06-22 04:08:56 +00:00
2026-07-15 20:11:00 +00:00
2023-08-01 23:16:37 +02:00
2025-10-20 17:44:50 +00:00
2026-03-04 11:06:15 +00:00
2026-06-22 04:08:56 +00:00

SpacetimeDB Logo SpacetimeDB Logo

SpacetimeDB SpacetimeDB

Development at the speed of light.

         

   

     

Discord   Twitter   GitHub   Twitch   YouTube   LinkedIn   StackOverflow


What is SpacetimeDB?

SpacetimeDB is a relational database that is also a server. You upload your application logic directly into the database, and clients connect to it without any server in between.

Write your schema and business logic as a module in Rust, C#, TypeScript, or C++. SpacetimeDB compiles it, runs it inside the database, and automatically synchronizes state to connected clients in real-time.

Instead of deploying a web or game server that sits in between your clients and your database, your clients connect directly to the database and execute your application logic in your module. You can write all of your permission and authorization logic right inside your module just as you would in a normal server.

This means that you can write your entire application in a single language and deploy it as a single binary. No more separate webserver, no more containers, no more Kubernetes, no more VMs, no more DevOps, no more caching later. Zero infrastructure to manage.

SpacetimeDB Architecture

SpacetimeDB application architecture
(elements in white are provided by SpacetimeDB)

SpacetimeDB is optimized for maximum speed and minimum latency. SpacetimeDB provides all the ACID guarantees of a traditional RDBMS, with all the speed of an optimized web server. All application state is held in memory for fast access, while a commit log on disk provides durability and crash recovery. The entire backend of our MMORPG BitCraft Online runs as a single SpacetimeDB module: chat, items, terrain, player positions, everything, synchronized to thousands of players in real-time.

Quick Start

1. Install

# macOS / Linux
curl -sSf https://install.spacetimedb.com | sh

# Windows (PowerShell)
iwr https://windows.spacetimedb.com -useb | iex

2. Log in

spacetime login

This opens a browser to authenticate with GitHub. Your identity is linked to your account so you can publish databases.

3. Start developing

spacetime dev --template chat-react-ts

That is it. This creates a project from a template, publishes it to Maincloud, and watches for file changes, automatically rebuilding and republishing on save. See pricing for details.

How It Works

SpacetimeDB modules define tables (your data) and reducers (your logic). Clients connect, call reducers, and subscribe to tables. When data changes, SpacetimeDB pushes updates to subscribed clients automatically.

// Define a table
#[spacetimedb::table(accessor = messages, public)]
pub struct Message {
    #[primary_key]
    #[auto_inc]
    id: u64,
    sender: Identity,
    text: String,
}

// Define a reducer (your API endpoint)
#[spacetimedb::reducer]
pub fn send_message(ctx: &ReducerContext, text: String) {
    ctx.db.messages().insert(Message {
        id: 0,
        sender: ctx.sender,
        text,
    });
}

On the client side, subscribe and get live updates:

const [messages] = useTable(tables.message);
// messages updates automatically when the server state changes.
// No polling. No refetching.

Language Support

Server Modules

Write your database logic in any of these languages:

Language Quickstart
Rust Get started
C# Get started
TypeScript Get started
C++ Get started

Client SDKs

Connect from any of these platforms:

SDK Quickstart
TypeScript (React, Next.js, Vue, Svelte, Angular, Node.js, Bun, Deno) Get started
Rust Get started
C# (standalone and Unity) Get started
C++ (Unreal Engine) Get started

Running with Docker

docker run --rm --pull always -p 3000:3000 clockworklabs/spacetime start

Building from Source

If you need features from master that have not been released yet:

# Prerequisites: Rust toolchain with wasm32-unknown-unknown target
curl https://sh.rustup.rs -sSf | sh

git clone https://github.com/clockworklabs/SpacetimeDB
cd SpacetimeDB
cargo build --locked --release -p spacetimedb-standalone -p spacetimedb-update -p spacetimedb-cli

Then install the binaries:

macOS / Linux
mkdir -p ~/.local/bin
STDB_VERSION="$(./target/release/spacetimedb-cli --version | sed -n 's/.*spacetimedb tool version \([0-9.]*\);.*/\1/p')"
mkdir -p ~/.local/share/spacetime/bin/$STDB_VERSION

cp target/release/spacetimedb-update ~/.local/bin/spacetime
cp target/release/spacetimedb-cli ~/.local/share/spacetime/bin/$STDB_VERSION
cp target/release/spacetimedb-standalone ~/.local/share/spacetime/bin/$STDB_VERSION

# Add to your shell config if not already present:
export PATH="$HOME/.local/bin:$PATH"

# Set the active version:
spacetime version use $STDB_VERSION
Windows (PowerShell)
$stdbDir = "$HOME\AppData\Local\SpacetimeDB"
$stdbVersion = & ".\target\release\spacetimedb-cli" --version |
    Select-String -Pattern 'spacetimedb tool version ([0-9.]+);' |
    ForEach-Object { $_.Matches.Groups[1].Value }
New-Item -ItemType Directory -Path "$stdbDir\bin\$stdbVersion" -Force | Out-Null

Copy-Item "target\release\spacetimedb-update.exe" "$stdbDir\spacetime.exe"
Copy-Item "target\release\spacetimedb-cli.exe" "$stdbDir\bin\$stdbVersion\"
Copy-Item "target\release\spacetimedb-standalone.exe" "$stdbDir\bin\$stdbVersion\"

# Add to your system PATH: %USERPROFILE%\AppData\Local\SpacetimeDB
# Then in a new shell:
spacetime version use $stdbVersion

Verify with spacetime --version.

Documentation

Full documentation is available at spacetimedb.com/docs, including:

License

SpacetimeDB is licensed under the Business Source License 1.1 (BSL). It converts to the AGPL v3.0 with a linking exception after a few years. The linking exception means you are not required to open-source your own code if you use SpacetimeDB. You only need to contribute back changes to SpacetimeDB itself.

Why did we choose this license? We chose to license SpacetimeDB under the MariaDB Business Source License for 4 years because we can't compete with AWS while also building our products for them.

We chose GPLv3 with linking exception as the open source license because we want contributions merged back into mainline (just like Linux), but we don't want to make anyone else open source their own code (i.e. linking exception).

Languages
Rust 59%
TypeScript 16.4%
C++ 11.9%
C# 8.3%
CSS 1.2%
Other 2.9%