spacetime dev bug when running with a project path (#4809)
# Description of Changes
Fixes an issue where running `spacetime dev <database name> --template
chat-react-ts --server maincloud` for an existing database and a new
local project folder would fail with this error:
```sh
Building...
Error: Failed to build project
Caused by:
Module directory does not exist: '/Users/aasoni/./spacetimedb'. Check your --module-path flag or the module-path setting in spacetime.json.
```
Summary of the bug:
- determine_publish_configs was called at line 373 before the project
existed, storing <cwd>/./spacetimedb as the module path
- After init correctly updated spacetimedb_dir to the new project's
path, a later block (lines 454-468) re-read the stale path from the
early publish config and overwrote the correct value
- The rebuild guard at line 498 never triggered because publish_configs
was non-empty (due to the database name CLI argument)
The fix clears publish_configs at the end of the init block, causing the
rebuild at line 498 to run with the correct, post-init spacetimedb_dir.
# API and ABI breaking changes
No
# Expected complexity level and risk
1
# Testing
<!-- Describe any testing you've done, and any testing you'd like your
reviewers to do,
so that you're confident that all the changes work as expected! -->
- [x] Re-ran `spacetime dev` with various flags to confirm they all
still worked
- [x] Verified that the specific error case was fixed
Development at the speed of light.
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 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:
- Quickstart guides for every supported language and framework
- Core concepts: tables, reducers, subscriptions, authentication
- Tutorials: chat app, Unity multiplayer, Unreal Engine multiplayer
- Deployment guide: publishing to Maincloud
- CLI reference
- SQL reference
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).