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TypeScript Quickstart

Get a SpacetimeDB TypeScript app running in under 5 minutes.

Prerequisites​

Create your project

Run the spacetime dev command to create a new project with a TypeScript SpacetimeDB module.

This will start the local SpacetimeDB server, publish your module, and generate TypeScript client bindings.

spacetime dev --template basic-typescript
Explore the project structure

Your project contains both server and client code.

Edit spacetimedb/src/index.ts to add tables and reducers. Use the generated bindings in client/src/module_bindings/ to build your client.

my-spacetime-app/
├── spacetimedb/          # Your SpacetimeDB module
│   └── src/
│       └── index.ts      # Server-side logic
├── client/               # Client application
│   └── src/
│       ├── index.ts
│       └── module_bindings/  # Auto-generated types
└── package.json
Understand tables and reducers

Open spacetimedb/src/index.ts to see the module code. The template includes a person table and two reducers: add to insert a person, and say_hello to greet everyone.

Tables store your data. Reducers are functions that modify data — they're the only way to write to the database.

import { schema, table, t } from 'spacetimedb/server';

export const spacetimedb = schema(
  table(
    { name: 'person' },
    {
      name: t.string(),
    }
  )
);

spacetimedb.reducer('add', { name: t.string() }, (ctx, { name }) => {
  ctx.db.person.insert({ name });
});

spacetimedb.reducer('say_hello', (ctx) => {
  for (const person of ctx.db.person.iter()) {
    console.info(`Hello, ${person.name}!`);
  }
  console.info('Hello, World!');
});
Test with the CLI

Use the SpacetimeDB CLI to call reducers and query your data directly.

# Call the add reducer to insert a person
spacetime call <database-name> add Alice

# Query the person table
spacetime sql <database-name> "SELECT * FROM person"
 name
---------
 "Alice"

# Call say_hello to greet everyone
spacetime call <database-name> say_hello

# View the module logs
spacetime logs <database-name>
2025-01-13T12:00:00.000000Z  INFO: Hello, Alice!
2025-01-13T12:00:00.000000Z  INFO: Hello, World!

Next steps​