Deno quickstart (#4191)

# Description of Changes

Adds a Deno quickstart template and documentation.

**Template (`templates/deno-ts/`):**
- `deno.json` with tasks and import map for spacetimedb
- `src/main.ts` using Deno-native APIs (`Deno.stdin`,
`Deno.readTextFile`, `Deno.writeTextFile`, `Deno.env`)
- `spacetimedb/` server module (TypeScript)
- Pre-generated `module_bindings/`

**Documentation
(`docs/docs/00100-intro/00200-quickstarts/00275-deno.md`):**
- Step-by-step quickstart following existing pattern
- Covers project structure, tables/reducers, running the client, CLI
usage
- Documents Deno-specific features: permissions, built-in TypeScript,
import maps, no node_modules
- Explains `--unstable-sloppy-imports` flag (required because generated
bindings use extensionless imports)

# API and ABI breaking changes

None. This is a new template and documentation addition.

# Expected complexity level and risk

**1** - Trivial addition. New template files and documentation only, no
changes to existing code or generator.

# Testing

- [x] Server module publishes successfully
- [x] Bindings generate correctly
- [x] Run `deno task start` and verify connection to SpacetimeDB
- [x] Test interactive CLI commands: add names, `list`, `hello`

Author: bradleyshep

docs/docs/00100-intro/00200-quickstarts/00275-deno.md

@@ -0,0 +1,275 @@
+---
+title: Deno Quickstart
+sidebar_label: Deno
+slug: /quickstarts/deno
+hide_table_of_contents: true
+---
+
+import { InstallCardLink } from "@site/src/components/InstallCardLink";
+import { StepByStep, Step, StepText, StepCode } from "@site/src/components/Steps";
+
+Get a SpacetimeDB Deno app running in under 5 minutes.
+
+## Prerequisites
+
+- [Deno](https://deno.land/) installed
+- [SpacetimeDB CLI](https://spacetimedb.com/install) installed
+
+<InstallCardLink />
+
+---
+
+<StepByStep>
+  <Step title="Create your project">
+    <StepText>
+      Run the `spacetime dev` command to create a new project with a SpacetimeDB module and Deno client.
+
+      This will start the local SpacetimeDB server, publish your module, and generate TypeScript bindings.
+    </StepText>
+    <StepCode>
+
+```bash
+spacetime dev --template deno-ts
+```
+
+    </StepCode>
+
+  </Step>
+
+  <Step title="Explore the project structure">
+    <StepText>
+      Your project contains both server and client code.
+
+      Edit `spacetimedb/src/index.ts` to add tables and reducers. Edit `src/main.ts` to build your Deno client.
+    </StepText>
+    <StepCode>
+
+```
+my-spacetime-app/
+├── spacetimedb/          # Your SpacetimeDB module
+│   └── src/
+│       └── index.ts      # Server-side logic
+├── src/
+│   ├── main.ts           # Deno client script
+│   └── module_bindings/  # Auto-generated types
+└── deno.json             # Deno config and tasks
+```
+
+    </StepCode>
+
+  </Step>
+
+  <Step title="Understand tables and reducers">
+    <StepText>
+      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.
+    </StepText>
+    <StepCode>
+
+```typescript
+import { schema, table, t } from 'spacetimedb/server';
+
+export const spacetimedb = schema(
+  table(
+    { name: 'person', public: true },
+    {
+      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!');
+});
+```
+
+    </StepCode>
+
+  </Step>
+
+  <Step title="Run the client">
+    <StepText>
+      In a new terminal, run the Deno client. It will connect to SpacetimeDB and start an interactive CLI where you can add people and query the database.
+    </StepText>
+    <StepCode>
+```bash
+# Run with auto-reload during development
+deno task dev
+
+# Or run once
+
+deno task start
+
+```
+    </StepCode>
+  </Step>
+
+  <Step title="Use the interactive CLI">
+    <StepText>
+      The client provides a command-line interface to interact with your SpacetimeDB module. Type a name to add a person, or use the built-in commands.
+    </StepText>
+    <StepCode>
+```
+
+Connecting to SpacetimeDB...
+URI: ws://localhost:3000
+Module: deno-ts
+
+Connected to SpacetimeDB!
+Identity: abc123def456...
+
+Current people (0):
+(none yet)
+
+Commands:
+<name> - Add a person with that name
+list - Show all people
+hello - Greet everyone (check server logs)
+Ctrl+C - Quit
+
+> Alice
+> [Added] Alice
+
+> Bob
+> [Added] Bob
+
+> list
+> People in database:
+
+- Alice
+- Bob
+
+> hello
+> Called say_hello reducer (check server logs)
+
+````
+    </StepCode>
+  </Step>
+
+  <Step title="Understand the client code">
+    <StepText>
+      Open `src/main.ts` to see the Deno client. It uses `DbConnection.builder()` to connect to SpacetimeDB, subscribes to tables, and sets up the interactive CLI using Deno's native APIs.
+
+      Unlike browser apps, Deno stores the authentication token in a file using `Deno.readTextFile()` and `Deno.writeTextFile()`.
+    </StepText>
+    <StepCode>
+```typescript
+import { DbConnection } from './module_bindings/index.ts';
+
+// Build and establish connection
+DbConnection.builder()
+  .withUri(HOST)
+  .withModuleName(DB_NAME)
+  .withToken(await loadToken())  // Load saved token from file
+  .onConnect((conn, identity, token) => {
+    console.log('Connected! Identity:', identity.toHexString());
+    saveToken(token);  // Save token for future connections
+
+    // Subscribe to all tables
+    conn.subscriptionBuilder()
+      .onApplied((ctx) => {
+        // Show current data, start CLI
+        setupCLI(conn);
+      })
+      .subscribeToAllTables();
+
+    // Listen for table changes
+    conn.db.person.onInsert((ctx, person) => {
+      console.log(`[Added] ${person.name}`);
+    });
+  })
+  .build();
+````
+
+    </StepCode>
+
+  </Step>
+
+  <Step title="Test with the SpacetimeDB CLI">
+    <StepText>
+      You can also use the SpacetimeDB CLI to call reducers and query your data directly. Changes made via the CLI will appear in your Deno client in real-time.
+    </StepText>
+    <StepCode>
+```bash
+# Call the add reducer to insert a person
+spacetime call <database-name> add Charlie
+
+# Query the person table
+
+spacetime sql <database-name> "SELECT \* FROM person"
+name
+
+---
+
+"Alice"
+"Bob"
+"Charlie"
+
+# 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, Bob!
+2025-01-13T12:00:00.000000Z INFO: Hello, Charlie!
+2025-01-13T12:00:00.000000Z INFO: Hello, World!
+
+````
+    </StepCode>
+  </Step>
+
+  <Step title="Deno-specific features">
+    <StepText>
+      **Permissions:** Deno requires explicit permissions. The template uses `--allow-net` for WebSocket connections, `--allow-read` and `--allow-write` for token persistence, and `--allow-env` for configuration.
+
+      **Sloppy imports:** The `--unstable-sloppy-imports` flag is required because the generated module bindings use extensionless imports (Node.js convention), while Deno requires explicit file extensions. This flag enables Node.js-style module resolution.
+
+      **Built-in TypeScript:** Deno runs TypeScript directly without transpilation, making startup faster and eliminating the need for build tools.
+
+      **Import maps:** The `deno.json` file defines import maps, allowing you to import `spacetimedb` directly without `npm:` prefix in your code.
+
+      **No node_modules:** Deno caches dependencies globally, so there's no `node_modules` folder to manage.
+    </StepText>
+    <StepCode>
+```bash
+# Configure via environment variables
+SPACETIMEDB_HOST=ws://localhost:3000 \
+SPACETIMEDB_DB_NAME=my-app \
+deno task start
+
+# Or run with explicit permissions
+deno run --allow-net --allow-read --allow-write --allow-env --unstable-sloppy-imports src/main.ts
+
+# The deno.json configures tasks and imports
+cat deno.json
+{
+  "tasks": {
+    "dev": "deno run --watch --allow-net --allow-read --allow-write --allow-env --unstable-sloppy-imports src/main.ts",
+    "start": "deno run --allow-net --allow-read --allow-write --allow-env --unstable-sloppy-imports src/main.ts"
+  },
+  "imports": {
+    "spacetimedb": "npm:spacetimedb@1.*"
+  }
+}
+````
+
+    </StepCode>
+
+  </Step>
+</StepByStep>
+
+## Next steps
+
+- See the [Chat App Tutorial](/tutorials/chat-app) for a complete example
+- Read the [TypeScript SDK Reference](/sdks/typescript) for detailed API docs

templates/deno-ts/.template.json

@@ -0,0 +1,5 @@
+{
+  "description": "Deno TypeScript client and server template",
+  "client_lang": "typescript",
+  "server_lang": "typescript"
+}

templates/deno-ts/LICENSE

@@ -0,0 +1 @@
+../../licenses/apache2.txt

templates/deno-ts/deno.json

@@ -0,0 +1,10 @@
+{
+  "tasks": {
+    "dev": "deno run --watch --allow-net --allow-read --allow-write --allow-env --unstable-sloppy-imports src/main.ts",
+    "start": "deno run --allow-net --allow-read --allow-write --allow-env --unstable-sloppy-imports src/main.ts",
+    "spacetime:generate": "spacetime generate --lang typescript --out-dir src/module_bindings --project-path spacetimedb"
+  },
+  "imports": {
+    "spacetimedb": "npm:spacetimedb@1.*"
+  }
+}

templates/deno-ts/spacetimedb/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "spacetime-module",
+  "version": "1.0.0",
+  "description": "",
+  "scripts": {
+    "build": "spacetime build",
+    "publish": "spacetime publish"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "spacetimedb": "1.*"
+  }
+}

templates/deno-ts/spacetimedb/src/index.ts

@@ -0,0 +1,33 @@
+import { schema, table, t } from 'spacetimedb/server';
+
+export const spacetimedb = schema(
+  table(
+    { name: 'person', public: true },
+    {
+      name: t.string(),
+    }
+  )
+);
+
+spacetimedb.init(_ctx => {
+  // Called when the module is initially published
+});
+
+spacetimedb.clientConnected(_ctx => {
+  // Called every time a new client connects
+});
+
+spacetimedb.clientDisconnected(_ctx => {
+  // Called every time a client disconnects
+});
+
+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!');
+});

templates/deno-ts/spacetimedb/tsconfig.json

@@ -0,0 +1,23 @@
+/*
+ * This tsconfig is used for TypeScript projects created with `spacetimedb init
+ * --lang typescript`. You can modify it as needed for your project, although
+ * some options are required by SpacetimeDB.
+ */
+{
+  "compilerOptions": {
+    "strict": true,
+    "skipLibCheck": true,
+    "moduleResolution": "bundler",
+    "jsx": "react-jsx",
+
+    /* The following options are required by SpacetimeDB
+     * and should not be modified
+     */
+    "target": "ESNext",
+    "lib": ["ES2021", "dom"],
+    "module": "ESNext",
+    "isolatedModules": true,
+    "noEmit": true
+  },
+  "include": ["./**/*"]
+}