Use when writing new packages, adding CLI commands, creating build plugins, or following Meteor code patterns. Covers package.js structure, file naming, and common code patterns.
Package structure, file naming, and code patterns for the Meteor codebase.
Every Meteor package follows this structure:
packages/my-package/
├── package.js # Package manifest (name, version, dependencies, exports)
├── my-package.js # Main implementation (or split by concern)
├── my-package-server.js # Server-only code (optional)
├── my-package-client.js # Client-only code (optional)
├── my-package-tests.js # Tests (loaded via api.addFiles in test mode)
└── README.md # Documentation (optional)
Package.describe({
name: 'my-package',
version: '1.0.0',
summary: 'Brief description',
git: 'https://github.com/meteor/meteor.git',
documentation: 'README.md'
});
Package.onUse(function(api) {
api.versionsFrom(['3.0']); // Minimum Meteor version
api.use([
'ecmascript', // ES2015+ support
'mongo', // MongoDB integration
'tracker' // Reactivity (client)
]);
api.use('accounts-base', { weak: true }); // Optional dependency
api.mainModule('my-package-server.js', 'server');
api.mainModule('my-package-client.js', 'client');
api.export('MyPackage'); // Global export
});
Package.onTest(function(api) {
api.use(['tinytest', 'my-package']);
api.addFiles('my-package-tests.js');
});
Npm.depends({
'lodash': '4.17.21' // npm dependencies
});
| Pattern | Purpose |
|---|---|
*-server.js | Server-only code |
*-client.js | Client-only code |
*-common.js | Shared code |
*-tests.js | Test files |
*.d.ts | TypeScript declarations |
/packages/my-package/package.js with proper dependencies*-tests.jsKey files to understand:
/tools/isobuild/bundler.js - High-level bundling/tools/isobuild/compiler.js - Package compilation/tools/project-context.js - Dependency resolution/tools/cli/commands.js - CLI command handlersEdit /tools/cli/commands.js or create new command file:
main.registerCommand({
name: 'my-command',
options: {
'option-name': { type: String, short: 'o' }
},
catalogRefresh: new catalog.Refresh.Never()
}, function(options) {
// Implementation
});
import { WebApp } from 'meteor/webapp';
// Add middleware before Meteor's default handlers
WebApp.rawConnectHandlers.use('/api', (req, res, next) => {
// Runs before authentication
next();
});
// Add middleware after authentication
WebApp.connectHandlers.use('/api', (req, res, next) => {
// req.userId available if authenticated
next();
});
// In package.js
Package.registerBuildPlugin({
name: 'compile-my-files',
use: ['ecmascript', 'caching-compiler'],
sources: ['plugin.js'],
npmDependencies: { 'my-compiler': '1.0.0' }
});
// In plugin.js
Plugin.registerCompiler({
extensions: ['myext'],
archMatching: 'web'
}, () => new MyCompiler());
class MyCompiler extends CachingCompiler {
getCacheKey(inputFile) {
return inputFile.getSourceHash();
}
compileOneFile(inputFile) {
const source = inputFile.getContentsAsString();
const compiled = transform(source);
inputFile.addJavaScript({
data: compiled,
path: inputFile.getPathInPackage() + '.js'
});
}
}
// In package.js
api.use('tools-core');
// In implementation
import {
logProgress,
checkNpmDependencyExists,
getMeteorAppConfig,
spawnProcess
} from 'meteor/tools-core';
// Check and install dependencies
if (!checkNpmDependencyExists('@rspack/core')) {
installNpmDependency(['@rspack/core@^1.7.1']);
}
// Spawn external process
const proc = spawnProcess('npx', ['rspack', 'build'], {
cwd: getMeteorAppDir(),
onStdout: (data) => logProgress(data)
});
Meteor uses X.Y.Z-rcN.M versioning where:
X.Y.Z - Semantic versionrcN - Release candidate numberM - Package-specific revision