meteor

name: meteor description: Use when working with Meteor.js, the full-stack JavaScript platform. Covers building Meteor apps, writing or modifying core packages, navigating the build system (Isobuild), using the CLI, working with DDP/MongoDB/accounts, running tests (TinyTest, self-test, E2E), understanding the rspack bundler integration, or using tools-core utilities. Trigger when user mentions Meteor, meteor create, meteor run, meteor packages, Isobuild, DDP, Minimongo, or any Meteor-specific API. Also use when looking up which Meteor package handles a specific feature (auth, build, reactivity, etc.).

Meteor

Full-stack JavaScript platform for web and mobile apps. Reactive data (DDP + Minimongo), isomorphic code, integrated build system (Isobuild), 100+ core packages.

Essential Commands

meteor create my-app                         # New app (add --react, --vue, --svelte, etc.)
meteor run                                   # Dev server with HMR
meteor build ../output                       # Production bundle
meteor add <package>                         # Add core package
meteor remove <package>                      # Remove core package
meteor test-packages ./packages/<name>       # Test a core package
meteor self-test "test name"                 # CLI self-tests

Repository Structure

packages/          # 100+ core packages (auth, data, build, web, reactivity)
tools/             # CLI & build system (Isobuild)
  cli/             #   Command handlers (commands.js)
  isobuild/        #   Bundler, compiler, linker
  runners/         #   App/Mongo/HMR runners
npm-packages/      # Published @meteorjs/* npm packages
scripts/           # Build & release automation

Common Workflows

Adding or Modifying a Core Package

1. Read conventions reference for package.js structure
2. Create/edit in packages/<name>/
3. Use api.mainModule() for server/client entry points, api.export() for globals
4. Add tests in *-tests.js, register in Package.onTest()
5. Run: meteor test-packages ./packages/<name>

Working with the Build System

1. Read codebase reference for the full pipeline
2. Entry: tools/cli/commands.js → dispatches to isobuild
3. Pipeline: Project Context → Bundler → Compiler → Linker → Output
4. Build plugins register via Package.registerBuildPlugin() + Plugin.registerCompiler()
5. Debug: METEOR_DEBUG_BUILD=1 meteor run or METEOR_PROFILE=1 meteor build

Finding Which Package Does What

Load packages reference — organized by domain:

• Auth: accounts-base, accounts-password, accounts-oauth, accounts-2fa
• Data: mongo, minimongo, ddp-server, ddp-client, ejson
• Build: babel-compiler, ecmascript, typescript, rspack, modules
• Web: webapp (Express 5.x), autoupdate, reload, browser-policy
• Reactivity: tracker, reactive-var, reactive-dict

Running Tests

Load testing reference for full details. Quick decision tree:

• Testing a core package? → meteor test-packages ./packages/<name>
• Testing CLI/tool behavior? → meteor self-test "test name"
• E2E with modern bundler? → npm run test:modern (Jest + Playwright)
• Need headless package tests? → PUPPETEER_DOWNLOAD_PATH=~/.npm/chromium ./packages/test-in-console/run.sh

Using Modern Tooling (tools-core / rspack)

Load modern-tools reference for full API. Key modules:

• Logging: logProgress, logError, logSuccess, logInfo from meteor/tools-core
• NPM: checkNpmDependencyExists, installNpmDependency, isYarnProject
• Process: spawnProcess, stopProcess, waitForPort
• Config: getMeteorAppDir, getMeteorAppConfig, getMeteorAppEntrypoints
• Git: isGitRepository, ensureGitignoreExists, addGitignoreEntries

Build Targets

Key Architectural Decisions

• Packages use api.versionsFrom(['3.0']) for Meteor 3.x compatibility
• webapp wraps Express 5.x — access via WebApp.expressApp
• tools-core is the foundation for modern integrations (rspack, etc.)
• Rspack (@rspack/core) replaces legacy bundling for modern apps
• DDP over WebSockets provides real-time client-server data sync

Reference Files

Load these as needed — not all at once: