codeaashu-claude-code/prompts/15-production-bundle.md

Prompt 15: Production Bundle & Packaging

Context

You are working in /workspaces/claude-code. By now you should have a working development runner (Prompt 14) and build system (Prompt 03). This prompt focuses on creating a production-quality bundle.

Task

Part A: Optimize the esbuild configuration

Update scripts/build-bundle.ts for production:

1. Tree shaking — esbuild does this by default, but verify:

   • Feature-gated code with if (feature('X')) where X is false should be eliminated
   • process.env.USER_TYPE === 'ant' branches should be eliminated (set define to replace with false)

2. Define replacements — Inline constants at build time:

   define: {
     'process.env.USER_TYPE': '"external"',  // Not 'ant' (Anthropic internal)
     'process.env.NODE_ENV': '"production"',
   }
   

3. Minification — Enable for production (--minify flag)

4. Source maps — External source maps for production debugging

5. Target — Ensure compatibility with both Bun 1.1+ and Node.js 20+

Part B: Handle chunking/splitting

The full bundle will be large (~2-5 MB minified). Consider:

1. Single file — Simplest, works everywhere (recommended for CLI tools)
2. Code splitting — Multiple chunks, only useful if we want lazy loading

Go with single file unless it causes issues.

Part C: Create the executable

After bundling to dist/cli.mjs:

1. Add shebang — #!/usr/bin/env node (already in banner)
2. Make executable — chmod +x dist/cli.mjs
3. Test it runs — ./dist/cli.mjs --version

Part D: Platform packaging

Create packaging scripts for distribution:

npm package (scripts/package-npm.ts):

// Generate a publishable npm package in dist/npm/
// - package.json with bin, main, version
// - The bundled CLI file
// - README.md

Standalone binary (optional, via Bun):

bun build --compile src/entrypoints/cli.tsx --outfile dist/claude

This creates a single binary with Bun runtime embedded. Not all features will work, but it's worth testing.

Part E: Docker build

Update the existing Dockerfile to produce a runnable container:

FROM oven/bun:1-alpine AS builder
WORKDIR /app
COPY package.json bun.lockb* ./
RUN bun install --frozen-lockfile || bun install
COPY . .
RUN bun run build:prod

FROM oven/bun:1-alpine
WORKDIR /app
COPY --from=builder /app/dist/cli.mjs /app/
RUN apk add --no-cache git ripgrep
ENTRYPOINT ["bun", "/app/cli.mjs"]

Part F: Verify production build

1. bun run build:prod succeeds
2. ls -lh dist/cli.mjs — check file size
3. node dist/cli.mjs --version — works with Node.js
4. bun dist/cli.mjs --version — works with Bun
5. ANTHROPIC_API_KEY=... node dist/cli.mjs -p "hello" — end-to-end works

Part G: CI build script

Create scripts/ci-build.sh:

#!/bin/bash
set -euo pipefail

echo "=== Installing dependencies ==="
bun install

echo "=== Type checking ==="
bun run typecheck

echo "=== Linting ==="
bun run lint

echo "=== Building ==="
bun run build:prod

echo "=== Verifying build ==="
node dist/cli.mjs --version

echo "=== Done ==="

Verification

1. bun run build:prod produces dist/cli.mjs
2. The bundle is < 10 MB (ideally < 5 MB)
3. node dist/cli.mjs --version works
4. docker build . succeeds (if Docker is available)
5. CI script runs end-to-end without errors