Stop Letting Agents Fill Your SSD With npm

Last week I asked an AI agent to prototype three small web apps. It spun up three Vite projects, configured Tailwind, and ran test builds.

Thirty minutes in, my laptop showed a low disk space alert.

The agent had downloaded three separate copies of React, Vite, TypeScript, and ESLint. Each project had its own 600 MB node_modules directory. If you run multiple subagents or test throwaway ideas during the week, you lose dozens of gigabytes to duplicate JavaScript packages.

The default to npm

Language models learn from millions of public repositories, tutorials, and issue threads that tell people to run npm install. When an agent needs a library, it types npm i.

You can write "use pnpm" in your prompt. It works for a few messages. Then the context window rolls over, a subagent spawns without prompt history, or the model runs a one-off shell check and goes back to npm.

Hard links versus duplicate folders

Standard npm isolates each project by copying every package into the local node_modules folder. Five projects using TypeScript put five full copies of TypeScript on disk.

pnpm writes packages once to a global store at ~/.local/share/pnpm/store. Projects link to those files using filesystem hard links. Ten projects using the same library version share one physical copy on disk.

Intercepting terminal commands

I built always-pnpm to stop fighting prompt instructions.

The tool hooks directly into the agent runtime. When Antigravity, Claude Code, OpenCode, or Codex runs a shell command starting with npm or npx, always-pnpm parses the string and rewrites it to pnpm in under three milliseconds.

Agent proposal:

npm install express lodash

Command executed in your shell:

pnpm add express lodash

The model gets its packages, the project runs, and your drive stores those files once.

Command mapping

The parser translates common flags and subcommands:

• npm i -D <pkgs> becomes pnpm add -D <pkgs>
• npx <cmd> becomes pnpm dlx <cmd>
• npm ci becomes pnpm install --frozen-lockfile
• npm cache clean --force becomes pnpm store prune
• npm init <template> becomes pnpm create <template>

Commands that only mention npm inside strings or arguments, like git commit -m "fix npm bug" or grep -r "npm" ., stay untouched.

Setup

Run the installer to detect your agent runtimes and configure their native hooks:

curl -fsSL https://raw.githubusercontent.com/youxufkhan/always-pnpm/main/scripts/install.sh | bash

You can also target specific agents directly:

# Target Claude Code
./scripts/install.sh --claude

# Target Antigravity
./scripts/install.sh --antigravity

# Target OpenCode or Codex
./scripts/install.sh --opencode
./scripts/install.sh --codex

The repository and test suite are on GitHub: github.com/youxufkhan/always-pnpm.