shwoop

Download templates from anywhere and replace {{KEY}} variables in file contents, file names, and directory names. Supports Eta for conditionals and loops, and shwoop.json for declaring variables, defaults, validation, interactive prompts, exclusion rules, and post-download hooks.

Built on giget for git-hosted templates (GitHub, GitLab, Bitbucket), with additional providers for AWS S3, Cloudflare R2, Google Cloud Storage, Google Drive, npm registry, any HTTP URL, and local files.

Quick Start

No install required (except for Bun)

bunx shwoop gh:jeff/cold-soup/template ./my-app FLAVOR=gazpacho SEATS=42

or

npx shwoop gh:jeff/cold-soup/template ./my-app FLAVOR=gazpacho SEATS=42

or

pnpm dlx shwoop gh:jeff/cold-soup/template ./my-app FLAVOR=gazpacho SEATS=42

To install globally: bun add -g shwoop

Sources

Prefix	Source
gh:	GitHub
gl:	GitLab
bb:	Bitbucket
npm:	npm registry
s3:	AWS S3
r2:	Cloudflare R2
gs:	Google Cloud Storage
gdrive:	Google Drive (public)
https://	Any URL (tarball/zip)
file:	Local filesystem

Usage

npx shwoop <source> <dest> [KEY=value ...]

Examples

# GitHub subdirectory with variables
npx shwoop gh:dept-of-birds/registry/templates/app ./my-app NAME=gerald PORT=1337

# Local template
npx shwoop file:./templates/skill ~/.claude/skills/log VAULT_PATH=/opt/questionable

# S3 tarball
npx shwoop s3:receipts-2019/templates/api.tar.gz ./api ENV=chaos

# Google Cloud Storage tarball
npx shwoop gs:lost-and-found/templates/api.tar.gz ./api ENV=staging

# npm package as template
npx shwoop npm:@disputed/toast ./project AUTHOR=the-temps

# Pin a specific version
npx shwoop npm:@disputed/toast@2.0.0 ./project AUTHOR=the-temps

# Use a dist-tag
npx shwoop npm:left-pad@latest ./project

# Any URL
npx shwoop https://example.com/sourdough-starter.tar.gz ./out KEY=value

# Google Drive (public share file ID)
npx shwoop gdrive:1a2b3c4d5e ./out NAME=gerald

Variables

Use {{KEY}} in any file. shwoop replaces all occurrences with the value you pass.

host: {{HOST}}
port: {{PORT}}

npx shwoop file:./template ./out HOST=localhost PORT=8080

Result:

host: localhost
port: 8080

Binary files are skipped automatically.

Advanced templates (Eta)

For templates that need logic, shwoop uses Eta — a lightweight, zero-dependency TypeScript template engine. Eta syntax is auto-detected; simple {{KEY}} templates work without it.

Conditionals:

{{ if(it.DOCKER) { }}
FROM node:20
COPY . /app
{{ } }}

Loops:

{{ it.DEPS.split(",").forEach(function(dep) { }}
  - {{= dep }}
{{ }) }}

Interpolation:

name: {{= it.NAME }}

Eta uses {{= expr }} for interpolation and {{ code }} for JS execution. Variables are accessed via it.KEY.

You can mix both styles in the same file — {{KEY}} placeholders are replaced first, then Eta runs for logic.

Configuration

Template authors can include a shwoop.json at the template root to declare variables, set defaults, validate input, exclude files conditionally, and run a command after everything is done.

{
  "vars": {
    "NAME": "",
    "HOST": "localhost",
    "FONT": ["helvetica", "comic-sans", "papyrus"],
    "SLUG": { "default": "", "pattern": "^[a-z][a-z0-9-]*$" }
  },
  "exclude": {
    "DOCKER": ["Dockerfile", ".dockerignore"],
    "CI": [".github/**"]
  },
  "postShwoop": "bun install"
}

Field	Purpose
vars	Declares variables your template expects. Controls prompting, defaults, and validation.
"NAME": ""	Required — empty string or null means it must be provided.
"HOST": "localhost"	Optional — uses the string as default, CLI overrides.
"FONT": [...]	Choice — must be one of the listed values, first is default.
"SLUG": {default, pattern}	Validated — must match the regex pattern.
exclude	Maps a variable name to file patterns (supports globs). Files are deleted when the variable is not provided or empty/"false".
postShwoop	Shell command that runs in the output directory after replacement and exclusion. Runs via sh -c.

Interactive prompts

When required variables are missing and stdin is a TTY, shwoop prompts interactively instead of erroring:

$ npx shwoop gh:dept-of-birds/registry/template ./out
Downloading from giget...
? NAME: gerald
? FONT:
  1) helvetica
  2) comic-sans
  3) papyrus
  Choose (1-3): 1
? SLUG (pattern: ^[a-z][a-z0-9-]*$): gerald
Replacing 3 variable(s)...
Done → ./out

In CI or piped input (non-TTY), missing required variables still produce errors. Pass all variables as CLI args to skip prompts entirely.

Conditional file exclusion

Files listed under exclude are removed when their key variable is not provided (or empty/"false"). Pass the variable to keep them:

# Keeps Dockerfile and .github/ in output
npx shwoop gh:dept-of-birds/registry/template ./out NAME=gerald DOCKER=true CI=true

Post-download hook

postShwoop runs a shell command in the output directory after variable replacement and file exclusion are complete. The command runs via sh -c, so pipes and chaining work:

"postShwoop": "bun install && git init"

$ npx shwoop gh:dept-of-birds/registry/template ./out NAME=gerald
Downloading from giget...
Replacing 3 variable(s)...
Running: bun install && git init
Done → ./out

If the command exits non-zero, shwoop fails with an error.

File and directory name replacement

{{KEY}} placeholders in file and directory names are replaced too:

template/{{NAME}}/{{NAME}}.config.ts  →  gerald/gerald.config.ts

Behavior overview

Scenario	Result
No shwoop.json, no args	Download only
No shwoop.json, with args	Replace with CLI args
shwoop.json with defaults	Merge defaults, CLI overrides
shwoop.json with required ("") not passed	Error listing missing vars
Choice variable with invalid value	Error listing valid choices
Pattern variable with invalid value	Error showing expected pattern

Missing required variable:

$ npx shwoop gh:dept-of-birds/registry/template ./out
Downloading from giget...
Error: Missing required variable: NAME

The shwoop.json file is removed from the output after processing. The legacy flat format (top-level key-value pairs) is still supported for simple cases.

Cloud Provider Setup

S3

# s3:<bucket>/<key> — key must point to an archive (.tar.gz, .tgz, .zip)
bunx shwoop s3:my-bucket/templates/api.tar.gz ./api ENV=prod

shwoop tries the aws CLI first (inherits all your configured auth). If the CLI isn't installed, it falls back to aws4fetch using AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables.

For public S3 buckets, use the https:// prefix instead — no credentials needed:

bunx shwoop https://my-bucket.s3.amazonaws.com/template.tar.gz ./out

R2

Requires R2_ENDPOINT pointing to your Cloudflare account's S3-compatible API:

export R2_ENDPOINT=https://<account-id>.r2.cloudflarestorage.com
bunx shwoop r2:my-bucket/templates/api.tar.gz ./api ENV=prod

Same fallback as S3 — aws CLI first, then aws4fetch with env var credentials.

GCS

bunx shwoop gs:my-bucket/templates/service.tar.gz ./out NAME=auth-service

shwoop tries gcloud CLI first. If not installed, falls back to aws4fetch using GCS HMAC keys via the same AWS_ACCESS_KEY_ID/AWS_SECRET_ACCESS_KEY env vars.

Public buckets: If the bucket allows public access, skip gs: and use the HTTPS URL directly — no gcloud CLI or authentication needed:

npx shwoop https://storage.googleapis.com/my-bucket/templates/api.tar.gz ./out NAME=auth-service

Google Drive

Download a publicly shared archive from Google Drive by file ID. The file ID is the long string in a Google Drive share link:

https://drive.google.com/file/d/1a2b3c4d5e6f7g8h/view
                                 ^^^^^^^^^^^^^^^ this part

npx shwoop gdrive:1a2b3c4d5e6f7g8h ./out NAME=gerald

The shared file must be a .tar.gz, .tgz, or .zip archive. shwoop downloads via Google Drive's public export endpoint (/uc?export=download), extracts the archive, then applies variable replacement.

Requirements:

• The file must be shared as "Anyone with the link" in Google Drive
• No authentication or API key is needed for public files

Limitations:

• Large files (>100 MB) may trigger Google Drive's virus-scan interstitial page — shwoop detects this and fails with a clear error rather than silently extracting HTML
• The /uc?export=download endpoint is being tightened by Google over time; very large files may require the Drive API v3 with an API key (not currently supported)
• The file must be an archive — plain files (single .ts, .json, etc.) are not supported as templates

npm

Uses npm pack under the hood — any specifier that npm pack accepts works:

# Unscoped package
npx shwoop npm:left-pad ./out

# Scoped package
npx shwoop npm:@disputed/toast ./out AUTHOR=the-temps

# Pinned version
npx shwoop npm:@disputed/toast@2.0.0 ./out AUTHOR=the-temps

# Dist-tag
npx shwoop npm:left-pad@next ./out

The package tarball is downloaded to a temp directory, extracted (stripping the package/ prefix npm adds), then variable replacement runs as usual. The temp directory is cleaned up regardless of success or failure.

Requirements:

• npm CLI available on PATH (ships with Node.js)
• Registry authentication configured in .npmrc if the package is private

Contributing

Clone the repo and install dependencies with bun install.

bun test          # run tests
bun run build     # compile to dist/
bun run lint      # check with oxlint + oxfmt
bun run format    # auto-fix with oxfmt

License

MIT