@bigconfig/bb

Run babashka (bb) without installing anything first. On its first invocation this package downloads a pinned babashka binary and an Eclipse Temurin JDK into a shared user cache, then forwards every argument to bb.

Usage

npx @bigconfig/bb tasks        # -> bb tasks
npx @bigconfig/bb <args...>    # -> bb <args...>

All arguments (including flags) are passed through verbatim, and bb runs in your current working directory, so it picks up the local bb.edn.

What happens on first run

1. The host OS/CPU are resolved to the matching babashka release asset and Adoptium API parameters.
2. babashka is downloaded from its GitHub releases and cached.
3. A Temurin JDK is downloaded from the Adoptium API and cached.
4. bb is launched with JAVA_HOME / PATH pointing at the cached JDK — the environment change applies only to the bb subprocess, nothing system-wide.

Subsequent runs reuse the cache and start immediately.

git (Linux only)

On Linux, if git is not on PATH, it is installed via the system package manager (apt-get, dnf, yum, zypper, pacman, or apk), using sudo when not running as root. This is skipped when git is already present, and is a no-op on macOS/Windows. Unlike babashka/JDK, this modifies the system and may prompt for a sudo password; in non-interactive environments without passwordless sudo it will fail with an actionable message — pre-install git to avoid this entirely.

bb.edn bootstrap (optional)

If the current directory has no bb.edn and BB_EDN_REPO=owner/project is set, that repo's bb.edn is downloaded (pinned to its default branch's latest commit) and the repo itself is added to :deps as io.github.<owner>/<project> {:git/sha "<sha>"}. The edit is done with borkdude/rewrite-edn, so existing comments and formatting are preserved.

Any dependency using :local/root (in :deps or a task's :extra-deps) is removed first, since those paths don't exist once the file is downloaded. Valid Maven/git deps are kept.

• Skipped entirely if BB_EDN_REPO is unset or a bb.edn already exists.
• Fatal error if the repo is missing/inaccessible or has no bb.edn.
• Set GITHUB_TOKEN for private repos or to avoid GitHub's unauthenticated API rate limit.

BB_EDN_REPO=my-org/shared-tasks npx @bigconfig/bb tasks

Cache location

A single shared directory, reused across all projects:

| Platform | Path | | ------------- | -------------------------------------------- | | macOS / Linux | $XDG_CACHE_HOME or ~/.cache → bigconfig-bb/ | | Windows | %LOCALAPPDATA% → bigconfig-bb/ |

Delete that directory to force a clean reinstall.

Configuration

| Env var | Default | Effect | | --------------------- | ---------- | ----------------------------------------------- | | BB_VERSION | 1.12.196 | babashka release version to install | | JDK_VERSION | 21 | Temurin feature version (e.g. 17, 21, 25) | | BB_EDN_REPO | (unset) | owner/project to bootstrap a bb.edn from (see below) | | GITHUB_TOKEN | (unset) | Used for BB_EDN_REPO (private repos / higher API rate limit) | | REWRITE_EDN_VERSION | 0.5.9 | borkdude/rewrite-edn version used to edit the bb.edn |

Supported platforms

macOS arm64, macOS x64, Linux x64, Linux arm64, Windows x64.

Notes:

• Linux x64 uses babashka's glibc build (may not run on musl distros such as Alpine). Linux arm64 uses babashka's static build, which runs on both glibc and musl.
• Extraction uses the system tar (present on macOS, Linux, and Windows 10+); Windows falls back to PowerShell Expand-Archive for .zip if tar is unavailable.

Requirements

Node.js >= 18.