Perfect-Lasso

A Swift reimplementation of the Lasso web-scripting language and server (lasso-perfect-server) — still in active development and not yet production-ready, though validated against real code from multiple production e-commerce sites.

This repo has no pre-built binary releases yet — you build it from source, against your own toolchain and Homebrew setup. That turns out to be simple: builds are proven to work from a completely standalone clone, with no other repos or sibling checkouts required nearby.

Releases

See the GitHub Releases page for what's changed in each version. As of this release, both macOS and Linux are fully validated — build and the complete 1110-test suite pass clean on both, verified from a clean rebuild in a Linux container. The three Perfect-Lasso-internal Linux gaps and one real cross-platform bug found along the way are documented in the release notes.

Trying it against your own site

If you have an existing Lasso site and are curious how much of it this server already handles, the best way to find out is to actually point it at your own code and see what breaks — that's exactly how this project has been developed and tested so far. If you hit something that doesn't render correctly, crashes, or is simply unimplemented, please open an issue with what you found — real-world Lasso source is what this project improves against, and reports of what's still fragile or missing are the most useful thing you can contribute right now.

Requirements

• Xcode 27 or later (Swift 6.4 toolchain, confirmed working). Package.swift declares a swift-tools-version: 6.2 minimum, but only Xcode 27 has been verified.

• macOS 12.0 (Monterey) or later at runtime, on either Apple Silicon or Intel. Package.swift declares this as the deployment target across the whole dependency graph; Intel support has been verified via real cross-compilation (swift build --triple x86_64-apple-macosx12.0), not just assumed from the code. See Documentation/macos-deployment-targets.md for the full findings. If you're on older Intel hardware Apple no longer supports past macOS 10.15/11, native support for that was attempted and set aside as too much ongoing maintenance burden for one hardware tier — see that document's Verdict section. The recommended path there is OpenCore Legacy Patcher to get the machine onto 12.0+, where this project already just works.

• Homebrew, with one formula installed:

  brew install mysql-client

  That's the only Homebrew package this needs. libxml2 and zlib — the other two C libraries this project links against — resolve against macOS's own system copies automatically; you don't need to install anything for them, and having either one also installed via Homebrew for an unrelated project is fine too — both dependencies (Perfect-XML, Perfect-NIO) skip pkg-config for these on macOS specifically so a Homebrew copy can never collide with the SDK's own bundled headers. (Older pins predating that fix could still hit a "conflicting types" build failure — see Documentation/libxml2-pkgconfig-collision.md if you ever do.)

Build

git clone https://github.com/taplin/Perfect-Lasso.git
cd Perfect-Lasso
swift build -c release --product lasso-perfect-server

The built binary's exact location varies by SwiftPM version — always ask it directly rather than assuming a path:

swift build -c release --show-bin-path

Run

At minimum, lasso-perfect-server needs to know what directory to serve:

LASSO_SITE_ROOT=/path/to/your/lasso/site \
"$(swift build -c release --show-bin-path)/lasso-perfect-server"

It starts listening on http://localhost:8181 by default and prints a short startup banner confirming the site root, port, and which optional subsystems (datasources, sessions, admin console) are active.

Configuration

Everything is environment-variable- or config-file-driven — no source edits, no compiled-in paths. The full reference, including:

• LASSO_SERVER_PORT, LASSO_RENDER_EXTENSIONS, LASSO_STARTUP_PATH
• LASSO_DATASOURCE_CONFIG_PATH — a JSON file for MySQL/FileMaker datasource aliases, credentials, and SMTP relay/DKIM settings (recommended over passing credentials as bare env vars)
• crawl-report and sitemap-discovery options

is documented in Documentation/lasso-perfect-server.md's "Configuration" section.

For the optional browser-based operations dashboard (live datasource switching, log tailing, zero-downtime restart), see Documentation/admin-console.md.

One startup requirement worth knowing up front: if you configure SMTP with DKIM signing, the server does a hard (not just a warning) permission check on the DKIM private key file at startup — it refuses to boot if that file is group- or world-readable. chmod 600 it first.

Using a specific release instead of main

main moves — if you'd rather build against a stable, known-working snapshot, check the Releases page for a tagged version and either:

git clone --branch vX.Y.Z https://github.com/taplin/Perfect-Lasso.git

or download that tag's "Source code" archive directly from its Release page, unpack it, and build the same way as above. Each tagged release commits a known-good Package.resolved, so you get the exact dependency versions that were verified working at that point — not whatever the tracked main branches of this project's dependencies have drifted to since.

(Maintainers: see Documentation/releasing.md for the release-cutting process itself.)