mantle-brain

Open-source build guides for recreating Mantle’s billing, analytics, and automation tooling in your own app.

What this is

mantle-brain is a library of self-contained guides that explain how Mantle’s core features worked and how to rebuild them yourself. Each top-level folder covers one capability — the data model, the formulas, the edge cases, and the order of operations — so you can stand the feature back up in your own stack instead of losing it when Mantle goes away.

This is about strategy, not source code. The guides hand you the hard-won decisions (how MRR is reconstructed as-of a past date, how to bill flexibly without re-triggering Shopify’s approval screen, how to reproduce the “derived” events your automations relied on) rather than a drop-in Mantle codebase.

Who it’s for

Shopify Partners and app developers who relied on Mantle and need to keep running after it’s gone.

The guides are stack-agnostic: they describe behavior, data models, and algorithms, not Mantle’s internals. Wherever a step is specific to Mantle’s own infrastructure, the guide says so and tells you to skip or substitute it — so you can map the rest onto whatever you already run (any language, any database, your own queue or warehouse).

What’s inside

Three ways to use each guide

Every topic offers three on-ramps to the same material — pick the one that fits how you want to work:

1. Read it yourself. Each topic’s README.md is a human-readable walkthrough of how the feature worked and what it takes to rebuild.
2. Hand it to a coding agent. Paste the topic’s implementation-spec.md into Claude Code, Cursor, or similar and say “implement this in my app.” It’s a dense, imperative build spec — data model, exact shapes, pseudocode, and acceptance tests.
3. Install the skill. Each topic ships an installable Claude Code / Agent skill under skill// that drives the build for you (see below).

Some topics also ship extra companions — a one-shot pipeline prompt, an n8n workflow generator, an inventory template. Check the topic’s own README for what’s included.

Installing a skill

Each skill lives at /skill//. To use one, copy that folder into your project’s .claude/skills/ directory:

cp -R flex-billing/skill/shopify-flex-billing /path/to/your-app/.claude/skills/

Open the project in Claude Code and the skill is available — the agent follows its SKILL.md, pulling in the bundled spec and references as needed. Each skill folder is self-contained, so you can copy it out on its own. The implementation-spec.md files are editor-agnostic if you’d rather paste them into another agent directly.

License

MIT © Hey-Mantle