Build custom sections once, in the app, and hand off a clean theme. No write_themes scope, no code pasted into the client's theme, no Monday support call after a Sunday theme update. Every section survives every update, on every client store you manage.
Every tool decision multiplies across your whole client book. The apps that paste code into a theme were built for a merchant with one store — not for an agency carrying the liability for dozens.
A client's hero section has a bug. You fixed the same bug last month — but on a different store, on a different theme, in a .liquid file copied into that theme. Now you're grepping through theme files across accounts trying to remember where the good version lives. There's no single source of truth, because the code lives inside each theme.
Your client updates their theme on a Sunday. Sections that were copied into the old theme are now tied to a theme version that no longer exists — frozen, drifted, or gone. Monday morning, it's your inbox, your emergency, your unbilled hours. You didn't touch anything, but you own the fix.
Apps that write into the theme need the write_themes scope. That means code you didn't audit, sitting in a theme you'll hand to a client — and residue left behind when the app is removed. When something breaks a year later, the client calls you, not the app vendor. You're on the hook for code you didn't fully control.
The client wants a redesign, or a new theme. Every custom section pasted into the old theme is now work you have to find, port, and re-test by hand — or quietly lose. Paid-for work becomes throwaway work, and “just swap the theme” turns into a project.
SectionGuard keeps custom sections, CSS/JS, and metafield displays in the app, rendered through one theme-safe app block. That single architectural choice fixes each pain above.
Solves “which theme copy has the fix?” Each install keeps its sections in that shop's own app account, not scattered across theme files. Fix a section once and it's fixed everywhere it's referenced inside that shop — no hunting through theme code across client accounts.
Solves rebuilding the same section for every client. Export a section as a JSON file from shop A and import it straight into shop B, C and D. Build your library once; reusing it across shops is an export/import, not a rebuild.
Solves the Sunday update. Because sections aren't theme files, a theme update can't overwrite or freeze them — they keep rendering through the app block. Your client can update their theme whenever they want. Your phone stays quiet.
Solves per-client emergencies. Every section keeps a version history. If a change goes wrong on a client store, restore it in one click — no re-pasting code, no re-buying, no digging for the old file. A revert is instant and scoped to that store.
Solves the liability. SectionGuard requests no write_themes scope. Nothing is written into the client's theme, so there's no residue to clean up and no un-audited code baked in. Hand off a theme that stays clean and updatable — the way you'd want to inherit it yourself.
Solves the redesign fear. Swap the theme, run the redesign, migrate to a new base — your sections live in the app and keep rendering. The work you were paid for isn't trapped inside a theme you're about to replace.
Write the section in the in-app editor — HTML, CSS, JS, with syntax highlighting and token autocomplete. Drop in server-side tokens like {{ product.title }}, {{ collection.title }}, and metafields (with filters like truncatewords and default). The tokens render server-side, so there's no raw client Liquid that can break a theme.
Pick the section by name in Shopify's native theme editor and drop it where it belongs. It renders through one theme-safe app block — the client edits it in the editor they already know.
No code copied in, no write_themes residue. If the app is ever removed and reinstalled, sections auto re-sync. The client owns a theme that stays clean and updatable — and your section stays in your own workflow: export it as JSON and reuse it the next time a different client needs the same thing.
Because sections live in the app, they render while the app is installed — and they stop rendering if the app is uninstalled. In exchange, they survive every theme update, on every store. For agencies, that's the right side of the trade: your clients update themes far more often than they uninstall an app you put there on purpose. Apps that copy .liquid into the theme made the opposite choice — their sections survive uninstall, but each becomes a static copy tied to a theme version, which can drift or break on a theme update and can't be fixed centrally.
Start free with up to 3 sections. Go unlimited when you're ready, and add the 35-template library on Pro. Billed through Shopify.
Free for up to 3 sections · No credit card · Works on OS 2.0 & Horizon.