Complex Shopify requirement? We design, build, and deploy it — starting from €750. Request a Custom Rule →
For Shopify Plus merchants & agencies

Complex Shopify rules, built for you.

We design, build, test, and deploy custom Shopify checkout, shipping, payment, discount, and validation logic that standard apps can't handle.

Request a Custom Rule → Book a Consultation

# no scoping call to start · we reply within 48h

payment-rules / wholesale-net-30.rule
● matched evaluating…
Built with
Shopify Functions Rust GraphQL WebAssembly Shopify Polaris
The problem

Standard apps handle simple rules. Complex requirements need custom engineering.

A single toggle — hide a payment method, show a banner — is a solved problem. The moment a requirement chains conditions across customer data, order history, and metafields, most apps stop being an option.

Complex checkout validation

MOQ by collection, quantity caps, multi-condition eligibility checks before checkout can complete.

Advanced shipping rules

Freight-only for oversized carts, per-market carrier logic, delivery rules apps can't chain together.

Payment restrictions

Hide, gate, or reorder payment methods by tag, market, cart value, or company approval.

B2B & customer-specific logic

Net terms for approved companies, tiered pricing, wholesale-only payment methods.

Complex discount conditions

Stacked, conditional, or customer-specific discounts standard discount apps can't express.

Shopify Scripts migration

Scripts stopped running June 30, 2026. We rebuild that logic as native Functions.

What we build

Native Shopify Functions — not templates, not workarounds.

Every rule compiles to a real Shopify Function running inside Shopify's checkout, payment, and discount extensibility APIs. We design around the platform's real technical ceilings from day one — most teams discover them the hard way, in production.

Built by people who've hit the real Function limits.

These aren't edge cases — they're the reason a rule that works fine on paper can fail outright once it's deployed, if nobody accounts for them.

11M instruction limit — functions fail on large carts 128kB function input cap Metafields over 10,000 bytes return null in function input
Our main offer

Custom Shopify Rule Development

Send us your requirement. We analyze it, build the solution, test it, and deploy it to your store.

Starting from €750

Final price depends on complexity — quoted after we review your requirement, before any work starts.

Request a Custom Rule →
How it works

Describe → Analyze → Build → Test → Deploy → Support.

01

Describe

Tell us exactly what the rule needs to do — the more detail, the tighter the quote.

02

Analyze

We check it against Shopify Functions' real technical limits and price it, fixed.

03

Build

Implemented as a native Shopify Function — not a workaround, not a shim.

04

Test

Simulated against realistic checkout scenarios before anything goes live.

05

Deploy

Staged first, then production, with documentation and an exported config.

06

Support

Need a change later? We're a message away, not a new vendor search.

For agencies

One solution. Multiple client stores.

Turning away checkout work because the dev team's maxed out?

Build a rule once for one client, and we hand it back as exported config you redeploy to the next client store yourself — no rebuilding the same net-terms rule, MOQ check, or per-market payment logic from scratch every time. If you're not capacity-constrained, billing those hours directly probably makes more sense than paying us to save them.

Fixed-scope engagements Exported, reusable config One point of contact Volume pricing across stores
Other services

Already know what you need?

Two fixed-price engagements we run alongside custom rule development.

audit

Checkout Audit

€400 · 48 hours

We review one store and tell you exactly what's broken since the Scripts shutdown.

Script gapsSilent failsMetafield limits

# written report, severity-ranked

Book an audit →
migration

Scripts Migration

from €1,800

We rebuild your Scripts logic as native Shopify Functions, tested before deploy.

PaymentDeliveryDiscountsValidation

# docs + exported config included

Get a quote →
retainer

Checkout Retainer

from €600/mo

Ongoing rule builds, changes, and monitoring — one flat monthly rate.

New rulesOnboardingMonitoring

# the natural end state once requests turn monthly

Talk to us →
Examples

What a custom rule actually looks like.

Illustrative examples of the kind of requirement we build — not real client case studies yet. Those replace these as we deliver them.

example

B2B net terms, done right

Problem: Net 30 was showing to anyone tagged "wholesale" — not just approved companies with a resale certificate on file.

Result: Five chained conditions, deployed as a native Function, simulated before going live.

example

A discount apps can't scope

Problem: A loyalty discount that should only apply to repeat customers buying a second unit from one collection.

Result: One rule, reused across every client store running the same program.

try it

See it evaluate live

The simulator below runs seven chained rules — B2B approval, resale certs, regional duty thresholds — in real time as you change the checkout context.

See it live ↓
rulic simulate — store: wholesale-na.myshopify.com 7 rules · evaluated in 0.4ms

Checkout context

# reads customer tags, B2B approval, resale certs, and cart metafields — no test checkouts, no redeploys.

Rules (priority order)

Resulting checkout

Credit Cardvisible
Invoicevisible
Net 30hidden
Cash on Deliveryvisible
Express Shippingvisible
Freight shippinghidden
✓ checkout allowed
This took 7 chained rules and 0 lines of code for you to write. Imagine your most complex client requirement. Request a Custom Rule →
Rulic Platform — coming soon

An AI-powered way to describe and deploy complex Shopify rules yourself.

Describe a rule in plain language, and Rulic will compile it into a native Shopify Function — no scoping call, no engineer required. It's in development; every rule on this page today is still built by hand, by us.

# free during early access · no credit card

Questions merchants & agencies ask us.

How much does a custom rule cost? +
Starting from €750 — final price depends on complexity. We quote a fixed price after reviewing your requirement, before any work starts.
How long does a custom rule take? +
Most rules ship in 1–3 weeks depending on complexity. We confirm a real timeline once we've reviewed exactly what you need — not before.
Does it require Shopify Plus? +
No — most payment, shipping, and validation logic works on any Shopify plan. B2B features like company-account net terms do require Plus, since B2B on Shopify itself is a Plus-only capability.
Why not just use a checkout app? +
For a single, simple rule, a free or cheap app is the right call. Custom rule development is for logic apps can't express: chained conditions across metafields, tags, order history, and B2B data.
Can I migrate from Shopify Scripts? +
Yes. Scripts stopped running June 30, 2026 — we rebuild that logic as native Shopify Functions, with full test coverage before cutover.
What's the Rulic Platform, and when does it ship? COMING SOON +
It's the self-serve, AI-powered way to describe a rule in plain language and have it compiled automatically — in development. Until it ships, every rule on this page is still built by hand, by us.
Can I test a rule before it goes live? +
Yes — every rule we build is run through simulated checkout scenarios before deployment. See it working in the interactive example above.
We manage multiple client stores — does this scale? +
Yes. Build a rule once, and we hand it back as exported config you redeploy to the next client store yourself — that's the core of the agency offer.
Request a Custom Rule

Tell us what you need. We'll quote a fixed price before any work starts.

This isn't a generic contact form — the more detail you give us here, the tighter the quote and the faster we can start.

# we reply within 48h · fixed-price quote, no surprises

What happens next

We review your requirement and reply with a fixed-price quote within 48 hours — no obligation, no scoping call to start.

Pricing

Starting from €750, based on complexity. No surprises once we've quoted it.

Prefer email? Support@Rulic.app

For partnerships, press, or anything that doesn't fit the form.