Custom Shopify apps
BEYOND PUBLIC APPS
Custom Shopify apps
BEYOND PUBLIC APPS
Custom apps for business logic public apps can't handle.
Shopify agents that can search, decide, and act
Connect AI agents to Shopify products, carts, checkout, orders, and internal systems. We build customer-facing and operational workflows with controlled access to real commerce data.
ERP & OMS sync
SYSTEM INTEGRATION
ERP & OMS sync
SYSTEM INTEGRATION
Keep orders, inventory, and product data in sync.
AI agents
AGENTIC WORKFLOWS
AI agents
AGENTIC WORKFLOWS
Agents that act across Shopify and connected systems.
Shopify brands we've built for
Apps and integrations we've built.
What we build
What can AI agents actually do inside Shopify?
We build the agents and the Shopify systems underneath them, so search, decisions, and actions run on live commerce data with clear boundaries.
Customer-facing commerce agents
Help shoppers discover, compare, and select products, build carts, and move into Shopify checkout using live catalog and commerce context.
Operational agents
Give agents controlled access to order, fulfillment, customer, inventory, and support workflows so repetitive decisions can be handled without another manual queue.
Custom apps and system tools
Build the Shopify apps, APIs, ERP/OMS/PIM connections, and internal tools that give agents reliable data and safe actions.
Guardrails
Agents need permissions before intelligence
We make agents useful without giving an LLM unrestricted access to your store. Permissions, approvals, and audit trails come before automation.
Read vs. write access
Define exactly what the agent can inspect and what it can change.
Human approval
High-impact actions can require approval before they touch orders, customers, pricing, or fulfillment.
Failure recovery
Retries, idempotency, fallbacks, and escalation paths prevent one failed tool call from becoming an operational incident.
Auditability
Log the context, tool call, decision, and result so your team can understand what the agent actually did.
Our approach
How we build agents that can safely act
We map the decision first, then give the agent only the tools and permissions it needs to act safely on real commerce data.
- 01
Map the decision
Define what the human does today, what data drives the decision, and which parts are actually worth automating.
- 02
Define tools and boundaries
Shopify APIs, MCP, external systems, permissions, approval thresholds, fallbacks, and expected outputs are defined before the agent is built.
- 03
Build and validate
Connect the model to real tools and test successful paths, incorrect decisions, missing data, failures, and edge cases.
- 04
Release with control
Start with limited permissions, observe real decisions, expand autonomy where results justify it, and keep monitoring in place.
Fit
When an AI agent is actually worth building
We'll recommend standard automation when the workflow is deterministic. Agentic systems make sense when context, judgment, and multiple systems are part of the decision.
Standard automation is better when
The workflow is deterministic
If X always results in Y, Shopify Flow, an integration, or ordinary application logic is usually simpler.
A public app already solves it
Don't introduce an AI agent where configuration is enough.
Shopify developmentErrors have no acceptable recovery path
Some workflows should remain deterministic or require explicit human approval.
Agentic workflows make sense when
The decision changes with context
The right action depends on customer, order, inventory, conversation, policy, or multiple systems.
Humans repeatedly inspect several systems
A team member gathers context from Shopify, ERP, support, logistics, or internal documentation before deciding what to do.
The workflow contains judgment
Classification, prioritization, recommendations, exception handling, or selecting between several valid actions.
What our customers say
“One custom app built by EXTFOX replaced five of the tools we were juggling. It manages our discount tiers, runs 40% faster, and saved us $12K a year. We finally have one system instead of a pile of workarounds.
Engagement
How can we work on agentic workflows together?
Whether you need an assessment, a defined agent or integration build, or ongoing operations, the shape follows the workflow. Model, infrastructure, and third-party API usage are separate.
Agentic workflow assessment
Scoped after workflow review.
Who it is for
Map the current process, automation opportunity, systems, permissions, risks, and expected ROI before committing to development.
What is included
- Current workflow and decision mapping across systems
- Permissions, risk, and build vs buy assessment
- Recommended architecture with expected ROI and next steps
How it ends
Ends with a clear recommendation on whether an agent is worth building and a scoped plan if it is.
Agent / integration build
From $15,000 USD
Scoped to a defined agent, integration, or MCP workflow.
Who it is for
Build a defined agent, Shopify integration, MCP workflow, or internal automation.
What is included
- Agent or integration development with tools and boundaries defined
- Testing across success paths, failures, and edge cases
- Controlled release with monitoring and handover documentation
How it ends
Results in a working agent or integration with clear maintenance procedures and monitoring in place.
Agentic operations
From $3,500 per month USD
Monthly. Three months minimum for meaningful results.
Who it is for
Monitoring, prompt and tool improvements, new workflows, API maintenance, model changes, and capability expansion.
What is included
- Monitoring, incident response, and permission reviews
- Prompt, tool, and workflow improvements based on real decisions
- API maintenance, model changes, and new capability delivery
How it ends
Runs as an ongoing partnership with controlled expansion of agent autonomy and capabilities.
Not sure which shape fits? Book a meeting with the team.
Not ready to book?
Complementary services
What works alongside agentic workflows
Agents often need search, checkout, and storefront context around them. These services commonly pair with agentic Shopify work.
Let's meet
Book directly with Dusan J., Founder at EXTFOX. We'll map the workflow, decide whether it needs an agent, standard automation, or a custom integration, and identify the smallest useful version to build first.
Have a Shopify workflow your team still handles manually?
Pick a time that works for you. You'll get instant confirmation and a calendar invite.
Prefer to call? (862) 259-6969
Not ready to book?
FAQ
Build custom when your business logic doesn't fit existing apps, you need complete control over data and features, or you require deep integration with other systems. Public apps work for common use cases, but custom apps are necessary when your requirements are unique, you need specific admin UI, or existing apps create operational friction.
Private apps are built specifically for your store and business needs. They're not listed in the App Store and can access your store's data directly. Public apps are distributed through Shopify's App Store and must work for multiple merchants. Private apps give you complete control but require maintenance. Public apps offer broader support but less customization.
ERP integration complexity depends on data synchronization needs, real-time requirements, and system architecture. Simple integrations might sync inventory and orders nightly. Complex setups require real-time inventory updates, multi-location fulfillment routing, and bidirectional data flow. We assess your specific ERP system and design appropriate integration architecture.
Agentic workflows use AI to automate and optimize business processes that traditionally require human decision-making. Examples include intelligent order routing based on inventory and customer location, dynamic pricing that responds to demand patterns, and automated customer service that escalates appropriately. They adapt to your business patterns and improve operations over time.
Timeline depends on app complexity and integration requirements. Simple admin apps might take 4-6 weeks. Complex integrations with external systems typically require 8-16 weeks. Agentic workflows with AI components can take longer. We provide detailed timelines during the architecture phase based on your specific requirements and technical complexity.
Integrations need ongoing maintenance for API version updates, security patches, performance monitoring, and feature enhancements. Shopify regularly updates APIs, and connected systems evolve. We provide maintenance retainers that include monitoring, updates, and enhancements so your integrations stay reliable and current.