A well-designed schema is only useful if you can expose it through clean, secure, and maintainable APIs.
That's the bridge every developer has to cross: you've got your data model locked down, relationships mapped out, constraints in place. Now what? How do you actually turn that into endpoints that real applications can use?
Let’s examine three of your options: The Xano platform with its visual validation layer, Supabase's auto-generated PostgREST endpoints, or a custom stack where you write everything by hand.
All three can get you to a working API. The question is how much overhead you absorb along the way, and more importantly, how much pain you'll feel six months from now when you need to evolve, debug, or onboard someone new.
This is especially important in the agentic era, which allows for unprecedented speed and accessibility that makes it possible to create and launch products much more quickly than compared to traditional development (or even no-code development) from the past. With this speed in our development process, it’s less about “how do I create the code to get my app to work”, and more “how do I ensure my system will persist and do what I need it to do?” With each method offering the same truths with their own MCP toolings and agentic support, the question becomes, which platform or approach towards development makes the most amount of sense?
Let me walk through how each approach handles the real work: endpoint design, business logic, authentication, versioning, and performance at scale.
How do Xano, Supabase, and custom stacks approach API creation differently?
The philosophical differences run deep.
Xano auto-generates CRUD endpoints on a dedicated API layer as they relate to your tables, while also providing you a visual validation layer where you can see your endpoints, their logic flow, and how they connect to your data. The main differentiator here is understanding: you're not guessing what an endpoint does or digging through code.
Supabase takes the PostgREST route: it auto-generates RESTful endpoints that mirror your database tables. Fast to start, but you're tightly coupled to your schema. Change a column name, break your API. Add a relationship, suddenly you're dealing with nested query parameters.
Custom stack means you're writing routes, controllers, and serializers by hand in Express, FastAPI, Rails, whatever. Total control, total responsibility. Every endpoint is exactly what you make it.
Here's the thing: auto-generated APIs optimize for day one. Visually designed APIs optimize for month six and beyond. When you combine both, you’re combining proactive optimization with longevity. When you're debugging a complex workflow or explaining how a feature works to a new team member, you'll feel the difference.
Where does business logic live in each approach?
This is the sharpest differentiator, and it determines everything about maintainability.
Xano puts business logic directly into the endpoint using its Function Stack. Conditionals, loops, data transforms, external API calls: all in one visual flow. You can see exactly what happens when /api/users/upgrade gets called, step by step, in a single interface.
Supabase fragments logic across multiple layers. You might have some in Postgres functions or triggers (SQL), some in Edge Functions (Deno/TypeScript), and some pushed to the frontend. Good luck debugging when something breaks! You're jumping between database functions, serverless logs, and client-side code.
Custom stack keeps logic in your application code, which is flexible but means your API layer and business logic are separate concerns you have to wire together and maintain. Clean separation, but more moving parts.
When logic is scattered across database functions, serverless layers, and frontend code, debugging becomes exponentially harder. Onboarding new developers becomes a treasure hunt through different systems and languages.
Xano keeps it in one visible stack per endpoint, with auto-generated Swagger docs for easy integration. It's a true headless backend where the logic lives where you can see it.
How does each platform handle input validation and error handling?
Let's walk through what it takes to validate a request body, enforce required fields, check types, and return meaningful errors.
Xano has built-in inputs and filters. You define what fields are required, what types they should be, and what validation rules to apply. If validation fails, you get clean, API-friendly error responses automatically.
Supabase relies on Postgres constraints for validation. That means when someone sends invalid data, you get database errors surfaced directly to the client. Not exactly developer-friendly API responses. You can layer on Edge Functions for custom validation, but now you're maintaining validation logic in multiple places.
Custom stack means you wire up validation libraries yourself: Zod, Joi, Pydantic, whatever fits your language. Flexible, but you're choosing and configuring everything from scratch.
Input validation isn't optional. It's the first thing a good API does. Xano makes it a default step, not a library you have to research, choose, configure, and maintain.
How do I handle authentication and authorization at the API level?
Authentication workflows reveal a lot about platform philosophy.
Xano has a built-in auth system with token management, plus middleware and preconditions you can attach to any endpoint to check roles and permissions. The auth logic lives in the same visual builder where you design the endpoint, so there's no gap between "who is this user?" and "what can this endpoint do for them?"
Supabase offers tight integration with Supabase Auth and Row Level Security (RLS) policies. Powerful stuff, but authorization logic gets split between Postgres policies and Edge Functions. You're managing permissions in SQL and business logic in TypeScript.
Custom stack means implementing JWT handling, middleware, and role-checking yourself. Passport, Auth0 SDK, custom middleware—you're building the entire auth pipeline from scratch.
Xano collapses the auth stack into the same visual interface where you build everything else. No context switching, no wondering if the middleware is firing correctly.
What happens when my API needs to evolve without breaking existing clients?
This is where platform architecture really shows.
Xano lets you keep v1 endpoints intact while cloning them into v2 versions. You can evolve the new contract without breaking existing clients. Branches let you develop safely and publish to production, with rollback capabilities via backups. You can also add test/live headers for different environments to ensure changes don’t break prod.
Supabase creates a challenge: the default REST API is auto-generated from your Postgres schema via PostgREST. Clients calling those endpoints are inherently coupled to your schema. Additive changes are usually fine, but renames, removals, or type changes propagate as breaking API changes unless you introduce a stability layer with views or RPC functions.
Custom stack gives you full control over URL versioning, header versioning, whatever you want. But you own the cost of maintaining parallel codepaths and orchestrating migrations across multiple client applications.
The difference is philosophical: do you want your API to be a direct reflection of your database, or do you want it to be a stable contract that can evolve independently?
How does each approach handle performance, caching, and scale?
Brief reality check on what you get out of the box.
Xano provides managed infrastructure with built-in request scaling and the ability to optimize individual endpoint logic. You can see performance bottlenecks in the visual flow and optimize where it matters without managing servers. Worker pools and other items that have historically been considered ‘DevOps’ are offloaded to the platform, not you. Xano also supports streaming out-of-the-box to help with transporting large amounts of data easily!
Supabase scales Postgres and Edge Functions independently, but you're tuning PostgREST configuration and connection pooling yourself. Great for read-heavy workloads, but complex business logic can create performance headaches.
Custom stack gives you full control over caching layers, CDNs, rate limiting—but you're building and operating all of it. Performance tuning becomes a full-time job.
Performance optimization on a custom stack requires dedicated infrastructure expertise. Xano gives you sensible defaults with the ability to optimize where it actually matters. Plus, with Xano’s autoscaling and load balancing, true performance can be observed immediately.
Can I integrate third-party services and external APIs from each platform?
Modern APIs rarely exist in isolation. How does each platform handle outbound API calls, webhooks, and integrations?
Xano treats external API requests as a native step in the Function Stack. You can call Stripe, send a Slack notification, hit a weather API, transform the response, and use it in the same endpoint flow. External calls are first-class building blocks, not afterthoughts.
Supabase requires Edge Functions or external tooling for integrations. Your core PostgREST endpoints can't make outbound calls, so integrations live outside the main API layer. You're managing integration logic separately from your data logic.
Custom stack makes integrations straightforward in application code, but each integration adds dependencies and error-handling surface area you have to maintain.
Xano recognizes that modern applications are compositions of multiple services. It makes external calls as easy as database queries.
How does each approach support AI-assisted and agentic development?
Building in the agentic era means your development environment needs to be legible to AI tools, not just human developers.
Xano offers a native MCP server that lets AI clients like Claude directly inspect and interact with your backend, querying table schemas, browsing API definitions, reviewing request history, and even modifying your data model. Because Xano consolidates logic and schema in a single structured layer, its MCP server can give an AI assistant a coherent, complete view of your system, rather than requiring it to piece together intent from scattered files across multiple languages and services.
Supbase has MCP support as well, allowing AI tools to interact with your Postgres database and project configuration. It's a solid integration, though the fragmentation of logic across PostgREST, Edge Functions, and RLS policies means an AI assistant still has to piece together a complete picture from multiple places.
Custom stack puts the burden entirely on you. You can connect AI tools via custom MCP servers or OpenAPI specs, but you're building and maintaining that integration layer yourself. How well an AI understands your system depends entirely on how well-documented and consistently structured your codebase is.
The differentiator isn't just whether a platform has MCP support, it's whether the underlying architecture makes your system comprehensible to an AI in the first place. A visual, structured backend gives AI tools something coherent to work with.
So which approach should I choose for building APIs?
Here's the decision framework:
Custom stack: Choose it if your team has dedicated backend engineers and highly specialized requirements that can justify the significant cost/resource overhead. You'll get exactly what you build, but you'll build everything.
Supabase: Choose it if you want fast CRUD access to your database and your business logic is simple. Great for read-heavy applications with straightforward data access patterns.
Xano: Choose it if you want to design intentional, logic-rich APIs that can evolve with your product without needing to hire a backend team to maintain them. The visual validation layer means you can understand, debug, and evolve your APIs without having to worry about scaling, performance, or anything else that gets in the way of your application and its users.
The real question isn't which platform is "best." It's which approach matches your team's strengths and your product's complexity.
If you're building the next Stripe, you probably need a custom stack. If you're building a content management system, Supabase might be perfect. If you're building a SaaS product with complex workflows and integrations, Xano's visual approach will save you months of development and debugging time.
Ready to see how visual API design works in practice? Try Xano for free and experience the difference between auto-generated and intentionally designed APIs.
