Standard Schema Explained: Flexible Validation Without Lock-In
You’ve built your app with Zod. Your forms work, your API validates requests, and TypeScript catches type mismatches at compile time. Then your team adopts a new router that only supports Valibot. Or you want to try ArkType for its performance benefits. Suddenly, you’re facing a rewrite—or maintaining adapters between incompatible validation libraries.
This is the vendor lock-in problem that Standard Schema solves. It’s a small interface that lets validation libraries speak a common language, so the tools consuming them don’t need to care which library you chose.
Key Takeaways
- Standard Schema is a TypeScript interface (not a validation library) that enables interoperability between validation libraries like Zod, Valibot, and ArkType.
- It reduces the adapter problem from N×M relationships to N+M by providing a common contract between schema producers and consumers.
- Major validation libraries and ecosystem tools already support the spec, allowing you to switch validators without rewriting forms, routers, or API handlers.
- The
~standardproperty exposes a validate method, type inference helpers, and a stable versioned contract.
What Standard Schema Is (and Isn’t)
Standard Schema is not another validation library. It’s not competing with Zod, Valibot, or ArkType. It’s also unrelated to JSON Schema or schema.org.
Instead, it’s a TypeScript interface—roughly 60 lines of types—that validation libraries can implement. When a library exposes the ~standard property on its schemas, any tool that understands Standard Schema can validate data without knowing which library created the schema.
Think of it as a producer-consumer contract. Validation libraries are producers: they define schemas and implement the interface. Frameworks and tools are consumers: they accept any schema that follows the contract.
The Adapter Proliferation Problem
Before Standard Schema, ecosystem tools faced an impossible maintenance burden. Consider the math: if you have 6 popular validation libraries and 50 tools that need validation, you’re looking at 300 potential adapters. Each adapter requires maintenance, testing, and updates when either side changes.
The Zod, Valibot, and ArkType ecosystem grew rapidly, but this growth created fragmentation. A form library might support Zod natively but require community adapters for everything else. Those adapters often lagged behind, broke with updates, or simply didn’t exist.
Standard Schema reduces this from N×M relationships to N+M. Libraries implement the spec once. Tools consume it once. Everyone benefits.
How the Interface Works
The spec defines three essential things:
A validate method that accepts unknown input and returns either a success result with the typed value or a failure result with an array of issues.
Type inference helpers that let tools extract input and output types from any compliant schema, regardless of which library created it.
A stable contract versioned as StandardSchemaV1 with a guarantee of no breaking changes without a major version bump.
The ~standard property uses a tilde prefix deliberately—it sorts to the bottom of autocomplete lists, staying out of your way during normal development.
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Vendor-Neutral Validation in Practice
This flexible validation without lock-in shows up across your entire stack:
Forms: TanStack Form and React Hook Form accept Standard Schema validators. Write your validation logic once, switch libraries without touching form code.
Routing: TanStack Router validates route params and search parameters using any compliant schema. Standard Schema in forms and routing means consistent validation patterns across your app.
APIs: Tools like tRPC validate request bodies without coupling to a specific validation library.
Configuration: Tools like envin validate environment variables at build time using whichever validator you prefer.
Testing: Assert response shapes in tests using the same schemas that validate production data.
Libraries That Implement the Spec
The major players already support Standard Schema:
- Zod (v3.24.0+)
- Valibot (v1.0+)
- ArkType (v2.0+)
- Yup (v1.6.0+)
- Typia (v7.3.0+)
Many libraries now implement the spec, with dozens of tools consuming it. Check the official Standard Schema repository for the current list of supported libraries and their minimum versions.
What This Means for Your Stack
You can start with Zod because it’s familiar, switch to Valibot for smaller bundles, or adopt ArkType for type-level validation—all without rewriting your forms, routers, or API handlers.
The vendor-neutral validation approach means your architectural decisions aren’t permanent. You evaluate libraries on their merits: API design, bundle size, performance, error messages. The rest of your stack stays stable.
Conclusion
Standard Schema represents a maturing ecosystem. Instead of competing validation libraries fragmenting the tooling landscape, we get interoperability. Your choice of validator becomes a local decision rather than a stack-wide commitment.
Check if your current tools support the spec. If they do, you already have flexible validation without lock-in—you just need to use it.
FAQs
No. Standard Schema is just a TypeScript interface specification. Validation libraries that support it expose the ~standard property automatically. You use your chosen validation library as usual, and compatible tools detect the interface without additional dependencies.
Switching libraries requires rewriting your schema definitions since each library has its own API. However, the consuming tools like form libraries and routers will continue working without changes because they interact through the Standard Schema interface, not the library-specific API.
Look for Standard Schema mentioned in the tool's documentation, typically in sections about validation or type safety. You can also check if the tool accepts schemas with a ~standard property or references StandardSchemaV1 in its TypeScript types.
You can create a thin wrapper that implements the ~standard interface around your existing schemas. This involves exposing a validate method that returns the expected result format. Check the Standard Schema repository for implementation examples and guidance.
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