Struct tags can't bend
Go's tag validators hard-code the shape at compile time. Third-party payloads and dynamic forms don't fit that mold.
rigid v2.0 · zero dependencies, Go 1.24
JSON that arrives messy, leaves validated.
Flatten any document into dotted keys, target them with wildcards or regex, then run each value through a pipeline of validators and operators. Typed errors, no panics.
$
go get github.com/ashbeelghouri/json-schematics-v2@latestThe gap
Validation libraries assume your JSON is well behaved.
One assertion, one panic
Reflection-heavy validators panic on the value they didn't expect. A bad request shouldn't take down the handler.
unsafeRules live in code, not data
Changing a rule means a redeploy. Schematics keeps rules as JSON, so a schema is data you can load, ship, and localize.
declarativeHow it works
Watch one document move through the pipeline.
Five stages, each colored by what it does. Hover to pause, click a stage to inspect it.
Any nested document collapses into dotted keys. Objects and arrays become paths like user.tags.0.
input
user{ profile, tags }
user.profile{ name, age }
user.tags[ ... ]
flattened
user.profile.name" ada "
user.profile.age200
user.tags.0"go"
user.tags.1"go"
One small library, a lot of leverage.
Everything below ships in the box, standard library only. No plugins, no code generation.
{ }
Flatten & target
Nested documents become dotted keys. Match one literally, sweep an array with *, or use a full regex.
→
Operator pipelines
Transform values in a separate pass: trim, capitalize, math, and reshape arrays into objects.
?
Conditions with boolean logic
Gate fields with when and dependsOn, composing any, all, and not groups as deep as the rule needs.
!
Errors with stable codes
Every failure carries a machine-readable code that survives rewording and translation. Never a panic.
/
Pointers and problem+json
Each error knows its RFC 6901 location, and any handler can answer with an RFC 7807 response.
@
HTTP request validation
Validate request headers, query, and body per endpoint with the API type, body size capped.
文
Message catalogs
Load per-locale message bundles from JSON or TOML, with fallback chains and ICU-style plurals.
~
Observability hooks
Observer, metrics, and tracing adapters that cost a nil check when nothing is attached.
≫
Streaming and a CLI
Validate arrays that do not fit in memory, and check schemas in CI without writing any Go.
Validate your first document in five minutes.
Follow the guide, or try a live schema in the playground right now.