# contract

Generated API projects use this package to compile Go field tags once and bind
each request without depending on a specific HTTP server. `New[T]` validates a
struct and returns an immutable Binder. `ForType` provides the same compiler to
the CLI. `BodySchema`, `Parameters`, and `ResponseSchema` return detached OpenAPI
snapshots. `MustNew[T]` is intended for generated, already checked declarations.

```go
type Request struct {
    ID int64 `path:"id,range=[1:100]"`
    Name string `json:"name" binding:"required,max=50"`
}

var request = contract.MustNew[Request]()

func Handle(c *httpx.Context) error {
    var req Request
    if err := request.Bind(c.Request(), httpx.RouteParams(c.Context()), &req); err != nil {
        return err
    }
    return c.OK(req.Name)
}
```

The default body limit is 1 MiB. An optional positive final argument to Bind
overrides it. Application transport read timeouts still control slow clients.
See [API.md](../API.md) for source tags, validation rules, null/presence behavior,
strict decoding and supported type limits. This API leaves the existing
`Context.BindJSON/BindQuery/BindURI` behavior unchanged.