diff --git a/pkg/codegen/schema.go b/pkg/codegen/schema.go
index a476a9f96b..4e429e08ec 100644
--- a/pkg/codegen/schema.go
+++ b/pkg/codegen/schema.go
@@ -2,6 +2,8 @@ package codegen
 
 import (
 	"fmt"
+	"regexp"
+	"sort"
 	"strings"
 
 	"github.com/getkin/kin-openapi/openapi3"
@@ -13,10 +15,14 @@ type Schema struct {
 	GoType  string // The Go type needed to represent the schema
 	RefType string // If the type has a type name, this is set
 
+	IsExternal  bool // Whether it was defined externally, i.e. "x-go-type"
+	Validations Validations
+
 	ArrayType *Schema // The schema of array element
 
 	EnumValues map[string]string // Enum values
 
+	EmbeddedFields           []string         // For an allOf struct
 	Properties               []Property       // For an object, the fields with names
 	HasAdditionalProperties  bool             // Whether we support additional properties
 	AdditionalPropertiesType *Schema          // And if we do, their type
@@ -27,6 +33,30 @@ type Schema struct {
 	Description string // The description of the element
 }
 
+// Validations describes validations for a schema.
+type Validations struct {
+	// String
+	MinLength uint64
+	MaxLength *uint64
+	Pattern   string
+	Values    []string
+
+	// Number
+	Min          *float64
+	ExclusiveMin bool
+	Max          *float64
+	ExclusiveMax bool
+	MultipleOf   *float64
+
+	// Array
+	MinItems uint64
+	MaxItems *uint64
+
+	// Additional Properties
+	MinProps uint64
+	MaxProps *uint64
+}
+
 func (s Schema) IsRef() bool {
 	return s.RefType != ""
 }
@@ -194,6 +224,7 @@ func GenerateGoSchema(sref *openapi3.SchemaRef, path []string) (Schema, error) {
 			return outSchema, errors.Wrapf(err, "invalid value for %q", extPropGoType)
 		}
 		outSchema.GoType = typeName
+		outSchema.IsExternal = true
 		return outSchema, nil
 	}
 
@@ -269,6 +300,9 @@ func GenerateGoSchema(sref *openapi3.SchemaRef, path []string) (Schema, error) {
 					return Schema{}, errors.Wrap(err, "error generating type for additional properties")
 				}
 				outSchema.AdditionalPropertiesType = &additionalSchema
+				// Validation rules:
+				outSchema.Validations.MinProps = schema.MinProps
+				outSchema.Validations.MaxProps = schema.MaxProps
 			}
 
 			outSchema.GoType = GenStructFromSchema(outSchema)
@@ -306,6 +340,12 @@ func GenerateGoSchema(sref *openapi3.SchemaRef, path []string) (Schema, error) {
 			outSchema.RefType = typeName
 		}
 		//outSchema.RefType = typeName
+
+		outSchema.Validations.Values = make([]string, 0, len(outSchema.EnumValues))
+		for _, value := range outSchema.EnumValues {
+			outSchema.Validations.Values = append(outSchema.Validations.Values, value)
+		}
+		sort.Sort(sort.StringSlice(outSchema.Validations.Values))
 	} else {
 		err := resolveType(schema, path, &outSchema)
 		if err != nil {
@@ -336,6 +376,8 @@ func resolveType(schema *openapi3.Schema, path []string, outSchema *Schema) erro
 			outSchema.AdditionalTypes = append(outSchema.AdditionalTypes, additionalTypes...)
 		}
 		outSchema.Properties = arrayType.Properties
+		outSchema.Validations.MinItems = schema.MinItems
+		outSchema.Validations.MaxItems = schema.MaxItems
 	case "integer":
 		// We default to int if format doesn't ask for something else.
 		if f == "int64" {
@@ -351,6 +393,11 @@ func resolveType(schema *openapi3.Schema, path []string, outSchema *Schema) erro
 		} else {
 			return fmt.Errorf("invalid integer format: %s", f)
 		}
+		outSchema.Validations.Min = schema.Min
+		outSchema.Validations.ExclusiveMin = schema.ExclusiveMin
+		outSchema.Validations.Max = schema.Max
+		outSchema.Validations.ExclusiveMax = schema.ExclusiveMax
+		outSchema.Validations.MultipleOf = schema.MultipleOf
 	case "number":
 		// We default to float for "number"
 		if f == "double" {
@@ -360,6 +407,8 @@ func resolveType(schema *openapi3.Schema, path []string, outSchema *Schema) erro
 		} else {
 			return fmt.Errorf("invalid number format: %s", f)
 		}
+		outSchema.Validations.Min = schema.Min
+		outSchema.Validations.Max = schema.Max
 	case "boolean":
 		if f != "" {
 			return fmt.Errorf("invalid format (%s) for boolean", f)
@@ -382,6 +431,14 @@ func resolveType(schema *openapi3.Schema, path []string, outSchema *Schema) erro
 		default:
 			// All unrecognized formats are simply a regular string.
 			outSchema.GoType = "string"
+			outSchema.Validations.MinLength = schema.MinLength
+			outSchema.Validations.MaxLength = schema.MaxLength
+			if schema.Pattern != "" {
+				// Try to compile it first
+				if _, err := regexp.Compile(schema.Pattern); err == nil {
+					outSchema.Validations.Pattern = schema.Pattern
+				}
+			}
 		}
 	default:
 		return fmt.Errorf("unhandled Schema type: %s", t)
@@ -468,6 +525,7 @@ func MergeSchemas(allOf []*openapi3.SchemaRef, path []string) (Schema, error) {
 			if err != nil {
 				return Schema{}, errors.Wrap(err, "error converting reference path to a go type")
 			}
+			outSchema.EmbeddedFields = append(outSchema.EmbeddedFields, refType)
 		}
 
 		schema, err := GenerateGoSchema(schemaOrRef, path)