diff --git a/api/v1alpha1/samples_validation_test.go b/api/v1alpha1/samples_validation_test.go
new file mode 100644
index 00000000..6773edfa
--- /dev/null
+++ b/api/v1alpha1/samples_validation_test.go
@@ -0,0 +1,154 @@
+/*
+Copyright 2025.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1alpha1
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"sigs.k8s.io/yaml"
+)
+
+// splitYAMLDocs splits a multi-document YAML file on lines that are exactly
+// "---", tolerating trailing whitespace. Simpler than a full YAML reader and
+// sufficient for the hand-authored sample manifests.
+func splitYAMLDocs(data []byte) []string {
+	var docs []string
+	var cur []string
+	for _, line := range strings.Split(string(data), "\n") {
+		if strings.TrimRight(line, " \t") == "---" {
+			docs = append(docs, strings.Join(cur, "\n"))
+			cur = nil
+			continue
+		}
+		cur = append(cur, line)
+	}
+	return append(docs, strings.Join(cur, "\n"))
+}
+
+// objForKind returns a fresh typed object for the LLMKube CRD kinds this repo
+// owns, or nil for foreign kinds (KEDA HTTPScaledObject, core Secret/Service)
+// that some samples also carry and which we do not validate here.
+func objForKind(kind string) any {
+	switch kind {
+	case "Model":
+		return &Model{}
+	case "InferenceService":
+		return &InferenceService{}
+	case "ModelRouter":
+		return &ModelRouter{}
+	default:
+		return nil
+	}
+}
+
+// TestConfigSamplesDecodeStrict guards config/samples/*.yaml against
+// hallucinated or mistyped CRD fields. Every Model / InferenceService /
+// ModelRouter document must strict-decode into its typed struct, so an
+// unknown field (e.g. a coder inventing spec.url or spec.parameters) or a
+// wrong type (e.g. modelRef as an object when the field is a string) fails
+// here instead of shipping a sample that kubectl apply would reject.
+//
+// Motivated by #699/#1021: a coder rewrote a sample with url/parameters/
+// modelRef-object/runtime-object/service and it GATE-PASSed, because the
+// Go-only gate never validated the YAML against the schema.
+func TestConfigSamplesDecodeStrict(t *testing.T) {
+	files, err := filepath.Glob("../../config/samples/*.yaml")
+	if err != nil {
+		t.Fatalf("glob samples: %v", err)
+	}
+	if len(files) == 0 {
+		t.Fatal("no config/samples/*.yaml found; check the relative path from api/v1alpha1")
+	}
+	for _, f := range files {
+		data, err := os.ReadFile(f)
+		if err != nil {
+			t.Fatalf("read %s: %v", f, err)
+		}
+		for i, doc := range splitYAMLDocs(data) {
+			if strings.TrimSpace(doc) == "" {
+				continue
+			}
+			var head struct {
+				Kind string `json:"kind"`
+			}
+			if err := yaml.Unmarshal([]byte(doc), &head); err != nil {
+				t.Errorf("%s doc %d: could not read kind: %v", filepath.Base(f), i, err)
+				continue
+			}
+			obj := objForKind(head.Kind)
+			if obj == nil {
+				continue
+			}
+			if err := yaml.UnmarshalStrict([]byte(doc), obj); err != nil {
+				t.Errorf("%s doc %d (%s): strict decode failed (unknown or mistyped field?): %v",
+					filepath.Base(f), i, head.Kind, err)
+			}
+		}
+	}
+}
+
+// TestConfigSamplesDecodeStrict_CatchesBadFields proves the guard actually
+// rejects the #699 failure class: unknown fields and a map where a string is
+// expected. If strict decoding ever silently accepted these, the samples test
+// above would be worthless.
+func TestConfigSamplesDecodeStrict_CatchesBadFields(t *testing.T) {
+	cases := map[string]string{
+		"unknown Model field (url instead of source)": `
+apiVersion: inference.llmkube.dev/v1alpha1
+kind: Model
+metadata: {name: x}
+spec:
+  url: https://example.com/m.gguf
+  format: gguf
+`,
+		"unknown Model block (parameters)": `
+apiVersion: inference.llmkube.dev/v1alpha1
+kind: Model
+metadata: {name: x}
+spec:
+  source: https://example.com/m.gguf
+  parameters: {contextSize: 4096}
+`,
+		"modelRef as object when field is a string": `
+apiVersion: inference.llmkube.dev/v1alpha1
+kind: InferenceService
+metadata: {name: x}
+spec:
+  modelRef: {name: x}
+`,
+	}
+	for name, doc := range cases {
+		t.Run(name, func(t *testing.T) {
+			var head struct {
+				Kind string `json:"kind"`
+			}
+			if err := yaml.Unmarshal([]byte(doc), &head); err != nil {
+				t.Fatalf("read kind: %v", err)
+			}
+			obj := objForKind(head.Kind)
+			if obj == nil {
+				t.Fatalf("no type for kind %q", head.Kind)
+			}
+			if err := yaml.UnmarshalStrict([]byte(doc), obj); err == nil {
+				t.Errorf("strict decode should have rejected %q, but it passed", name)
+			}
+		})
+	}
+}