diff --git a/test/integration/api/schema/allocation_test.go b/test/integration/api/schema/allocation_test.go
new file mode 100644
index 0000000..78b9cb4
--- /dev/null
+++ b/test/integration/api/schema/allocation_test.go
@@ -0,0 +1,83 @@
+package schema
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/opencost/opencost-integration-tests/pkg/api"
+)
+
+// Description - Assert that /allocation responses retain their expected public
+// JSON fields, nested objects, and important field types.
+//
+// Implementation Details
+// - Raw JSON is inspected instead of typed API structs so removed or renamed
+//   fields are detected.
+// - Additional response fields are allowed to preserve compatible API extensions.
+// - The test is skipped when the endpoint returns no allocation items.
+//
+// Passing Criteria
+// - The endpoint returns a successful response.
+// - Every allocation item contains the required fields.
+// - Required window, properties, name, and totalCost values have expected types.
+
+var allocationRequiredFields = []string{
+	"name",
+	"cpuCost",
+	"ramCost",
+	"gpuCost",
+	"pvCost",
+	"networkCost",
+	"loadBalancerCost",
+	"sharedCost",
+	"externalCost",
+	"totalCost",
+	"minutes",
+	"window",
+	"properties",
+}
+
+func TestAllocationResponseSchemaStability(t *testing.T) {
+	apiClient := api.NewAPI()
+
+	resp := fetchRawEndpoint(t, apiClient, "/allocation", api.AutocompleteRequest{
+		Window: "1h",
+	})
+
+	requireSuccessfulResponse(t, "/allocation response", resp)
+
+	data := requireArray(t, "/allocation data", resp["data"])
+	if len(data) == 0 {
+		t.Skip("/allocation returned no data sets")
+	}
+
+	validatedItems := 0
+
+	for setIndex, rawSet := range data {
+		setContext := fmt.Sprintf("/allocation data[%d]", setIndex)
+		set := requireMap(t, setContext, rawSet)
+
+		for itemName, rawItem := range set {
+			validatedItems++
+
+			itemContext := fmt.Sprintf("/allocation item %q", itemName)
+			item := requireMap(t, itemContext, rawItem)
+
+			requireFields(t, itemContext, item, allocationRequiredFields)
+			requireString(t, itemContext+" name", item["name"])
+			requireNumber(t, itemContext+" totalCost", item["totalCost"])
+
+			windowContext := itemContext + " window"
+			window := requireMap(t, windowContext, item["window"])
+			requireFields(t, windowContext, window, windowRequiredFields)
+			requireString(t, windowContext+" start", window["start"])
+			requireString(t, windowContext+" end", window["end"])
+
+			requireMap(t, itemContext+" properties", item["properties"])
+		}
+	}
+
+	if validatedItems == 0 {
+		t.Skip("/allocation returned no allocation items")
+	}
+}
\ No newline at end of file
diff --git a/test/integration/api/schema/assets_test.go b/test/integration/api/schema/assets_test.go
new file mode 100644
index 0000000..59d090a
--- /dev/null
+++ b/test/integration/api/schema/assets_test.go
@@ -0,0 +1,91 @@
+package schema
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/opencost/opencost-integration-tests/pkg/api"
+)
+
+// Description - Assert that /assets responses retain their expected public
+// JSON fields, nested objects, and important field types.
+//
+// Implementation Details
+// - Fields shared by every asset are validated separately from fields that are
+//   specific to Node assets.
+// - Additional response fields and non-Node asset types are allowed.
+// - The test is skipped when the endpoint returns no assets.
+//
+// Passing Criteria
+// - The endpoint returns a successful response.
+// - Every asset contains the common required fields.
+// - Node assets contain their Node-specific fields and properties.
+
+var assetCommonRequiredFields = []string{
+	"type",
+	"properties",
+	"window",
+	"start",
+	"end",
+	"minutes",
+	"totalCost",
+}
+
+var assetCommonPropertiesRequiredFields = []string{
+	"category",
+	"provider",
+	"service",
+}
+
+var assetNodeRequiredFields = []string{
+	"cpuCost",
+	"ramCost",
+	"gpuCost",
+	"nodeType",
+	"cpuCores",
+	"ramBytes",
+}
+
+var assetNodePropertiesRequiredFields = []string{
+	"name",
+	"providerID",
+}
+
+func TestAssetsResponseSchemaStability(t *testing.T) {
+	apiClient := api.NewAPI()
+
+	resp := fetchRawEndpoint(t, apiClient, "/assets", api.AutocompleteRequest{
+		Window: "1h",
+	})
+
+	requireSuccessfulResponse(t, "/assets response", resp)
+
+	data := requireMap(t, "/assets data", resp["data"])
+	if len(data) == 0 {
+		t.Skip("/assets returned no asset items")
+	}
+
+	for assetName, rawAsset := range data {
+		itemContext := fmt.Sprintf("/assets item %q", assetName)
+		asset := requireMap(t, itemContext, rawAsset)
+
+		requireFields(t, itemContext, asset, assetCommonRequiredFields)
+		requireNumber(t, itemContext+" totalCost", asset["totalCost"])
+
+		windowContext := itemContext + " window"
+		window := requireMap(t, windowContext, asset["window"])
+		requireFields(t, windowContext, window, windowRequiredFields)
+		requireString(t, windowContext+" start", window["start"])
+		requireString(t, windowContext+" end", window["end"])
+
+		propertiesContext := itemContext + " properties"
+		properties := requireMap(t, propertiesContext, asset["properties"])
+		requireFields(t, propertiesContext, properties, assetCommonPropertiesRequiredFields)
+
+		assetType := requireString(t, itemContext+" type", asset["type"])
+		if assetType == "Node" {
+			requireFields(t, itemContext, asset, assetNodeRequiredFields)
+			requireFields(t, propertiesContext, properties, assetNodePropertiesRequiredFields)
+		}
+	}
+}
\ No newline at end of file
diff --git a/test/integration/api/schema/cloudcost_test.go b/test/integration/api/schema/cloudcost_test.go
new file mode 100644
index 0000000..3799361
--- /dev/null
+++ b/test/integration/api/schema/cloudcost_test.go
@@ -0,0 +1,116 @@
+package schema
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/opencost/opencost-integration-tests/pkg/api"
+)
+
+// Description - Assert that /cloudCost responses retain their expected public
+// JSON fields, nested objects, and important field types.
+//
+// Implementation Details
+// - Each CloudCost item, properties object, window, and nested cost object is
+//   validated using raw JSON.
+// - Empty sets are ignored while other returned sets continue to be validated.
+// - The test is skipped when no CloudCost items are returned.
+//
+// Passing Criteria
+// - The endpoint returns a successful response.
+// - Every CloudCost item contains the required fields and properties.
+// - Each supported nested cost object contains numeric cost and
+//   kubernetesPercent fields.
+
+var cloudCostPropertiesRequiredFields = []string{
+	"provider",
+	"accountID",
+	"accountName",
+	"invoiceEntityID",
+	"invoiceEntityName",
+	"service",
+	"category",
+}
+
+var cloudCostCostObjectRequiredFields = []string{
+	"cost",
+	"kubernetesPercent",
+}
+
+var cloudCostFields = []string{
+	"netCost",
+	"amortizedCost",
+	"amortizedNetCost",
+	"invoicedCost",
+	"listCost",
+}
+
+var cloudCostItemRequiredFields = append(
+	[]string{
+		"properties",
+		"window",
+	},
+	cloudCostFields...,
+)
+
+func TestCloudCostResponseSchemaStability(t *testing.T) {
+	apiClient := api.NewAPI()
+
+	resp := fetchRawEndpoint(t, apiClient, "/cloudCost", api.AutocompleteRequest{
+		Window: "1d",
+	})
+
+	requireSuccessfulResponse(t, "/cloudCost response", resp)
+
+	data := requireMap(t, "/cloudCost data", resp["data"])
+	requireFields(t, "/cloudCost data", data, []string{"sets"})
+
+	sets := requireArray(t, "/cloudCost data.sets", data["sets"])
+	if len(sets) == 0 {
+		t.Skip("/cloudCost returned no sets")
+	}
+
+	validatedItems := 0
+
+	for setIndex, rawSet := range sets {
+		setContext := fmt.Sprintf("/cloudCost set[%d]", setIndex)
+		set := requireMap(t, setContext, rawSet)
+
+		requireFields(t, setContext, set, []string{"cloudCosts"})
+
+		cloudCostsContext := setContext + ".cloudCosts"
+		cloudCosts := requireMap(t, cloudCostsContext, set["cloudCosts"])
+
+		for itemName, rawItem := range cloudCosts {
+			validatedItems++
+
+			itemContext := fmt.Sprintf("/cloudCost item %q", itemName)
+			item := requireMap(t, itemContext, rawItem)
+
+			requireFields(t, itemContext, item, cloudCostItemRequiredFields)
+
+			windowContext := itemContext + " window"
+			window := requireMap(t, windowContext, item["window"])
+			requireFields(t, windowContext, window, windowRequiredFields)
+			requireString(t, windowContext+" start", window["start"])
+			requireString(t, windowContext+" end", window["end"])
+
+			propertiesContext := itemContext + " properties"
+			properties := requireMap(t, propertiesContext, item["properties"])
+			requireFields(t, propertiesContext, properties, cloudCostPropertiesRequiredFields)
+
+			for _, costField := range cloudCostFields {
+				costContext := itemContext + " " + costField
+				costObject := requireMap(t, costContext, item[costField])
+
+				requireFields(t, costContext, costObject, cloudCostCostObjectRequiredFields)
+				requireNumber(t, costContext+" cost", costObject["cost"])
+				requireNumber(t, costContext+" kubernetesPercent", costObject["kubernetesPercent"])
+			}
+		}
+	}
+
+	if validatedItems == 0 {
+		t.Skip("/cloudCost returned no cloud cost items")
+	}
+}
\ No newline at end of file
diff --git a/test/integration/api/schema/helpers_test.go b/test/integration/api/schema/helpers_test.go
new file mode 100644
index 0000000..2fac5e0
--- /dev/null
+++ b/test/integration/api/schema/helpers_test.go
@@ -0,0 +1,114 @@
+package schema
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/opencost/opencost-integration-tests/pkg/api"
+)
+
+var windowRequiredFields = []string{
+	"start",
+	"end",
+}
+
+// fetchRawEndpoint fetches and decodes a raw API response. GetAutocompleteStatus
+// is currently the only API helper that exposes both the HTTP status and raw
+// response body. AutocompleteRequest supplies the shared window query parameter.
+func fetchRawEndpoint(t *testing.T, apiClient *api.API, path string, req api.AutocompleteRequest) map[string]any {
+	t.Helper()
+
+	status, body, err := apiClient.GetAutocompleteStatus(path, req)
+	if err != nil {
+		t.Fatalf("%s request failed: %v", path, err)
+	}
+
+	if status != http.StatusOK {
+		t.Fatalf("%s returned HTTP %d: %s", path, status, strings.TrimSpace(string(body)))
+	}
+
+	var parsed map[string]any
+	if err := json.Unmarshal(body, &parsed); err != nil {
+		t.Fatalf(
+			"%s returned non-JSON or malformed JSON: %v\nbody: %s",
+			path,
+			err,
+			strings.TrimSpace(string(body)),
+		)
+	}
+
+	return parsed
+}
+
+// requireSuccessfulResponse verifies the common successful API response fields.
+func requireSuccessfulResponse(t *testing.T, context string, response map[string]any) {
+	t.Helper()
+
+	requireFields(t, context, response, []string{"code", "data"})
+
+	code := requireNumber(t, context+" code", response["code"])
+	if code != http.StatusOK {
+		t.Fatalf("%s code was %.0f, expected %d", context, code, http.StatusOK)
+	}
+}
+
+// requireFields verifies that all required fields are present.
+func requireFields(t *testing.T, context string, obj map[string]any, fields []string) {
+	t.Helper()
+
+	for _, field := range fields {
+		if _, ok := obj[field]; !ok {
+			t.Errorf("%s missing required field %q", context, field)
+		}
+	}
+}
+
+// requireMap verifies that a value is a JSON object.
+func requireMap(t *testing.T, context string, value any) map[string]any {
+	t.Helper()
+
+	obj, ok := value.(map[string]any)
+	if !ok {
+		t.Fatalf("%s expected object, got %T", context, value)
+	}
+
+	return obj
+}
+
+// requireArray verifies that a value is a JSON array.
+func requireArray(t *testing.T, context string, value any) []any {
+	t.Helper()
+
+	arr, ok := value.([]any)
+	if !ok {
+		t.Fatalf("%s expected array, got %T", context, value)
+	}
+
+	return arr
+}
+
+// requireString verifies that a value is a JSON string.
+func requireString(t *testing.T, context string, value any) string {
+	t.Helper()
+
+	result, ok := value.(string)
+	if !ok {
+		t.Fatalf("%s expected string, got %T", context, value)
+	}
+
+	return result
+}
+
+// requireNumber verifies that a value is a JSON number.
+func requireNumber(t *testing.T, context string, value any) float64 {
+	t.Helper()
+
+	result, ok := value.(float64)
+	if !ok {
+		t.Fatalf("%s expected number, got %T", context, value)
+	}
+
+	return result
+}
\ No newline at end of file
diff --git a/test/integration/api/schema/test.bats b/test/integration/api/schema/test.bats
new file mode 100644
index 0000000..ce974c9
--- /dev/null
+++ b/test/integration/api/schema/test.bats
@@ -0,0 +1,20 @@
+setup() {
+    DIR="$(cd "$(dirname "$BATS_TEST_FILENAME")" >/dev/null 2>&1 && pwd)"
+    cd "$DIR"
+}
+
+teardown() {
+    : # Nothing to tear down.
+}
+
+@test "api: Allocation Response Schema Stability" {
+    go test -count=1 . -run '^TestAllocationResponseSchemaStability$'
+}
+
+@test "api: Assets Response Schema Stability" {
+    go test -count=1 . -run '^TestAssetsResponseSchemaStability$'
+}
+
+@test "api: CloudCost Response Schema Stability" {
+    go test -count=1 . -run '^TestCloudCostResponseSchemaStability$'
+}
\ No newline at end of file