diff --git a/clients/cache/inmemory.go b/clients/cache/inmemory.go
new file mode 100644
index 0000000..437f935
--- /dev/null
+++ b/clients/cache/inmemory.go
@@ -0,0 +1,97 @@
+package cache
+
+import (
+	"context"
+	"sync"
+	"time"
+)
+
+// InMemoryCache is an in-memory implementation of the Cache interface.
+type InMemoryCache struct {
+	data  map[string]cacheItem
+	mutex sync.RWMutex
+}
+
+// Ensure InMemoryCache implements the Cache interface.
+var _ Cache = (*InMemoryCache)(nil)
+
+// cacheItem represents an item stored in the cache.
+type cacheItem struct {
+	data       []byte
+	expiration time.Time
+}
+
+// NewInMemoryCache creates a new instance of InMemoryCache.
+func NewInMemoryCache() *InMemoryCache {
+	return &InMemoryCache{
+		data: make(map[string]cacheItem),
+	}
+}
+
+// Set sets the value of a key in the cache.
+func (c *InMemoryCache) Set(
+	ctx context.Context,
+	key string,
+	data []byte,
+	expiration time.Duration,
+) error {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
+	expiry := time.Now().Add(expiration)
+
+	if expiration == 0 {
+		// 100 years in the future to prevent expiry
+		expiry = time.Now().AddDate(100, 0, 0)
+	}
+
+	c.data[key] = cacheItem{
+		data:       data,
+		expiration: expiry,
+	}
+
+	return nil
+}
+
+// Get retrieves the value of a key from the cache.
+func (c *InMemoryCache) Get(ctx context.Context, key string) ([]byte, bool) {
+	c.mutex.RLock()
+	defer c.mutex.RUnlock()
+
+	item, ok := c.data[key]
+	if !ok || time.Now().After(item.expiration) {
+		// Not a real ttl but just replicates it for fetching
+		delete(c.data, key)
+
+		return nil, false
+	}
+
+	return item.data, true
+}
+
+// GetAll returns all the non-expired data in the cache.
+func (c *InMemoryCache) GetAll(ctx context.Context) map[string][]byte {
+	c.mutex.RLock()
+	defer c.mutex.RUnlock()
+
+	result := make(map[string][]byte)
+
+	for key, item := range c.data {
+		if time.Now().After(item.expiration) {
+			delete(c.data, key)
+		} else {
+			result[key] = item.data
+		}
+	}
+
+	return result
+}
+
+// Delete removes a key from the cache.
+func (c *InMemoryCache) Delete(ctx context.Context, key string) error {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
+	delete(c.data, key)
+	return nil
+}
diff --git a/service/cachemdw/cache.go b/service/cachemdw/cache.go
index fe7e3db..664ff42 100644
--- a/service/cachemdw/cache.go
+++ b/service/cachemdw/cache.go
@@ -59,7 +59,8 @@ func (c *ServiceCache) GetCachedQueryResponse(
 	requestHost string,
 	req *decode.EVMRPCRequestEnvelope,
 ) ([]byte, bool) {
-	chainID, found := c.GetCachedChainID(ctx, requestHost)
+	chainID, err := c.GetAndCacheChainID(ctx, requestHost)
+	found := err == nil // TODO(yevhenii): refactor
 	if !found {
 		return nil, false
 	}
diff --git a/service/cachemdw/cache_test.go b/service/cachemdw/cache_test.go
index 378c7ee..3463efa 100644
--- a/service/cachemdw/cache_test.go
+++ b/service/cachemdw/cache_test.go
@@ -2,12 +2,15 @@ package cachemdw
 
 import (
 	"context"
-	"math/big"
-	"testing"
-
+	"fmt"
 	"github.com/ethereum/go-ethereum/common"
 	ethctypes "github.com/ethereum/go-ethereum/core/types"
+	"github.com/kava-labs/kava-proxy-service/clients/cache"
+	"github.com/kava-labs/kava-proxy-service/service"
 	"github.com/stretchr/testify/require"
+	"math/big"
+	"testing"
+	"time"
 
 	"github.com/kava-labs/kava-proxy-service/decode"
 )
@@ -25,7 +28,7 @@ func (c *MockEVMClient) BlockByHash(ctx context.Context, hash common.Hash) (*eth
 }
 
 func (c *MockEVMClient) ChainID(ctx context.Context) (*big.Int, error) {
-	panic("not implemented")
+	return big.NewInt(1), nil
 }
 
 func TestUnitTestIsCacheable(t *testing.T) {
@@ -63,3 +66,21 @@ func TestUnitTestIsCacheable(t *testing.T) {
 		})
 	}
 }
+
+func TestUnitTestCacheQueryResponse(t *testing.T) {
+	inMemoryCache := cache.NewInMemoryCache()
+	evmClient := NewMockEVMClient()
+	cacheTTL := time.Hour
+
+	serviceCache := NewServiceCache(inMemoryCache, evmClient, cacheTTL, service.DecodedRequestContextKey)
+
+	req := decode.EVMRPCRequestEnvelope{
+		JSONRPCVersion: "2.0",
+		ID:             1,
+		Method:         "eth_getBalance",
+		Params:         []interface{}{"0x1234", "42"},
+	}
+	resp, err := serviceCache.GetCachedQueryResponse(context.Background(), "api.kava.io", &req)
+
+	fmt.Printf("resp: %v, err: %v\n", resp, err)
+}