diff --git a/internal/handlers/server/api.go b/internal/handlers/server/api.go
new file mode 100644
index 0000000..646458c
--- /dev/null
+++ b/internal/handlers/server/api.go
@@ -0,0 +1,60 @@
+package server
+
+type (
+	OKResponse struct {
+		Ok          bool           `json:"ok"`
+		Description string         `json:"description"`
+		Result      map[string]any `json:"result"`
+	}
+
+	ErrResponse struct {
+		Ok          bool   `json:"ok"`
+		Description string `json:"description"`
+		ErrCode     string `json:"errorCode"`
+	}
+
+	TransferRequest struct {
+		From         string `json:"from" validate:"required,eth_addr_checksum"`
+		To           string `json:"to" validate:"required,eth_addr_checksum"`
+		TokenAddress string `json:"tokenAddress" validate:"required,eth_addr_checksum"`
+		Amount       string `json:"amount" validate:"required,number,gt=0"`
+	}
+
+	PoolSwapRequest struct {
+		From             string `json:"from" validate:"required,eth_addr_checksum"`
+		FromTokenAddress string `json:"fromTokenAddress" validate:"required,eth_addr_checksum"`
+		ToTokenAddress   string `json:"toTokenAddress" validate:"required,eth_addr_checksum"`
+		PoolAddress      string `json:"poolAddress" validate:"required,eth_addr_checksum"`
+		Amount           string `json:"amount" validate:"required,number,gt=0"`
+	}
+
+	PoolDepositRequest struct {
+		From         string `json:"from" validate:"required,eth_addr_checksum"`
+		TokenAddress string `json:"tokenAddress" validate:"required,eth_addr_checksum"`
+		PoolAddress  string `json:"poolAddress" validate:"required,eth_addr_checksum"`
+		Amount       string `json:"amount" validate:"required,number,gt=0"`
+	}
+
+	AccountAddressParam struct {
+		Address string `param:"address"  validate:"required,eth_addr_checksum"`
+	}
+
+	TrackingIDParam struct {
+		TrackingID string `param:"trackingId"  validate:"required,uuid"`
+	}
+
+	OTXByAccountRequest struct {
+		Address string `param:"address" validate:"required,eth_addr_checksum"`
+		PerPage int    `query:"perPage" validate:"required,number,gt=0"`
+		Cursor  int    `query:"cursor" validate:"number"`
+		Next    bool   `query:"next"`
+	}
+)
+
+const (
+	ErrCodeInternalServerError = "E01"
+	ErrCodeInvalidJSON         = "E02"
+	ErrCodeInvalidAPIKey       = "E03"
+	ErrCodeValidationFailed    = "E04"
+	ErrCodeAccountNotExists    = "E05"
+)