diff --git a/pkg/rpc/client/rpc_test.go b/pkg/rpc/client/rpc_test.go
index bafb99d4e..c14ddc130 100644
--- a/pkg/rpc/client/rpc_test.go
+++ b/pkg/rpc/client/rpc_test.go
@@ -1649,8 +1649,8 @@ func wrapInitResponse(r *request.In, resp string) string {
 	case "getversion":
 		response = `{"id":1,"jsonrpc":"2.0","result":{"network":42,"tcpport":20332,"wsport":20342,"nonce":2153672787,"useragent":"/NEO-GO:0.73.1-pre-273-ge381358/"}}`
 	case "getcontractstate":
-		p, _ := r.Params()
-		name, _ := p.ValueWithType(0, request.StringT).GetString()
+		p := request.Params(r.RawParams)
+		name, _ := p.Value(0).GetString()
 		switch name {
 		case "NeoToken":
 			response = `{"id":1,"jsonrpc":"2.0","result":{"id":-1,"script":"DANORU9Ba2d4Cw==","manifest":{"name":"NEO","abi":{"hash":"0xde5f57d430d3dece511cf975a8d37848cb9e0525","methods":[{"name":"name","offset":0,"parameters":null,"returntype":"String"},{"name":"symbol","offset":0,"parameters":null,"returntype":"String"},{"name":"decimals","offset":0,"parameters":null,"returntype":"Integer"},{"name":"totalSupply","offset":0,"parameters":null,"returntype":"Integer"},{"name":"balanceOf","offset":0,"parameters":[{"name":"account","type":"Hash160"}],"returntype":"Integer"},{"name":"transfer","offset":0,"parameters":[{"name":"from","type":"Hash160"},{"name":"to","type":"Hash160"},{"name":"amount","type":"Integer"}],"returntype":"Boolean"},{"name":"onPersist","offset":0,"parameters":null,"returntype":"Void"},{"name":"postPersist","offset":0,"parameters":null,"returntype":"Void"},{"name":"unclaimedGas","offset":0,"parameters":[{"name":"account","type":"Hash160"},{"name":"end","type":"Integer"}],"returntype":"Integer"},{"name":"registerCandidate","offset":0,"parameters":[{"name":"pubkey","type":"PublicKey"}],"returntype":"Boolean"},{"name":"unregisterCandidate","offset":0,"parameters":[{"name":"pubkey","type":"PublicKey"}],"returntype":"Boolean"},{"name":"vote","offset":0,"parameters":[{"name":"account","type":"Hash160"},{"name":"pubkey","type":"PublicKey"}],"returntype":"Boolean"},{"name":"getCandidates","offset":0,"parameters":null,"returntype":"Array"},{"name":"getСommittee","offset":0,"parameters":null,"returntype":"Array"},{"name":"getNextBlockValidators","offset":0,"parameters":null,"returntype":"Array"},{"name":"getGasPerBlock","offset":0,"parameters":null,"returntype":"Integer"},{"name":"setGasPerBlock","offset":0,"parameters":[{"name":"gasPerBlock","type":"Integer"}],"returntype":"Boolean"}],"events":[{"name":"Transfer","parameters":null}]},"groups":[],"permissions":[{"contract":"*","methods":"*"}],"supportedstandards":["NEP-5"],"trusts":[],"safemethods":["name","symbol","decimals","totalSupply","balanceOf","unclaimedGas","getCandidates","getСommittee","getNextBlockValidators"],"extra":null},"hash":"0xde5f57d430d3dece511cf975a8d37848cb9e0525"}}`
diff --git a/pkg/rpc/client/wsclient.go b/pkg/rpc/client/wsclient.go
index 8c52ec345..f2ed6aed8 100644
--- a/pkg/rpc/client/wsclient.go
+++ b/pkg/rpc/client/wsclient.go
@@ -134,9 +134,7 @@ readloop:
 				// Bad event received.
 				break
 			}
-			var slice []json.RawMessage
-			err = json.Unmarshal(rr.RawParams, &slice)
-			if err != nil || (event != response.MissedEventID && len(slice) != 1) {
+			if event != response.MissedEventID && len(rr.RawParams) != 1 {
 				// Bad event received.
 				break
 			}
@@ -159,7 +157,7 @@ readloop:
 				break readloop
 			}
 			if event != response.MissedEventID {
-				err = json.Unmarshal(slice[0], val)
+				err = json.Unmarshal(rr.RawParams[0].RawMessage, val)
 				if err != nil {
 					// Bad event received.
 					break
diff --git a/pkg/rpc/client/wsclient_test.go b/pkg/rpc/client/wsclient_test.go
index 6ba2d4199..2f43e77b6 100644
--- a/pkg/rpc/client/wsclient_test.go
+++ b/pkg/rpc/client/wsclient_test.go
@@ -187,10 +187,8 @@ func TestWSFilteredSubscriptions(t *testing.T) {
 			},
 			func(t *testing.T, p *request.Params) {
 				param := p.Value(1)
-				raw, ok := param.Value.(json.RawMessage)
-				require.True(t, ok)
 				filt := new(request.BlockFilter)
-				require.NoError(t, json.Unmarshal(raw, filt))
+				require.NoError(t, json.Unmarshal(param.RawMessage, filt))
 				require.Equal(t, 3, filt.Primary)
 			},
 		},
@@ -202,10 +200,8 @@ func TestWSFilteredSubscriptions(t *testing.T) {
 			},
 			func(t *testing.T, p *request.Params) {
 				param := p.Value(1)
-				raw, ok := param.Value.(json.RawMessage)
-				require.True(t, ok)
 				filt := new(request.TxFilter)
-				require.NoError(t, json.Unmarshal(raw, filt))
+				require.NoError(t, json.Unmarshal(param.RawMessage, filt))
 				require.Equal(t, util.Uint160{1, 2, 3, 4, 5}, *filt.Sender)
 				require.Nil(t, filt.Signer)
 			},
@@ -218,10 +214,8 @@ func TestWSFilteredSubscriptions(t *testing.T) {
 			},
 			func(t *testing.T, p *request.Params) {
 				param := p.Value(1)
-				raw, ok := param.Value.(json.RawMessage)
-				require.True(t, ok)
 				filt := new(request.TxFilter)
-				require.NoError(t, json.Unmarshal(raw, filt))
+				require.NoError(t, json.Unmarshal(param.RawMessage, filt))
 				require.Nil(t, filt.Sender)
 				require.Equal(t, util.Uint160{0, 42}, *filt.Signer)
 			},
@@ -235,10 +229,8 @@ func TestWSFilteredSubscriptions(t *testing.T) {
 			},
 			func(t *testing.T, p *request.Params) {
 				param := p.Value(1)
-				raw, ok := param.Value.(json.RawMessage)
-				require.True(t, ok)
 				filt := new(request.TxFilter)
-				require.NoError(t, json.Unmarshal(raw, filt))
+				require.NoError(t, json.Unmarshal(param.RawMessage, filt))
 				require.Equal(t, util.Uint160{1, 2, 3, 4, 5}, *filt.Sender)
 				require.Equal(t, util.Uint160{0, 42}, *filt.Signer)
 			},
@@ -251,10 +243,8 @@ func TestWSFilteredSubscriptions(t *testing.T) {
 			},
 			func(t *testing.T, p *request.Params) {
 				param := p.Value(1)
-				raw, ok := param.Value.(json.RawMessage)
-				require.True(t, ok)
 				filt := new(request.NotificationFilter)
-				require.NoError(t, json.Unmarshal(raw, filt))
+				require.NoError(t, json.Unmarshal(param.RawMessage, filt))
 				require.Equal(t, util.Uint160{1, 2, 3, 4, 5}, *filt.Contract)
 				require.Nil(t, filt.Name)
 			},
@@ -267,10 +257,8 @@ func TestWSFilteredSubscriptions(t *testing.T) {
 			},
 			func(t *testing.T, p *request.Params) {
 				param := p.Value(1)
-				raw, ok := param.Value.(json.RawMessage)
-				require.True(t, ok)
 				filt := new(request.NotificationFilter)
-				require.NoError(t, json.Unmarshal(raw, filt))
+				require.NoError(t, json.Unmarshal(param.RawMessage, filt))
 				require.Equal(t, "my_pretty_notification", *filt.Name)
 				require.Nil(t, filt.Contract)
 			},
@@ -284,10 +272,8 @@ func TestWSFilteredSubscriptions(t *testing.T) {
 			},
 			func(t *testing.T, p *request.Params) {
 				param := p.Value(1)
-				raw, ok := param.Value.(json.RawMessage)
-				require.True(t, ok)
 				filt := new(request.NotificationFilter)
-				require.NoError(t, json.Unmarshal(raw, filt))
+				require.NoError(t, json.Unmarshal(param.RawMessage, filt))
 				require.Equal(t, util.Uint160{1, 2, 3, 4, 5}, *filt.Contract)
 				require.Equal(t, "my_pretty_notification", *filt.Name)
 			},
@@ -300,10 +286,8 @@ func TestWSFilteredSubscriptions(t *testing.T) {
 			},
 			func(t *testing.T, p *request.Params) {
 				param := p.Value(1)
-				raw, ok := param.Value.(json.RawMessage)
-				require.True(t, ok)
 				filt := new(request.ExecutionFilter)
-				require.NoError(t, json.Unmarshal(raw, filt))
+				require.NoError(t, json.Unmarshal(param.RawMessage, filt))
 				require.Equal(t, "FAULT", filt.State)
 			},
 		},
@@ -320,9 +304,8 @@ func TestWSFilteredSubscriptions(t *testing.T) {
 					req := request.In{}
 					err = ws.ReadJSON(&req)
 					require.NoError(t, err)
-					params, err := req.Params()
-					require.NoError(t, err)
-					c.serverCode(t, params)
+					params := request.Params(req.RawParams)
+					c.serverCode(t, &params)
 					err = ws.SetWriteDeadline(time.Now().Add(2 * time.Second))
 					require.NoError(t, err)
 					err = ws.WriteMessage(1, []byte(`{"jsonrpc": "2.0", "id": 1, "result": "0"}`))
diff --git a/pkg/rpc/request/param.go b/pkg/rpc/request/param.go
index 03834d050..eacc6ea27 100644
--- a/pkg/rpc/request/param.go
+++ b/pkg/rpc/request/param.go
@@ -22,11 +22,9 @@ type (
 	// the server or to send to a server using
 	// the client.
 	Param struct {
-		Type  paramType
-		Value interface{}
+		json.RawMessage
 	}
 
-	paramType int
 	// FuncParam represents a function argument parameter used in the
 	// invokefunction RPC method.
 	FuncParam struct {
@@ -64,68 +62,151 @@ type (
 	}
 )
 
-// These are parameter types accepted by RPC server.
-const (
-	defaultT paramType = iota
-	StringT
-	NumberT
-	BooleanT
-	ArrayT
-	FuncParamT
-	BlockFilterT
-	TxFilterT
-	NotificationFilterT
-	ExecutionFilterT
-	SignerWithWitnessT
+var (
+	jsonNullBytes       = []byte("null")
+	jsonFalseBytes      = []byte("false")
+	jsonTrueBytes       = []byte("true")
+	errMissingParameter = errors.New("parameter is missing")
+	errNotAString       = errors.New("not a string")
+	errNotAnInt         = errors.New("not an integer")
+	errNotABool         = errors.New("not a boolean")
+	errNotAnArray       = errors.New("not an array")
 )
 
-var errMissingParameter = errors.New("parameter is missing")
-
 func (p Param) String() string {
-	return fmt.Sprintf("%v", p.Value)
+	str, _ := p.GetString()
+	return str
 }
 
-// GetString returns string value of the parameter.
+// GetStringStrict returns string value of the parameter.
+func (p *Param) GetStringStrict() (string, error) {
+	if p == nil {
+		return "", errMissingParameter
+	}
+	if p.IsNull() {
+		return "", errNotAString
+	}
+	var s string
+	err := json.Unmarshal(p.RawMessage, &s)
+	if err != nil {
+		return "", errNotAString
+	}
+	return s, nil
+}
+
+// GetString returns string value of the parameter or tries to cast parameter to a string value.
 func (p *Param) GetString() (string, error) {
 	if p == nil {
 		return "", errMissingParameter
 	}
-	str, ok := p.Value.(string)
-	if !ok {
-		return "", errors.New("not a string")
+	if p.IsNull() {
+		return "", errNotAString
 	}
-	return str, nil
+	var s string
+	err := json.Unmarshal(p.RawMessage, &s)
+	if err == nil {
+		return s, nil
+	}
+	var i int
+	err = json.Unmarshal(p.RawMessage, &i)
+	if err == nil {
+		return strconv.Itoa(i), nil
+	}
+	var b bool
+	err = json.Unmarshal(p.RawMessage, &b)
+	if err == nil {
+		if b {
+			return "true", nil
+		}
+		return "false", nil
+	}
+	return "", errNotAString
 }
 
-// GetBoolean returns boolean value of the parameter.
-func (p *Param) GetBoolean() bool {
+// GetBooleanStrict returns boolean value of the parameter.
+func (p *Param) GetBooleanStrict() (bool, error) {
 	if p == nil {
-		return false
+		return false, errMissingParameter
 	}
-	switch p.Type {
-	case NumberT:
-		return p.Value != 0
-	case StringT:
-		return p.Value != ""
-	case BooleanT:
-		return p.Value == true
-	default:
-		return true
+	if bytes.Equal(p.RawMessage, jsonTrueBytes) {
+		return true, nil
 	}
+	if bytes.Equal(p.RawMessage, jsonFalseBytes) {
+		return false, nil
+	}
+	return false, errNotABool
 }
 
-// GetInt returns int value of te parameter.
+// GetBoolean returns boolean value of the parameter or tries to cast parameter to a bool value.
+func (p *Param) GetBoolean() (bool, error) {
+	if p == nil {
+		return false, errMissingParameter
+	}
+	if p.IsNull() {
+		return false, errNotABool
+	}
+	var b bool
+	err := json.Unmarshal(p.RawMessage, &b)
+	if err == nil {
+		return b, nil
+	}
+	var s string
+	err = json.Unmarshal(p.RawMessage, &s)
+	if err == nil {
+		return s != "", nil
+	}
+	var i int
+	err = json.Unmarshal(p.RawMessage, &i)
+	if err == nil {
+		return i != 0, nil
+	}
+	return false, errNotABool
+}
+
+// GetIntStrict returns int value of the parameter if the parameter is integer.
+func (p *Param) GetIntStrict() (int, error) {
+	if p == nil {
+		return 0, errMissingParameter
+	}
+	if p.IsNull() {
+		return 0, errNotAnInt
+	}
+	var i int
+	err := json.Unmarshal(p.RawMessage, &i)
+	if err != nil {
+		return i, errNotAnInt
+	}
+	return i, nil
+}
+
+// GetInt returns int value of the parameter or tries to cast parameter to an int value.
 func (p *Param) GetInt() (int, error) {
 	if p == nil {
 		return 0, errMissingParameter
 	}
-	i, ok := p.Value.(int)
-	if ok {
+	if p.IsNull() {
+		return 0, errNotAnInt
+	}
+	var i int
+	err := json.Unmarshal(p.RawMessage, &i)
+	if err == nil {
 		return i, nil
-	} else if s, ok := p.Value.(string); ok {
+	}
+	var s string
+	err = json.Unmarshal(p.RawMessage, &s)
+	if err == nil {
 		return strconv.Atoi(s)
 	}
-	return 0, errors.New("not an integer")
+	var b bool
+	err = json.Unmarshal(p.RawMessage, &b)
+	if err == nil {
+		i = 0
+		if b {
+			i = 1
+		}
+		return i, nil
+	}
+	return 0, errNotAnInt
 }
 
 // GetArray returns a slice of Params stored in the parameter.
@@ -133,21 +214,14 @@ func (p *Param) GetArray() ([]Param, error) {
 	if p == nil {
 		return nil, errMissingParameter
 	}
-	a, ok := p.Value.([]Param)
-	if ok {
-		return a, nil
+	if p.IsNull() {
+		return nil, errNotAnArray
 	}
-	raw, ok := p.Value.(json.RawMessage)
-	if !ok {
-		return nil, errors.New("not an array")
-	}
-
-	a = []Param{}
-	err := json.Unmarshal(raw, &a)
+	a := []Param{}
+	err := json.Unmarshal(p.RawMessage, &a)
 	if err != nil {
-		return nil, errors.New("not an array")
+		return nil, errNotAnArray
 	}
-	p.Value = a
 	return a, nil
 }
 
@@ -200,20 +274,9 @@ func (p *Param) GetFuncParam() (FuncParam, error) {
 	if p == nil {
 		return FuncParam{}, errMissingParameter
 	}
-	fp, ok := p.Value.(FuncParam)
-	if ok {
-		return fp, nil
-	}
-	raw, ok := p.Value.(json.RawMessage)
-	if !ok {
-		return FuncParam{}, errors.New("not a function parameter")
-	}
-	err := json.Unmarshal(raw, &fp)
-	if err != nil {
-		return fp, err
-	}
-	p.Value = fp
-	return fp, nil
+	fp := FuncParam{}
+	err := json.Unmarshal(p.RawMessage, &fp)
+	return fp, err
 }
 
 // GetBytesHex returns []byte value of the parameter if
@@ -240,25 +303,19 @@ func (p *Param) GetBytesBase64() ([]byte, error) {
 
 // GetSignerWithWitness returns SignerWithWitness value of the parameter.
 func (p *Param) GetSignerWithWitness() (SignerWithWitness, error) {
-	c, ok := p.Value.(SignerWithWitness)
-	if ok {
-		return c, nil
-	}
-	raw, ok := p.Value.(json.RawMessage)
-	if !ok {
-		return SignerWithWitness{}, errors.New("not a signer")
-	}
 	aux := new(signerWithWitnessAux)
-	err := json.Unmarshal(raw, aux)
+	err := json.Unmarshal(p.RawMessage, aux)
 	if err != nil {
-		return SignerWithWitness{}, errors.New("not a signer")
+		return SignerWithWitness{}, fmt.Errorf("not a signer: %w", err)
 	}
-	accParam := Param{StringT, aux.Account}
-	acc, err := accParam.GetUint160FromAddressOrHex()
+	acc, err := util.Uint160DecodeStringLE(strings.TrimPrefix(aux.Account, "0x"))
 	if err != nil {
-		return SignerWithWitness{}, errors.New("not a signer")
+		acc, err = address.StringToUint160(aux.Account)
 	}
-	c = SignerWithWitness{
+	if err != nil {
+		return SignerWithWitness{}, fmt.Errorf("not a signer: %w", err)
+	}
+	c := SignerWithWitness{
 		Signer: transaction.Signer{
 			Account:          acc,
 			Scopes:           aux.Scopes,
@@ -270,7 +327,6 @@ func (p *Param) GetSignerWithWitness() (SignerWithWitness, error) {
 			VerificationScript: aux.VerificationScript,
 		},
 	}
-	p.Value = c
 	return c, nil
 }
 
@@ -309,48 +365,9 @@ func (p Param) GetSignersWithWitnesses() ([]transaction.Signer, []transaction.Wi
 	return signers, witnesses, nil
 }
 
-// UnmarshalJSON implements json.Unmarshaler interface.
-func (p *Param) UnmarshalJSON(data []byte) error {
-	r := bytes.NewReader(data)
-	jd := json.NewDecoder(r)
-	jd.UseNumber()
-	tok, err := jd.Token()
-	if err != nil {
-		return err
-	}
-	switch t := tok.(type) {
-	case json.Delim:
-		if t == json.Delim('[') {
-			var arr []Param
-			err := json.Unmarshal(data, &arr)
-			if err != nil {
-				return err
-			}
-			p.Type = ArrayT
-			p.Value = arr
-		} else {
-			p.Type = defaultT
-			p.Value = json.RawMessage(data)
-		}
-	case bool:
-		p.Type = BooleanT
-		p.Value = t
-	case float64: // unexpected because of `UseNumber`.
-		panic("unexpected")
-	case json.Number:
-		value, err := strconv.Atoi(string(t))
-		if err != nil {
-			return err
-		}
-		p.Type = NumberT
-		p.Value = value
-	case string:
-		p.Type = StringT
-		p.Value = t
-	default: // null
-		p.Type = defaultT
-	}
-	return nil
+// IsNull returns whether parameter represents JSON nil value.
+func (p *Param) IsNull() bool {
+	return bytes.Equal(p.RawMessage, jsonNullBytes)
 }
 
 // signerWithWitnessAux is an auxiluary struct for JSON marshalling. We need it because of
diff --git a/pkg/rpc/request/param_test.go b/pkg/rpc/request/param_test.go
index 7303006c9..1b5900700 100644
--- a/pkg/rpc/request/param_test.go
+++ b/pkg/rpc/request/param_test.go
@@ -4,6 +4,7 @@ import (
 	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
+	"fmt"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
@@ -15,66 +16,178 @@ import (
 )
 
 func TestParam_UnmarshalJSON(t *testing.T) {
-	msg := `["str1", 123, null, ["str2", 3], [{"type": "String", "value": "jajaja"}],
-                 {"account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569"},
-                 {"account": "NYxb4fSZVKAz8YsgaPK2WkT3KcAE9b3Vag", "scopes": "Global"},
-                 [{"account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569", "scopes": "Global"}]]`
-	expected := Params{
+	type testCase struct {
+		check              func(t *testing.T, p *Param)
+		expectedRawMessage []byte
+	}
+	msg := `["123", 123, null, ["str2", 3], [{"type": "String", "value": "jajaja"}],
+	  {"account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569"},
+	  {"account": "NYxb4fSZVKAz8YsgaPK2WkT3KcAE9b3Vag", "scopes": "Global"},
+	  [{"account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569", "scopes": "Global"}]]`
+	expected := []testCase{
 		{
-			Type:  StringT,
-			Value: "str1",
-		},
-		{
-			Type:  NumberT,
-			Value: 123,
-		},
-		{
-			Type: defaultT,
-		},
-		{
-			Type: ArrayT,
-			Value: []Param{
-				{
-					Type:  StringT,
-					Value: "str2",
-				},
-				{
-					Type:  NumberT,
-					Value: 3,
-				},
+			check: func(t *testing.T, p *Param) {
+				expectedS := "123"
+				actualS, err := p.GetStringStrict()
+				require.NoError(t, err)
+				require.Equal(t, expectedS, actualS)
+				actualS, err = p.GetString()
+				require.NoError(t, err)
+				require.Equal(t, expectedS, actualS)
+
+				expectedI := 123
+				_, err = p.GetIntStrict()
+				require.Error(t, err)
+				actualI, err := p.GetInt()
+				require.NoError(t, err)
+				require.Equal(t, expectedI, actualI)
+
+				expectedB := true
+				_, err = p.GetBooleanStrict()
+				require.Error(t, err)
+				actualB, err := p.GetBoolean()
+				require.NoError(t, err)
+				require.Equal(t, expectedB, actualB)
+
+				_, err = p.GetArray()
+				require.Error(t, err)
 			},
+			expectedRawMessage: []byte(`"123"`),
 		},
 		{
-			Type: ArrayT,
-			Value: []Param{
-				{
-					Type:  defaultT,
-					Value: json.RawMessage(`{"type": "String", "value": "jajaja"}`),
-				},
+			check: func(t *testing.T, p *Param) {
+				expectedS := "123"
+				_, err := p.GetStringStrict()
+				require.Error(t, err)
+				actualS, err := p.GetString()
+				require.NoError(t, err)
+				require.Equal(t, expectedS, actualS)
+
+				expectedI := 123
+				actualI, err := p.GetIntStrict()
+				require.NoError(t, err)
+				require.Equal(t, expectedI, actualI)
+				actualI, err = p.GetInt()
+				require.NoError(t, err)
+				require.Equal(t, expectedI, actualI)
+
+				expectedB := true
+				_, err = p.GetBooleanStrict()
+				require.Error(t, err)
+				actualB, err := p.GetBoolean()
+				require.NoError(t, err)
+				require.Equal(t, expectedB, actualB)
+
+				_, err = p.GetArray()
+				require.Error(t, err)
 			},
+			expectedRawMessage: []byte(`123`),
 		},
 		{
-			Type:  defaultT,
-			Value: json.RawMessage(`{"account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569"}`),
-		},
-		{
-			Type:  defaultT,
-			Value: json.RawMessage(`{"account": "NYxb4fSZVKAz8YsgaPK2WkT3KcAE9b3Vag", "scopes": "Global"}`),
-		},
-		{
-			Type: ArrayT,
-			Value: []Param{
-				{
-					Type:  defaultT,
-					Value: json.RawMessage(`{"account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569", "scopes": "Global"}`),
-				},
+			check: func(t *testing.T, p *Param) {
+				_, err := p.GetStringStrict()
+				require.Error(t, err)
+				_, err = p.GetString()
+				require.Error(t, err)
+
+				_, err = p.GetIntStrict()
+				require.Error(t, err)
+				_, err = p.GetInt()
+				require.Error(t, err)
+
+				_, err = p.GetBooleanStrict()
+				require.Error(t, err)
+				_, err = p.GetBoolean()
+				require.Error(t, err)
+
+				_, err = p.GetArray()
+				require.Error(t, err)
 			},
+			expectedRawMessage: []byte(`null`),
+		},
+		{
+			check: func(t *testing.T, p *Param) {
+				_, err := p.GetStringStrict()
+				require.Error(t, err)
+				_, err = p.GetString()
+				require.Error(t, err)
+
+				_, err = p.GetIntStrict()
+				require.Error(t, err)
+				_, err = p.GetInt()
+				require.Error(t, err)
+
+				_, err = p.GetBooleanStrict()
+				require.Error(t, err)
+				_, err = p.GetBoolean()
+				require.Error(t, err)
+
+				a, err := p.GetArray()
+				require.NoError(t, err)
+				require.Equal(t, []Param{
+					{RawMessage: json.RawMessage(`"str2"`)},
+					{RawMessage: json.RawMessage(`3`)},
+				}, a)
+			},
+			expectedRawMessage: []byte(`["str2", 3]`),
+		},
+		{
+			check: func(t *testing.T, p *Param) {
+				a, err := p.GetArray()
+				require.NoError(t, err)
+				require.Equal(t, 1, len(a))
+				fp, err := a[0].GetFuncParam()
+				require.NoError(t, err)
+				require.Equal(t, smartcontract.StringType, fp.Type)
+				strVal, err := fp.Value.GetStringStrict()
+				require.NoError(t, err)
+				require.Equal(t, "jajaja", strVal)
+			},
+			expectedRawMessage: []byte(`[{"type": "String", "value": "jajaja"}]`),
+		},
+		{
+			check: func(t *testing.T, p *Param) {
+				actual, err := p.GetSignerWithWitness()
+				require.NoError(t, err)
+				expectedAcc, err := util.Uint160DecodeStringLE("cadb3dc2faa3ef14a13b619c9a43124755aa2569")
+				require.NoError(t, err)
+				require.Equal(t, SignerWithWitness{Signer: transaction.Signer{Account: expectedAcc}}, actual)
+			},
+			expectedRawMessage: []byte(`{"account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569"}`),
+		},
+		{
+			check: func(t *testing.T, p *Param) {
+				actual, err := p.GetSignerWithWitness()
+				require.NoError(t, err)
+				expectedAcc, err := address.StringToUint160("NYxb4fSZVKAz8YsgaPK2WkT3KcAE9b3Vag")
+				require.NoError(t, err)
+				require.Equal(t, SignerWithWitness{Signer: transaction.Signer{Account: expectedAcc, Scopes: transaction.Global}}, actual)
+			},
+			expectedRawMessage: []byte(`{"account": "NYxb4fSZVKAz8YsgaPK2WkT3KcAE9b3Vag", "scopes": "Global"}`),
+		},
+		{
+			check: func(t *testing.T, p *Param) {
+				actualSigs, actualWtns, err := p.GetSignersWithWitnesses()
+				require.NoError(t, err)
+				require.Equal(t, 1, len(actualSigs))
+				require.Equal(t, 1, len(actualWtns))
+				expectedAcc, err := util.Uint160DecodeStringLE("cadb3dc2faa3ef14a13b619c9a43124755aa2569")
+				require.NoError(t, err)
+				require.Equal(t, transaction.Signer{Account: expectedAcc, Scopes: transaction.Global}, actualSigs[0])
+				require.Equal(t, transaction.Witness{}, actualWtns[0])
+			},
+			expectedRawMessage: []byte(`[{"account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569", "scopes": "Global"}]`),
 		},
 	}
 
 	var ps Params
 	require.NoError(t, json.Unmarshal([]byte(msg), &ps))
-	require.Equal(t, expected, ps)
+	require.Equal(t, len(expected), len(ps))
+	for i, tc := range expected {
+		require.NotNil(t, ps[i])
+		require.Equal(t, json.RawMessage(tc.expectedRawMessage), ps[i].RawMessage, i)
+		tc.check(t, &ps[i])
+	}
 }
 
 func TestGetWitness(t *testing.T) {
@@ -108,11 +221,10 @@ func TestGetWitness(t *testing.T) {
 	}
 
 	for _, tc := range testCases {
-		p := Param{Value: json.RawMessage(tc.raw)}
+		p := Param{RawMessage: json.RawMessage(tc.raw)}
 		actual, err := p.GetSignerWithWitness()
 		require.NoError(t, err)
 		require.Equal(t, tc.expected, actual)
-		require.Equal(t, tc.expected, p.Value)
 
 		actual, err = p.GetSignerWithWitness() // valid second invocation.
 		require.NoError(t, err)
@@ -120,57 +232,24 @@ func TestGetWitness(t *testing.T) {
 	}
 }
 
-func TestParamGetString(t *testing.T) {
-	p := Param{StringT, "jajaja"}
-	str, err := p.GetString()
-	assert.Equal(t, "jajaja", str)
-	require.Nil(t, err)
-
-	p = Param{StringT, int(100500)}
-	_, err = p.GetString()
-	require.NotNil(t, err)
-}
-
-func TestParamGetInt(t *testing.T) {
-	p := Param{NumberT, int(100500)}
-	i, err := p.GetInt()
-	assert.Equal(t, 100500, i)
-	require.Nil(t, err)
-
-	p = Param{NumberT, "jajaja"}
-	_, err = p.GetInt()
-	require.NotNil(t, err)
-}
-
-func TestParamGetArray(t *testing.T) {
-	p := Param{ArrayT, []Param{{NumberT, 42}}}
-	a, err := p.GetArray()
-	assert.Equal(t, []Param{{NumberT, 42}}, a)
-	require.Nil(t, err)
-
-	p = Param{ArrayT, 42}
-	_, err = p.GetArray()
-	require.NotNil(t, err)
-}
-
 func TestParamGetUint256(t *testing.T) {
 	gas := "602c79718b16e442de58778e148d0b1084e3b2dffd5de6b7b16cee7969282de7"
 	u256, _ := util.Uint256DecodeStringLE(gas)
-	p := Param{StringT, gas}
+	p := Param{RawMessage: []byte(fmt.Sprintf(`"%s"`, gas))}
 	u, err := p.GetUint256()
 	assert.Equal(t, u256, u)
 	require.Nil(t, err)
 
-	p = Param{StringT, "0x" + gas}
+	p = Param{RawMessage: []byte(fmt.Sprintf(`"0x%s"`, gas))}
 	u, err = p.GetUint256()
 	require.NoError(t, err)
 	assert.Equal(t, u256, u)
 
-	p = Param{StringT, 42}
+	p = Param{RawMessage: []byte(`42`)}
 	_, err = p.GetUint256()
 	require.NotNil(t, err)
 
-	p = Param{StringT, "qq2c79718b16e442de58778e148d0b1084e3b2dffd5de6b7b16cee7969282de7"}
+	p = Param{RawMessage: []byte(`"qq2c79718b16e442de58778e148d0b1084e3b2dffd5de6b7b16cee7969282de7"`)}
 	_, err = p.GetUint256()
 	require.NotNil(t, err)
 }
@@ -178,16 +257,16 @@ func TestParamGetUint256(t *testing.T) {
 func TestParamGetUint160FromHex(t *testing.T) {
 	in := "50befd26fdf6e4d957c11e078b24ebce6291456f"
 	u160, _ := util.Uint160DecodeStringLE(in)
-	p := Param{StringT, in}
+	p := Param{RawMessage: []byte(fmt.Sprintf(`"%s"`, in))}
 	u, err := p.GetUint160FromHex()
 	assert.Equal(t, u160, u)
 	require.Nil(t, err)
 
-	p = Param{StringT, 42}
+	p = Param{RawMessage: []byte(`42`)}
 	_, err = p.GetUint160FromHex()
 	require.NotNil(t, err)
 
-	p = Param{StringT, "wwbefd26fdf6e4d957c11e078b24ebce6291456f"}
+	p = Param{RawMessage: []byte(`"wwbefd26fdf6e4d957c11e078b24ebce6291456f"`)}
 	_, err = p.GetUint160FromHex()
 	require.NotNil(t, err)
 }
@@ -195,16 +274,16 @@ func TestParamGetUint160FromHex(t *testing.T) {
 func TestParamGetUint160FromAddress(t *testing.T) {
 	in := "NPAsqZkx9WhNd4P72uhZxBhLinSuNkxfB8"
 	u160, _ := address.StringToUint160(in)
-	p := Param{StringT, in}
+	p := Param{RawMessage: []byte(fmt.Sprintf(`"%s"`, in))}
 	u, err := p.GetUint160FromAddress()
 	assert.Equal(t, u160, u)
 	require.Nil(t, err)
 
-	p = Param{StringT, 42}
+	p = Param{RawMessage: []byte(`42`)}
 	_, err = p.GetUint160FromAddress()
 	require.NotNil(t, err)
 
-	p = Param{StringT, "QK2nJJpJr6o664CWJKi1QRXjqeic2zRp8y"}
+	p = Param{RawMessage: []byte(`"QK2nJJpJr6o664CWJKi1QRXjqeic2zRp8y"`)}
 	_, err = p.GetUint160FromAddress()
 	require.NotNil(t, err)
 }
@@ -214,14 +293,14 @@ func TestParam_GetUint160FromAddressOrHex(t *testing.T) {
 	inHex, _ := address.StringToUint160(in)
 
 	t.Run("Address", func(t *testing.T) {
-		p := Param{StringT, in}
+		p := Param{RawMessage: []byte(fmt.Sprintf(`"%s"`, in))}
 		u, err := p.GetUint160FromAddressOrHex()
 		require.NoError(t, err)
 		require.Equal(t, inHex, u)
 	})
 
 	t.Run("Hex", func(t *testing.T) {
-		p := Param{StringT, inHex.StringLE()}
+		p := Param{RawMessage: []byte(fmt.Sprintf(`"%s"`, inHex.StringLE()))}
 		u, err := p.GetUint160FromAddressOrHex()
 		require.NoError(t, err)
 		require.Equal(t, inHex, u)
@@ -230,21 +309,15 @@ func TestParam_GetUint160FromAddressOrHex(t *testing.T) {
 
 func TestParamGetFuncParam(t *testing.T) {
 	fp := FuncParam{
-		Type: smartcontract.StringType,
-		Value: Param{
-			Type:  StringT,
-			Value: "jajaja",
-		},
-	}
-	p := Param{
-		Type:  FuncParamT,
-		Value: fp,
+		Type:  smartcontract.StringType,
+		Value: Param{RawMessage: []byte(`"jajaja"`)},
 	}
+	p := Param{RawMessage: []byte(`{"type": "String", "value": "jajaja"}`)}
 	newfp, err := p.GetFuncParam()
 	assert.Equal(t, fp, newfp)
 	require.Nil(t, err)
 
-	p = Param{FuncParamT, 42}
+	p = Param{RawMessage: []byte(`42`)}
 	_, err = p.GetFuncParam()
 	require.NotNil(t, err)
 }
@@ -252,16 +325,17 @@ func TestParamGetFuncParam(t *testing.T) {
 func TestParamGetBytesHex(t *testing.T) {
 	in := "602c79718b16e442de58778e148d0b1084e3b2dffd5de6b7b16cee7969282de7"
 	inb, _ := hex.DecodeString(in)
-	p := Param{StringT, in}
+	p := Param{RawMessage: []byte(fmt.Sprintf(`"%s"`, in))}
 	bh, err := p.GetBytesHex()
 	assert.Equal(t, inb, bh)
 	require.Nil(t, err)
 
-	p = Param{StringT, 42}
-	_, err = p.GetBytesHex()
-	require.NotNil(t, err)
+	p = Param{RawMessage: []byte(`42`)}
+	h, err := p.GetBytesHex()
+	assert.Equal(t, []byte{0x42}, h) // that's the way how C# works: 42 -> "42" -> []byte{0x42}
+	require.Nil(t, err)
 
-	p = Param{StringT, "qq2c79718b16e442de58778e148d0b1084e3b2dffd5de6b7b16cee7969282de7"}
+	p = Param{RawMessage: []byte(`"qq2c79718b16e442de58778e148d0b1084e3b2dffd5de6b7b16cee7969282de7"`)}
 	_, err = p.GetBytesHex()
 	require.NotNil(t, err)
 }
@@ -270,16 +344,16 @@ func TestParamGetBytesBase64(t *testing.T) {
 	in := "Aj4A8DoW6HB84EXrQu6A05JFFUHuUQ3BjhyL77rFTXQm"
 	inb, err := base64.StdEncoding.DecodeString(in)
 	require.NoError(t, err)
-	p := Param{StringT, in}
+	p := Param{RawMessage: []byte(fmt.Sprintf(`"%s"`, in))}
 	bh, err := p.GetBytesBase64()
 	assert.Equal(t, inb, bh)
 	require.Nil(t, err)
 
-	p = Param{StringT, 42}
+	p = Param{RawMessage: []byte(`42`)}
 	_, err = p.GetBytesBase64()
 	require.NotNil(t, err)
 
-	p = Param{StringT, "@j4A8DoW6HB84EXrQu6A05JFFUHuUQ3BjhyL77rFTXQm"}
+	p = Param{RawMessage: []byte("@j4A8DoW6HB84EXrQu6A05JFFUHuUQ3BjhyL77rFTXQm")}
 	_, err = p.GetBytesBase64()
 	require.NotNil(t, err)
 }
@@ -296,12 +370,12 @@ func TestParamGetSigner(t *testing.T) {
 			VerificationScript: []byte{1, 2, 3},
 		},
 	}
-	p := Param{Type: SignerWithWitnessT, Value: c}
+	p := Param{RawMessage: []byte(`{"account": "0x0000000000000000000000000000000004030201", "scopes": "Global", "invocation": "AQID", "verification": "AQID"}`)}
 	actual, err := p.GetSignerWithWitness()
 	require.NoError(t, err)
 	require.Equal(t, c, actual)
 
-	p = Param{Type: SignerWithWitnessT, Value: `{"account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569", "scopes": 0}`}
+	p = Param{RawMessage: []byte(`"not a signer"`)}
 	_, err = p.GetSignerWithWitness()
 	require.Error(t, err)
 }
@@ -310,10 +384,7 @@ func TestParamGetSigners(t *testing.T) {
 	u1 := util.Uint160{1, 2, 3, 4}
 	u2 := util.Uint160{5, 6, 7, 8}
 	t.Run("from hashes", func(t *testing.T) {
-		p := Param{ArrayT, []Param{
-			{Type: StringT, Value: u1.StringLE()},
-			{Type: StringT, Value: u2.StringLE()},
-		}}
+		p := Param{RawMessage: []byte(fmt.Sprintf(`["%s", "%s"]`, u1.StringLE(), u2.StringLE()))}
 		actual, _, err := p.GetSignersWithWitnesses()
 		require.NoError(t, err)
 		require.Equal(t, 2, len(actual))
@@ -321,56 +392,8 @@ func TestParamGetSigners(t *testing.T) {
 		require.True(t, u2.Equals(actual[1].Account))
 	})
 
-	t.Run("from signers", func(t *testing.T) {
-		c1 := SignerWithWitness{
-			Signer: transaction.Signer{
-				Account: u1,
-				Scopes:  transaction.Global,
-			},
-			Witness: transaction.Witness{
-				InvocationScript:   []byte{1, 2, 3},
-				VerificationScript: []byte{1, 2, 3},
-			},
-		}
-		c2 := SignerWithWitness{
-			Signer: transaction.Signer{
-				Account: u2,
-				Scopes:  transaction.CustomContracts,
-				AllowedContracts: []util.Uint160{
-					{1, 2, 3},
-					{4, 5, 6},
-				},
-			},
-		}
-		p := Param{ArrayT, []Param{
-			{Type: SignerWithWitnessT, Value: c1},
-			{Type: SignerWithWitnessT, Value: c2},
-		}}
-		actualS, actualW, err := p.GetSignersWithWitnesses()
-		require.NoError(t, err)
-		require.Equal(t, 2, len(actualS))
-		require.Equal(t, transaction.Signer{
-			Account: c1.Account,
-			Scopes:  c1.Scopes,
-		}, actualS[0])
-		require.Equal(t, transaction.Signer{
-			Account:          c2.Account,
-			Scopes:           c2.Scopes,
-			AllowedContracts: c2.AllowedContracts,
-		}, actualS[1])
-		require.EqualValues(t, 2, len(actualW))
-		require.EqualValues(t, transaction.Witness{
-			InvocationScript:   c1.InvocationScript,
-			VerificationScript: c1.VerificationScript,
-		}, actualW[0])
-		require.Equal(t, transaction.Witness{}, actualW[1])
-	})
-
 	t.Run("bad format", func(t *testing.T) {
-		p := Param{ArrayT, []Param{
-			{Type: StringT, Value: u1.StringLE()},
-			{Type: StringT, Value: "bla"},
-		}}
+		p := Param{RawMessage: []byte(`"not a signer"`)}
 		_, _, err := p.GetSignersWithWitnesses()
 		require.Error(t, err)
 	})
diff --git a/pkg/rpc/request/params.go b/pkg/rpc/request/params.go
index c35e13b43..9ba8fb159 100644
--- a/pkg/rpc/request/params.go
+++ b/pkg/rpc/request/params.go
@@ -17,15 +17,6 @@ func (p Params) Value(index int) *Param {
 	return nil
 }
 
-// ValueWithType returns the param struct at the given index if it
-// exists and matches the given type.
-func (p Params) ValueWithType(index int, valType paramType) *Param {
-	if val := p.Value(index); val != nil && val.Type == valType {
-		return val
-	}
-	return nil
-}
-
 func (p Params) String() string {
 	return fmt.Sprintf("%v", []Param(p))
 }
diff --git a/pkg/rpc/request/txBuilder.go b/pkg/rpc/request/txBuilder.go
index f8a64b1de..f0dbc6747 100644
--- a/pkg/rpc/request/txBuilder.go
+++ b/pkg/rpc/request/txBuilder.go
@@ -70,8 +70,8 @@ func ExpandArrayIntoScript(script *io.BinWriter, slice []Param) error {
 			}
 			emit.Int(script, int64(val))
 		case smartcontract.BoolType:
-			val, ok := fp.Value.Value.(bool)
-			if !ok {
+			val, err := fp.Value.GetBoolean() // not GetBooleanStrict(), because that's the way C# code works
+			if err != nil {
 				return errors.New("not a bool")
 			}
 			if val {
@@ -102,29 +102,21 @@ func ExpandArrayIntoScript(script *io.BinWriter, slice []Param) error {
 func CreateFunctionInvocationScript(contract util.Uint160, method string, params Params) ([]byte, error) {
 	script := io.NewBufBinWriter()
 	for i := len(params) - 1; i >= 0; i-- {
-		switch params[i].Type {
-		case StringT:
-			emit.String(script.BinWriter, params[i].String())
-		case NumberT:
-			num, err := params[i].GetInt()
-			if err != nil {
-				return nil, err
-			}
-			emit.String(script.BinWriter, strconv.Itoa(num))
-		case BooleanT:
-			val := params[i].GetBoolean()
-			emit.Bool(script.BinWriter, val)
-		case ArrayT:
-			slice, err := params[i].GetArray()
-			if err != nil {
-				return nil, err
-			}
+		if slice, err := params[i].GetArray(); err == nil {
 			err = ExpandArrayIntoScript(script.BinWriter, slice)
 			if err != nil {
 				return nil, err
 			}
 			emit.Int(script.BinWriter, int64(len(slice)))
 			emit.Opcodes(script.BinWriter, opcode.PACK)
+		} else if s, err := params[i].GetStringStrict(); err == nil {
+			emit.String(script.BinWriter, s)
+		} else if n, err := params[i].GetIntStrict(); err == nil {
+			emit.String(script.BinWriter, strconv.Itoa(n))
+		} else if b, err := params[i].GetBooleanStrict(); err == nil {
+			emit.Bool(script.BinWriter, b)
+		} else {
+			return nil, fmt.Errorf("failed to convert parmeter %s to script parameter", params[i])
 		}
 	}
 	if len(params) == 0 {
diff --git a/pkg/rpc/request/tx_builder_test.go b/pkg/rpc/request/tx_builder_test.go
index 9bc6a8214..52a36627b 100644
--- a/pkg/rpc/request/tx_builder_test.go
+++ b/pkg/rpc/request/tx_builder_test.go
@@ -2,10 +2,10 @@ package request
 
 import (
 	"encoding/hex"
+	"fmt"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/pkg/io"
-	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
 	"github.com/stretchr/testify/assert"
@@ -13,7 +13,7 @@ import (
 )
 
 func TestInvocationScriptCreationGood(t *testing.T) {
-	p := Param{Type: StringT, Value: "50befd26fdf6e4d957c11e078b24ebce6291456f"}
+	p := Param{RawMessage: []byte(`"50befd26fdf6e4d957c11e078b24ebce6291456f"`)}
 	contract, err := p.GetUint160FromHex()
 	require.Nil(t, err)
 
@@ -21,49 +21,60 @@ func TestInvocationScriptCreationGood(t *testing.T) {
 		ps     Params
 		script string
 	}{{
-		ps:     Params{{Type: StringT, Value: "transfer"}},
+		ps:     Params{{RawMessage: []byte(`"transfer"`)}},
 		script: "c21f0c087472616e736665720c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: NumberT, Value: 42}},
+		ps:     Params{{RawMessage: []byte(`42`)}},
 		script: "c21f0c0234320c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: StringT, Value: "m"}, {Type: BooleanT, Value: true}},
+		ps:     Params{{RawMessage: []byte(`"m"`)}, {RawMessage: []byte(`true`)}},
 		script: "11db201f0c016d0c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: StringT, Value: "a"}, {Type: ArrayT, Value: []Param{}}},
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[]`)}},
 		script: "10c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: StringT, Value: "a"}, {Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.ByteArrayType, Value: Param{Type: StringT, Value: "AwEtR+diEK7HO+Oas9GG4KQP6Nhr+j1Pq/2le6E7iPlq"}}}}}},
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "ByteString", "value": "AwEtR+diEK7HO+Oas9GG4KQP6Nhr+j1Pq/2le6E7iPlq"}]`)}},
 		script: "0c2103012d47e76210aec73be39ab3d186e0a40fe8d86bfa3d4fabfda57ba13b88f96a11c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: StringT, Value: "a"}, {Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.SignatureType, Value: Param{Type: StringT, Value: "4edf5005771de04619235d5a4c7a9a11bb78e008541f1da7725f654c33380a3c87e2959a025da706d7255cb3a3fa07ebe9c6559d0d9e6213c68049168eb1056f"}}}}}},
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "Signature", "value": "4edf5005771de04619235d5a4c7a9a11bb78e008541f1da7725f654c33380a3c87e2959a025da706d7255cb3a3fa07ebe9c6559d0d9e6213c68049168eb1056f"}]`)}},
 		script: "0c404edf5005771de04619235d5a4c7a9a11bb78e008541f1da7725f654c33380a3c87e2959a025da706d7255cb3a3fa07ebe9c6559d0d9e6213c68049168eb1056f11c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: StringT, Value: "a"}, {Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.StringType, Value: Param{Type: StringT, Value: "50befd26fdf6e4d957c11e078b24ebce6291456f"}}}}}},
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "String", "value": "50befd26fdf6e4d957c11e078b24ebce6291456f"}]`)}},
 		script: "0c283530626566643236666466366534643935376331316530373862323465626365363239313435366611c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: StringT, Value: "a"}, {Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.Hash160Type, Value: Param{Type: StringT, Value: "50befd26fdf6e4d957c11e078b24ebce6291456f"}}}}}},
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "Hash160", "value": "50befd26fdf6e4d957c11e078b24ebce6291456f"}]`)}},
 		script: "0c146f459162ceeb248b071ec157d9e4f6fd26fdbe5011c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: StringT, Value: "a"}, {Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.Hash256Type, Value: Param{Type: StringT, Value: "602c79718b16e442de58778e148d0b1084e3b2dffd5de6b7b16cee7969282de7"}}}}}},
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "Hash256", "value": "602c79718b16e442de58778e148d0b1084e3b2dffd5de6b7b16cee7969282de7"}]`)}},
 		script: "0c20e72d286979ee6cb1b7e65dfddfb2e384100b8d148e7758de42e4168b71792c6011c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: StringT, Value: "a"}, {Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.PublicKeyType, Value: Param{Type: StringT, Value: "03c089d7122b840a4935234e82e26ae5efd0c2acb627239dc9f207311337b6f2c1"}}}}}},
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "PublicKey", "value": "03c089d7122b840a4935234e82e26ae5efd0c2acb627239dc9f207311337b6f2c1"}]`)}},
 		script: "0c2103c089d7122b840a4935234e82e26ae5efd0c2acb627239dc9f207311337b6f2c111c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: StringT, Value: "a"}, {Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.IntegerType, Value: Param{Type: NumberT, Value: 42}}}}}},
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "Integer", "value": 42}]`)}},
 		script: "002a11c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: StringT, Value: "a"}, {Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.BoolType, Value: Param{Type: BooleanT, Value: true}}}}}},
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "Integer", "value": "42"}]`)}}, // C# code doesn't use strict type assertions for JSON-ised params
+		script: "002a11c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
+	}, {
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "Integer", "value": true}]`)}}, // C# code doesn't use strict type assertions for JSON-ised params
 		script: "1111c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}, {
-		ps:     Params{{Type: StringT, Value: "a"}, {Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.BoolType, Value: Param{Type: BooleanT, Value: false}}}}}},
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "Boolean", "value": true}]`)}},
+		script: "1111c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
+	}, {
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "Boolean", "value": false}]`)}},
 		script: "1011c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
+	}, {
+		ps:     Params{{RawMessage: []byte(`"a"`)}, {RawMessage: []byte(`[{"type": "Boolean", "value": "blah"}]`)}}, // C# code doesn't use strict type assertions for JSON-ised params
+		script: "1111c01f0c01610c146f459162ceeb248b071ec157d9e4f6fd26fdbe5041627d5b52",
 	}}
-	for _, ps := range paramScripts {
-		script, err := CreateFunctionInvocationScript(contract, ps.ps[0].String(), ps.ps[1:])
+	for i, ps := range paramScripts {
+		method, err := ps.ps[0].GetString()
+		require.NoError(t, err, fmt.Sprintf("testcase #%d", i))
+		script, err := CreateFunctionInvocationScript(contract, method, ps.ps[1:])
 		assert.Nil(t, err)
-		assert.Equal(t, ps.script, hex.EncodeToString(script))
+		assert.Equal(t, ps.script, hex.EncodeToString(script), fmt.Sprintf("testcase #%d", i))
 	}
 }
 
@@ -71,25 +82,18 @@ func TestInvocationScriptCreationBad(t *testing.T) {
 	contract := util.Uint160{}
 
 	var testParams = []Params{
-		{{Type: NumberT, Value: "qwerty"}},
-		{{Type: ArrayT, Value: 42}},
-		{{Type: ArrayT, Value: []Param{{Type: NumberT, Value: 42}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.ByteArrayType, Value: Param{Type: StringT, Value: "qwerty"}}}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.SignatureType, Value: Param{Type: StringT, Value: "qwerty"}}}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.StringType, Value: Param{Type: NumberT, Value: 42}}}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.Hash160Type, Value: Param{Type: StringT, Value: "qwerty"}}}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.Hash256Type, Value: Param{Type: StringT, Value: "qwerty"}}}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.PublicKeyType, Value: Param{Type: NumberT, Value: 42}}}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.PublicKeyType, Value: Param{Type: StringT, Value: "qwerty"}}}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.IntegerType, Value: Param{Type: StringT, Value: "qwerty"}}}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.IntegerType, Value: Param{Type: BooleanT, Value: true}}}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.BoolType, Value: Param{Type: NumberT, Value: 42}}}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.BoolType, Value: Param{Type: StringT, Value: "qwerty"}}}}}},
-		{{Type: ArrayT, Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.UnknownType, Value: Param{}}}}}},
+		{{RawMessage: []byte(`[{"type": "ByteArray", "value": "qwerty"}]`)}},
+		{{RawMessage: []byte(`[{"type": "Signature", "value": "qwerty"}]`)}},
+		{{RawMessage: []byte(`[{"type": "Hash160", "value": "qwerty"}]`)}},
+		{{RawMessage: []byte(`[{"type": "Hash256", "value": "qwerty"}]`)}},
+		{{RawMessage: []byte(`[{"type": "PublicKey", "value": 42}]`)}},
+		{{RawMessage: []byte(`[{"type": "PublicKey", "value": "qwerty"}]`)}},
+		{{RawMessage: []byte(`[{"type": "Integer", "value": "123q"}]`)}},
+		{{RawMessage: []byte(`[{"type": "Unknown"}]`)}},
 	}
-	for _, ps := range testParams {
+	for i, ps := range testParams {
 		_, err := CreateFunctionInvocationScript(contract, "", ps)
-		assert.NotNil(t, err)
+		assert.NotNil(t, err, fmt.Sprintf("testcase #%d", i))
 	}
 }
 
@@ -99,11 +103,11 @@ func TestExpandArrayIntoScript(t *testing.T) {
 		Expected []byte
 	}{
 		{
-			Input:    []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.StringType, Value: Param{Value: "a"}}}},
+			Input:    []Param{{RawMessage: []byte(`{"type": "String", "value": "a"}`)}},
 			Expected: []byte{byte(opcode.PUSHDATA1), 1, byte('a')},
 		},
 		{
-			Input:    []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.ArrayType, Value: Param{Value: []Param{{Type: FuncParamT, Value: FuncParam{Type: smartcontract.StringType, Value: Param{Value: "a"}}}}}}}},
+			Input:    []Param{{RawMessage: []byte(`{"type": "Array", "value": [{"type": "String", "value": "a"}]}`)}},
 			Expected: []byte{byte(opcode.PUSHDATA1), 1, byte('a'), byte(opcode.PUSH1), byte(opcode.PACK)},
 		},
 	}
@@ -115,10 +119,10 @@ func TestExpandArrayIntoScript(t *testing.T) {
 	}
 	errorCases := [][]Param{
 		{
-			{Type: FuncParamT, Value: FuncParam{Type: smartcontract.ArrayType, Value: Param{Value: "a"}}},
+			{RawMessage: []byte(`{"type": "Array", "value": "a"}`)},
 		},
 		{
-			{Type: FuncParamT, Value: FuncParam{Type: smartcontract.ArrayType, Value: Param{Value: []Param{{Type: FuncParamT, Value: nil}}}}},
+			{RawMessage: []byte(`{"type": "Array", "value": null}`)},
 		},
 	}
 	for _, c := range errorCases {
diff --git a/pkg/rpc/request/types.go b/pkg/rpc/request/types.go
index 450815489..654771060 100644
--- a/pkg/rpc/request/types.go
+++ b/pkg/rpc/request/types.go
@@ -53,7 +53,7 @@ type Request struct {
 type In struct {
 	JSONRPC   string          `json:"jsonrpc"`
 	Method    string          `json:"method"`
-	RawParams json.RawMessage `json:"params,omitempty"`
+	RawParams []Param         `json:"params,omitempty"`
 	RawID     json.RawMessage `json:"id,omitempty"`
 }
 
@@ -134,16 +134,3 @@ func NewIn() *In {
 		JSONRPC: JSONRPCVersion,
 	}
 }
-
-// Params takes a slice of any type and attempts to bind
-// the params to it.
-func (r *In) Params() (*Params, error) {
-	params := Params{}
-
-	err := json.Unmarshal(r.RawParams, &params)
-	if err != nil {
-		return nil, fmt.Errorf("error parsing params: %w", err)
-	}
-
-	return &params, nil
-}
diff --git a/pkg/rpc/server/server.go b/pkg/rpc/server/server.go
index 051dda712..a1ee03739 100644
--- a/pkg/rpc/server/server.go
+++ b/pkg/rpc/server/server.go
@@ -335,10 +335,7 @@ func (s *Server) handleIn(req *request.In, sub *subscriber) response.Abstract {
 		return s.packResponse(req, nil, response.NewInvalidParamsError("Problem parsing JSON", fmt.Errorf("invalid version, expected 2.0 got: '%s'", req.JSONRPC)))
 	}
 
-	reqParams, err := req.Params()
-	if err != nil {
-		return s.packResponse(req, nil, response.NewInvalidParamsError("Problem parsing request parameters", err))
-	}
+	reqParams := request.Params(req.RawParams)
 
 	s.log.Debug("processing rpc request",
 		zap.String("method", req.Method),
@@ -349,11 +346,11 @@ func (s *Server) handleIn(req *request.In, sub *subscriber) response.Abstract {
 	resErr = response.NewMethodNotFoundError(fmt.Sprintf("Method '%s' not supported", req.Method), nil)
 	handler, ok := rpcHandlers[req.Method]
 	if ok {
-		res, resErr = handler(s, *reqParams)
+		res, resErr = handler(s, reqParams)
 	} else if sub != nil {
 		handler, ok := rpcWsHandlers[req.Method]
 		if ok {
-			res, resErr = handler(s, *reqParams, sub)
+			res, resErr = handler(s, reqParams, sub)
 		}
 	}
 	return s.packResponse(req, res, resErr)
@@ -468,21 +465,18 @@ func (s *Server) blockHashFromParam(param *request.Param) (util.Uint256, *respon
 		return hash, response.ErrInvalidParams
 	}
 
-	switch param.Type {
-	case request.StringT:
+	if _, err := param.GetStringStrict(); err == nil {
 		var err error
 		hash, err = param.GetUint256()
 		if err != nil {
 			return hash, response.ErrInvalidParams
 		}
-	case request.NumberT:
+	} else {
 		num, err := s.blockHeightFromParam(param)
 		if err != nil {
 			return hash, response.ErrInvalidParams
 		}
 		hash = s.chain.GetHeaderHash(num)
-	default:
-		return hash, response.ErrInvalidParams
 	}
 	return hash, nil
 }
@@ -499,7 +493,7 @@ func (s *Server) getBlock(reqParams request.Params) (interface{}, *response.Erro
 		return nil, response.NewInternalServerError(fmt.Sprintf("Problem locating block with hash: %s", hash), err)
 	}
 
-	if reqParams.Value(1).GetBoolean() {
+	if v, _ := reqParams.Value(1).GetBoolean(); v {
 		return result.NewBlock(block, s.chain), nil
 	}
 	writer := io.NewBufBinWriter()
@@ -508,11 +502,7 @@ func (s *Server) getBlock(reqParams request.Params) (interface{}, *response.Erro
 }
 
 func (s *Server) getBlockHash(reqParams request.Params) (interface{}, *response.Error) {
-	param := reqParams.ValueWithType(0, request.NumberT)
-	if param == nil {
-		return nil, response.ErrInvalidParams
-	}
-	num, err := s.blockHeightFromParam(param)
+	num, err := s.blockHeightFromParam(reqParams.Value(0))
 	if err != nil {
 		return nil, response.ErrInvalidParams
 	}
@@ -557,7 +547,7 @@ func (s *Server) getPeers(_ request.Params) (interface{}, *response.Error) {
 }
 
 func (s *Server) getRawMempool(reqParams request.Params) (interface{}, *response.Error) {
-	verbose := reqParams.Value(0).GetBoolean()
+	verbose, _ := reqParams.Value(0).GetBoolean()
 	mp := s.chain.GetMemPool()
 	hashList := make([]util.Uint256, 0)
 	for _, item := range mp.GetVerifiedTransactions() {
@@ -574,11 +564,15 @@ func (s *Server) getRawMempool(reqParams request.Params) (interface{}, *response
 }
 
 func (s *Server) validateAddress(reqParams request.Params) (interface{}, *response.Error) {
-	param := reqParams.Value(0)
-	if param == nil {
+	param, err := reqParams.Value(0).GetString()
+	if err != nil {
 		return nil, response.ErrInvalidParams
 	}
-	return validateAddress(param.Value), nil
+
+	return result.ValidateAddress{
+		Address: reqParams.Value(0),
+		IsValid: validateAddress(param),
+	}, nil
 }
 
 // calculateNetworkFee calculates network fee for the transaction.
@@ -669,11 +663,11 @@ func (s *Server) getApplicationLog(reqParams request.Params) (interface{}, *resp
 
 	trig := trigger.All
 	if len(reqParams) > 1 {
-		trigString := reqParams.ValueWithType(1, request.StringT)
-		if trigString == nil {
+		trigString, err := reqParams.Value(1).GetString()
+		if err != nil {
 			return nil, response.ErrInvalidParams
 		}
-		trig, err = trigger.FromString(trigString.String())
+		trig, err = trigger.FromString(trigString)
 		if err != nil {
 			return nil, response.ErrInvalidParams
 		}
@@ -902,19 +896,13 @@ func (s *Server) contractIDFromParam(param *request.Param) (int32, *response.Err
 	if param == nil {
 		return 0, response.ErrInvalidParams
 	}
-	switch param.Type {
-	case request.StringT:
-		var err error
-		scriptHash, err := param.GetUint160FromHex()
-		if err != nil {
-			return 0, response.ErrInvalidParams
-		}
+	if scriptHash, err := param.GetUint160FromHex(); err == nil {
 		cs := s.chain.GetContractState(scriptHash)
 		if cs == nil {
 			return 0, response.ErrUnknown
 		}
 		result = cs.ID
-	case request.NumberT:
+	} else {
 		id, err := param.GetInt()
 		if err != nil {
 			return 0, response.ErrInvalidParams
@@ -923,8 +911,6 @@ func (s *Server) contractIDFromParam(param *request.Param) (int32, *response.Err
 			return 0, response.WrapErrorWithData(response.ErrInvalidParams, err)
 		}
 		result = int32(id)
-	default:
-		return 0, response.ErrInvalidParams
 	}
 	return result, nil
 }
@@ -935,8 +921,7 @@ func (s *Server) contractScriptHashFromParam(param *request.Param) (util.Uint160
 	if param == nil {
 		return result, response.ErrInvalidParams
 	}
-	switch param.Type {
-	case request.StringT:
+	if _, err := param.GetStringStrict(); err == nil {
 		var err error
 		result, err = param.GetUint160FromAddressOrHex()
 		if err == nil {
@@ -950,7 +935,7 @@ func (s *Server) contractScriptHashFromParam(param *request.Param) (util.Uint160
 		if err != nil {
 			return result, response.NewRPCError("Unknown contract: querying by name is supported for native contracts only", "", nil)
 		}
-	case request.NumberT:
+	} else {
 		id, err := param.GetInt()
 		if err != nil {
 			return result, response.ErrInvalidParams
@@ -962,8 +947,6 @@ func (s *Server) contractScriptHashFromParam(param *request.Param) (util.Uint160
 		if err != nil {
 			return result, response.NewRPCError("Unknown contract", "", err)
 		}
-	default:
-		return result, response.ErrInvalidParams
 	}
 	return result, nil
 }
@@ -1244,7 +1227,7 @@ func (s *Server) getrawtransaction(reqParams request.Params) (interface{}, *resp
 		err = fmt.Errorf("invalid transaction %s: %w", txHash, err)
 		return nil, response.NewRPCError("Unknown transaction", err.Error(), err)
 	}
-	if reqParams.Value(1).GetBoolean() {
+	if v, _ := reqParams.Value(1).GetBoolean(); v {
 		if height == math.MaxUint32 {
 			return result.NewTransactionOutputRaw(tx, nil, nil, s.chain), nil
 		}
@@ -1299,12 +1282,7 @@ func (s *Server) getNativeContracts(_ request.Params) (interface{}, *response.Er
 
 // getBlockSysFee returns the system fees of the block, based on the specified index.
 func (s *Server) getBlockSysFee(reqParams request.Params) (interface{}, *response.Error) {
-	param := reqParams.ValueWithType(0, request.NumberT)
-	if param == nil {
-		return 0, response.ErrInvalidParams
-	}
-
-	num, err := s.blockHeightFromParam(param)
+	num, err := s.blockHeightFromParam(reqParams.Value(0))
 	if err != nil {
 		return 0, response.NewRPCError("Invalid height", "", nil)
 	}
@@ -1331,7 +1309,7 @@ func (s *Server) getBlockHeader(reqParams request.Params) (interface{}, *respons
 		return nil, respErr
 	}
 
-	verbose := reqParams.Value(1).GetBoolean()
+	verbose, _ := reqParams.Value(1).GetBoolean()
 	h, err := s.chain.GetHeader(hash)
 	if err != nil {
 		return nil, response.NewRPCError("unknown block", "", nil)
@@ -1351,7 +1329,7 @@ func (s *Server) getBlockHeader(reqParams request.Params) (interface{}, *respons
 
 // getUnclaimedGas returns unclaimed GAS amount of the specified address.
 func (s *Server) getUnclaimedGas(ps request.Params) (interface{}, *response.Error) {
-	u, err := ps.ValueWithType(0, request.StringT).GetUint160FromAddressOrHex()
+	u, err := ps.Value(0).GetUint160FromAddressOrHex()
 	if err != nil {
 		return nil, response.ErrInvalidParams
 	}
@@ -1423,7 +1401,11 @@ func (s *Server) invokeFunction(reqParams request.Params) (interface{}, *respons
 	if len(tx.Signers) == 0 {
 		tx.Signers = []transaction.Signer{{Account: util.Uint160{}, Scopes: transaction.None}}
 	}
-	script, err := request.CreateFunctionInvocationScript(scriptHash, reqParams[1].String(), reqParams[2:checkWitnessHashesIndex])
+	method, err := reqParams[1].GetString()
+	if err != nil {
+		return nil, response.ErrInvalidParams
+	}
+	script, err := request.CreateFunctionInvocationScript(scriptHash, method, reqParams[2:checkWitnessHashesIndex])
 	if err != nil {
 		return nil, response.NewInternalServerError("can't create invocation script", err)
 	}
@@ -1545,7 +1527,7 @@ func (s *Server) runScriptInVM(t trigger.Type, script []byte, contractScriptHash
 
 // submitBlock broadcasts a raw block over the NEO network.
 func (s *Server) submitBlock(reqParams request.Params) (interface{}, *response.Error) {
-	blockBytes, err := reqParams.ValueWithType(0, request.StringT).GetBytesBase64()
+	blockBytes, err := reqParams.Value(0).GetBytesBase64()
 	if err != nil {
 		return nil, response.NewInvalidParamsError("missing parameter or not base64", err)
 	}
@@ -1670,34 +1652,27 @@ func (s *Server) subscribe(reqParams request.Params, sub *subscriber) (interface
 	// Optional filter.
 	var filter interface{}
 	if p := reqParams.Value(1); p != nil {
-		param, ok := p.Value.(json.RawMessage)
-		if !ok {
-			return nil, response.ErrInvalidParams
-		}
-		jd := json.NewDecoder(bytes.NewReader(param))
+		param := *p
+		jd := json.NewDecoder(bytes.NewReader(param.RawMessage))
 		jd.DisallowUnknownFields()
 		switch event {
 		case response.BlockEventID:
 			flt := new(request.BlockFilter)
 			err = jd.Decode(flt)
-			p.Type = request.BlockFilterT
-			p.Value = *flt
+			filter = *flt
 		case response.TransactionEventID, response.NotaryRequestEventID:
 			flt := new(request.TxFilter)
 			err = jd.Decode(flt)
-			p.Type = request.TxFilterT
-			p.Value = *flt
+			filter = *flt
 		case response.NotificationEventID:
 			flt := new(request.NotificationFilter)
 			err = jd.Decode(flt)
-			p.Type = request.NotificationFilterT
-			p.Value = *flt
+			filter = *flt
 		case response.ExecutionEventID:
 			flt := new(request.ExecutionFilter)
 			err = jd.Decode(flt)
 			if err == nil && (flt.State == "HALT" || flt.State == "FAULT") {
-				p.Type = request.ExecutionFilterT
-				p.Value = *flt
+				filter = *flt
 			} else if err == nil {
 				err = errors.New("invalid state")
 			}
@@ -1705,7 +1680,6 @@ func (s *Server) subscribe(reqParams request.Params, sub *subscriber) (interface
 		if err != nil {
 			return nil, response.ErrInvalidParams
 		}
-		filter = p.Value
 	}
 
 	s.subsLock.Lock()
@@ -1937,7 +1911,7 @@ drainloop:
 func (s *Server) blockHeightFromParam(param *request.Param) (int, *response.Error) {
 	num, err := param.GetInt()
 	if err != nil {
-		return 0, nil
+		return 0, response.ErrInvalidParams
 	}
 
 	if num < 0 || num > int(s.chain.BlockHeight()) {
@@ -1971,10 +1945,8 @@ func (s *Server) logRequestError(r *request.Request, jsonErr *response.Error) {
 
 	if r.In != nil {
 		logFields = append(logFields, zap.String("method", r.In.Method))
-		params, err := r.In.Params()
-		if err == nil {
-			logFields = append(logFields, zap.Any("params", params))
-		}
+		params := request.Params(r.In.RawParams)
+		logFields = append(logFields, zap.Any("params", params))
 	}
 
 	s.log.Error("Error encountered with rpc request", logFields...)
@@ -2021,11 +1993,10 @@ func (s *Server) writeHTTPServerResponse(r *request.Request, w http.ResponseWrit
 
 // validateAddress verifies that the address is a correct NEO address
 // see https://docs.neo.org/en-us/node/cli/2.9.4/api/validateaddress.html
-func validateAddress(addr interface{}) result.ValidateAddress {
-	resp := result.ValidateAddress{Address: addr}
+func validateAddress(addr interface{}) bool {
 	if addr, ok := addr.(string); ok {
 		_, err := address.StringToUint160(addr)
-		resp.IsValid = (err == nil)
+		return err == nil
 	}
-	return resp
+	return false
 }
diff --git a/pkg/rpc/server/server_test.go b/pkg/rpc/server/server_test.go
index cd640ca35..af7c194f2 100644
--- a/pkg/rpc/server/server_test.go
+++ b/pkg/rpc/server/server_test.go
@@ -455,10 +455,6 @@ var rpcTestCases = map[string][]rpcTestCase{
 				return &v
 			},
 		},
-		{
-			params: "1",
-			fail:   true,
-		},
 	},
 	"getblock": {
 		{