diff --git a/cli/paramcontext/context.go b/cli/paramcontext/context.go
index 361af66fe..5ebfe9efc 100644
--- a/cli/paramcontext/context.go
+++ b/cli/paramcontext/context.go
@@ -12,14 +12,9 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/wallet"
 )
 
-// validUntilBlockIncrement is the number of extra blocks to add to an exported transaction.
-const validUntilBlockIncrement = 50
-
 // InitAndSave creates an incompletely signed transaction which can be used
 // as an input to `multisig sign`.
 func InitAndSave(net netmode.Magic, tx *transaction.Transaction, acc *wallet.Account, filename string) error {
-	// avoid fast transaction expiration
-	tx.ValidUntilBlock += validUntilBlockIncrement
 	priv := acc.PrivateKey()
 	pub := priv.PublicKey()
 	sign := priv.SignHashable(uint32(net), tx)
diff --git a/cli/smartcontract/smart_contract.go b/cli/smartcontract/smart_contract.go
index 642a576e7..ee81daeb9 100644
--- a/cli/smartcontract/smart_contract.go
+++ b/cli/smartcontract/smart_contract.go
@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"github.com/nspcc-dev/neo-go/cli/cmdargs"
 	"github.com/nspcc-dev/neo-go/cli/flags"
@@ -23,6 +24,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/encoding/fixedn"
 	"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient"
+	"github.com/nspcc-dev/neo-go/pkg/rpcclient/actor"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/nef"
@@ -663,6 +665,7 @@ func invokeWithArgs(ctx *cli.Context, acc *wallet.Account, wall *wallet.Wallet,
 		resp              *result.Invoke
 		sender            util.Uint160
 		signAndPush       = acc != nil
+		act               *actor.Actor
 	)
 	if signAndPush {
 		gas = flags.Fixed8FromContext(ctx, "gas")
@@ -683,75 +686,101 @@ func invokeWithArgs(ctx *cli.Context, acc *wallet.Account, wall *wallet.Wallet,
 	if err != nil {
 		return sender, err
 	}
-
+	if signAndPush {
+		// This will eventually be handled in cmdargs.GetSignersAccounts.
+		asa := make([]actor.SignerAccount, 0, len(cosigners)+1)
+		asa = append(asa, actor.SignerAccount{
+			Signer: transaction.Signer{
+				Account: sender,
+				Scopes:  transaction.None,
+			},
+			Account: acc,
+		})
+		for _, c := range cosignersAccounts {
+			if c.Signer.Account == sender {
+				asa[0].Signer = c.Signer
+				continue
+			}
+			asa = append(asa, actor.SignerAccount{
+				Signer:  c.Signer,
+				Account: c.Account,
+			})
+		}
+		act, err = actor.New(c, asa)
+		if err != nil {
+			return sender, cli.NewExitError(fmt.Errorf("failed to create RPC actor: %w", err), 1)
+		}
+	}
 	out := ctx.String("out")
+	// It's a bit easier to keep this as is (not using invoker.Invoker)
+	// during transition period. Mostly because of the need to convert params
+	// to []interface{}.
 	resp, err = c.InvokeFunction(script, operation, params, cosigners)
 	if err != nil {
 		return sender, cli.NewExitError(err, 1)
 	}
 	if resp.State != "HALT" {
 		errText := fmt.Sprintf("Warning: %s VM state returned from the RPC node: %s", resp.State, resp.FaultException)
-		if out == "" && !signAndPush {
+		if !signAndPush {
 			return sender, cli.NewExitError(errText, 1)
 		}
 
 		action := "save"
 		process := "Saving"
-		if signAndPush {
-			if out != "" {
-				action += "and send"
-				process += "and sending"
-			} else {
-				action = "send"
-				process = "Sending"
-			}
+		if out != "" {
+			action += "and send"
+			process += "and sending"
+		} else {
+			action = "send"
+			process = "Sending"
 		}
 		if !ctx.Bool("force") {
 			return sender, cli.NewExitError(errText+".\nUse --force flag to "+action+" the transaction anyway.", 1)
 		}
 		fmt.Fprintln(ctx.App.Writer, errText+".\n"+process+" transaction...")
 	}
-	if out != "" {
-		tx, err := c.CreateTxFromScript(resp.Script, acc, resp.GasConsumed+int64(sysgas), int64(gas), cosignersAccounts)
-		if err != nil {
-			return sender, cli.NewExitError(fmt.Errorf("failed to create tx: %w", err), 1)
-		}
-		m, err := c.GetNetwork()
-		if err != nil {
-			return sender, cli.NewExitError(fmt.Errorf("failed to save tx: %w", err), 1)
-		}
-		if err := paramcontext.InitAndSave(m, tx, acc, out); err != nil {
-			return sender, cli.NewExitError(err, 1)
-		}
-		fmt.Fprintln(ctx.App.Writer, tx.Hash().StringLE())
-		return sender, nil
-	}
-	if signAndPush {
-		if len(resp.Script) == 0 {
-			return sender, cli.NewExitError(errors.New("no script returned from the RPC node"), 1)
-		}
-		tx, err := c.CreateTxFromScript(resp.Script, acc, resp.GasConsumed+int64(sysgas), int64(gas), cosignersAccounts)
-		if err != nil {
-			return sender, cli.NewExitError(fmt.Errorf("failed to create tx: %w", err), 1)
-		}
-		if !ctx.Bool("force") {
-			err := input.ConfirmTx(ctx.App.Writer, tx)
-			if err != nil {
-				return sender, cli.NewExitError(err, 1)
-			}
-		}
-		txHash, err := c.SignAndPushTx(tx, acc, cosignersAccounts)
-		if err != nil {
-			return sender, cli.NewExitError(fmt.Errorf("failed to push invocation tx: %w", err), 1)
-		}
-		fmt.Fprintf(ctx.App.Writer, "Sent invocation transaction %s\n", txHash.StringLE())
-	} else {
+	if !signAndPush {
 		b, err := json.MarshalIndent(resp, "", "  ")
 		if err != nil {
 			return sender, cli.NewExitError(err, 1)
 		}
 
 		fmt.Fprintln(ctx.App.Writer, string(b))
+	} else {
+		if len(resp.Script) == 0 {
+			return sender, cli.NewExitError(errors.New("no script returned from the RPC node"), 1)
+		}
+		ver := act.GetVersion()
+		tx, err := act.MakeUnsignedUncheckedRun(resp.Script, resp.GasConsumed+int64(sysgas), nil)
+		if err != nil {
+			return sender, cli.NewExitError(fmt.Errorf("failed to create tx: %w", err), 1)
+		}
+		tx.NetworkFee += int64(gas)
+		if out != "" {
+			// Make a long-lived transaction, it's to be signed manually.
+			tx.ValidUntilBlock += (ver.Protocol.MaxValidUntilBlockIncrement - uint32(ver.Protocol.ValidatorsCount)) - 2
+			m := act.GetNetwork()
+			if err := paramcontext.InitAndSave(m, tx, acc, out); err != nil {
+				return sender, cli.NewExitError(err, 1)
+			}
+			fmt.Fprintln(ctx.App.Writer, tx.Hash().StringLE())
+		} else {
+			if !ctx.Bool("force") {
+				promptTime := time.Now()
+				err := input.ConfirmTx(ctx.App.Writer, tx)
+				if err != nil {
+					return sender, cli.NewExitError(err, 1)
+				}
+				waitTime := time.Since(promptTime)
+				// Compensate for confirmation waiting.
+				tx.ValidUntilBlock += uint32((waitTime.Milliseconds() / int64(ver.Protocol.MillisecondsPerBlock))) + 1
+			}
+			txHash, _, err := act.SignAndSend(tx)
+			if err != nil {
+				return sender, cli.NewExitError(fmt.Errorf("failed to push invocation tx: %w", err), 1)
+			}
+			fmt.Fprintf(ctx.App.Writer, "Sent invocation transaction %s\n", txHash.StringLE())
+		}
 	}
 
 	return sender, nil
diff --git a/cli/wallet/nep11.go b/cli/wallet/nep11.go
index 4be67dc5c..82154e056 100644
--- a/cli/wallet/nep11.go
+++ b/cli/wallet/nep11.go
@@ -280,6 +280,12 @@ func signAndSendNEP11Transfer(ctx *cli.Context, c *rpcclient.Client, acc *wallet
 	tx.SystemFee += int64(sysgas)
 
 	if outFile := ctx.String("out"); outFile != "" {
+		ver, err := c.GetVersion()
+		if err != nil {
+			return cli.NewExitError(fmt.Errorf("RPC failure: %w", err), 1)
+		}
+		// Make a long-lived transaction, it's to be signed manually.
+		tx.ValidUntilBlock += (ver.Protocol.MaxValidUntilBlockIncrement - uint32(ver.Protocol.ValidatorsCount)) - 2
 		m, err := c.GetNetwork()
 		if err != nil {
 			return cli.NewExitError(fmt.Errorf("failed to save tx: %w", err), 1)
@@ -294,7 +300,7 @@ func signAndSendNEP11Transfer(ctx *cli.Context, c *rpcclient.Client, acc *wallet
 				return cli.NewExitError(err, 1)
 			}
 		}
-		_, err := c.SignAndPushTx(tx, acc, cosigners)
+		_, err := c.SignAndPushTx(tx, acc, cosigners) //nolint:staticcheck // SA1019: c.SignAndPushTx is deprecated
 		if err != nil {
 			return cli.NewExitError(err, 1)
 		}
diff --git a/cli/wallet/nep17.go b/cli/wallet/nep17.go
index 948574809..43ff8d418 100644
--- a/cli/wallet/nep17.go
+++ b/cli/wallet/nep17.go
@@ -659,6 +659,12 @@ func signAndSendNEP17Transfer(ctx *cli.Context, c *rpcclient.Client, acc *wallet
 	tx.SystemFee += int64(sysgas)
 
 	if outFile := ctx.String("out"); outFile != "" {
+		ver, err := c.GetVersion()
+		if err != nil {
+			return cli.NewExitError(fmt.Errorf("RPC failure: %w", err), 1)
+		}
+		// Make a long-lived transaction, it's to be signed manually.
+		tx.ValidUntilBlock += (ver.Protocol.MaxValidUntilBlockIncrement - uint32(ver.Protocol.ValidatorsCount)) - 2
 		m, err := c.GetNetwork()
 		if err != nil {
 			return cli.NewExitError(fmt.Errorf("failed to save tx: %w", err), 1)
@@ -673,7 +679,7 @@ func signAndSendNEP17Transfer(ctx *cli.Context, c *rpcclient.Client, acc *wallet
 				return cli.NewExitError(err, 1)
 			}
 		}
-		_, err := c.SignAndPushTx(tx, acc, cosigners)
+		_, err := c.SignAndPushTx(tx, acc, cosigners) //nolint:staticcheck // SA1019: c.SignAndPushTx is deprecated
 		if err != nil {
 			return cli.NewExitError(err, 1)
 		}
diff --git a/cli/wallet/validator.go b/cli/wallet/validator.go
index 649545691..5f6a5aeb7 100644
--- a/cli/wallet/validator.go
+++ b/cli/wallet/validator.go
@@ -127,7 +127,7 @@ func handleCandidate(ctx *cli.Context, method string, sysGas int64) error {
 	if err != nil {
 		return cli.NewExitError(err, 1)
 	}
-	res, err := c.SignAndPushInvocationTx(script, acc, sysGas, gas, []rpcclient.SignerAccount{{
+	res, err := c.SignAndPushInvocationTx(script, acc, sysGas, gas, []rpcclient.SignerAccount{{ //nolint:staticcheck // SA1019: c.SignAndPushInvocationTx is deprecated
 		Signer: transaction.Signer{
 			Account: acc.Contract.ScriptHash(),
 			Scopes:  transaction.CalledByEntry,
@@ -191,7 +191,7 @@ func handleVote(ctx *cli.Context) error {
 	if err != nil {
 		return cli.NewExitError(err, 1)
 	}
-	res, err := c.SignAndPushInvocationTx(script, acc, -1, gas, []rpcclient.SignerAccount{{
+	res, err := c.SignAndPushInvocationTx(script, acc, -1, gas, []rpcclient.SignerAccount{{ //nolint:staticcheck // SA1019: c.SignAndPushInvocationTx is deprecated
 		Signer: transaction.Signer{
 			Account: acc.Contract.ScriptHash(),
 			Scopes:  transaction.CalledByEntry,
diff --git a/docs/rpc.md b/docs/rpc.md
index 1872ccfa3..a894a93f9 100644
--- a/docs/rpc.md
+++ b/docs/rpc.md
@@ -162,6 +162,15 @@ latest state synchronization point P the node working against,
 `LastUpdatedBlock` equals P. For NEP-11 NFTs `LastUpdatedBlock` is equal for
 all tokens of the same asset.
 
+##### `getversion`
+
+NeoGo can return additional fields in the `protocol` object depending on the
+extensions enabled. Specifically that's `p2psigextensions` and
+`staterootinheader` booleans and `committeehistory` and `validatorshistory`
+objects (that are effectively maps from stringified integers to other
+integers. These fields are only returned when corresponding settings are
+enabled in the server's protocol configuration.
+
 ##### `getnep11transfers` and `getnep17transfers`
 `transfernotifyindex` is not tracked by NeoGo, thus this field is always zero.
 
diff --git a/pkg/neorpc/result/version.go b/pkg/neorpc/result/version.go
index e1f3b49e6..9f9102949 100644
--- a/pkg/neorpc/result/version.go
+++ b/pkg/neorpc/result/version.go
@@ -39,8 +39,18 @@ type (
 		MemoryPoolMaxTransactions   int
 		ValidatorsCount             byte
 		InitialGasDistribution      fixedn.Fixed8
+
+		// Below are NeoGo-specific extensions to the protocol that are
+		// returned by the server in case they're enabled.
+
+		// CommitteeHistory stores height:size map of the committee size.
+		CommitteeHistory map[uint32]int
+		// P2PSigExtensions is true when Notary subsystem is enabled on the network.
+		P2PSigExtensions bool
 		// StateRootInHeader is true if state root is contained in block header.
 		StateRootInHeader bool
+		// ValidatorsHistory stores height:size map of the validators count.
+		ValidatorsHistory map[uint32]int
 	}
 )
 
@@ -67,7 +77,11 @@ type (
 		MemoryPoolMaxTransactions   int           `json:"memorypoolmaxtransactions"`
 		ValidatorsCount             byte          `json:"validatorscount"`
 		InitialGasDistribution      int64         `json:"initialgasdistribution"`
-		StateRootInHeader           bool          `json:"staterootinheader,omitempty"`
+
+		CommitteeHistory  map[uint32]int `json:"committeehistory,omitempty"`
+		P2PSigExtensions  bool           `json:"p2psigextensions,omitempty"`
+		StateRootInHeader bool           `json:"staterootinheader,omitempty"`
+		ValidatorsHistory map[uint32]int `json:"validatorshistory,omitempty"`
 	}
 
 	// versionUnmarshallerAux is an auxiliary struct used for Version JSON unmarshalling.
@@ -92,7 +106,11 @@ type (
 		MemoryPoolMaxTransactions   int             `json:"memorypoolmaxtransactions"`
 		ValidatorsCount             byte            `json:"validatorscount"`
 		InitialGasDistribution      json.RawMessage `json:"initialgasdistribution"`
-		StateRootInHeader           bool            `json:"staterootinheader,omitempty"`
+
+		CommitteeHistory  map[uint32]int `json:"committeehistory,omitempty"`
+		P2PSigExtensions  bool           `json:"p2psigextensions,omitempty"`
+		StateRootInHeader bool           `json:"staterootinheader,omitempty"`
+		ValidatorsHistory map[uint32]int `json:"validatorshistory,omitempty"`
 	}
 )
 
@@ -118,7 +136,11 @@ func (v *Version) MarshalJSON() ([]byte, error) {
 			MemoryPoolMaxTransactions:   v.Protocol.MemoryPoolMaxTransactions,
 			ValidatorsCount:             v.Protocol.ValidatorsCount,
 			InitialGasDistribution:      int64(v.Protocol.InitialGasDistribution),
-			StateRootInHeader:           v.Protocol.StateRootInHeader,
+
+			CommitteeHistory:  v.Protocol.CommitteeHistory,
+			P2PSigExtensions:  v.Protocol.P2PSigExtensions,
+			StateRootInHeader: v.Protocol.StateRootInHeader,
+			ValidatorsHistory: v.Protocol.ValidatorsHistory,
 		},
 		StateRootInHeader: v.StateRootInHeader,
 	}
@@ -145,7 +167,10 @@ func (v *Version) UnmarshalJSON(data []byte) error {
 	v.Protocol.MaxTransactionsPerBlock = aux.Protocol.MaxTransactionsPerBlock
 	v.Protocol.MemoryPoolMaxTransactions = aux.Protocol.MemoryPoolMaxTransactions
 	v.Protocol.ValidatorsCount = aux.Protocol.ValidatorsCount
+	v.Protocol.CommitteeHistory = aux.Protocol.CommitteeHistory
+	v.Protocol.P2PSigExtensions = aux.Protocol.P2PSigExtensions
 	v.Protocol.StateRootInHeader = aux.Protocol.StateRootInHeader
+	v.Protocol.ValidatorsHistory = aux.Protocol.ValidatorsHistory
 	v.StateRootInHeader = aux.StateRootInHeader
 	if len(aux.Protocol.InitialGasDistribution) == 0 {
 		return nil
diff --git a/pkg/rpcclient/actor/actor.go b/pkg/rpcclient/actor/actor.go
new file mode 100644
index 000000000..abf79530f
--- /dev/null
+++ b/pkg/rpcclient/actor/actor.go
@@ -0,0 +1,204 @@
+/*
+Package actor provides a way to change chain state via RPC client.
+
+This layer builds on top of the basic RPC client and simplifies creating,
+signing and sending transactions to the network (since that's the only way chain
+state is changed). It's generic enough to be used for any contract that you may
+want to invoke and contract-specific functions can build on top of it.
+*/
+package actor
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
+	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
+	"github.com/nspcc-dev/neo-go/pkg/rpcclient/invoker"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neo-go/pkg/wallet"
+)
+
+// RPCActor is an interface required from the RPC client to successfully
+// create and send transactions.
+type RPCActor interface {
+	invoker.RPCInvoke
+
+	CalculateNetworkFee(tx *transaction.Transaction) (int64, error)
+	GetBlockCount() (uint32, error)
+	GetVersion() (*result.Version, error)
+	SendRawTransaction(tx *transaction.Transaction) (util.Uint256, error)
+}
+
+// SignerAccount represents combination of the transaction.Signer and the
+// corresponding wallet.Account. It's used to create and sign transactions, each
+// transaction has a set of signers that must witness the transaction with their
+// signatures.
+type SignerAccount struct {
+	Signer  transaction.Signer
+	Account *wallet.Account
+}
+
+// Actor keeps a connection to the RPC endpoint and allows to perform
+// state-changing actions (via transactions that can also be created without
+// sending them to the network) on behalf of a set of signers. It also provides
+// an Invoker interface to perform test calls with the same set of signers.
+type Actor struct {
+	invoker.Invoker
+
+	client    RPCActor
+	signers   []SignerAccount
+	txSigners []transaction.Signer
+	version   *result.Version
+}
+
+// New creates an Actor instance using the specified RPC interface and the set of
+// signers with corresponding accounts. Every transaction created by this Actor
+// will have this set of signers and all communication will be performed via this
+// RPC. Upon Actor instance creation a GetVersion call is made and the result of
+// it is cached forever (and used for internal purposes).
+func New(ra RPCActor, signers []SignerAccount) (*Actor, error) {
+	if len(signers) < 1 {
+		return nil, errors.New("at least one signer (sender) is required")
+	}
+	invSigners := make([]transaction.Signer, len(signers))
+	for i := range signers {
+		if signers[i].Account.Contract == nil {
+			return nil, fmt.Errorf("empty contract for account %s", signers[i].Account.Address)
+		}
+		if !signers[i].Account.Contract.Deployed && signers[i].Account.Contract.ScriptHash() != signers[i].Signer.Account {
+			return nil, fmt.Errorf("signer account doesn't match script hash for signer %s", signers[i].Account.Address)
+		}
+
+		invSigners[i] = signers[i].Signer
+	}
+	inv := invoker.New(ra, invSigners)
+	version, err := ra.GetVersion()
+	if err != nil {
+		return nil, err
+	}
+	return &Actor{
+		Invoker:   *inv,
+		client:    ra,
+		signers:   signers,
+		txSigners: invSigners,
+		version:   version,
+	}, nil
+}
+
+// NewSimple makes it easier to create an Actor for the most widespread case
+// when transactions have only one signer that uses CalledByEntry scope. When
+// other scopes or multiple signers are needed use New.
+func NewSimple(ra RPCActor, acc *wallet.Account) (*Actor, error) {
+	return New(ra, []SignerAccount{{
+		Signer: transaction.Signer{
+			Account: acc.Contract.ScriptHash(),
+			Scopes:  transaction.CalledByEntry,
+		},
+		Account: acc,
+	}})
+}
+
+// CalculateNetworkFee wraps RPCActor's CalculateNetworkFee, making it available
+// to Actor users directly. It returns network fee value for the given
+// transaction.
+func (a *Actor) CalculateNetworkFee(tx *transaction.Transaction) (int64, error) {
+	return a.client.CalculateNetworkFee(tx)
+}
+
+// GetBlockCount wraps RPCActor's GetBlockCount, making it available to
+// Actor users directly. It returns current number of blocks in the chain.
+func (a *Actor) GetBlockCount() (uint32, error) {
+	return a.client.GetBlockCount()
+}
+
+// GetNetwork is a convenience method that returns the network's magic number.
+func (a *Actor) GetNetwork() netmode.Magic {
+	return a.version.Protocol.Network
+}
+
+// GetVersion returns version data from the RPC endpoint.
+func (a *Actor) GetVersion() result.Version {
+	return *a.version
+}
+
+// Send allows to send arbitrary prepared transaction to the network. It returns
+// transaction hash and ValidUntilBlock value.
+func (a *Actor) Send(tx *transaction.Transaction) (util.Uint256, uint32, error) {
+	h, err := a.client.SendRawTransaction(tx)
+	return h, tx.ValidUntilBlock, err
+}
+
+// Sign adds signatures to arbitrary transaction using Actor signers wallets.
+// Most of the time it shouldn't be used directly since it'll be successful only
+// if the transaction is made using the same set of accounts as the one used
+// for Actor creation.
+func (a *Actor) Sign(tx *transaction.Transaction) error {
+	if len(tx.Signers) != len(a.signers) {
+		return errors.New("incorrect number of signers in the transaction")
+	}
+	for i, signer := range a.signers {
+		err := signer.Account.SignTx(a.GetNetwork(), tx)
+		if err != nil { // then account is non-contract-based and locked, but let's provide more detailed error
+			if paramNum := len(signer.Account.Contract.Parameters); paramNum != 0 && signer.Account.Contract.Deployed {
+				return fmt.Errorf("failed to add contract-based witness for signer #%d (%s): "+
+					"%d parameters must be provided to construct invocation script", i, signer.Account.Address, paramNum)
+			}
+			return fmt.Errorf("failed to add witness for signer #%d (%s): account should be unlocked to add the signature. "+
+				"Store partially-signed transaction and then use 'wallet sign' command to cosign it", i, signer.Account.Address)
+		}
+	}
+	return nil
+}
+
+// SignAndSend signs arbitrary transaction (see also Sign) and sends it to the
+// network.
+func (a *Actor) SignAndSend(tx *transaction.Transaction) (util.Uint256, uint32, error) {
+	return a.sendWrapper(tx, a.Sign(tx))
+}
+
+// sendWrapper simplifies wrapping methods that create transactions.
+func (a *Actor) sendWrapper(tx *transaction.Transaction, err error) (util.Uint256, uint32, error) {
+	if err != nil {
+		return util.Uint256{}, 0, err
+	}
+	return a.Send(tx)
+}
+
+// SendCall creates a transaction that calls the given method of the given
+// contract with the given parameters (see also MakeCall) and sends it to the
+// network.
+func (a *Actor) SendCall(contract util.Uint160, method string, params ...interface{}) (util.Uint256, uint32, error) {
+	return a.sendWrapper(a.MakeCall(contract, method, params...))
+}
+
+// SendTunedCall creates a transaction that calls the given method of the given
+// contract with the given parameters (see also MakeTunedCall) and attributes,
+// allowing to check for execution results of this call and modify transaction
+// before it's signed; this transaction is then sent to the network.
+func (a *Actor) SendTunedCall(contract util.Uint160, method string, attrs []transaction.Attribute, txHook TransactionCheckerModifier, params ...interface{}) (util.Uint256, uint32, error) {
+	return a.sendWrapper(a.MakeTunedCall(contract, method, attrs, txHook, params...))
+}
+
+// SendRun creates a transaction with the given executable script (see also
+// MakeRun) and sends it to the network.
+func (a *Actor) SendRun(script []byte) (util.Uint256, uint32, error) {
+	return a.sendWrapper(a.MakeRun(script))
+}
+
+// SendTunedRun creates a transaction with the given executable script and
+// attributes, allowing to check for execution results of this script and modify
+// transaction before it's signed (see also MakeTunedRun). This transaction is
+// then sent to the network.
+func (a *Actor) SendTunedRun(script []byte, attrs []transaction.Attribute, txHook TransactionCheckerModifier) (util.Uint256, uint32, error) {
+	return a.sendWrapper(a.MakeTunedRun(script, attrs, txHook))
+}
+
+// SendUncheckedRun creates a transaction with the given executable script and
+// attributes that can use up to sysfee GAS for its execution, allowing to modify
+// this transaction before it's signed (see also MakeUncheckedRun). This
+// transaction is then sent to the network.
+func (a *Actor) SendUncheckedRun(script []byte, sysfee int64, attrs []transaction.Attribute, txHook TransactionModifier) (util.Uint256, uint32, error) {
+	return a.sendWrapper(a.MakeUncheckedRun(script, sysfee, attrs, txHook))
+}
diff --git a/pkg/rpcclient/actor/actor_test.go b/pkg/rpcclient/actor/actor_test.go
new file mode 100644
index 000000000..46cdd3906
--- /dev/null
+++ b/pkg/rpcclient/actor/actor_test.go
@@ -0,0 +1,254 @@
+package actor
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
+	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neo-go/pkg/wallet"
+	"github.com/stretchr/testify/require"
+)
+
+type RPCClient struct {
+	err     error
+	invRes  *result.Invoke
+	netFee  int64
+	bCount  uint32
+	version *result.Version
+	hash    util.Uint256
+}
+
+func (r *RPCClient) InvokeContractVerify(contract util.Uint160, params []smartcontract.Parameter, signers []transaction.Signer, witnesses ...transaction.Witness) (*result.Invoke, error) {
+	return r.invRes, r.err
+}
+func (r *RPCClient) InvokeFunction(contract util.Uint160, operation string, params []smartcontract.Parameter, signers []transaction.Signer) (*result.Invoke, error) {
+	return r.invRes, r.err
+}
+func (r *RPCClient) InvokeScript(script []byte, signers []transaction.Signer) (*result.Invoke, error) {
+	return r.invRes, r.err
+}
+func (r *RPCClient) CalculateNetworkFee(tx *transaction.Transaction) (int64, error) {
+	return r.netFee, r.err
+}
+func (r *RPCClient) GetBlockCount() (uint32, error) {
+	return r.bCount, r.err
+}
+func (r *RPCClient) GetVersion() (*result.Version, error) {
+	verCopy := *r.version
+	return &verCopy, r.err
+}
+func (r *RPCClient) SendRawTransaction(tx *transaction.Transaction) (util.Uint256, error) {
+	return r.hash, r.err
+}
+
+func testRPCAndAccount(t *testing.T) (*RPCClient, *wallet.Account) {
+	client := &RPCClient{
+		version: &result.Version{
+			Protocol: result.Protocol{
+				Network:              netmode.UnitTestNet,
+				MillisecondsPerBlock: 1000,
+				ValidatorsCount:      7,
+			},
+		},
+	}
+	acc, err := wallet.NewAccount()
+	require.NoError(t, err)
+	return client, acc
+}
+
+func TestNew(t *testing.T) {
+	client, acc := testRPCAndAccount(t)
+
+	// No signers.
+	_, err := New(client, nil)
+	require.Error(t, err)
+
+	_, err = New(client, []SignerAccount{})
+	require.Error(t, err)
+
+	// Good simple.
+	a, err := NewSimple(client, acc)
+	require.NoError(t, err)
+	require.Equal(t, 1, len(a.signers))
+	require.Equal(t, 1, len(a.txSigners))
+	require.Equal(t, transaction.CalledByEntry, a.signers[0].Signer.Scopes)
+	require.Equal(t, transaction.CalledByEntry, a.txSigners[0].Scopes)
+
+	// Contractless account.
+	badAcc, err := wallet.NewAccount()
+	require.NoError(t, err)
+	badAccHash := badAcc.Contract.ScriptHash()
+	badAcc.Contract = nil
+
+	signers := []SignerAccount{{
+		Signer: transaction.Signer{
+			Account: acc.Contract.ScriptHash(),
+			Scopes:  transaction.None,
+		},
+		Account: acc,
+	}, {
+		Signer: transaction.Signer{
+			Account: badAccHash,
+			Scopes:  transaction.CalledByEntry,
+		},
+		Account: badAcc,
+	}}
+
+	_, err = New(client, signers)
+	require.Error(t, err)
+
+	// GetVersion returning error.
+	client.err = errors.New("bad")
+	_, err = NewSimple(client, acc)
+	require.Error(t, err)
+	client.err = nil
+
+	// Account mismatch.
+	acc2, err := wallet.NewAccount()
+	require.NoError(t, err)
+	signers = []SignerAccount{{
+		Signer: transaction.Signer{
+			Account: acc2.Contract.ScriptHash(),
+			Scopes:  transaction.None,
+		},
+		Account: acc,
+	}, {
+		Signer: transaction.Signer{
+			Account: acc2.Contract.ScriptHash(),
+			Scopes:  transaction.CalledByEntry,
+		},
+		Account: acc2,
+	}}
+	_, err = New(client, signers)
+	require.Error(t, err)
+
+	// Good multiaccount.
+	signers[0].Signer.Account = acc.Contract.ScriptHash()
+	a, err = New(client, signers)
+	require.NoError(t, err)
+	require.Equal(t, 2, len(a.signers))
+	require.Equal(t, 2, len(a.txSigners))
+}
+
+func TestSimpleWrappers(t *testing.T) {
+	client, acc := testRPCAndAccount(t)
+	origVer := *client.version
+
+	a, err := NewSimple(client, acc)
+	require.NoError(t, err)
+
+	client.netFee = 42
+	nf, err := a.CalculateNetworkFee(new(transaction.Transaction))
+	require.NoError(t, err)
+	require.Equal(t, int64(42), nf)
+
+	client.bCount = 100500
+	bc, err := a.GetBlockCount()
+	require.NoError(t, err)
+	require.Equal(t, uint32(100500), bc)
+
+	require.Equal(t, netmode.UnitTestNet, a.GetNetwork())
+	client.version.Protocol.Network = netmode.TestNet
+	require.Equal(t, netmode.UnitTestNet, a.GetNetwork())
+	require.Equal(t, origVer, a.GetVersion())
+
+	a, err = NewSimple(client, acc)
+	require.NoError(t, err)
+	require.Equal(t, netmode.TestNet, a.GetNetwork())
+	require.Equal(t, *client.version, a.GetVersion())
+
+	client.hash = util.Uint256{1, 2, 3}
+	h, vub, err := a.Send(&transaction.Transaction{ValidUntilBlock: 123})
+	require.NoError(t, err)
+	require.Equal(t, client.hash, h)
+	require.Equal(t, uint32(123), vub)
+}
+
+func TestSign(t *testing.T) {
+	client, acc := testRPCAndAccount(t)
+	acc2, err := wallet.NewAccount()
+	require.NoError(t, err)
+
+	a, err := New(client, []SignerAccount{{
+		Signer: transaction.Signer{
+			Account: acc.Contract.ScriptHash(),
+			Scopes:  transaction.None,
+		},
+		Account: acc,
+	}, {
+		Signer: transaction.Signer{
+			Account: acc2.Contract.ScriptHash(),
+			Scopes:  transaction.CalledByEntry,
+		},
+		Account: &wallet.Account{ // Looks like acc2, but has no private key.
+			Address:      acc2.Address,
+			EncryptedWIF: acc2.EncryptedWIF,
+			Contract:     acc2.Contract,
+		},
+	}})
+	require.NoError(t, err)
+
+	script := []byte{1, 2, 3}
+	client.hash = util.Uint256{2, 5, 6}
+	client.invRes = &result.Invoke{State: "HALT", GasConsumed: 3, Script: script}
+
+	tx, err := a.MakeUnsignedRun(script, nil)
+	require.NoError(t, err)
+	require.Error(t, a.Sign(tx))
+	_, _, err = a.SignAndSend(tx)
+	require.Error(t, err)
+}
+
+func TestSenders(t *testing.T) {
+	client, acc := testRPCAndAccount(t)
+	a, err := NewSimple(client, acc)
+	require.NoError(t, err)
+	script := []byte{1, 2, 3}
+
+	// Bad.
+	client.invRes = &result.Invoke{State: "FAULT", GasConsumed: 3, Script: script}
+	_, _, err = a.SendCall(util.Uint160{1}, "method", 42)
+	require.Error(t, err)
+	_, _, err = a.SendTunedCall(util.Uint160{1}, "method", nil, nil, 42)
+	require.Error(t, err)
+	_, _, err = a.SendRun(script)
+	require.Error(t, err)
+	_, _, err = a.SendTunedRun(script, nil, nil)
+	require.Error(t, err)
+	_, _, err = a.SendUncheckedRun(script, 1, nil, func(t *transaction.Transaction) error {
+		return errors.New("bad")
+	})
+	require.Error(t, err)
+
+	// Good.
+	client.hash = util.Uint256{2, 5, 6}
+	client.invRes = &result.Invoke{State: "HALT", GasConsumed: 3, Script: script}
+	h, vub, err := a.SendCall(util.Uint160{1}, "method", 42)
+	require.NoError(t, err)
+	require.Equal(t, client.hash, h)
+	require.Equal(t, uint32(8), vub)
+
+	h, vub, err = a.SendTunedCall(util.Uint160{1}, "method", nil, nil, 42)
+	require.NoError(t, err)
+	require.Equal(t, client.hash, h)
+	require.Equal(t, uint32(8), vub)
+
+	h, vub, err = a.SendRun(script)
+	require.NoError(t, err)
+	require.Equal(t, client.hash, h)
+	require.Equal(t, uint32(8), vub)
+
+	h, vub, err = a.SendTunedRun(script, nil, nil)
+	require.NoError(t, err)
+	require.Equal(t, client.hash, h)
+	require.Equal(t, uint32(8), vub)
+
+	h, vub, err = a.SendUncheckedRun(script, 1, nil, nil)
+	require.NoError(t, err)
+	require.Equal(t, client.hash, h)
+	require.Equal(t, uint32(8), vub)
+}
diff --git a/pkg/rpcclient/actor/maker.go b/pkg/rpcclient/actor/maker.go
new file mode 100644
index 000000000..392a84391
--- /dev/null
+++ b/pkg/rpcclient/actor/maker.go
@@ -0,0 +1,204 @@
+package actor
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neo-go/pkg/vm/vmstate"
+)
+
+// TransactionCheckerModifier is a callback that receives the result of
+// test-invocation and the transaction that can perform the same invocation
+// on chain. This callback is accepted by methods that create transactions, it
+// can examine both arguments and return an error if there is anything wrong
+// there which will abort the creation process. Notice that when used this
+// callback is completely responsible for invocation result checking, including
+// checking for HALT execution state (so if you don't check for it in a callback
+// you can send a transaction that is known to end up in FAULT state). It can
+// also modify the transaction (see TransactionModifier).
+type TransactionCheckerModifier func(r *result.Invoke, t *transaction.Transaction) error
+
+// TransactionModifier is a callback that receives the transaction before
+// it's signed from a method that creates signed transactions. It can check
+// fees and other fields of the transaction and return an error if there is
+// anything wrong there which will abort the creation process. It also can modify
+// Nonce, SystemFee, NetworkFee and ValidUntilBlock values taking full
+// responsibility on the effects of these modifications (smaller fee values, too
+// low or too high ValidUntilBlock or bad Nonce can render transaction invalid).
+// Modifying other fields is not supported. Mostly it's useful for increasing
+// fee values since by default they're just enough for transaction to be
+// successfully accepted and executed.
+type TransactionModifier func(t *transaction.Transaction) error
+
+// MakeCall creates a transaction that calls the given method of the given
+// contract with the given parameters. Test call is performed and checked for
+// HALT status, if more checks are needed or transaction should have some
+// additional attributes use MakeTunedCall.
+func (a *Actor) MakeCall(contract util.Uint160, method string, params ...interface{}) (*transaction.Transaction, error) {
+	return a.MakeTunedCall(contract, method, nil, nil, params...)
+}
+
+// MakeTunedCall creates a transaction with the given attributes that calls the
+// given method of the given contract with the given parameters. It's filtered
+// through the provided callback (see TransactionCheckerModifier documentation),
+// so the process can be aborted and transaction can be modified before signing.
+// If no callback is given then the result is checked for HALT state.
+func (a *Actor) MakeTunedCall(contract util.Uint160, method string, attrs []transaction.Attribute, txHook TransactionCheckerModifier, params ...interface{}) (*transaction.Transaction, error) {
+	r, err := a.Call(contract, method, params...)
+	return a.makeUncheckedWrapper(r, err, attrs, txHook)
+}
+
+// MakeRun creates a transaction with the given executable script. Test
+// invocation of this script is performed and expected to end up in HALT
+// state. If more checks are needed or transaction should have some additional
+// attributes use MakeTunedRun.
+func (a *Actor) MakeRun(script []byte) (*transaction.Transaction, error) {
+	return a.MakeTunedRun(script, nil, nil)
+}
+
+// MakeTunedRun creates a transaction with the given attributes that executes
+// the given script. It's filtered through the provided callback (see
+// TransactionCheckerModifier documentation), so the process can be aborted and
+// transaction can be modified before signing. If no callback is given then the
+// result is checked for HALT state.
+func (a *Actor) MakeTunedRun(script []byte, attrs []transaction.Attribute, txHook TransactionCheckerModifier) (*transaction.Transaction, error) {
+	r, err := a.Run(script)
+	return a.makeUncheckedWrapper(r, err, attrs, txHook)
+}
+
+func (a *Actor) makeUncheckedWrapper(r *result.Invoke, err error, attrs []transaction.Attribute, txHook TransactionCheckerModifier) (*transaction.Transaction, error) {
+	if err != nil {
+		return nil, fmt.Errorf("test invocation failed: %w", err)
+	}
+	return a.MakeUncheckedRun(r.Script, r.GasConsumed, attrs, func(tx *transaction.Transaction) error {
+		if txHook == nil {
+			if r.State != vmstate.Halt.String() {
+				return fmt.Errorf("script failed (%s state) due to an error: %s", r.State, r.FaultException)
+			}
+			return nil
+		}
+		return txHook(r, tx)
+	})
+}
+
+// MakeUncheckedRun creates a transaction with the given attributes that executes
+// the given script and is expected to use up to sysfee GAS for its execution.
+// The transaction is filtered through the provided callback (see
+// TransactionModifier documentation), so the process can be aborted and
+// transaction can be modified before signing. This method is mostly useful when
+// test invocation is already performed and the script and required system fee
+// values are already known.
+func (a *Actor) MakeUncheckedRun(script []byte, sysfee int64, attrs []transaction.Attribute, txHook TransactionModifier) (*transaction.Transaction, error) {
+	tx, err := a.MakeUnsignedUncheckedRun(script, sysfee, attrs)
+	if err != nil {
+		return nil, err
+	}
+	if txHook != nil {
+		err = txHook(tx)
+		if err != nil {
+			return nil, err
+		}
+	}
+	err = a.Sign(tx)
+	if err != nil {
+		return nil, err
+	}
+	return tx, nil
+}
+
+// MakeUnsignedCall creates an unsigned transaction with the given attributes
+// that calls the given method of the given contract with the given parameters.
+// Test-invocation is performed and is expected to end up in HALT state, the
+// transaction returned has correct SystemFee and NetworkFee values.
+func (a *Actor) MakeUnsignedCall(contract util.Uint160, method string, attrs []transaction.Attribute, params ...interface{}) (*transaction.Transaction, error) {
+	r, err := a.Call(contract, method, params...)
+	return a.makeUnsignedWrapper(r, err, attrs)
+}
+
+// MakeUnsignedRun creates an unsigned transaction with the given attributes
+// that executes the given script. Test-invocation is performed and is expected
+// to end up in HALT state, the transaction returned has correct SystemFee and
+// NetworkFee values.
+func (a *Actor) MakeUnsignedRun(script []byte, attrs []transaction.Attribute) (*transaction.Transaction, error) {
+	r, err := a.Run(script)
+	return a.makeUnsignedWrapper(r, err, attrs)
+}
+
+func (a *Actor) makeUnsignedWrapper(r *result.Invoke, err error, attrs []transaction.Attribute) (*transaction.Transaction, error) {
+	if err != nil {
+		return nil, fmt.Errorf("failed to test-invoke: %w", err)
+	}
+	if r.State != vmstate.Halt.String() {
+		return nil, fmt.Errorf("test invocation faulted (%s): %s", r.State, r.FaultException)
+	}
+	return a.MakeUnsignedUncheckedRun(r.Script, r.GasConsumed, attrs)
+}
+
+// MakeUnsignedUncheckedRun creates an unsigned transaction containing the given
+// script with the system fee value and attributes. It's expected to be used when
+// test invocation is already done and the script and system fee value are already
+// known to be good, so it doesn't do test invocation internally. But it fills
+// Signers with Actor's signers, calculates proper ValidUntilBlock and NetworkFee
+// values. The resulting transaction can be changed in its Nonce, SystemFee,
+// NetworkFee and ValidUntilBlock values and then be signed and sent or
+// exchanged via context.ParameterContext.
+func (a *Actor) MakeUnsignedUncheckedRun(script []byte, sysFee int64, attrs []transaction.Attribute) (*transaction.Transaction, error) {
+	var err error
+
+	if len(script) == 0 {
+		return nil, errors.New("empty script")
+	}
+	if sysFee < 0 {
+		return nil, errors.New("negative system fee")
+	}
+
+	tx := transaction.New(script, sysFee)
+	tx.Signers = a.txSigners
+	tx.Attributes = attrs
+
+	tx.ValidUntilBlock, err = a.CalculateValidUntilBlock()
+	if err != nil {
+		return nil, fmt.Errorf("calculating validUntilBlock: %w", err)
+	}
+
+	tx.Scripts = make([]transaction.Witness, len(a.signers))
+	for i := range a.signers {
+		if !a.signers[i].Account.Contract.Deployed {
+			tx.Scripts[i].VerificationScript = a.signers[i].Account.Contract.Script
+		}
+	}
+	// CalculateNetworkFee doesn't call Hash or Size, only serializes the
+	// transaction via Bytes, so it's safe wrt internal caching.
+	tx.NetworkFee, err = a.client.CalculateNetworkFee(tx)
+	if err != nil {
+		return nil, fmt.Errorf("calculating network fee: %w", err)
+	}
+
+	return tx, nil
+}
+
+// CalculateValidUntilBlock returns correct ValidUntilBlock value for a new
+// transaction relative to the current blockchain height. It uses "height +
+// number of validators + 1" formula suggesting shorter transaction lifetime
+// than the usual "height + MaxValidUntilBlockIncrement" approach. Shorter
+// lifetime can be useful to control transaction acceptance wait time because
+// it can't be added into a block after ValidUntilBlock.
+func (a *Actor) CalculateValidUntilBlock() (uint32, error) {
+	blockCount, err := a.client.GetBlockCount()
+	if err != nil {
+		return 0, fmt.Errorf("can't get block count: %w", err)
+	}
+	var vc = int(a.version.Protocol.ValidatorsCount)
+	var bestH = uint32(0)
+	for h, n := range a.version.Protocol.ValidatorsHistory { // In case it's enabled.
+		if h >= bestH && h <= blockCount {
+			vc = n
+			bestH = h
+		}
+	}
+
+	return blockCount + uint32(vc+1), nil
+}
diff --git a/pkg/rpcclient/actor/maker_test.go b/pkg/rpcclient/actor/maker_test.go
new file mode 100644
index 000000000..116baf46b
--- /dev/null
+++ b/pkg/rpcclient/actor/maker_test.go
@@ -0,0 +1,178 @@
+package actor
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCalculateValidUntilBlock(t *testing.T) {
+	client, acc := testRPCAndAccount(t)
+	a, err := NewSimple(client, acc)
+	require.NoError(t, err)
+
+	client.err = errors.New("error")
+	_, err = a.CalculateValidUntilBlock()
+	require.Error(t, err)
+
+	client.err = nil
+	client.bCount = 42
+	vub, err := a.CalculateValidUntilBlock()
+	require.NoError(t, err)
+	require.Equal(t, uint32(42+7+1), vub)
+
+	client.version.Protocol.ValidatorsHistory = map[uint32]int{
+		0:  7,
+		40: 4,
+		80: 10,
+	}
+	a, err = NewSimple(client, acc)
+	require.NoError(t, err)
+
+	vub, err = a.CalculateValidUntilBlock()
+	require.NoError(t, err)
+	require.Equal(t, uint32(42+4+1), vub)
+
+	client.bCount = 101
+	vub, err = a.CalculateValidUntilBlock()
+	require.NoError(t, err)
+	require.Equal(t, uint32(101+10+1), vub)
+}
+
+func TestMakeUnsigned(t *testing.T) {
+	client, acc := testRPCAndAccount(t)
+	a, err := NewSimple(client, acc)
+	require.NoError(t, err)
+
+	// Bad parameters.
+	script := []byte{1, 2, 3}
+	_, err = a.MakeUnsignedUncheckedRun(script, -1, nil)
+	require.Error(t, err)
+	_, err = a.MakeUnsignedUncheckedRun([]byte{}, 1, nil)
+	require.Error(t, err)
+	_, err = a.MakeUnsignedUncheckedRun(nil, 1, nil)
+	require.Error(t, err)
+
+	// RPC error.
+	client.err = errors.New("err")
+	_, err = a.MakeUnsignedUncheckedRun(script, 1, nil)
+	require.Error(t, err)
+
+	// Good unchecked.
+	client.netFee = 42
+	client.bCount = 100500
+	client.err = nil
+	tx, err := a.MakeUnsignedUncheckedRun(script, 1, nil)
+	require.NoError(t, err)
+	require.Equal(t, script, tx.Script)
+	require.Equal(t, 1, len(tx.Signers))
+	require.Equal(t, acc.Contract.ScriptHash(), tx.Signers[0].Account)
+	require.Equal(t, 1, len(tx.Scripts))
+	require.Equal(t, acc.Contract.Script, tx.Scripts[0].VerificationScript)
+	require.Nil(t, tx.Scripts[0].InvocationScript)
+
+	// Bad run.
+	client.err = errors.New("")
+	_, err = a.MakeUnsignedRun(script, nil)
+	require.Error(t, err)
+
+	// Faulted run.
+	client.invRes = &result.Invoke{State: "FAULT", GasConsumed: 3, Script: script}
+	client.err = nil
+	_, err = a.MakeUnsignedRun(script, nil)
+	require.Error(t, err)
+
+	// Good run.
+	client.invRes = &result.Invoke{State: "HALT", GasConsumed: 3, Script: script}
+	_, err = a.MakeUnsignedRun(script, nil)
+	require.NoError(t, err)
+}
+
+func TestMakeSigned(t *testing.T) {
+	client, acc := testRPCAndAccount(t)
+	a, err := NewSimple(client, acc)
+	require.NoError(t, err)
+
+	// Bad script.
+	_, err = a.MakeUncheckedRun(nil, 0, nil, nil)
+	require.Error(t, err)
+
+	// Good, no hook.
+	script := []byte{1, 2, 3}
+	_, err = a.MakeUncheckedRun(script, 0, nil, nil)
+	require.NoError(t, err)
+
+	// Bad, can't sign because of a hook.
+	_, err = a.MakeUncheckedRun(script, 0, nil, func(t *transaction.Transaction) error {
+		t.Signers = append(t.Signers, transaction.Signer{})
+		return nil
+	})
+	require.Error(t, err)
+
+	// Bad, hook returns an error.
+	_, err = a.MakeUncheckedRun(script, 0, nil, func(t *transaction.Transaction) error {
+		return errors.New("")
+	})
+	require.Error(t, err)
+
+	// Good with a hook.
+	tx, err := a.MakeUncheckedRun(script, 0, nil, func(t *transaction.Transaction) error {
+		t.ValidUntilBlock = 777
+		return nil
+	})
+	require.NoError(t, err)
+	require.Equal(t, uint32(777), tx.ValidUntilBlock)
+
+	// Checked
+
+	// Bad, invocation fails.
+	client.err = errors.New("")
+	_, err = a.MakeTunedRun(script, nil, func(r *result.Invoke, t *transaction.Transaction) error {
+		return nil
+	})
+	require.Error(t, err)
+
+	// Bad, hook returns an error.
+	client.err = nil
+	client.invRes = &result.Invoke{State: "HALT", GasConsumed: 3, Script: script}
+	_, err = a.MakeTunedRun(script, nil, func(r *result.Invoke, t *transaction.Transaction) error {
+		return errors.New("")
+	})
+	require.Error(t, err)
+
+	// Good, no hook.
+	_, err = a.MakeTunedRun(script, []transaction.Attribute{{Type: transaction.HighPriority}}, nil)
+	require.NoError(t, err)
+	_, err = a.MakeRun(script)
+	require.NoError(t, err)
+
+	// Bad, invocation returns FAULT.
+	client.invRes = &result.Invoke{State: "FAULT", GasConsumed: 3, Script: script}
+	_, err = a.MakeTunedRun(script, nil, nil)
+	require.Error(t, err)
+
+	// Good, invocation returns FAULT, but callback ignores it.
+	_, err = a.MakeTunedRun(script, nil, func(r *result.Invoke, t *transaction.Transaction) error {
+		return nil
+	})
+	require.NoError(t, err)
+
+	// Good, via call and with a callback.
+	_, err = a.MakeTunedCall(util.Uint160{}, "something", []transaction.Attribute{{Type: transaction.HighPriority}}, func(r *result.Invoke, t *transaction.Transaction) error {
+		return nil
+	}, "param", 1)
+	require.NoError(t, err)
+
+	// Bad, it still is a FAULT.
+	_, err = a.MakeCall(util.Uint160{}, "method")
+	require.Error(t, err)
+
+	// Good.
+	client.invRes = &result.Invoke{State: "HALT", GasConsumed: 3, Script: script}
+	_, err = a.MakeCall(util.Uint160{}, "method", 1)
+	require.NoError(t, err)
+}
diff --git a/pkg/rpcclient/nep17.go b/pkg/rpcclient/nep17.go
index 06d0a4209..329f88fca 100644
--- a/pkg/rpcclient/nep17.go
+++ b/pkg/rpcclient/nep17.go
@@ -97,6 +97,9 @@ func (c *Client) CreateNEP17MultiTransferTx(acc *wallet.Account, gas int64,
 // CreateTxFromScript creates transaction and properly sets cosigners and NetworkFee.
 // If sysFee <= 0, it is determined via result of `invokescript` RPC. You should
 // initialize network magic with Init before calling CreateTxFromScript.
+//
+// Deprecated: please use actor.Actor API, this method will be removed in future
+// versions.
 func (c *Client) CreateTxFromScript(script []byte, acc *wallet.Account, sysFee, netFee int64,
 	cosigners []SignerAccount) (*transaction.Transaction, error) {
 	signers, accounts, err := getSigners(acc, cosigners)
diff --git a/pkg/rpcclient/rpc.go b/pkg/rpcclient/rpc.go
index 85020d5b1..84333fb9d 100644
--- a/pkg/rpcclient/rpc.go
+++ b/pkg/rpcclient/rpc.go
@@ -755,6 +755,9 @@ func (c *Client) SubmitRawOracleResponse(ps []interface{}) error {
 // possible. It spends the amount of gas specified. It returns a hash of the
 // invocation transaction and an error. If one of the cosigners accounts is
 // neither contract-based nor unlocked, an error is returned.
+//
+// Deprecated: please use actor.Actor API, this method will be removed in future
+// versions.
 func (c *Client) SignAndPushInvocationTx(script []byte, acc *wallet.Account, sysfee int64, netfee fixedn.Fixed8, cosigners []SignerAccount) (util.Uint256, error) {
 	tx, err := c.CreateTxFromScript(script, acc, sysfee, int64(netfee), cosigners)
 	if err != nil {
@@ -767,6 +770,9 @@ func (c *Client) SignAndPushInvocationTx(script []byte, acc *wallet.Account, sys
 // it to the chain. It returns a hash of the transaction and an error. If one of
 // the cosigners accounts is neither contract-based nor unlocked, an error is
 // returned.
+//
+// Deprecated: please use actor.Actor API, this method will be removed in future
+// versions.
 func (c *Client) SignAndPushTx(tx *transaction.Transaction, acc *wallet.Account, cosigners []SignerAccount) (util.Uint256, error) {
 	var (
 		txHash util.Uint256
@@ -1007,6 +1013,9 @@ func (c *Client) ValidateAddress(address string) error {
 // current blockchain height + number of validators. Number of validators
 // is the length of blockchain validators list got from GetNextBlockValidators()
 // method. Validators count is being cached and updated every 100 blocks.
+//
+// Deprecated: please use (*Actor).CalculateValidUntilBlock. This method will be
+// removed in future versions.
 func (c *Client) CalculateValidUntilBlock() (uint32, error) {
 	var (
 		result          uint32
@@ -1040,6 +1049,9 @@ func (c *Client) CalculateValidUntilBlock() (uint32, error) {
 
 // AddNetworkFee adds network fee for each witness script and optional extra
 // network fee to transaction. `accs` is an array signer's accounts.
+//
+// Deprecated: please use CalculateNetworkFee or actor.Actor. This method will
+// be removed in future versions.
 func (c *Client) AddNetworkFee(tx *transaction.Transaction, extraFee int64, accs ...*wallet.Account) error {
 	if len(tx.Signers) != len(accs) {
 		return errors.New("number of signers must match number of scripts")
diff --git a/pkg/services/rpcsrv/client_test.go b/pkg/services/rpcsrv/client_test.go
index a53ce077f..354bf38d8 100644
--- a/pkg/services/rpcsrv/client_test.go
+++ b/pkg/services/rpcsrv/client_test.go
@@ -116,7 +116,7 @@ func TestAddNetworkFeeCalculateNetworkFee(t *testing.T) {
 			Account: accs[0].PrivateKey().GetScriptHash(),
 			Scopes:  transaction.CalledByEntry,
 		}}
-		require.Error(t, c.AddNetworkFee(tx, extraFee, accs[0], accs[1]))
+		require.Error(t, c.AddNetworkFee(tx, extraFee, accs[0], accs[1])) //nolint:staticcheck // SA1019: c.AddNetworkFee is deprecated
 	})
 	t.Run("Simple", func(t *testing.T) {
 		acc0 := wallet.NewAccountFromPrivateKey(testchain.PrivateKeyByID(0))
@@ -137,7 +137,7 @@ func TestAddNetworkFeeCalculateNetworkFee(t *testing.T) {
 			require.NoError(t, err)
 
 			tx.Scripts = nil
-			require.NoError(t, c.AddNetworkFee(tx, extraFee, acc0))
+			require.NoError(t, c.AddNetworkFee(tx, extraFee, acc0)) //nolint:staticcheck // SA1019: c.AddNetworkFee is deprecated
 			actual := tx.NetworkFee
 
 			require.NoError(t, acc0.SignTx(testchain.Network(), tx))
@@ -203,7 +203,7 @@ func TestAddNetworkFeeCalculateNetworkFee(t *testing.T) {
 
 			tx.Scripts = nil
 
-			require.NoError(t, c.AddNetworkFee(tx, extraFee, acc0, acc1))
+			require.NoError(t, c.AddNetworkFee(tx, extraFee, acc0, acc1)) //nolint:staticcheck // SA1019: c.AddNetworkFee is deprecated
 			actual := tx.NetworkFee
 
 			require.NoError(t, acc0.SignTx(testchain.Network(), tx))
@@ -276,7 +276,7 @@ func TestAddNetworkFeeCalculateNetworkFee(t *testing.T) {
 				require.NoError(t, err)
 				tx.Scripts = nil
 
-				require.NoError(t, c.AddNetworkFee(tx, extraFee, acc0, acc1))
+				require.NoError(t, c.AddNetworkFee(tx, extraFee, acc0, acc1)) //nolint:staticcheck // SA1019: c.AddNetworkFee is deprecated
 				require.NoError(t, acc0.SignTx(testchain.Network(), tx))
 				tx.Scripts = append(tx.Scripts, transaction.Witness{})
 				require.Equal(t, tx.NetworkFee, actual+extraFee)
@@ -315,7 +315,7 @@ func TestAddNetworkFeeCalculateNetworkFee(t *testing.T) {
 					Scopes:  transaction.Global,
 				},
 			}
-			require.Error(t, c.AddNetworkFee(tx, 10, acc0, acc1))
+			require.Error(t, c.AddNetworkFee(tx, 10, acc0, acc1)) //nolint:staticcheck // SA1019: c.AddNetworkFee is deprecated
 		})
 		t.Run("InvalidContract", func(t *testing.T) {
 			tx := newTx(t)
@@ -330,7 +330,7 @@ func TestAddNetworkFeeCalculateNetworkFee(t *testing.T) {
 					Scopes:  transaction.Global,
 				},
 			}
-			require.Error(t, c.AddNetworkFee(tx, 10, acc0, acc1))
+			require.Error(t, c.AddNetworkFee(tx, 10, acc0, acc1)) //nolint:staticcheck // SA1019: c.AddNetworkFee is deprecated
 		})
 	})
 }
@@ -458,7 +458,7 @@ func TestSignAndPushInvocationTx(t *testing.T) {
 
 	t.Run("good", func(t *testing.T) {
 		t.Run("signer0: sig", func(t *testing.T) {
-			h, err := c.SignAndPushInvocationTx([]byte{byte(opcode.PUSH1)}, acc0, 30, 0, []rpcclient.SignerAccount{
+			h, err := c.SignAndPushInvocationTx([]byte{byte(opcode.PUSH1)}, acc0, 30, 0, []rpcclient.SignerAccount{ //nolint:staticcheck // SA1019: c.SignAndPushInvocationTx is deprecated
 				{
 					Signer: transaction.Signer{
 						Account: priv0.GetScriptHash(),
@@ -471,7 +471,7 @@ func TestSignAndPushInvocationTx(t *testing.T) {
 			check(t, h)
 		})
 		t.Run("signer0: sig; signer1: sig", func(t *testing.T) {
-			h, err := c.SignAndPushInvocationTx([]byte{byte(opcode.PUSH1)}, acc0, 30, 0, []rpcclient.SignerAccount{
+			h, err := c.SignAndPushInvocationTx([]byte{byte(opcode.PUSH1)}, acc0, 30, 0, []rpcclient.SignerAccount{ //nolint:staticcheck // SA1019: c.SignAndPushInvocationTx is deprecated
 				{
 					Signer: transaction.Signer{
 						Account: priv0.GetScriptHash(),
@@ -491,7 +491,7 @@ func TestSignAndPushInvocationTx(t *testing.T) {
 			check(t, h)
 		})
 		t.Run("signer0: sig; signer1: contract-based paramless", func(t *testing.T) {
-			h, err := c.SignAndPushInvocationTx([]byte{byte(opcode.PUSH1)}, acc0, 30, 0, []rpcclient.SignerAccount{
+			h, err := c.SignAndPushInvocationTx([]byte{byte(opcode.PUSH1)}, acc0, 30, 0, []rpcclient.SignerAccount{ //nolint:staticcheck // SA1019: c.SignAndPushInvocationTx is deprecated
 				{
 					Signer: transaction.Signer{
 						Account: priv0.GetScriptHash(),
@@ -513,7 +513,7 @@ func TestSignAndPushInvocationTx(t *testing.T) {
 	})
 	t.Run("error", func(t *testing.T) {
 		t.Run("signer0: sig; signer1: contract-based with params", func(t *testing.T) {
-			_, err := c.SignAndPushInvocationTx([]byte{byte(opcode.PUSH1)}, acc0, 30, 0, []rpcclient.SignerAccount{
+			_, err := c.SignAndPushInvocationTx([]byte{byte(opcode.PUSH1)}, acc0, 30, 0, []rpcclient.SignerAccount{ //nolint:staticcheck // SA1019: c.SignAndPushInvocationTx is deprecated
 				{
 					Signer: transaction.Signer{
 						Account: priv0.GetScriptHash(),
@@ -541,7 +541,7 @@ func TestSignAndPushInvocationTx(t *testing.T) {
 					Parameters: []wallet.ContractParam{{Name: "parameter0", Type: smartcontract.SignatureType}},
 				},
 			}
-			_, err = c.SignAndPushInvocationTx([]byte{byte(opcode.PUSH1)}, acc0, 30, 0, []rpcclient.SignerAccount{
+			_, err = c.SignAndPushInvocationTx([]byte{byte(opcode.PUSH1)}, acc0, 30, 0, []rpcclient.SignerAccount{ //nolint:staticcheck // SA1019: c.SignAndPushInvocationTx is deprecated
 				{
 					Signer: transaction.Signer{
 						Account: priv0.GetScriptHash(),
@@ -693,7 +693,7 @@ func TestCreateTxFromScript(t *testing.T) {
 	priv := testchain.PrivateKey(0)
 	acc := wallet.NewAccountFromPrivateKey(priv)
 	t.Run("NoSystemFee", func(t *testing.T) {
-		tx, err := c.CreateTxFromScript([]byte{byte(opcode.PUSH1)}, acc, -1, 10, nil)
+		tx, err := c.CreateTxFromScript([]byte{byte(opcode.PUSH1)}, acc, -1, 10, nil) //nolint:staticcheck // SA1019: c.CreateTxFromScript is deprecated
 		require.NoError(t, err)
 		require.True(t, tx.ValidUntilBlock > chain.BlockHeight())
 		require.EqualValues(t, 30, tx.SystemFee) // PUSH1
@@ -701,7 +701,7 @@ func TestCreateTxFromScript(t *testing.T) {
 		require.Equal(t, acc.PrivateKey().GetScriptHash(), tx.Signers[0].Account)
 	})
 	t.Run("ProvideSystemFee", func(t *testing.T) {
-		tx, err := c.CreateTxFromScript([]byte{byte(opcode.PUSH1)}, acc, 123, 10, nil)
+		tx, err := c.CreateTxFromScript([]byte{byte(opcode.PUSH1)}, acc, 123, 10, nil) //nolint:staticcheck // SA1019: c.CreateTxFromScript is deprecated
 		require.NoError(t, err)
 		require.True(t, tx.ValidUntilBlock > chain.BlockHeight())
 		require.EqualValues(t, 123, tx.SystemFee)
diff --git a/pkg/services/rpcsrv/server.go b/pkg/services/rpcsrv/server.go
index b7534c13b..e67c801a0 100644
--- a/pkg/services/rpcsrv/server.go
+++ b/pkg/services/rpcsrv/server.go
@@ -694,7 +694,11 @@ func (s *Server) getVersion(_ params.Params) (interface{}, *neorpc.Error) {
 			MemoryPoolMaxTransactions:   cfg.MemPoolSize,
 			ValidatorsCount:             byte(cfg.GetNumOfCNs(s.chain.BlockHeight())),
 			InitialGasDistribution:      cfg.InitialGASSupply,
-			StateRootInHeader:           cfg.StateRootInHeader,
+
+			CommitteeHistory:  cfg.CommitteeHistory,
+			P2PSigExtensions:  cfg.P2PSigExtensions,
+			StateRootInHeader: cfg.StateRootInHeader,
+			ValidatorsHistory: cfg.ValidatorsHistory,
 		},
 	}, nil
 }
diff --git a/pkg/services/rpcsrv/server_test.go b/pkg/services/rpcsrv/server_test.go
index 77b73fd46..011ca030b 100644
--- a/pkg/services/rpcsrv/server_test.go
+++ b/pkg/services/rpcsrv/server_test.go
@@ -875,7 +875,11 @@ var rpcTestCases = map[string][]rpcTestCase{
 				require.EqualValues(t, cfg.MemPoolSize, resp.Protocol.MemoryPoolMaxTransactions)
 				require.EqualValues(t, cfg.ValidatorsCount, resp.Protocol.ValidatorsCount)
 				require.EqualValues(t, cfg.InitialGASSupply, resp.Protocol.InitialGasDistribution)
-				require.EqualValues(t, false, resp.Protocol.StateRootInHeader)
+
+				require.Equal(t, 0, len(resp.Protocol.CommitteeHistory))
+				require.True(t, resp.Protocol.P2PSigExtensions) // Yeah, notary is enabled.
+				require.False(t, resp.Protocol.StateRootInHeader)
+				require.Equal(t, 0, len(resp.Protocol.ValidatorsHistory))
 			},
 		},
 	},
diff --git a/pkg/smartcontract/doc_test.go b/pkg/smartcontract/doc_test.go
index d1b7fe8cc..4dfdda4ca 100644
--- a/pkg/smartcontract/doc_test.go
+++ b/pkg/smartcontract/doc_test.go
@@ -5,8 +5,8 @@ import (
 	"encoding/hex"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
-	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient"
+	"github.com/nspcc-dev/neo-go/pkg/rpcclient/actor"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/wallet"
@@ -34,8 +34,8 @@ func ExampleBuilder() {
 
 	w, _ := wallet.NewWalletFromFile("somewhere")
 	// Assuming there is one Account inside
-	acc := w.Accounts[0]
-	from, _ := address.StringToUint160(acc.Address)
+	a, _ := actor.NewSimple(c, w.Accounts[0])
+	from := w.Accounts[0].Contract.ScriptHash() // Assuming Contract is present.
 
 	// Multiple transfers in a single script. If any of them fail whole script fails.
 	b.InvokeWithAssert(neoHash, "transfer", from, util.Uint160{0x70}, 1, nil)
@@ -44,6 +44,7 @@ func ExampleBuilder() {
 	script, _ = b.Script()
 
 	// The script can then be used to create transaction or to invoke via RPC.
-	txid, _ := c.SignAndPushInvocationTx(script, acc, -1, 0, nil)
+	txid, vub, _ := a.SendRun(script)
 	_ = txid
+	_ = vub
 }
diff --git a/pkg/smartcontract/parameter.go b/pkg/smartcontract/parameter.go
index e4496fd20..dbd3c5342 100644
--- a/pkg/smartcontract/parameter.go
+++ b/pkg/smartcontract/parameter.go
@@ -303,6 +303,10 @@ func NewParameterFromValue(value interface{}) (Parameter, error) {
 	case uint64:
 		result.Type = IntegerType
 		result.Value = new(big.Int).SetUint64(v)
+	case *Parameter:
+		result = *v
+	case Parameter:
+		result = v
 	case util.Uint160:
 		result.Type = Hash160Type
 	case util.Uint256:
@@ -321,6 +325,11 @@ func NewParameterFromValue(value interface{}) (Parameter, error) {
 		}
 		result.Type = ArrayType
 		result.Value = arr
+	case []Parameter:
+		arr := make([]Parameter, len(v))
+		copy(arr, v)
+		result.Type = ArrayType
+		result.Value = arr
 	case []*keys.PublicKey:
 		return NewParameterFromValue(keys.PublicKeys(v))
 	case keys.PublicKeys:
diff --git a/pkg/smartcontract/parameter_test.go b/pkg/smartcontract/parameter_test.go
index 181901876..72b1070f7 100644
--- a/pkg/smartcontract/parameter_test.go
+++ b/pkg/smartcontract/parameter_test.go
@@ -616,6 +616,16 @@ func TestParameterFromValue(t *testing.T) {
 			expType: IntegerType,
 			expVal:  big.NewInt(100),
 		},
+		{
+			value:   Parameter{ByteArrayType, []byte{1, 2, 3}},
+			expType: ByteArrayType,
+			expVal:  []byte{1, 2, 3},
+		},
+		{
+			value:   &Parameter{ByteArrayType, []byte{1, 2, 3}},
+			expType: ByteArrayType,
+			expVal:  []byte{1, 2, 3},
+		},
 		{
 			value:   util.Uint160{1, 2, 3},
 			expType: Hash160Type,
@@ -641,6 +651,11 @@ func TestParameterFromValue(t *testing.T) {
 			expType: ArrayType,
 			expVal:  []Parameter{{ByteArrayType, []byte{1, 2, 3}}, {ByteArrayType, []byte{3, 2, 1}}},
 		},
+		{
+			value:   []Parameter{{ByteArrayType, []byte{1, 2, 3}}, {ByteArrayType, []byte{3, 2, 1}}},
+			expType: ArrayType,
+			expVal:  []Parameter{{ByteArrayType, []byte{1, 2, 3}}, {ByteArrayType, []byte{3, 2, 1}}},
+		},
 		{
 			value:   []*keys.PublicKey{pk1.PublicKey(), pk2.PublicKey()},
 			expType: ArrayType,
diff --git a/pkg/wallet/account.go b/pkg/wallet/account.go
index bc370eb23..7b1619707 100644
--- a/pkg/wallet/account.go
+++ b/pkg/wallet/account.go
@@ -85,7 +85,9 @@ func NewAccount() (*Account, error) {
 // SignTx signs transaction t and updates it's Witnesses.
 func (a *Account) SignTx(net netmode.Magic, t *transaction.Transaction) error {
 	if len(a.Contract.Parameters) == 0 {
-		t.Scripts = append(t.Scripts, transaction.Witness{})
+		if len(t.Signers) != len(t.Scripts) { // Sequential signing vs. existing scripts.
+			t.Scripts = append(t.Scripts, transaction.Witness{})
+		}
 		return nil
 	}
 	if a.privateKey == nil {