diff --git a/pkg/compiler/codegen.go b/pkg/compiler/codegen.go
index fc4b49893..f1d84e211 100644
--- a/pkg/compiler/codegen.go
+++ b/pkg/compiler/codegen.go
@@ -211,6 +211,7 @@ func (c *codegen) convertFuncDecl(file ast.Node, decl *ast.FuncDecl) {
 		f = c.newFunc(decl)
 	}
 
+	f.rng.Start = uint16(c.prog.Len())
 	c.scope = f
 	ast.Inspect(decl, c.scope.analyzeVoidCalls) // @OPTIMIZE
 
@@ -260,6 +261,8 @@ func (c *codegen) convertFuncDecl(file ast.Node, decl *ast.FuncDecl) {
 		emit.Opcode(c.prog.BinWriter, opcode.DROP)
 		emit.Opcode(c.prog.BinWriter, opcode.RET)
 	}
+
+	f.rng.End = uint16(c.prog.Len() - 1)
 }
 
 func (c *codegen) Visit(node ast.Node) ast.Visitor {
diff --git a/pkg/compiler/debug.go b/pkg/compiler/debug.go
new file mode 100644
index 000000000..178b47e3f
--- /dev/null
+++ b/pkg/compiler/debug.go
@@ -0,0 +1,242 @@
+package compiler
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"go/ast"
+	"go/types"
+	"strconv"
+	"strings"
+)
+
+// DebugInfo represents smart-contract debug information.
+type DebugInfo struct {
+	EntryPoint string            `json:"entrypoint"`
+	Documents  []string          `json:"documents"`
+	Methods    []MethodDebugInfo `json:"methods"`
+	Events     []EventDebugInfo  `json:"events"`
+}
+
+// MethodDebugInfo represents smart-contract's method debug information.
+type MethodDebugInfo struct {
+	ID string `json:"id"`
+	// Name is the name of the method together with the namespace it belongs to.
+	Name DebugMethodName `json:"name"`
+	// Range is the range of smart-contract's opcodes corresponding to the method.
+	Range DebugRange `json:"range"`
+	// Parameters is a list of method's parameters.
+	Parameters []DebugParam `json:"params"`
+	// ReturnType is method's return type.
+	ReturnType string   `json:"return-type"`
+	Variables  []string `json:"variables"`
+	// SeqPoints is a map between source lines and byte-code instruction offsets.
+	SeqPoints []DebugSeqPoint `json:"sequence-points"`
+}
+
+// DebugMethodName is a combination of a namespace and name.
+type DebugMethodName struct {
+	Namespace string
+	Name      string
+}
+
+// EventDebugInfo represents smart-contract's event debug information.
+type EventDebugInfo struct {
+	ID string `json:"id"`
+	// Name is a human-readable event name in a format "{namespace}-{name}".
+	Name       string       `json:"name"`
+	Parameters []DebugParam `json:"parameters"`
+}
+
+// DebugSeqPoint represents break-point for debugger.
+type DebugSeqPoint struct {
+	// Opcode is an opcode's address.
+	Opcode int
+	// Document is an index of file where sequence point occurs.
+	Document int
+	// StartLine is the first line of the break-pointed statement.
+	StartLine int
+	// StartCol is the first column of the break-pointed statement.
+	StartCol int
+	// EndLine is the last line of the break-pointed statement.
+	EndLine int
+	// EndCol is the last column of the break-pointed statement.
+	EndCol int
+}
+
+// DebugRange represents method's section in bytecode.
+type DebugRange struct {
+	Start uint16
+	End   uint16
+}
+
+// DebugParam represents variables's name and type.
+type DebugParam struct {
+	Name string
+	Type string
+}
+
+func (c *codegen) emitDebugInfo() *DebugInfo {
+	d := &DebugInfo{
+		EntryPoint: mainIdent,
+		Events:     []EventDebugInfo{},
+	}
+	for name, scope := range c.funcs {
+		m := c.methodInfoFromScope(name, scope)
+		if m.Range.Start == m.Range.End {
+			continue
+		}
+		d.Methods = append(d.Methods, *m)
+	}
+	return d
+}
+
+func (c *codegen) methodInfoFromScope(name string, scope *funcScope) *MethodDebugInfo {
+	ps := scope.decl.Type.Params
+	params := make([]DebugParam, 0, ps.NumFields())
+	for i := range params {
+		for j := range ps.List[i].Names {
+			params = append(params, DebugParam{
+				Name: ps.List[i].Names[j].Name,
+				Type: c.scTypeFromExpr(ps.List[i].Type),
+			})
+		}
+	}
+	return &MethodDebugInfo{
+		ID:         name,
+		Name:       DebugMethodName{Name: name},
+		Range:      scope.rng,
+		Parameters: params,
+		ReturnType: c.scReturnTypeFromScope(scope),
+	}
+}
+
+func (c *codegen) scReturnTypeFromScope(scope *funcScope) string {
+	results := scope.decl.Type.Results
+	switch results.NumFields() {
+	case 0:
+		return "Void"
+	case 1:
+		return c.scTypeFromExpr(results.List[0].Type)
+	default:
+		// multiple return values are not supported in debugger
+		return "Any"
+	}
+}
+
+func (c *codegen) scTypeFromExpr(typ ast.Expr) string {
+	switch t := c.typeInfo.Types[typ].Type.(type) {
+	case *types.Basic:
+		info := t.Info()
+		switch {
+		case info&types.IsInteger != 0:
+			return "Integer"
+		case info&types.IsBoolean != 0:
+			return "Boolean"
+		case info&types.IsString != 0:
+			return "String"
+		default:
+			return "Any"
+		}
+	case *types.Map:
+		return "Map"
+	case *types.Struct:
+		return "Struct"
+	case *types.Slice:
+		if isByteArrayType(t) {
+			return "ByteArray"
+		}
+		return "Array"
+	default:
+		return "Any"
+	}
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (d *DebugRange) MarshalJSON() ([]byte, error) {
+	return []byte(`"` + strconv.FormatUint(uint64(d.Start), 10) + `-` +
+		strconv.FormatUint(uint64(d.End), 10) + `"`), nil
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface.
+func (d *DebugRange) UnmarshalJSON(data []byte) error {
+	startS, endS, err := parsePairJSON(data, "-")
+	if err != nil {
+		return err
+	}
+	start, err := strconv.ParseUint(startS, 10, 16)
+	if err != nil {
+		return err
+	}
+	end, err := strconv.ParseUint(endS, 10, 16)
+	if err != nil {
+		return err
+	}
+
+	d.Start = uint16(start)
+	d.End = uint16(end)
+
+	return nil
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (d *DebugParam) MarshalJSON() ([]byte, error) {
+	return []byte(`"` + d.Name + `,` + d.Type + `"`), nil
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface.
+func (d *DebugParam) UnmarshalJSON(data []byte) error {
+	startS, endS, err := parsePairJSON(data, ",")
+	if err != nil {
+		return err
+	}
+
+	d.Name = startS
+	d.Type = endS
+
+	return nil
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (d *DebugMethodName) MarshalJSON() ([]byte, error) {
+	return []byte(`"` + d.Namespace + `,` + d.Name + `"`), nil
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface.
+func (d *DebugMethodName) UnmarshalJSON(data []byte) error {
+	startS, endS, err := parsePairJSON(data, ",")
+	if err != nil {
+		return err
+	}
+
+	d.Namespace = startS
+	d.Name = endS
+
+	return nil
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (d *DebugSeqPoint) MarshalJSON() ([]byte, error) {
+	s := fmt.Sprintf("%d[%d]%d:%d-%d:%d", d.Opcode, d.Document,
+		d.StartLine, d.StartCol, d.EndLine, d.EndCol)
+	return []byte(`"` + s + `"`), nil
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface.
+func (d *DebugSeqPoint) UnmarshalJSON(data []byte) error {
+	_, err := fmt.Sscanf(string(data), `"%d[%d]%d:%d-%d:%d"`,
+		&d.Opcode, &d.Document, &d.StartLine, &d.StartCol, &d.EndLine, &d.EndCol)
+	return err
+}
+
+func parsePairJSON(data []byte, sep string) (string, string, error) {
+	var s string
+	if err := json.Unmarshal(data, &s); err != nil {
+		return "", "", err
+	}
+	ss := strings.SplitN(s, sep, 2)
+	if len(ss) != 2 {
+		return "", "", errors.New("invalid range format")
+	}
+	return ss[0], ss[1], nil
+}
diff --git a/pkg/compiler/debug_test.go b/pkg/compiler/debug_test.go
new file mode 100644
index 000000000..f98493077
--- /dev/null
+++ b/pkg/compiler/debug_test.go
@@ -0,0 +1,43 @@
+package compiler
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neo-go/pkg/internal/testserdes"
+)
+
+func TestDebugInfo_MarshalJSON(t *testing.T) {
+	d := &DebugInfo{
+		EntryPoint: "main",
+		Documents:  []string{"/path/to/file"},
+		Methods: []MethodDebugInfo{
+			{
+				ID: "id1",
+				Name: DebugMethodName{
+					Namespace: "default",
+					Name:      "method1",
+				},
+				Range: DebugRange{Start: 10, End: 20},
+				Parameters: []DebugParam{
+					{"param1", "Integer"},
+					{"ok", "Boolean"},
+				},
+				ReturnType: "ByteArray",
+				Variables:  []string{},
+				SeqPoints: []DebugSeqPoint{
+					{
+						Opcode:    123,
+						Document:  1,
+						StartLine: 2,
+						StartCol:  3,
+						EndLine:   4,
+						EndCol:    5,
+					},
+				},
+			},
+		},
+		Events: []EventDebugInfo{},
+	}
+
+	testserdes.MarshalUnmarshalJSON(t, d, new(DebugInfo))
+}
diff --git a/pkg/compiler/func_scope.go b/pkg/compiler/func_scope.go
index f0af3d231..a43a0ec20 100644
--- a/pkg/compiler/func_scope.go
+++ b/pkg/compiler/func_scope.go
@@ -21,6 +21,9 @@ type funcScope struct {
 	// Program label of the scope
 	label uint16
 
+	// Range of opcodes corresponding to the function.
+	rng DebugRange
+
 	// Local variables
 	locals map[string]int