diff --git a/decoder/expr_type_declaration.go b/decoder/expr_type_declaration.go
index 1a245ede..1cef8120 100644
--- a/decoder/expr_type_declaration.go
+++ b/decoder/expr_type_declaration.go
@@ -1,9 +1,6 @@
 package decoder
 
 import (
-	"context"
-
-	"github.com/hashicorp/hcl-lang/lang"
 	"github.com/hashicorp/hcl-lang/schema"
 	"github.com/hashicorp/hcl/v2"
 )
@@ -16,11 +13,6 @@ type TypeDeclaration struct {
 	insideObject bool
 }
 
-func (td TypeDeclaration) SemanticTokens(ctx context.Context) []lang.SemanticToken {
-	// TODO
-	return nil
-}
-
 func isSingleArgTypeName(name string) bool {
 	return name == "list" || name == "set" || name == "map"
 }
diff --git a/decoder/expr_type_declaration_semtok.go b/decoder/expr_type_declaration_semtok.go
new file mode 100644
index 00000000..53d28abd
--- /dev/null
+++ b/decoder/expr_type_declaration_semtok.go
@@ -0,0 +1,133 @@
+package decoder
+
+import (
+	"context"
+
+	"github.com/hashicorp/hcl-lang/lang"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+)
+
+func (td TypeDeclaration) SemanticTokens(ctx context.Context) []lang.SemanticToken {
+	switch eType := td.expr.(type) {
+	case *hclsyntax.ScopeTraversalExpr:
+		if len(eType.Traversal) != 1 {
+			return []lang.SemanticToken{}
+		}
+
+		if isPrimitiveTypeDeclaration(eType.Traversal.RootName()) {
+			return []lang.SemanticToken{
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: []lang.SemanticTokenModifier{},
+					Range:     eType.Range(),
+				},
+			}
+		}
+	case *hclsyntax.FunctionCallExpr:
+		if isSingleArgTypeName(eType.Name) {
+			tokens := make([]lang.SemanticToken, 0)
+
+			tokens = append(tokens, lang.SemanticToken{
+				Type:      lang.TokenTypeCapsule,
+				Modifiers: []lang.SemanticTokenModifier{},
+				Range:     eType.NameRange,
+			})
+
+			if len(eType.Args) == 0 {
+				return tokens
+			}
+
+			if len(eType.Args) == 1 {
+				cons := TypeDeclaration{
+					expr:    eType.Args[0],
+					pathCtx: td.pathCtx,
+				}
+				tokens = append(tokens, cons.SemanticTokens(ctx)...)
+
+				return tokens
+			}
+
+			return []lang.SemanticToken{}
+		}
+
+		if eType.Name == "object" {
+			tokens := make([]lang.SemanticToken, 0)
+			tokens = append(tokens, lang.SemanticToken{
+				Type:      lang.TokenTypeCapsule,
+				Modifiers: []lang.SemanticTokenModifier{},
+				Range:     eType.NameRange,
+			})
+
+			if len(eType.Args) != 1 {
+				return tokens
+			}
+
+			objExpr, ok := eType.Args[0].(*hclsyntax.ObjectConsExpr)
+			if !ok {
+				return []lang.SemanticToken{}
+			}
+
+			cons := TypeDeclaration{
+				expr:         objExpr,
+				pathCtx:      td.pathCtx,
+				insideObject: true,
+			}
+
+			tokens = append(tokens, cons.SemanticTokens(ctx)...)
+
+			return tokens
+		}
+
+		if eType.Name == "tuple" {
+			tokens := make([]lang.SemanticToken, 0)
+			tokens = append(tokens, lang.SemanticToken{
+				Type:      lang.TokenTypeCapsule,
+				Modifiers: []lang.SemanticTokenModifier{},
+				Range:     eType.NameRange,
+			})
+
+			if len(eType.Args) != 1 {
+				return tokens
+			}
+
+			tupleExpr, ok := eType.Args[0].(*hclsyntax.TupleConsExpr)
+			if !ok {
+				return []lang.SemanticToken{}
+			}
+
+			for _, expr := range tupleExpr.Exprs {
+				cons := TypeDeclaration{
+					expr:    expr,
+					pathCtx: td.pathCtx,
+				}
+				tokens = append(tokens, cons.SemanticTokens(ctx)...)
+			}
+
+			return tokens
+		}
+	case *hclsyntax.ObjectConsExpr:
+		if !td.insideObject {
+			// no tokens in bare object notation w/out object()
+			return []lang.SemanticToken{}
+		}
+
+		tokens := make([]lang.SemanticToken, 0)
+
+		for _, item := range eType.Items {
+			tokens = append(tokens, lang.SemanticToken{
+				Type:      lang.TokenAttrName,
+				Modifiers: []lang.SemanticTokenModifier{},
+				Range:     item.KeyExpr.Range(),
+			})
+
+			cons := TypeDeclaration{
+				expr:    item.ValueExpr,
+				pathCtx: td.pathCtx,
+			}
+			tokens = append(tokens, cons.SemanticTokens(ctx)...)
+		}
+
+		return tokens
+	}
+	return nil
+}
diff --git a/decoder/expr_type_declaration_semtok_test.go b/decoder/expr_type_declaration_semtok_test.go
new file mode 100644
index 00000000..89270a21
--- /dev/null
+++ b/decoder/expr_type_declaration_semtok_test.go
@@ -0,0 +1,393 @@
+package decoder
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/hashicorp/hcl-lang/lang"
+	"github.com/hashicorp/hcl-lang/schema"
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+)
+
+func TestSemanticTokens_exprTypeDeclaration(t *testing.T) {
+	testCases := []struct {
+		testName       string
+		attrSchema     map[string]*schema.AttributeSchema
+		cfg            string
+		expectedTokens []lang.SemanticToken
+	}{
+		{
+			"primitive type",
+			map[string]*schema.AttributeSchema{
+				"attr": {
+					Constraint: schema.TypeDeclaration{},
+				},
+			},
+			`attr = string`,
+			[]lang.SemanticToken{
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 1, Byte: 0},
+						End:      hcl.Pos{Line: 1, Column: 5, Byte: 4},
+					},
+				},
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 8, Byte: 7},
+						End:      hcl.Pos{Line: 1, Column: 14, Byte: 13},
+					},
+				},
+			},
+		},
+		{
+			"invalid primitive type",
+			map[string]*schema.AttributeSchema{
+				"attr": {
+					Constraint: schema.TypeDeclaration{},
+				},
+			},
+			`attr = foobar`,
+			[]lang.SemanticToken{
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 1, Byte: 0},
+						End:      hcl.Pos{Line: 1, Column: 5, Byte: 4},
+					},
+				},
+			},
+		},
+		{
+			"single-argument complex type",
+			map[string]*schema.AttributeSchema{
+				"attr": {
+					Constraint: schema.TypeDeclaration{},
+				},
+			},
+			`attr = list(string)`,
+			[]lang.SemanticToken{
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 1, Byte: 0},
+						End:      hcl.Pos{Line: 1, Column: 5, Byte: 4},
+					},
+				},
+				{
+					Type:      lang.TokenTypeCapsule,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 8, Byte: 7},
+						End:      hcl.Pos{Line: 1, Column: 12, Byte: 11},
+					},
+				},
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 13, Byte: 12},
+						End:      hcl.Pos{Line: 1, Column: 19, Byte: 18},
+					},
+				},
+			},
+		},
+		{
+			"tuple",
+			map[string]*schema.AttributeSchema{
+				"attr": {
+					Constraint: schema.TypeDeclaration{},
+				},
+			},
+			`attr = tuple([string, bool, number])`,
+			[]lang.SemanticToken{
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 1, Byte: 0},
+						End:      hcl.Pos{Line: 1, Column: 5, Byte: 4},
+					},
+				},
+				{
+					Type:      lang.TokenTypeCapsule,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 8, Byte: 7},
+						End:      hcl.Pos{Line: 1, Column: 13, Byte: 12},
+					},
+				},
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 15, Byte: 14},
+						End:      hcl.Pos{Line: 1, Column: 21, Byte: 20},
+					},
+				},
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 23, Byte: 22},
+						End:      hcl.Pos{Line: 1, Column: 27, Byte: 26},
+					},
+				},
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 29, Byte: 28},
+						End:      hcl.Pos{Line: 1, Column: 35, Byte: 34},
+					},
+				},
+			},
+		},
+		{
+			"object",
+			map[string]*schema.AttributeSchema{
+				"attr": {
+					Constraint: schema.TypeDeclaration{},
+				},
+			},
+			`attr = object({
+  foo = string
+  bar = number
+})`,
+			[]lang.SemanticToken{
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 1, Byte: 0},
+						End:      hcl.Pos{Line: 1, Column: 5, Byte: 4},
+					},
+				},
+				{
+					Type:      lang.TokenTypeCapsule,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 8, Byte: 7},
+						End:      hcl.Pos{Line: 1, Column: 14, Byte: 13},
+					},
+				},
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 2, Column: 3, Byte: 18},
+						End:      hcl.Pos{Line: 2, Column: 6, Byte: 21},
+					},
+				},
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 2, Column: 9, Byte: 24},
+						End:      hcl.Pos{Line: 2, Column: 15, Byte: 30},
+					},
+				},
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 3, Column: 3, Byte: 33},
+						End:      hcl.Pos{Line: 3, Column: 6, Byte: 36},
+					},
+				},
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 3, Column: 9, Byte: 39},
+						End:      hcl.Pos{Line: 3, Column: 15, Byte: 45},
+					},
+				},
+			},
+		},
+		{
+			"object with complex types",
+			map[string]*schema.AttributeSchema{
+				"attr": {
+					Constraint: schema.TypeDeclaration{},
+				},
+			},
+			`attr = object({
+  foo = list(string)
+  bar = tuple([bool, string])
+  baz = object({
+    paw = string
+  })
+})`,
+			[]lang.SemanticToken{
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 1, Byte: 0},
+						End:      hcl.Pos{Line: 1, Column: 5, Byte: 4},
+					},
+				},
+				{
+					Type:      lang.TokenTypeCapsule,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 8, Byte: 7},
+						End:      hcl.Pos{Line: 1, Column: 14, Byte: 13},
+					},
+				},
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 2, Column: 3, Byte: 18},
+						End:      hcl.Pos{Line: 2, Column: 6, Byte: 21},
+					},
+				},
+				{
+					Type:      lang.TokenTypeCapsule,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 2, Column: 9, Byte: 24},
+						End:      hcl.Pos{Line: 2, Column: 13, Byte: 28},
+					},
+				},
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Start:    hcl.Pos{Line: 2, Column: 14, Byte: 29},
+						End:      hcl.Pos{Line: 2, Column: 20, Byte: 35},
+						Filename: "test.tf",
+					},
+				},
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Start:    hcl.Pos{Line: 3, Column: 3, Byte: 39},
+						End:      hcl.Pos{Line: 3, Column: 6, Byte: 42},
+						Filename: "test.tf",
+					},
+				},
+				{
+					Type:      lang.TokenTypeCapsule,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Start:    hcl.Pos{Line: 3, Column: 9, Byte: 45},
+						End:      hcl.Pos{Line: 3, Column: 14, Byte: 50},
+						Filename: "test.tf",
+					},
+				},
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Start:    hcl.Pos{Line: 3, Column: 16, Byte: 52},
+						End:      hcl.Pos{Line: 3, Column: 20, Byte: 56},
+						Filename: "test.tf",
+					},
+				},
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 3, Column: 22, Byte: 58},
+						End:      hcl.Pos{Line: 3, Column: 28, Byte: 64},
+					},
+				},
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 4, Column: 3, Byte: 69},
+						End:      hcl.Pos{Line: 4, Column: 6, Byte: 72},
+					},
+				},
+				{
+					Type:      lang.TokenTypeCapsule,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 4, Column: 9, Byte: 75},
+						End:      hcl.Pos{Line: 4, Column: 15, Byte: 81},
+					},
+				},
+				{
+					Type:      lang.TokenAttrName,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 5, Column: 5, Byte: 88},
+						End:      hcl.Pos{Line: 5, Column: 8, Byte: 91},
+					},
+				},
+				{
+					Type:      lang.TokenTypePrimitive,
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 5, Column: 11, Byte: 94},
+						End:      hcl.Pos{Line: 5, Column: 17, Byte: 100},
+					},
+				},
+			},
+		},
+	}
+	for i, tc := range testCases {
+		t.Run(fmt.Sprintf("%d-%s", i, tc.testName), func(t *testing.T) {
+			bodySchema := &schema.BodySchema{
+				Attributes: tc.attrSchema,
+			}
+
+			f, _ := hclsyntax.ParseConfig([]byte(tc.cfg), "test.tf", hcl.InitialPos)
+			d := testPathDecoder(t, &PathContext{
+				Schema: bodySchema,
+				Files: map[string]*hcl.File{
+					"test.tf": f,
+				},
+			})
+
+			ctx := context.Background()
+			hoverData, err := d.SemanticTokensInFile(ctx, "test.tf")
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if diff := cmp.Diff(tc.expectedTokens, hoverData); diff != "" {
+				t.Fatalf("unexpected tokens: %s", diff)
+			}
+		})
+	}
+}