Boeing · mvanhorn · Apr 28, 2026
@@ -41,7 +41,7 @@
 Config File Validator is a cross-platform CLI tool that validates configuration files in your project. Catch syntax errors, schema violations, and misconfigurations across all your config files — with one tool.
 
 - **Single binary, zero dependencies** — no runtimes, no package managers, just one executable
-- **16 file formats** — JSON, JSONC, YAML, TOML, XML, HCL, INI, HOCON, ENV, CSV, Properties, EDITORCONFIG, Justfile, PList, SARIF, and TOON
+- **17 file formats** — JSON, JSONC, YAML, TOML, XML, HCL, INI, HOCON, ENV, CSV, Properties, EDITORCONFIG, Justfile, KDL, PList, SARIF, and TOON
 - **Syntax + schema validation** — validates structure with [JSON Schema](https://json-schema.org/) and XSD, with automatic [SchemaStore](https://www.schemastore.org/) integration
 - **CI/CD ready** — JSON, JUnit, and SARIF output for GitHub Actions, GitLab CI, Jenkins, and more
 - **Configurable** — project-level `.cfv.toml` config files, glob patterns, schema mappings, and environment variables
@@ -77,6 +77,7 @@ Config File Validator is a cross-platform CLI tool that validates configuration
 | Justfile | ✅ | ❌ |
 | JSON | ✅ | ✅ |
 | JSONC | ✅ | ✅ |
+| KDL | ✅ | ❌ |
 | Properties | ✅ | ❌ |
 | SARIF | ✅ | ✅ |
 | TOML | ✅ | ✅ |

@@ -25,6 +25,8 @@ require (
 	howett.net/plist v1.0.1
 )
 
+require github.com/sblinch/kdl-go v0.0.0-20260121213736-8b7053306ca6
+
 require (
 	github.com/Boeing/go-just v0.0.0
 	github.com/agext/levenshtein v1.2.1 // indirect
@@ -35,13 +37,11 @@ require (
 	github.com/go-git/gcfg v1.5.1-0.20230307220236-3a3c6141e376 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
-	github.com/lestrrat-go/helium v0.0.1
 	github.com/lestrrat-go/pdebug v0.0.0-20210111095411-35b07dbf089b // indirect
 	github.com/mattn/go-colorable v0.1.14 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mitchellh/go-wordwrap v0.0.0-20150314170334-ad45545899c7 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/tailscale/hujson v0.0.0-20260302212456-ecc657c15afd
 	github.com/xeipuuv/gojsonpointer v0.0.0-20180127040702-4e3ac2762d5f // indirect
 	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
 	github.com/zclconf/go-cty v1.13.0 // indirect

@@ -64,6 +64,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
 github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
+github.com/sblinch/kdl-go v0.0.0-20260121213736-8b7053306ca6 h1:JsjzqC6ymELkN4XlTjZPSahSAem21GySugLbKz6uF5E=
+github.com/sblinch/kdl-go v0.0.0-20260121213736-8b7053306ca6/go.mod h1:b3oNGuAKOQzhsCKmuLc/urEOPzgHj6fB8vl8bwTBh28=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
@@ -104,18 +106,6 @@ golang.org/x/text v0.36.0 h1:JfKh3XmcRPqZPKevfXVpI1wXPTqbkE5f7JA92a55Yxg=
 golang.org/x/text v0.36.0/go.mod h1:NIdBknypM8iqVmPiuco0Dh6P5Jcdk8lJL0CUebqK164=
 golang.org/x/tools v0.43.0 h1:12BdW9CeB3Z+J/I/wj34VMl8X+fEXBxVR90JeMX5E7s=
 golang.org/x/tools v0.43.0/go.mod h1:uHkMso649BX2cZK6+RpuIPXS3ho2hZo4FVwfoy1vIk0=
-golang.org/x/mod v0.33.0 h1:tHFzIWbBifEmbwtGz65eaWyGiGZatSrT9prnU8DbVL8=
-golang.org/x/mod v0.33.0/go.mod h1:swjeQEj+6r7fODbD2cqrnje9PnziFuw4bmLbBZFrQ5w=
-golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
-golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
-golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
-golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
-golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
-golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
-golang.org/x/tools v0.42.0 h1:uNgphsn75Tdz5Ji2q36v/nsFSfR/9BRFvqhGBaJGd5k=
-golang.org/x/tools v0.42.0/go.mod h1:Ma6lCIwGZvHK6XtgbswSoWroEkhugApmsXyrUmBhfr0=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

@@ -158,6 +158,15 @@ var JustfileFileType = FileType{
 	Validator: validator.JustfileValidator{},
 }
 
+// Instance of the FileType object to
+// represent a KDL (KDL Document Language) file.
+// See https://kdl.dev/ for the spec.
+var KdlFileType = FileType{
+	Name:       "kdl",
+	Extensions: arrToMap("kdl"),
+	Validator:  validator.KdlValidator{},
+}
+
 // extraKnownFiles contains manual entries not covered by Linguist.
 var extraKnownFiles = map[string][]string{
 	"ini": {
@@ -187,6 +196,7 @@ var fileTypeRegistry = map[string]*FileType{
 	"toon":       &ToonFileType,
 	"sarif":      &SarifFileType,
 	"justfile":   &JustfileFileType,
+	"kdl":        &KdlFileType,
 }
 
 // excludeKnownFiles lists Linguist entries to skip because we have
@@ -258,6 +268,7 @@ func init() {
 		SarifFileType,
 		JSONCFileType,
 		JustfileFileType,
+		KdlFileType,
 	}
 }
 

@@ -0,0 +1,37 @@
+package validator
+
+import (
+	"bytes"
+	"regexp"
+	"strconv"
+
+	kdl "github.com/sblinch/kdl-go"
+)
+
+// kdlLineRe matches the "at line N, column M" suffix the upstream parser
+// appends to scan/parse errors so we can surface the position via
+// ValidationError instead of leaving it buried in the message.
+var kdlLineRe = regexp.MustCompile(`at line (\d+), column (\d+)`)
+
+// KdlValidator validates KDL Document Language files via the sblinch/kdl-go
+// parser. It implements ValidateSyntax only — KDL has no schema system, so
+// it does not implement SchemaValidator.
+//
+// See https://kdl.dev/ for the KDL spec.
+type KdlValidator struct{}
+
+var _ Validator = KdlValidator{}
+
+func (KdlValidator) ValidateSyntax(b []byte) (bool, error) {
+	if _, err := kdl.Parse(bytes.NewReader(b)); err != nil {
+		if m := kdlLineRe.FindStringSubmatch(err.Error()); m != nil {
+			line, lineErr := strconv.Atoi(m[1])
+			col, colErr := strconv.Atoi(m[2])
+			if lineErr == nil && colErr == nil {
+				return false, &ValidationError{Err: err, Line: line, Column: col}
+			}
+		}
+		return false, err
+	}
+	return true, nil
+}
@@ -162,6 +162,10 @@ var testData = []struct {
 	{"validJsoncTrailingComma", []byte(`{"a": 1, "b": 2,}`), true, JSONCValidator{}},
 	{"invalidJsonc", []byte(`{"bad": }`), false, JSONCValidator{}},
 	{"validJsoncNoComments", []byte(`{"key": "value"}`), true, JSONCValidator{}},
+	{"validKdl", []byte("name \"Bob\"\nage 76\nactive true\n"), true, KdlValidator{}},
+	{"validKdlChildren", []byte("package {\n    name \"foo\"\n    version \"1.0\"\n}\n"), true, KdlValidator{}},
+	{"invalidKdlUnterminatedString", []byte("name \"Bob\n"), false, KdlValidator{}},
+	{"invalidKdlUnclosedChildren", []byte("package {\n    name \"foo\"\n"), false, KdlValidator{}},
 }
 
 func Test_ValidationInput(t *testing.T) {