diff --git a/internal/language/language.go b/internal/language/language.go
new file mode 100644
index 0000000..a821a4f
--- /dev/null
+++ b/internal/language/language.go
@@ -0,0 +1,120 @@
+package language
+
+// Language represents a supported transcription language
+type Language struct {
+	Code       string // ISO 639-1 code (e.g., "en", "es", "zh")
+	Name       string // English name (e.g., "English", "Spanish")
+	NativeName string // Native name (e.g., "English", "Espanol", "中文")
+}
+
+// Auto represents auto-detection - used when user doesn't specify a language
+var Auto = Language{Code: "", Name: "Auto-detect", NativeName: ""}
+
+// languages is the master list of supported languages
+// derived from OpenAI Whisper's 57 supported languages
+var languages = []Language{
+	{Code: "af", Name: "Afrikaans", NativeName: "Afrikaans"},
+	{Code: "ar", Name: "Arabic", NativeName: "العربية"},
+	{Code: "hy", Name: "Armenian", NativeName: "Հdelays"},
+	{Code: "az", Name: "Azerbaijani", NativeName: "Azərbaycan"},
+	{Code: "be", Name: "Belarusian", NativeName: "Беларуская"},
+	{Code: "bs", Name: "Bosnian", NativeName: "Bosanski"},
+	{Code: "bg", Name: "Bulgarian", NativeName: "Български"},
+	{Code: "ca", Name: "Catalan", NativeName: "Català"},
+	{Code: "zh", Name: "Chinese", NativeName: "中文"},
+	{Code: "hr", Name: "Croatian", NativeName: "Hrvatski"},
+	{Code: "cs", Name: "Czech", NativeName: "Čeština"},
+	{Code: "da", Name: "Danish", NativeName: "Dansk"},
+	{Code: "nl", Name: "Dutch", NativeName: "Nederlands"},
+	{Code: "en", Name: "English", NativeName: "English"},
+	{Code: "et", Name: "Estonian", NativeName: "Eesti"},
+	{Code: "fi", Name: "Finnish", NativeName: "Suomi"},
+	{Code: "fr", Name: "French", NativeName: "Français"},
+	{Code: "gl", Name: "Galician", NativeName: "Galego"},
+	{Code: "de", Name: "German", NativeName: "Deutsch"},
+	{Code: "el", Name: "Greek", NativeName: "Ελληνικά"},
+	{Code: "he", Name: "Hebrew", NativeName: "עברית"},
+	{Code: "hi", Name: "Hindi", NativeName: "हिन्दी"},
+	{Code: "hu", Name: "Hungarian", NativeName: "Magyar"},
+	{Code: "is", Name: "Icelandic", NativeName: "Íslenska"},
+	{Code: "id", Name: "Indonesian", NativeName: "Bahasa Indonesia"},
+	{Code: "it", Name: "Italian", NativeName: "Italiano"},
+	{Code: "ja", Name: "Japanese", NativeName: "日本語"},
+	{Code: "kn", Name: "Kannada", NativeName: "ಕನ್ನಡ"},
+	{Code: "kk", Name: "Kazakh", NativeName: "Қазақ"},
+	{Code: "ko", Name: "Korean", NativeName: "한국어"},
+	{Code: "lv", Name: "Latvian", NativeName: "Latviešu"},
+	{Code: "lt", Name: "Lithuanian", NativeName: "Lietuvių"},
+	{Code: "mk", Name: "Macedonian", NativeName: "Македонски"},
+	{Code: "ms", Name: "Malay", NativeName: "Bahasa Melayu"},
+	{Code: "mr", Name: "Marathi", NativeName: "मराठी"},
+	{Code: "mi", Name: "Maori", NativeName: "Māori"},
+	{Code: "ne", Name: "Nepali", NativeName: "नेपाली"},
+	{Code: "no", Name: "Norwegian", NativeName: "Norsk"},
+	{Code: "fa", Name: "Persian", NativeName: "فارسی"},
+	{Code: "pl", Name: "Polish", NativeName: "Polski"},
+	{Code: "pt", Name: "Portuguese", NativeName: "Português"},
+	{Code: "ro", Name: "Romanian", NativeName: "Română"},
+	{Code: "ru", Name: "Russian", NativeName: "Русский"},
+	{Code: "sr", Name: "Serbian", NativeName: "Српски"},
+	{Code: "sk", Name: "Slovak", NativeName: "Slovenčina"},
+	{Code: "sl", Name: "Slovenian", NativeName: "Slovenščina"},
+	{Code: "es", Name: "Spanish", NativeName: "Español"},
+	{Code: "sw", Name: "Swahili", NativeName: "Kiswahili"},
+	{Code: "sv", Name: "Swedish", NativeName: "Svenska"},
+	{Code: "tl", Name: "Tagalog", NativeName: "Tagalog"},
+	{Code: "ta", Name: "Tamil", NativeName: "தமிழ்"},
+	{Code: "th", Name: "Thai", NativeName: "ไทย"},
+	{Code: "tr", Name: "Turkish", NativeName: "Türkçe"},
+	{Code: "uk", Name: "Ukrainian", NativeName: "Українська"},
+	{Code: "ur", Name: "Urdu", NativeName: "اردو"},
+	{Code: "vi", Name: "Vietnamese", NativeName: "Tiếng Việt"},
+	{Code: "cy", Name: "Welsh", NativeName: "Cymraeg"},
+}
+
+// codeIndex maps language codes to their Language structs for fast lookup
+var codeIndex map[string]Language
+
+func init() {
+	codeIndex = make(map[string]Language, len(languages)+1)
+	codeIndex[""] = Auto // auto-detect is valid
+	for _, lang := range languages {
+		codeIndex[lang.Code] = lang
+	}
+}
+
+// FromCode returns the Language for the given code.
+// Returns Auto if code is not found.
+func FromCode(code string) Language {
+	if lang, ok := codeIndex[code]; ok {
+		return lang
+	}
+	return Auto
+}
+
+// List returns all supported languages (excluding Auto)
+func List() []Language {
+	result := make([]Language, len(languages))
+	copy(result, languages)
+	return result
+}
+
+// Codes returns all language codes (excluding empty string for auto)
+func Codes() []string {
+	codes := make([]string, len(languages))
+	for i, lang := range languages {
+		codes[i] = lang.Code
+	}
+	return codes
+}
+
+// AllLanguageCodes is an alias for Codes - used by models that support all languages
+func AllLanguageCodes() []string {
+	return Codes()
+}
+
+// IsValidCode returns true if the code is recognized (including empty for auto)
+func IsValidCode(code string) bool {
+	_, ok := codeIndex[code]
+	return ok
+}
diff --git a/internal/language/language_test.go b/internal/language/language_test.go
new file mode 100644
index 0000000..7eda70e
--- /dev/null
+++ b/internal/language/language_test.go
@@ -0,0 +1,119 @@
+package language
+
+import "testing"
+
+func TestFromCode(t *testing.T) {
+	tests := []struct {
+		code     string
+		wantCode string
+		wantName string
+	}{
+		{"en", "en", "English"},
+		{"es", "es", "Spanish"},
+		{"zh", "zh", "Chinese"},
+		{"invalid", "", "Auto-detect"},
+		{"", "", "Auto-detect"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.code, func(t *testing.T) {
+			got := FromCode(tt.code)
+			if got.Code != tt.wantCode {
+				t.Errorf("FromCode(%q).Code = %q, want %q", tt.code, got.Code, tt.wantCode)
+			}
+			if got.Name != tt.wantName {
+				t.Errorf("FromCode(%q).Name = %q, want %q", tt.code, got.Name, tt.wantName)
+			}
+		})
+	}
+}
+
+func TestFromCodeEnglish(t *testing.T) {
+	lang := FromCode("en")
+	if lang.Code != "en" {
+		t.Errorf("FromCode('en').Code = %q, want 'en'", lang.Code)
+	}
+	if lang.Name != "English" {
+		t.Errorf("FromCode('en').Name = %q, want 'English'", lang.Name)
+	}
+	if lang.NativeName != "English" {
+		t.Errorf("FromCode('en').NativeName = %q, want 'English'", lang.NativeName)
+	}
+}
+
+func TestIsValidCode(t *testing.T) {
+	tests := []struct {
+		code string
+		want bool
+	}{
+		{"en", true},
+		{"es", true},
+		{"zh", true},
+		{"invalid", false},
+		{"", true}, // auto is valid
+		{"xyz", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.code, func(t *testing.T) {
+			got := IsValidCode(tt.code)
+			if got != tt.want {
+				t.Errorf("IsValidCode(%q) = %v, want %v", tt.code, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestList(t *testing.T) {
+	list := List()
+	if len(list) != 57 {
+		t.Errorf("List() returned %d languages, want 57", len(list))
+	}
+
+	// verify English is in the list
+	found := false
+	for _, lang := range list {
+		if lang.Code == "en" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Error("List() does not contain English")
+	}
+}
+
+func TestCodes(t *testing.T) {
+	codes := Codes()
+	if len(codes) != 57 {
+		t.Errorf("Codes() returned %d codes, want 57", len(codes))
+	}
+
+	// verify 'en' is in the codes
+	found := false
+	for _, code := range codes {
+		if code == "en" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Error("Codes() does not contain 'en'")
+	}
+}
+
+func TestAllLanguageCodes(t *testing.T) {
+	codes := AllLanguageCodes()
+	if len(codes) != 57 {
+		t.Errorf("AllLanguageCodes() returned %d codes, want 57", len(codes))
+	}
+}
+
+func TestAuto(t *testing.T) {
+	if Auto.Code != "" {
+		t.Errorf("Auto.Code = %q, want empty string", Auto.Code)
+	}
+	if Auto.Name != "Auto-detect" {
+		t.Errorf("Auto.Name = %q, want 'Auto-detect'", Auto.Name)
+	}
+}
diff --git a/progress.txt b/progress.txt
new file mode 100644
index 0000000..ddd2bd0
--- /dev/null
+++ b/progress.txt
@@ -0,0 +1,11 @@
+# Ralph Progress Log
+Started: Sun Feb  1 12:22:47 AM CET 2026
+---
+
+## Completed
+
+### Task 1: Create language package with core types and helpers
+- Created `internal/language/language.go` with Language struct, Auto constant
+- Implemented FromCode, List, Codes, AllLanguageCodes, IsValidCode
+- Full 57 language list from OpenAI Whisper
+- All tests passing, typecheck passes
diff --git a/tasks/prd.jsonc b/tasks/prd.jsonc
index 1aea892..81e600a 100644
--- a/tasks/prd.jsonc
+++ b/tasks/prd.jsonc
@@ -26,7 +26,7 @@
 				"IsValidCode('') returns true (auto is valid)",
 				"Typecheck passes"
 			],
-			"passes": false
+			"passes": true
 		},
 		{
 			"title": "Add language list and provider-specific mappings",