fix: distinct signal exit codes, mid-stream API error surfacing, require model name with base URL

.github/workflows/publish-npm.yml

@@ -16,6 +16,11 @@ jobs:
 
     steps:
       - uses: actions/checkout@v6
+        with:
+          # Check out the released tag (workflow_run head_branch is the tag
+          # name), not main HEAD, so the packaging scripts and README match
+          # the release being published.
+          ref: ${{ github.event.workflow_run.head_branch }}
 
       - uses: actions/setup-node@v4
         with:

.github/workflows/publish-pypi.yml

@@ -17,6 +17,11 @@ jobs:
 
     steps:
       - uses: actions/checkout@v6
+        with:
+          # Check out the released tag (workflow_run head_branch is the tag
+          # name), not main HEAD, so the packaging scripts and README match
+          # the release being published.
+          ref: ${{ github.event.workflow_run.head_branch }}
 
       - uses: actions/setup-python@v5
         with:
@@ -58,4 +63,4 @@ jobs:
         uses: pypa/gh-action-pypi-publish@release/v1
         with:
           packages-dir: dist/wheels/
-          skip_existing: true
+          skip-existing: true

AGENTS.md

@@ -44,6 +44,8 @@ binaries → `publish-pypi.yml` assembles wheels and uploads to PyPI.
 ```
 cmd/mint/main.go                     # entry point; cobra root command; viper config wiring
 internal/llm/llm.go                  # Completer interface for LLM backends
+internal/llm/writer.go               # TrailingNewlineWriter shared by provider backends
+internal/httpx/httpx.go              # shared tuned *http.Client used by every provider
 internal/provider/
   config.go                          # Config struct; provider validation
   provider.go                        # NewCompleter factory function
@@ -96,6 +98,6 @@ bin/mint                             # compiled binary (gitignored)
 - Source language: optional `--source` / `-s` flag (BCP-47 tag); flag-only, no env var (a source is per-input, not a persistent preference). When set it skips detection and anchors the rewrite prompt to translate *from* that language, so cross-language homographs (e.g. French `chat` → English `cat`) and romanized input (e.g. `konnichiwa` → `hello`) are translated rather than treated as already-target text. Empty (the default) preserves the original auto-detect behavior. Pure language-neutral input still passes through unchanged regardless.
 - Language-neutral pass-through: if detected language is `neutral`, input is printed unchanged with no translation call.
 - Same-language behavior: if detected input language matches the target language, the tool performs grammar and spelling correction instead of translation.
-- Target language priority: `--target` flag → `MINT_TARGET_LANG` env var → system locale (`$LC_ALL` / `$LANG`) → `en`.
+- Target language priority: `--target` flag → `MINT_TARGET_LANG` env var → system locale (`$LC_ALL` / `$LC_MESSAGES` / `$LANG`) → `en`.
 - Language rotation: `MINT_TARGET_LANG` accepts a comma-separated list (e.g., `en,zh-TW,ja`); when the detected input language matches a tag in the list, the tool translates to the next tag (wraps around). BCP-47 variants sharing the same primary subtag (e.g., `zh-HK` and `zh-TW`) are treated as equivalent.
 - Input from positional arg or stdin (auto-detected).

Makefile

@@ -1,4 +1,6 @@
-VERSION ?= $(shell git describe --tags --exact-match 2>/dev/null || git rev-parse --short HEAD)
+# Leading "v" is stripped to match goreleaser's {{.Version}}, so `mint --version`
+# prints the same string for local builds and released binaries.
+VERSION ?= $(shell (git describe --tags --exact-match 2>/dev/null || git rev-parse --short HEAD) | sed 's/^v//')
 COMMIT ?= $(shell git rev-parse HEAD)
 LDFLAGS ?= -s -w -X main.version=$(VERSION) -X main.commit=$(COMMIT)
 NEW_FROM_REV ?= HEAD

README.ja.md

@@ -203,7 +203,7 @@ mint "こんにちは"   # ja → en: Hello
 | `MINT_PROVIDER` | `google-genai` \| `openai` \| `anthropic` | — (必須) |
 | `MINT_API_KEY` | APIキー。デフォルトのエンドポイント使用時は必須。`MINT_BASE_URL`設定時は任意（プロキシ側で認証処理する場合） | — |
 | `MINT_BASE_URL` | カスタムAPIベースURL（ドメインのみ指定、パスは各プロバイダーが自動付与）。`openai`と組み合わせることで、Ollama（`http://localhost:11434`）、LM Studio（`http://localhost:1234`）、またはOpenAI互換エンドポイントを指定可能 | プロバイダーのデフォルト |
-| `MINT_MODEL_NAME` | 使用するモデル名 | `gemini-3.1-flash-lite` / `gpt-4o-mini` / `claude-haiku-4-5` |
+| `MINT_MODEL_NAME` | 使用するモデル名（`MINT_BASE_URL` 設定時は必須） | `gemini-3.1-flash-lite` / `gpt-4o-mini` / `claude-haiku-4-5` |
 | `MINT_TARGET_LANG` | ターゲット言語（例: `en` または `en,zh-TW,ja`） | システムのロケール設定 |
 | `MINT_VERBOSE` | `true`に設定すると詳細な診断出力が有効になります（`--verbose`相当） | `false` |
 

README.md

@@ -203,7 +203,7 @@ mint "こんにちは"   # ja → en: Hello
 | `MINT_PROVIDER` | `google-genai` \| `openai` \| `anthropic` | — (required) |
 | `MINT_API_KEY` | API key; required when using the default endpoint; optional when `MINT_BASE_URL` is set (proxy handles auth) | — |
 | `MINT_BASE_URL` | Custom API base URL (domain only; each provider appends its own path); use with `openai` to target Ollama (`http://localhost:11434`), LM Studio (`http://localhost:1234`), or any other OpenAI-compatible endpoint | Provider default |
-| `MINT_MODEL_NAME` | Model to use | `gemini-3.1-flash-lite` / `gpt-4o-mini` / `claude-haiku-4-5` |
+| `MINT_MODEL_NAME` | Model to use; required when `MINT_BASE_URL` is set | `gemini-3.1-flash-lite` / `gpt-4o-mini` / `claude-haiku-4-5` |
 | `MINT_TARGET_LANG` | Target language(s), e.g. `en` or `en,zh-TW,ja` | System locale |
 | `MINT_VERBOSE` | Set to `true` to enable verbose diagnostic output (equivalent to `--verbose`) | `false` |
 

README.zh-TW.md

@@ -203,7 +203,7 @@ mint "こんにちは"   # ja → en: Hello
 | `MINT_PROVIDER` | `google-genai` \| `openai` \| `anthropic` | — (必填) |
 | `MINT_API_KEY` | API 金鑰；使用預設 endpoint 時必填；設定 `MINT_BASE_URL` 時選填（由代理處理認證） | — |
 | `MINT_BASE_URL` | 自訂 API base URL（僅填 domain，各提供商自行附加路徑）；搭配 `openai` 可指向 Ollama（`http://localhost:11434`）、LM Studio（`http://localhost:1234`）或任何 OpenAI 相容端點 | 提供商預設 |
-| `MINT_MODEL_NAME` | 使用的模型 | `gemini-3.1-flash-lite` / `gpt-4o-mini` / `claude-haiku-4-5` |
+| `MINT_MODEL_NAME` | 使用的模型；設定 `MINT_BASE_URL` 時必填 | `gemini-3.1-flash-lite` / `gpt-4o-mini` / `claude-haiku-4-5` |
 | `MINT_TARGET_LANG` | 目標語言，例如 `en` 或 `en,zh-TW,ja` | 系統區域設定 |
 | `MINT_VERBOSE` | 設為 `true` 可啟用詳細診斷輸出（等同於 `--verbose`） | `false` |
 

cmd/mint/main.go

@@ -38,24 +38,56 @@ func main() {
 	os.Exit(run())
 }
 
+// signalError is the cancel cause recorded when a termination signal arrives;
+// it carries the signal so run() can map it to the conventional exit code.
+type signalError struct{ sig os.Signal }
+
+func (e *signalError) Error() string { return "interrupted by " + e.sig.String() }
+
+// exitCode maps the signal to the shell convention 128+N: 130 for SIGINT,
+// 143 for SIGTERM.
+func (e *signalError) exitCode() int {
+	if s, ok := e.sig.(syscall.Signal); ok {
+		return 128 + int(s)
+	}
+
+	return 130
+}
+
 func run() int {
 	// No request timeout: the CLI waits as long as the backend needs (handy for
 	// slow local models). Ctrl+C / SIGTERM cancels the in-flight request.
-	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
-	defer stop()
+	//
+	// signal.NotifyContext is not used because it hides which signal fired,
+	// and SIGINT (130) and SIGTERM (143) must map to different exit codes; the
+	// cancel cause carries the signal instead.
+	ctx, cancel := context.WithCancelCause(context.Background())
+	defer cancel(nil)
+
+	sigCh := make(chan os.Signal, 1)
+
+	signal.Notify(sigCh, os.Interrupt, syscall.SIGTERM)
+	defer signal.Stop(sigCh)
+
+	go func() {
+		cancel(&signalError{sig: <-sigCh})
+	}()
 
 	if err := newRootCmd().ExecuteContext(ctx); err != nil {
 		// Compare against context.Cause(ctx), not context.Canceled: net/http
-		// surfaces context.Cause(ctx), which signal.NotifyContext sets to a
-		// private signalError rather than context.Canceled. Checking errors.Is
+		// surfaces context.Cause(ctx), which the signal goroutine above sets
+		// to a *signalErr rather than context.Canceled. Checking errors.Is
 		// against the actual cause (instead of just ctx.Err() != nil) also
 		// makes sure an unrelated error isn't misreported as a clean interrupt
 		// merely because a signal happened to arrive around the same time.
 		// (context.Cause(ctx) is nil until ctx is done, and errors.Is(err, nil)
 		// is always false for a non-nil err, so no separate nil check is needed.)
-		if errors.Is(err, context.Cause(ctx)) {
+		cause := context.Cause(ctx)
+
+		var sigErr *signalError
+		if errors.Is(err, cause) && errors.As(cause, &sigErr) {
 			// Interrupted by the user — exit quietly with the conventional code.
-			return 130
+			return sigErr.exitCode()
 		}
 
 		fmt.Fprintln(os.Stderr, "Error:", err)
@@ -505,9 +537,10 @@ func buildDetectPrompt(text string) (system, user, nonce string) {
 	return system, user, nonce
 }
 
-// getSystemLanguage gets the system language from the OS locale.
+// getSystemLanguage gets the system language from the OS locale, following the
+// POSIX priority order: LC_ALL > LC_MESSAGES > LANG.
 func getSystemLanguage() string {
-	for _, env := range []string{"LC_ALL", "LANG"} {
+	for _, env := range []string{"LC_ALL", "LC_MESSAGES", "LANG"} {
 		if lang := os.Getenv(env); lang != "" {
 			// Strip encoding suffix before cutting on "_":
 			// "C.UTF-8" → "C"; "en_US.UTF-8" → "en_US" (no change here)

cmd/mint/main_signal_test.go

@@ -0,0 +1,95 @@
+// Copyright 2026 The Mint Authors.
+
+// Signal-delivery tests live behind a unix build tag: they send real POSIX
+// signals to the test process via syscall.Kill, which does not exist on
+// Windows (and neither does meaningful SIGINT/SIGTERM delivery there).
+
+//go:build unix
+
+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"syscall"
+	"testing"
+	"time"
+)
+
+// TestRunInterrupted covers both signals run() registers (os.Interrupt and
+// syscall.SIGTERM): either one must cancel an in-flight request and exit
+// quietly with the conventional 128+N code (130 for SIGINT, 143 for SIGTERM).
+func TestRunInterrupted(t *testing.T) {
+	signals := []struct {
+		name     string
+		sig      syscall.Signal
+		wantCode int
+	}{
+		{"SIGINT", syscall.SIGINT, 130},
+		{"SIGTERM", syscall.SIGTERM, 143},
+	}
+
+	for _, tt := range signals {
+		t.Run(tt.name, func(t *testing.T) {
+			started := make(chan struct{})
+			done := make(chan struct{})
+
+			srv := httptest.NewServer(http.HandlerFunc(func(_ http.ResponseWriter, _ *http.Request) {
+				close(started)
+				<-done // held open until the test releases it, regardless of client-side cancellation
+			}))
+
+			defer func() {
+				close(done)
+				srv.Close()
+			}()
+
+			t.Setenv("MINT_PROVIDER", "openai")
+			t.Setenv("MINT_API_KEY", "test")
+			t.Setenv("MINT_BASE_URL", srv.URL)
+			t.Setenv("MINT_MODEL_NAME", "test-model")
+
+			old := os.Args
+
+			os.Args = []string{"mint", "--target", "en", "hello"}
+			defer func() { os.Args = old }()
+
+			flushOut := captureStdout(t)
+			flushErr := captureStderr(t)
+
+			codeCh := make(chan int, 1)
+
+			go func() { codeCh <- run() }()
+
+			select {
+			case <-started:
+			case <-time.After(5 * time.Second):
+				t.Fatal("request never reached the server")
+			}
+
+			if err := syscall.Kill(os.Getpid(), tt.sig); err != nil {
+				t.Fatalf("failed to send %s: %v", tt.name, err)
+			}
+
+			var code int
+
+			select {
+			case code = <-codeCh:
+			case <-time.After(5 * time.Second):
+				t.Fatalf("run() did not return after %s", tt.name)
+			}
+
+			stderrOutput := flushErr()
+			_ = flushOut()
+
+			if code != tt.wantCode {
+				t.Errorf("expected exit code %d, got %d", tt.wantCode, code)
+			}
+
+			if stderrOutput != "" {
+				t.Errorf("expected no stderr output on interrupt, got: %q", stderrOutput)
+			}
+		})
+	}
+}