feat(gitea): support extra outbound HTTP headers via GITEA_EXTRA_HEADERS

Add a GITEA_EXTRA_HEADERS environment variable that accepts a JSON
object of header name/value pairs (e.g. Cloudflare Access
credentials) and applies them to every outbound request to Gitea,
both the raw pkg/gitea.DoJSON/DoBytes path and the SDK-backed
pkg/gitea.NewClient path, without overriding Authorization,
Content-Type, or Accept.

Co-Authored-By: Codet <codet@commitgo.dev> (GPT-5-Codex)

pkg/flag/flag.go

@@ -1,5 +1,7 @@
 package flag
 
+import "net/http"
+
 var (
 	Host    string
 	Bind    string
@@ -15,4 +17,5 @@ var (
 	Debug         bool
 	AllowedTools  map[string]struct{}
 	AllowedScopes map[string]struct{}
+	ExtraHeaders  http.Header
 )

pkg/gitea/gitea.go

@@ -30,6 +30,32 @@ func sharedTransport() *http.Transport {
 	return sharedTrans
 }
 
+// extraHeaderTransport injects flag.ExtraHeaders into every request, without
+// overriding headers the caller already set (e.g. Authorization, Content-Type,
+// Accept). It reads flag.ExtraHeaders on each round trip rather than caching
+// it, so tests can change it between requests.
+type extraHeaderTransport struct {
+	base http.RoundTripper
+}
+
+func (t *extraHeaderTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	headers := flag.ExtraHeaders
+	if len(headers) == 0 {
+		return t.base.RoundTrip(req)
+	}
+	cloned := req.Clone(req.Context())
+	for name, values := range headers {
+		if cloned.Header.Get(name) == "" {
+			cloned.Header[name] = values
+		}
+	}
+	return t.base.RoundTrip(cloned)
+}
+
+func giteaTransport() http.RoundTripper {
+	return &extraHeaderTransport{base: sharedTransport()}
+}
+
 // NewClient returns a cached *gitea.Client keyed by host+token. The SDK's per-client
 // version cache and the shared transport let us reuse keep-alive connections
 // and avoid the SDK's /api/v1/version preflight on every tool call.
@@ -40,7 +66,7 @@ func NewClient(token string) (*gitea.Client, error) {
 	}
 
 	httpClient := &http.Client{
-		Transport:     sharedTransport(),
+		Transport:     giteaTransport(),
 		CheckRedirect: checkRedirect,
 	}
 	opts := []gitea.ClientOption{

pkg/gitea/gitea_test.go

@@ -0,0 +1,49 @@
+package gitea
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"gitea.com/gitea/gitea-mcp/pkg/flag"
+)
+
+func TestNewClient_SendsExtraHeaders(t *testing.T) {
+	var gotClientID, gotAuthorization string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotClientID = r.Header.Get("CF-Access-Client-Id")
+		gotAuthorization = r.Header.Get("Authorization")
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte(`{"login":"octocat"}`))
+	}))
+	defer srv.Close()
+
+	origHost := flag.Host
+	origExtraHeaders := flag.ExtraHeaders
+	defer func() {
+		flag.Host = origHost
+		flag.ExtraHeaders = origExtraHeaders
+	}()
+	flag.Host = srv.URL
+	flag.ExtraHeaders = http.Header{
+		"Cf-Access-Client-Id": []string{"client-id"},
+		"Authorization":       []string{"should-not-override"},
+	}
+
+	client, err := NewClient("the-token")
+	if err != nil {
+		t.Fatalf("NewClient returned error: %v", err)
+	}
+	if _, _, err := client.Users.GetMyUserInfo(context.Background()); err != nil {
+		t.Fatalf("GetMyUserInfo returned error: %v", err)
+	}
+
+	if gotClientID != "client-id" {
+		t.Fatalf("CF-Access-Client-Id header = %q, want %q", gotClientID, "client-id")
+	}
+	if gotAuthorization != "token the-token" {
+		t.Fatalf("Authorization header = %q, want %q", gotAuthorization, "token the-token")
+	}
+}

pkg/gitea/rest.go

@@ -59,7 +59,7 @@ var (
 func restHTTPClient() *http.Client {
 	restClientOnce.Do(func() {
 		restClient = &http.Client{
-			Transport:     sharedTransport(),
+			Transport:     giteaTransport(),
 			Timeout:       httpClientTimeout,
 			CheckRedirect: checkRedirect,
 		}
@@ -180,7 +180,7 @@ func DoJSON(ctx context.Context, method, path string, query url.Values, body, re
 
 func attachmentHTTPClient(origin *url.URL) *http.Client {
 	return &http.Client{
-		Transport: sharedTransport(),
+		Transport: giteaTransport(),
 		CheckRedirect: func(req *http.Request, via []*http.Request) error {
 			if err := checkRedirect(req, via); err != nil {
 				return err

pkg/gitea/rest_test.go

@@ -62,3 +62,44 @@ func TestDoJSON_LimitsErrorResponseBody(t *testing.T) {
 		t.Fatalf("expected body length %d, got %d", errBodySnippetSize, len(httpErr.Body))
 	}
 }
+
+func TestDoJSON_SendsExtraHeaders(t *testing.T) {
+	var gotClientID, gotAuthorization string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotClientID = r.Header.Get("CF-Access-Client-Id")
+		gotAuthorization = r.Header.Get("Authorization")
+		w.WriteHeader(http.StatusOK)
+		_, _ = io.WriteString(w, "{}")
+	}))
+	defer srv.Close()
+
+	origHost := flag.Host
+	origToken := flag.Token
+	origExtraHeaders := flag.ExtraHeaders
+	defer func() {
+		flag.Host = origHost
+		flag.Token = origToken
+		flag.ExtraHeaders = origExtraHeaders
+	}()
+	flag.Host = srv.URL
+	flag.Token = "the-token"
+	flag.ExtraHeaders = http.Header{
+		"Cf-Access-Client-Id": []string{"client-id"},
+		"Authorization":       []string{"should-not-override"},
+	}
+
+	var out map[string]any
+	status, err := DoJSON(context.Background(), http.MethodGet, "repos/owner/repo", nil, nil, &out)
+	if err != nil {
+		t.Fatalf("DoJSON returned error: %v", err)
+	}
+	if status != http.StatusOK {
+		t.Fatalf("expected status %d, got %d", http.StatusOK, status)
+	}
+	if gotClientID != "client-id" {
+		t.Fatalf("CF-Access-Client-Id header = %q, want %q", gotClientID, "client-id")
+	}
+	if gotAuthorization != "token the-token" {
+		t.Fatalf("Authorization header = %q, want %q", gotAuthorization, "token the-token")
+	}
+}