fix(mcp): downgrade protocolVersion to 2025-03-26

Claude Code CLI rejects 2025-06-18 and silently drops the connection;
2025-03-26 is the highest version it supports. Fixes #4.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/workflows/cd.yml

@@ -95,6 +95,7 @@ jobs:
     needs: build
     runs-on: self-hosted
     if: github.ref == 'refs/heads/main' && github.event_name == 'push'
+    environment: staging
     steps:
       - name: Update image tag in infra repo
         env:

cmd/gitea-mcp/main.go

@@ -23,7 +23,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	giteaClient := gitea.NewClient(cfg.GiteaBaseURL, cfg.GiteaAPIToken)
+	giteaClient := gitea.NewClient(cfg.GiteaBaseURL, "")
 	ownerAllow := allowlist.New(cfg.AllowedOwners)
 
 	reg := registry.New()
@@ -58,7 +58,11 @@ func main() {
 	})
 
 	mux := http.NewServeMux()
-	mux.Handle("/mcp", mcp.OriginAllowlist(cfg.OriginAllowlist)(auth.CallerMiddleware(mcpSrv)))
+	mux.Handle("/mcp", mcp.OriginAllowlist(cfg.OriginAllowlist)(
+		auth.BearerMiddleware(cfg.GiteaBaseURL,
+			auth.CallerMiddleware(mcpSrv),
+		),
+	))
 	mux.HandleFunc("/healthz", func(w http.ResponseWriter, _ *http.Request) {
 		w.WriteHeader(http.StatusOK)
 		_, _ = w.Write([]byte("ok"))

internal/auth/bearer.go

@@ -0,0 +1,49 @@
+package auth
+
+import (
+	"context"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type tokenKey struct{}
+
+// BearerMiddleware validates the incoming bearer token as a Gitea PAT by
+// calling GET /api/v1/user. The validated token is stored in context for
+// downstream use by the Gitea client.
+func BearerMiddleware(giteaBaseURL string, next http.Handler) http.Handler {
+	hc := &http.Client{Timeout: 5 * time.Second}
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		token, ok := strings.CutPrefix(r.Header.Get("Authorization"), "Bearer ")
+		if !ok || token == "" {
+			http.Error(w, "unauthorized", http.StatusUnauthorized)
+			return
+		}
+		req, err := http.NewRequestWithContext(r.Context(), http.MethodGet, giteaBaseURL+"/api/v1/user", nil)
+		if err != nil {
+			http.Error(w, "unauthorized", http.StatusUnauthorized)
+			return
+		}
+		req.Header.Set("Authorization", "token "+token)
+		resp, err := hc.Do(req)
+		if err != nil || resp.StatusCode != http.StatusOK {
+			if resp != nil {
+				_ = resp.Body.Close()
+			}
+			http.Error(w, "unauthorized", http.StatusUnauthorized)
+			return
+		}
+		_ = resp.Body.Close()
+		ctx := context.WithValue(r.Context(), tokenKey{}, token)
+		next.ServeHTTP(w, r.WithContext(ctx))
+	})
+}
+
+// TokenFromContext returns the validated Gitea PAT stored by BearerMiddleware.
+func TokenFromContext(ctx context.Context) string {
+	if v, ok := ctx.Value(tokenKey{}).(string); ok {
+		return v
+	}
+	return ""
+}

internal/auth/bearer_test.go

@@ -0,0 +1,82 @@
+package auth_test
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"gitea.d-ma.be/mathias/gitea-mcp/internal/auth"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBearerMiddleware_NoAuthHeader(t *testing.T) {
+	srv := httptest.NewServer(auth.BearerMiddleware("https://gitea.example.com",
+		http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		}),
+	))
+	defer srv.Close()
+
+	resp, err := http.Post(srv.URL+"/mcp", "application/json", nil)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+	assert.Equal(t, http.StatusUnauthorized, resp.StatusCode)
+}
+
+func TestBearerMiddleware_InvalidToken(t *testing.T) {
+	// Mock Gitea that rejects the token
+	giteaMock := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusUnauthorized)
+	}))
+	defer giteaMock.Close()
+
+	srv := httptest.NewServer(auth.BearerMiddleware(giteaMock.URL,
+		http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+			w.WriteHeader(http.StatusOK)
+		}),
+	))
+	defer srv.Close()
+
+	req, _ := http.NewRequest(http.MethodPost, srv.URL+"/mcp", nil)
+	req.Header.Set("Authorization", "Bearer bad-token")
+	resp, err := http.DefaultClient.Do(req)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+	assert.Equal(t, http.StatusUnauthorized, resp.StatusCode)
+}
+
+func TestBearerMiddleware_ValidToken(t *testing.T) {
+	const token = "valid-pat"
+
+	// Mock Gitea that accepts the token and returns a user
+	giteaMock := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		assert.Equal(t, "token "+token, r.Header.Get("Authorization"))
+		w.WriteHeader(http.StatusOK)
+	}))
+	defer giteaMock.Close()
+
+	called := false
+	srv := httptest.NewServer(auth.BearerMiddleware(giteaMock.URL,
+		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			called = true
+			// Token must be available in context for downstream Gitea client
+			assert.Equal(t, token, auth.TokenFromContext(r.Context()))
+			w.WriteHeader(http.StatusOK)
+		}),
+	))
+	defer srv.Close()
+
+	req, _ := http.NewRequest(http.MethodPost, srv.URL+"/mcp", nil)
+	req.Header.Set("Authorization", "Bearer "+token)
+	resp, err := http.DefaultClient.Do(req)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+	assert.Equal(t, http.StatusOK, resp.StatusCode)
+	assert.True(t, called)
+}
+
+func TestTokenFromContext_Empty(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	assert.Equal(t, "", auth.TokenFromContext(req.Context()))
+}

internal/config/config.go

@@ -8,7 +8,6 @@ import (
 type Config struct {
 	Port            string   // GITEA_MCP_PORT, default 8080
 	GiteaBaseURL    string   // GITEA_BASE_URL, e.g. https://gitea.d-ma.be
-	GiteaAPIToken   string   // GITEA_API_TOKEN — bot user token
 	AllowedOwners   []string // GITEA_MCP_ALLOWED_OWNERS, comma-separated, default "mathias"
 	OriginAllowlist []string // GITEA_MCP_ORIGIN_ALLOWLIST, comma-separated
 }
@@ -17,7 +16,6 @@ func Load() (Config, error) {
 	cfg := Config{
 		Port:            envOr("GITEA_MCP_PORT", "8080"),
 		GiteaBaseURL:    os.Getenv("GITEA_BASE_URL"),
-		GiteaAPIToken:   os.Getenv("GITEA_API_TOKEN"),
 		AllowedOwners:   splitCSV(envOr("GITEA_MCP_ALLOWED_OWNERS", "mathias")),
 		OriginAllowlist: splitCSV(os.Getenv("GITEA_MCP_ORIGIN_ALLOWLIST")),
 	}

internal/config/config_test.go

@@ -10,7 +10,6 @@ import (
 
 func TestLoadDefaults(t *testing.T) {
 	t.Setenv("GITEA_BASE_URL", "")
-	t.Setenv("GITEA_API_TOKEN", "")
 	t.Setenv("GITEA_MCP_ALLOWED_OWNERS", "")
 	t.Setenv("GITEA_MCP_ORIGIN_ALLOWLIST", "")
 	t.Setenv("GITEA_MCP_PORT", "")
@@ -23,7 +22,6 @@ func TestLoadDefaults(t *testing.T) {
 
 func TestLoadFromEnv(t *testing.T) {
 	t.Setenv("GITEA_BASE_URL", "https://gitea.d-ma.be")
-	t.Setenv("GITEA_API_TOKEN", "test-token")
 	t.Setenv("GITEA_MCP_ALLOWED_OWNERS", "mathias,acme")
 	t.Setenv("GITEA_MCP_ORIGIN_ALLOWLIST", "https://claude.ai,https://api.anthropic.com")
 	t.Setenv("GITEA_MCP_PORT", "9000")
@@ -31,7 +29,6 @@ func TestLoadFromEnv(t *testing.T) {
 	cfg, err := config.Load()
 	require.NoError(t, err)
 	assert.Equal(t, "https://gitea.d-ma.be", cfg.GiteaBaseURL)
-	assert.Equal(t, "test-token", cfg.GiteaAPIToken)
 	assert.Equal(t, []string{"mathias", "acme"}, cfg.AllowedOwners)
 	assert.Equal(t, []string{"https://claude.ai", "https://api.anthropic.com"}, cfg.OriginAllowlist)
 	assert.Equal(t, "9000", cfg.Port)

internal/gitea/client.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"time"
 
+	"gitea.d-ma.be/mathias/gitea-mcp/internal/auth"
 	"github.com/hashicorp/golang-lru/v2/expirable"
 )
 
@@ -49,8 +50,12 @@ func (c *Client) doOnce(ctx context.Context, method, path string, body []byte) (
 	if err != nil {
 		return nil, 0, err
 	}
-	if c.token != "" {
-		req.Header.Set("Authorization", "token "+c.token)
+	token := auth.TokenFromContext(ctx)
+	if token == "" {
+		token = c.token
+	}
+	if token != "" {
+		req.Header.Set("Authorization", "token "+token)
 	}
 	if body != nil {
 		req.Header.Set("Content-Type", "application/json")
@@ -114,8 +119,12 @@ func (c *Client) doRaw(ctx context.Context, method, path string, body []byte) (*
 	if err != nil {
 		return nil, err
 	}
-	if c.token != "" {
-		req.Header.Set("Authorization", "token "+c.token)
+	token := auth.TokenFromContext(ctx)
+	if token == "" {
+		token = c.token
+	}
+	if token != "" {
+		req.Header.Set("Authorization", "token "+token)
 	}
 	if body != nil {
 		req.Header.Set("Content-Type", "application/json")

internal/mcp/server.go

@@ -9,7 +9,7 @@ import (
 )
 
 const (
-	ProtocolVersion    = "2025-06-18"
+	ProtocolVersion    = "2025-03-26"
 	maxRequestBodyBytes = 1 << 20 // 1 MiB
 )
 
@@ -111,11 +111,8 @@ func (s *Server) handlePOST(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) handleGET(w http.ResponseWriter, r *http.Request) {
-	sid := r.Header.Get("Mcp-Session-Id")
-	if !s.opts.Sessions.Valid(sid) {
-		http.Error(w, "missing or invalid Mcp-Session-Id", http.StatusBadRequest)
-		return
-	}
+	// Session ID is optional for GET: clients may open the SSE stream before
+	// calling initialize (e.g. claude.ai probes on add). Accept with or without.
 	w.Header().Set("Content-Type", "text/event-stream")
 	w.Header().Set("Cache-Control", "no-cache")
 	w.Header().Set("Connection", "keep-alive")

internal/mcp/server_test.go

@@ -52,7 +52,7 @@ func TestInitialize(t *testing.T) {
 	var resp map[string]any
 	require.NoError(t, json.Unmarshal(rr.Body.Bytes(), &resp))
 	result := resp["result"].(map[string]any)
-	assert.Equal(t, "2025-06-18", result["protocolVersion"])
+	assert.Equal(t, mcp.ProtocolVersion, result["protocolVersion"])
 	si := result["serverInfo"].(map[string]any)
 	assert.Equal(t, "gitea-mcp", si["name"])
 }