fix(api): remove duplicate /api/traces endpoint that broke React UI (#9427)

The API Traces tab in /app/traces always showed (0) traces despite requests
being recorded.

The /api/traces endpoint was registered in both localai.go and ui_api.go.
The ui_api.go version wrapped the response as {"traces": [...]} instead of
the flat []APIExchange array that both the React UI (Traces.jsx) and the
legacy Alpine.js UI (traces.html) expect. Because Echo matched the ui_api.go
handler, Array.isArray(apiData) always returned false, making the API Traces
tab permanently empty.

Remove the duplicate endpoints from ui_api.go so only the correct flat-array
version in localai.go is served.

Also use mime.ParseMediaType for the Content-Type check in the trace
middleware so requests with parameters (e.g. application/json; charset=utf-8)
are still traced.

Signed-off-by: Pawel Brzozowski <paul@ontux.net>
Co-authored-by: Pawel Brzozowski <paul@ontux.net>

Author: pjbrzozowski

core/http/middleware/trace.go

@@ -3,6 +3,7 @@ package middleware
 import (
 	"bytes"
 	"io"
+	"mime"
 	"net/http"
 	"slices"
 	"sync"
@@ -94,7 +95,8 @@ func TraceMiddleware(app *application.Application) echo.MiddlewareFunc {
 
 			initializeTracing(app.ApplicationConfig().TracingMaxItems)
 
-			if c.Request().Header.Get("Content-Type") != "application/json" {
+			ct, _, _ := mime.ParseMediaType(c.Request().Header.Get("Content-Type"))
+			if ct != "application/json" {
 				return next(c)
 			}
 

core/http/routes/ui_api.go

@@ -23,7 +23,6 @@ import (
 	"github.com/mudler/LocalAI/core/gallery"
 	"github.com/mudler/LocalAI/core/http/auth"
 	"github.com/mudler/LocalAI/core/http/endpoints/localai"
-	"github.com/mudler/LocalAI/core/http/middleware"
 	"github.com/mudler/LocalAI/core/p2p"
 	"github.com/mudler/LocalAI/core/services/galleryop"
 	"github.com/mudler/LocalAI/pkg/model"
@@ -1458,24 +1457,5 @@ func RegisterUIAPIRoutes(app *echo.Echo, cl *config.ModelConfigLoader, ml *model
 		app.POST("/api/settings", localai.UpdateSettingsEndpoint(applicationInstance), adminMiddleware)
 	}
 
-	// Logs API (admin only)
-	app.GET("/api/traces", func(c echo.Context) error {
-		if !appConfig.EnableTracing {
-			return c.JSON(503, map[string]any{
-				"error": "Tracing disabled",
-			})
-		}
-		traces := middleware.GetTraces()
-		return c.JSON(200, map[string]any{
-			"traces": traces,
-		})
-	}, adminMiddleware)
-
-	app.POST("/api/traces/clear", func(c echo.Context) error {
-		middleware.ClearTraces()
-		return c.JSON(200, map[string]any{
-			"message": "Traces cleared",
-		})
-	}, adminMiddleware)
 }