diff --git a/backend/cmd/main.go b/backend/cmd/main.go
index b7c5575..304e5f6 100644
--- a/backend/cmd/main.go
+++ b/backend/cmd/main.go
@@ -90,6 +90,19 @@ func main() {
 		logger.Info("PDF-Templates erfolgreich initialisiert")
 	}
 
+	// Initialize import/export adapter registry
+	logger.Debug("Initialisiere Adapter-Registry...")
+	adapterRegistry := importer.NewAdapterRegistry()
+	importer.InitializeRegistry(adapterRegistry)
+
+	// Register adapters from config (if any)
+	// TODO: Load adapters from environment variable IMPORT_ADAPTERS
+	// For now, registry is empty and adapters can be registered manually
+
+	// Start background health checker (runs every 30s)
+	adapterRegistry.StartBackgroundHealthChecker()
+	logger.Info("Adapter-Registry erfolgreich initialisiert und Health-Checker gestartet")
+
 	r := gin.Default()
 	router.SetupGin(r)
 
@@ -103,6 +116,7 @@ func main() {
 	equipment.RegisterRoutes(protected)
 	maintenance.RegisterRoutes(protected)
 	importero.RegisterRoutes(protected)
+	importer.RegisterRoutes(protected) // New pluggable import/export system
 	pdfrender.RegisterRoutes(protected)
 	transfero.RegisterRoutes(protected)
 	appsystem.RegisterRoutes(protected)
diff --git a/backend/importer/character.go b/backend/importer/character.go
index 0c63c8d..a9a09cc 100644
--- a/backend/importer/character.go
+++ b/backend/importer/character.go
@@ -1,5 +1,10 @@
 package importer
 
+import (
+	"bamort/models"
+	"fmt"
+)
+
 // This file contains the character import data structures.
 // These were copied from the deprecated importero package to break dependencies.
 
@@ -193,3 +198,84 @@ type CharacterImport struct {
 	Spezialisierung    []string           `json:"spezialisierung"`
 	Image              string             `json:"image,omitempty"`
 }
+
+// ConvertCharToImport converts a models.Char to CharacterImport format
+// This is used for the export functionality
+func ConvertCharToImport(char *models.Char) (*CharacterImport, error) {
+	if char == nil {
+		return nil, fmt.Errorf("character is nil")
+	}
+
+	// TODO: Implement full conversion from models.Char to CharacterImport
+	// For now, return a basic structure
+	charImport := &CharacterImport{
+		ID:   fmt.Sprintf("%d", char.ID),
+		Name: char.Name,
+		Typ:  char.Typ,
+		Grad: char.Grad,
+
+		// Basic attributes - TODO: Convert from char.Eigenschaften slice
+		Eigenschaften: Eigenschaften{},
+
+		// Life points
+		Lp: Lp{
+			Max:   char.Lp.Max,
+			Value: char.Lp.Value,
+		},
+
+		// Action points
+		Ap: Ap{
+			Max:   char.Ap.Max,
+			Value: char.Ap.Value,
+		},
+
+		// Movement
+		B: B{
+			Max:   char.B.Max,
+			Value: char.B.Value,
+		},
+
+		// Experience
+		Erfahrungsschatz: Erfahrungsschatz{
+			Value: char.Erfahrungsschatz.EP,
+		},
+
+		// Bennies
+		Bennies: Bennies{
+			Gg: char.Bennies.Gg,
+			Sg: char.Bennies.Sg,
+		},
+
+		// Physical attributes
+		Alter:   char.Alter,
+		Groesse: char.Groesse,
+		Gewicht: char.Gewicht,
+		Hand:    char.Hand,
+		Glaube:  char.Glaube,
+		Rasse:   char.Rasse,
+		Anrede:  char.Anrede,
+
+		// Appearance
+		Merkmale: Merkmale{
+			Augenfarbe: char.Merkmale.Augenfarbe,
+			Haarfarbe:  char.Merkmale.Haarfarbe,
+			Sonstige:   char.Merkmale.Sonstige,
+		},
+
+		Gestalt: Gestalt{
+			Breite:  char.Merkmale.Breite,
+			Groesse: char.Merkmale.Groesse,
+		},
+
+		// TODO: Load related data from database
+		// - Fertigkeiten (skills)
+		// - Zauber (spells)
+		// - Waffenfertigkeiten (weapon skills)
+		// - Ausruestung (equipment)
+		// - Waffen (weapons)
+		// - Behaeltnisse (containers)
+		// - Transportmittel (transportation)
+	}
+
+	return charImport, nil
+}
diff --git a/backend/importer/detector.go b/backend/importer/detector.go
index e223b57..f1f04f5 100644
--- a/backend/importer/detector.go
+++ b/backend/importer/detector.go
@@ -19,19 +19,23 @@ type DetectionCache struct {
 
 // Detector handles smart format detection with optimizations
 type Detector struct {
-	registry *AdapterRegistry
-	cache    map[string]*DetectionCache
-	cacheMu  sync.RWMutex
-	cacheTTL time.Duration
+	registry         *AdapterRegistry
+	cache            map[string]*DetectionCache
+	cacheMu          sync.RWMutex
+	cacheTTL         time.Duration
+	stopCacheCleanup chan struct{}
 }
 
 // NewDetector creates a new detector
 func NewDetector(registry *AdapterRegistry) *Detector {
-	return &Detector{
-		registry: registry,
-		cache:    make(map[string]*DetectionCache),
-		cacheTTL: 5 * time.Minute, // Default TTL
+	d := &Detector{
+		registry:         registry,
+		cache:            make(map[string]*DetectionCache),
+		cacheTTL:         5 * time.Minute, // Default TTL
+		stopCacheCleanup: make(chan struct{}),
 	}
+	d.startCacheCleanup()
+	return d
 }
 
 // DetectFormat implements smart format detection with short-circuit optimization
@@ -163,3 +167,37 @@ func getFileExtension(filename string) string {
 
 	return strings.ToLower(filename[lastDot:])
 }
+
+// startCacheCleanup starts a background goroutine to periodically clean expired cache entries
+func (d *Detector) startCacheCleanup() {
+	ticker := time.NewTicker(10 * time.Minute) // Cleanup every 10 minutes
+	go func() {
+		for {
+			select {
+			case <-ticker.C:
+				d.cleanupExpiredEntries()
+			case <-d.stopCacheCleanup:
+				ticker.Stop()
+				return
+			}
+		}
+	}()
+}
+
+// StopCacheCleanup stops the background cache cleanup goroutine
+func (d *Detector) StopCacheCleanup() {
+	close(d.stopCacheCleanup)
+}
+
+// cleanupExpiredEntries removes expired entries from the cache
+func (d *Detector) cleanupExpiredEntries() {
+	d.cacheMu.Lock()
+	defer d.cacheMu.Unlock()
+
+	now := time.Now()
+	for signature, entry := range d.cache {
+		if now.Sub(entry.cachedAt) > d.cacheTTL {
+			delete(d.cache, signature)
+		}
+	}
+}
diff --git a/backend/importer/handlers.go b/backend/importer/handlers.go
new file mode 100644
index 0000000..c9427b3
--- /dev/null
+++ b/backend/importer/handlers.go
@@ -0,0 +1,359 @@
+package importer
+
+import (
+	"bamort/database"
+	"bamort/models"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+
+	"github.com/gin-gonic/gin"
+)
+
+// Global registry instance (initialized on startup)
+var globalRegistry *AdapterRegistry
+
+// InitializeRegistry initializes the global adapter registry
+func InitializeRegistry(registry *AdapterRegistry) {
+	globalRegistry = registry
+}
+
+// DetectHandler handles format detection for uploaded files
+// POST /api/import/detect
+// Rate limit: 10 requests/minute per user
+func DetectHandler(c *gin.Context) {
+	// Accept multipart file upload
+	file, header, err := c.Request.FormFile("file")
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "No file uploaded"})
+		return
+	}
+	defer file.Close()
+
+	// Read file data
+	data, err := io.ReadAll(file)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to read file"})
+		return
+	}
+
+	// Validate JSON depth if JSON file
+	if err := ValidateJSONDepth(data, 100); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("Invalid JSON: %v", err)})
+		return
+	}
+
+	// Detect format using global registry
+	if globalRegistry == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "Import service not initialized"})
+		return
+	}
+
+	adapterID, confidence, err := globalRegistry.Detect(data, header.Filename)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": fmt.Sprintf("Detection failed: %v", err)})
+		return
+	}
+
+	// Get adapter metadata for suggested name
+	adapter := globalRegistry.Get(adapterID)
+	response := gin.H{
+		"adapter_id": adapterID,
+		"confidence": confidence,
+	}
+	if adapter != nil {
+		response["suggested_adapter_name"] = adapter.Name
+	}
+
+	c.JSON(http.StatusOK, response)
+}
+
+// ImportHandler handles character import from external formats
+// POST /api/import/import
+// Rate limit: 5 requests/minute per user
+func ImportHandler(c *gin.Context) {
+	// Get user ID from context
+	userID := getUserID(c)
+	if userID == 0 {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "User not authenticated"})
+		return
+	}
+
+	// Accept file and optional adapter_id
+	file, header, err := c.Request.FormFile("file")
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "No file uploaded"})
+		return
+	}
+	defer file.Close()
+
+	// Read file data
+	data, err := io.ReadAll(file)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to read file"})
+		return
+	}
+
+	// Validate JSON depth
+	if err := ValidateJSONDepth(data, 100); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("Invalid JSON: %v", err)})
+		return
+	}
+
+	// Get adapter ID from form or detect
+	adapterID := c.PostForm("adapter_id")
+	if adapterID == "" {
+		// Auto-detect
+		if globalRegistry == nil {
+			c.JSON(http.StatusServiceUnavailable, gin.H{"error": "Import service not initialized"})
+			return
+		}
+		detectedID, confidence, err := globalRegistry.Detect(data, header.Filename)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": fmt.Sprintf("Detection failed: %v", err)})
+			return
+		}
+		if confidence < 0.7 {
+			c.JSON(http.StatusBadRequest, gin.H{
+				"error":      "Could not reliably detect format",
+				"confidence": confidence,
+				"hint":       "Please specify adapter_id explicitly",
+			})
+			return
+		}
+		adapterID = detectedID
+	}
+
+	// Import via adapter
+	charImport, err := globalRegistry.Import(adapterID, data)
+	if err != nil {
+		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": fmt.Sprintf("Import failed: %v", err)})
+		return
+	}
+
+	// Validate the imported character
+	validator := NewValidator()
+	validationResult := validator.ValidateCharacter(charImport)
+	if !validationResult.Valid {
+		c.JSON(http.StatusBadRequest, gin.H{
+			"error":  "Character validation failed",
+			"errors": validationResult.Errors,
+		})
+		return
+	}
+
+	// Collect warnings but don't block
+	warnings := validationResult.Warnings
+
+	// Convert BMRTCharacter to CharacterImport for import logic
+	charData := &charImport.CharacterImport
+
+	// Import character with transaction safety
+	result, err := ImportCharacter(charData, userID, adapterID, data)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": fmt.Sprintf("Failed to create character: %v", err)})
+		return
+	}
+
+	// Merge validation warnings into result
+	result.Warnings = append(result.Warnings, warnings...)
+
+	c.JSON(http.StatusOK, result)
+}
+
+// ListAdaptersHandler returns all registered adapters
+// GET /api/import/adapters
+func ListAdaptersHandler(c *gin.Context) {
+	if globalRegistry == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "Import service not initialized"})
+		return
+	}
+
+	adapters := globalRegistry.GetHealthy()
+	c.JSON(http.StatusOK, gin.H{
+		"adapters": adapters,
+		"count":    len(adapters),
+	})
+}
+
+// ImportHistoryHandler returns user's import history with pagination
+// GET /api/import/history?page=1&per_page=20
+func ImportHistoryHandler(c *gin.Context) {
+	userID := getUserID(c)
+	if userID == 0 {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "User not authenticated"})
+		return
+	}
+
+	// Parse pagination parameters
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	perPage, _ := strconv.Atoi(c.DefaultQuery("per_page", "20"))
+	if page < 1 {
+		page = 1
+	}
+	if perPage < 1 || perPage > 100 {
+		perPage = 20
+	}
+
+	offset := (page - 1) * perPage
+
+	// Query import history
+	var histories []ImportHistory
+	var total int64
+
+	db := database.DB.Model(&ImportHistory{}).Where("user_id = ?", userID)
+	db.Count(&total)
+
+	err := db.Order("imported_at DESC").
+		Limit(perPage).
+		Offset(offset).
+		Find(&histories).Error
+
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to fetch import history"})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"histories": histories,
+		"total":     total,
+		"page":      page,
+		"per_page":  perPage,
+		"pages":     (total + int64(perPage) - 1) / int64(perPage),
+	})
+}
+
+// ImportDetailsHandler returns detailed information about a specific import
+// GET /api/import/history/:id
+func ImportDetailsHandler(c *gin.Context) {
+	userID := getUserID(c)
+	if userID == 0 {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "User not authenticated"})
+		return
+	}
+
+	importID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid import ID"})
+		return
+	}
+
+	// Fetch import history with ownership check
+	var history ImportHistory
+	err = database.DB.Where("id = ? AND user_id = ?", importID, userID).
+		First(&history).Error
+
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": "Import not found"})
+		return
+	}
+
+	// Fetch related master data imports
+	var masterDataImports []MasterDataImport
+	database.DB.Where("import_history_id = ?", importID).
+		Find(&masterDataImports)
+
+	c.JSON(http.StatusOK, gin.H{
+		"history":             history,
+		"master_data_imports": masterDataImports,
+	})
+}
+
+// ExportHandler exports a character to an external format
+// POST /api/import/export/:id?adapter_id=foundry-vtt-v1
+func ExportHandler(c *gin.Context) {
+	userID := getUserID(c)
+	if userID == 0 {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "User not authenticated"})
+		return
+	}
+
+	charID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid character ID"})
+		return
+	}
+
+	// Load character with ownership check
+	var char models.Char
+	err = database.DB.Where("id = ? AND user_id = ?", charID, userID).
+		First(&char).Error
+
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": "Character not found or access denied"})
+		return
+	}
+
+	// Determine adapter ID (override or original)
+	adapterID := c.Query("adapter_id")
+	if adapterID == "" {
+		// Try to get original adapter from import history
+		var history ImportHistory
+		err = database.DB.Where("character_id = ?", charID).
+			Order("imported_at DESC").
+			First(&history).Error
+
+		if err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{
+				"error": "No adapter specified and character has no import history",
+				"hint":  "Specify adapter_id query parameter",
+			})
+			return
+		}
+		adapterID = history.AdapterID
+	}
+
+	// Check adapter exists and is healthy
+	if globalRegistry == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "Import service not initialized"})
+		return
+	}
+
+	adapter := globalRegistry.Get(adapterID)
+	if adapter == nil {
+		// Suggest available adapters
+		available := globalRegistry.GetHealthy()
+		availableIDs := make([]string, len(available))
+		for i, a := range available {
+			availableIDs[i] = a.ID
+		}
+
+		c.JSON(http.StatusConflict, gin.H{
+			"error":              fmt.Sprintf("Adapter '%s' not available", adapterID),
+			"available_adapters": availableIDs,
+		})
+		return
+	}
+
+	if !adapter.Healthy {
+		c.JSON(http.StatusConflict, gin.H{
+			"error": fmt.Sprintf("Adapter '%s' is currently unhealthy", adapterID),
+		})
+		return
+	}
+
+	// Convert Char to CharacterImport
+	charImport, err := ConvertCharToImport(&char)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": fmt.Sprintf("Failed to convert character: %v", err)})
+		return
+	}
+
+	// Export via adapter
+	exportedData, err := globalRegistry.Export(adapterID, charImport)
+	if err != nil {
+		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": fmt.Sprintf("Export failed: %v", err)})
+		return
+	}
+
+	// Return file download
+	filename := fmt.Sprintf("%s_%s.json", char.Name, adapterID)
+	c.Header("Content-Disposition", fmt.Sprintf("attachment; filename=%s", filename))
+	c.Data(http.StatusOK, "application/json", exportedData)
+}
+
+// respondWithError is a helper to send error responses
+func respondWithError(c *gin.Context, status int, message string) {
+	c.JSON(status, gin.H{"error": message})
+}
diff --git a/backend/importer/handlers_test.go b/backend/importer/handlers_test.go
new file mode 100644
index 0000000..bfe2fae
--- /dev/null
+++ b/backend/importer/handlers_test.go
@@ -0,0 +1,297 @@
+package importer
+
+import (
+	"bamort/database"
+	"bytes"
+	"encoding/json"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/assert"
+)
+
+// setupTestEnvironment sets up the test environment
+func setupTestEnvironment(t *testing.T) {
+	original := os.Getenv("ENVIRONMENT")
+	os.Setenv("ENVIRONMENT", "test")
+	t.Cleanup(func() {
+		if original == "" {
+			os.Unsetenv("ENVIRONMENT")
+		} else {
+			os.Setenv("ENVIRONMENT", original)
+		}
+	})
+}
+
+// setupTestHandlerDB initializes the test database for handler tests
+func setupTestHandlerDB(t *testing.T) {
+	setupTestEnvironment(t)
+	// For now, just ensure migrations run - full DB setup will be added later
+	if database.DB != nil {
+		err := MigrateStructure(database.DB)
+		assert.NoError(t, err)
+	}
+
+	t.Cleanup(func() {
+		// Clean up test data
+		if database.DB != nil {
+			database.DB.Exec("DELETE FROM import_histories")
+			database.DB.Exec("DELETE FROM master_data_imports")
+		}
+	})
+}
+
+// createTestFile creates a multipart file for testing
+func createTestFile(t *testing.T, fieldName, filename string, content []byte) (*bytes.Buffer, string) {
+	body := &bytes.Buffer{}
+	writer := multipart.NewWriter(body)
+
+	part, err := writer.CreateFormFile(fieldName, filename)
+	assert.NoError(t, err)
+
+	_, err = part.Write(content)
+	assert.NoError(t, err)
+
+	err = writer.Close()
+	assert.NoError(t, err)
+
+	return body, writer.FormDataContentType()
+}
+
+// mockAdapter creates a mock adapter for testing
+func mockAdapter() *AdapterMetadata {
+	return &AdapterMetadata{
+		ID:                  "test-adapter-v1",
+		Name:                "Test Adapter",
+		Version:             "1.0",
+		BmrtVersions:        []string{"1.0"},
+		SupportedExtensions: []string{".json"},
+		BaseURL:             "http://localhost:8999",
+		Capabilities:        []string{"import", "export", "detect"},
+		Healthy:             true,
+	}
+}
+
+// TestDetectHandler tests the format detection endpoint
+func TestDetectHandler(t *testing.T) {
+	setupTestHandlerDB(t)
+	gin.SetMode(gin.TestMode)
+
+	// Setup mock registry
+	registry := NewAdapterRegistry()
+	registry.Register(*mockAdapter())
+	InitializeRegistry(registry)
+
+	// Create test file
+	testData := []byte(`{"name": "Test Character", "type": "test"}`)
+	body, contentType := createTestFile(t, "file", "test.json", testData)
+
+	// Create request
+	req := httptest.NewRequest("POST", "/api/import/detect", body)
+	req.Header.Set("Content-Type", contentType)
+	w := httptest.NewRecorder()
+
+	// Setup context
+	c, _ := gin.CreateTestContext(w)
+	c.Request = req
+
+	// Call handler (with mock detect - would need adapter server for real test)
+	// For now, we verify the handler validates input correctly
+	DetectHandler(c)
+
+	// Without a real adapter server, we expect an error
+	// This test mainly validates the request parsing
+	assert.Equal(t, http.StatusInternalServerError, w.Code)
+}
+
+// TestImportHandler_NoFile tests import with missing file
+func TestImportHandler_NoFile(t *testing.T) {
+	setupTestHandlerDB(t)
+	gin.SetMode(gin.TestMode)
+
+	registry := NewAdapterRegistry()
+	InitializeRegistry(registry)
+
+	req := httptest.NewRequest("POST", "/api/import/import", nil)
+	w := httptest.NewRecorder()
+
+	c, _ := gin.CreateTestContext(w)
+	c.Request = req
+	c.Set("userID", uint(1))
+
+	ImportHandler(c)
+
+	assert.Equal(t, http.StatusBadRequest, w.Code)
+
+	var response map[string]interface{}
+	err := json.Unmarshal(w.Body.Bytes(), &response)
+	assert.NoError(t, err)
+	assert.Contains(t, response["error"], "No file uploaded")
+}
+
+// TestImportHandler_NoAuth tests import without authentication
+func TestImportHandler_NoAuth(t *testing.T) {
+	setupTestHandlerDB(t)
+	gin.SetMode(gin.TestMode)
+
+	registry := NewAdapterRegistry()
+	InitializeRegistry(registry)
+
+	testData := []byte(`{"name": "Test"}`)
+	body, contentType := createTestFile(t, "file", "test.json", testData)
+
+	req := httptest.NewRequest("POST", "/api/import/import", body)
+	req.Header.Set("Content-Type", contentType)
+	w := httptest.NewRecorder()
+
+	c, _ := gin.CreateTestContext(w)
+	c.Request = req
+	// No userID set - simulates unauthenticated request
+
+	ImportHandler(c)
+
+	assert.Equal(t, http.StatusUnauthorized, w.Code)
+}
+
+// TestListAdaptersHandler tests listing registered adapters
+func TestListAdaptersHandler(t *testing.T) {
+	setupTestHandlerDB(t)
+	gin.SetMode(gin.TestMode)
+
+	registry := NewAdapterRegistry()
+	registry.Register(*mockAdapter())
+	InitializeRegistry(registry)
+
+	req := httptest.NewRequest("GET", "/api/import/adapters", nil)
+	w := httptest.NewRecorder()
+
+	c, _ := gin.CreateTestContext(w)
+	c.Request = req
+
+	ListAdaptersHandler(c)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+
+	var response map[string]interface{}
+	err := json.Unmarshal(w.Body.Bytes(), &response)
+	assert.NoError(t, err)
+	assert.Contains(t, response, "adapters")
+	assert.Contains(t, response, "count")
+}
+
+// TestImportHistoryHandler tests import history retrieval
+func TestImportHistoryHandler(t *testing.T) {
+	setupTestHandlerDB(t)
+	gin.SetMode(gin.TestMode)
+
+	// Skip if database not available
+	if database.DB == nil {
+		t.Skip("Database not available")
+	}
+
+	registry := NewAdapterRegistry()
+	InitializeRegistry(registry)
+
+	req := httptest.NewRequest("GET", "/api/import/history", nil)
+	w := httptest.NewRecorder()
+
+	c, _ := gin.CreateTestContext(w)
+	c.Request = req
+	c.Set("userID", uint(1))
+
+	ImportHistoryHandler(c)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+
+	var response map[string]interface{}
+	err := json.Unmarshal(w.Body.Bytes(), &response)
+	assert.NoError(t, err)
+	assert.Contains(t, response, "histories")
+	assert.Contains(t, response, "total")
+	assert.Contains(t, response, "page")
+}
+
+// TestImportHistoryHandler_Pagination tests pagination
+func TestImportHistoryHandler_Pagination(t *testing.T) {
+	setupTestHandlerDB(t)
+	gin.SetMode(gin.TestMode)
+
+	// Skip if database not available
+	if database.DB == nil {
+		t.Skip("Database not available")
+	}
+
+	registry := NewAdapterRegistry()
+	InitializeRegistry(registry)
+
+	req := httptest.NewRequest("GET", "/api/import/history?page=2&per_page=10", nil)
+	w := httptest.NewRecorder()
+
+	c, _ := gin.CreateTestContext(w)
+	c.Request = req
+	c.Set("userID", uint(1))
+
+	ImportHistoryHandler(c)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+
+	var response map[string]interface{}
+	err := json.Unmarshal(w.Body.Bytes(), &response)
+	assert.NoError(t, err)
+	assert.Equal(t, float64(2), response["page"])
+	assert.Equal(t, float64(10), response["per_page"])
+}
+
+// TestExportHandler_NotFound tests export with non-existent character
+func TestExportHandler_NotFound(t *testing.T) {
+	setupTestHandlerDB(t)
+	gin.SetMode(gin.TestMode)
+
+	// Skip if database not available
+	if database.DB == nil {
+		t.Skip("Database not available")
+	}
+
+	registry := NewAdapterRegistry()
+	InitializeRegistry(registry)
+
+	req := httptest.NewRequest("POST", "/api/import/export/999999", nil)
+	w := httptest.NewRecorder()
+
+	c, _ := gin.CreateTestContext(w)
+	c.Request = req
+	c.Set("userID", uint(1))
+	c.Params = gin.Params{gin.Param{Key: "id", Value: "999999"}}
+
+	ExportHandler(c)
+
+	assert.Equal(t, http.StatusNotFound, w.Code)
+}
+
+// TestValidateFileSizeMiddleware tests file size validation
+func TestValidateFileSizeMiddleware(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	// Create middleware with 100 byte limit
+	middleware := ValidateFileSizeMiddleware(100)
+
+	// Create large content
+	largeContent := bytes.Repeat([]byte("a"), 200)
+
+	req := httptest.NewRequest("POST", "/test", bytes.NewReader(largeContent))
+	w := httptest.NewRecorder()
+
+	c, _ := gin.CreateTestContext(w)
+	c.Request = req
+
+	middleware(c)
+
+	// Try to read more than limit - should error
+	_, err := io.ReadAll(c.Request.Body)
+	assert.Error(t, err)
+}
diff --git a/backend/importer/registry.go b/backend/importer/registry.go
index 3b8c6c6..58bf86c 100644
--- a/backend/importer/registry.go
+++ b/backend/importer/registry.go
@@ -36,9 +36,10 @@ func (m *AdapterMetadata) SupportsCapability(capability string) bool {
 
 // AdapterRegistry manages registered adapter services
 type AdapterRegistry struct {
-	adapters map[string]*AdapterMetadata
-	mu       sync.RWMutex
-	client   *http.Client
+	adapters          map[string]*AdapterMetadata
+	mu                sync.RWMutex
+	client            *http.Client
+	stopHealthChecker chan struct{}
 }
 
 // NewAdapterRegistry creates a new adapter registry
@@ -51,6 +52,7 @@ func NewAdapterRegistry() *AdapterRegistry {
 				return http.ErrUseLastResponse // Disable redirects for security
 			},
 		},
+		stopHealthChecker: make(chan struct{}),
 	}
 }
 
@@ -72,6 +74,28 @@ func (r *AdapterRegistry) Register(meta AdapterMetadata) error {
 	return nil
 }
 
+// StartBackgroundHealthChecker starts a background goroutine that periodically checks adapter health
+// Runs every 30 seconds as specified in the plan
+func (r *AdapterRegistry) StartBackgroundHealthChecker() {
+	ticker := time.NewTicker(30 * time.Second)
+	go func() {
+		for {
+			select {
+			case <-ticker.C:
+				_ = r.HealthCheck() // Ignore errors, they're logged in adapter metadata
+			case <-r.stopHealthChecker:
+				ticker.Stop()
+				return
+			}
+		}
+	}()
+}
+
+// StopBackgroundHealthChecker stops the background health checker
+func (r *AdapterRegistry) StopBackgroundHealthChecker() {
+	close(r.stopHealthChecker)
+}
+
 // Get retrieves an adapter by ID
 func (r *AdapterRegistry) Get(id string) *AdapterMetadata {
 	r.mu.RLock()
diff --git a/backend/importer/routes.go b/backend/importer/routes.go
new file mode 100644
index 0000000..ecdfd13
--- /dev/null
+++ b/backend/importer/routes.go
@@ -0,0 +1,40 @@
+package importer
+
+import (
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
+
+// RegisterRoutes registers all import/export API endpoints
+// Following the plan: POST /detect, POST /import, GET /adapters, GET /history, etc.
+func RegisterRoutes(r *gin.RouterGroup) {
+	// Rate limiters per endpoint as specified in the plan
+	detectLimiter := NewRateLimiter(10, time.Minute) // 10/min
+	importLimiter := NewRateLimiter(5, time.Minute)  // 5/min
+	exportLimiter := NewRateLimiter(20, time.Minute) // 20/min
+
+	// File size limit (10MB as per plan)
+	maxFileSize := int64(10 << 20)
+
+	importer := r.Group("/import")
+	importer.Use(ValidateFileSizeMiddleware(maxFileSize))
+
+	// Format detection endpoint
+	importer.POST("/detect", detectLimiter.Middleware(), DetectHandler)
+
+	// Import character from external format
+	importer.POST("/import", importLimiter.Middleware(), ImportHandler)
+
+	// List registered adapters
+	importer.GET("/adapters", ListAdaptersHandler)
+
+	// Get user's import history
+	importer.GET("/history", ImportHistoryHandler)
+
+	// Get details for specific import
+	importer.GET("/history/:id", ImportDetailsHandler)
+
+	// Export character to external format
+	importer.POST("/export/:id", exportLimiter.Middleware(), ExportHandler)
+}