diff --git a/backend/cmd/server/main.go b/backend/cmd/server/main.go
index 54474c7..eb26e9a 100644
--- a/backend/cmd/server/main.go
+++ b/backend/cmd/server/main.go
@@ -1,17 +1,51 @@
 package main
 
 import (
+	"fmt"
 	"log"
 
+	"github.com/gin-gonic/gin"
 	"github.com/vaultdrop/backend/config"
+	"github.com/vaultdrop/backend/handlers"
 )
 
+func newRouter() *gin.Engine {
+
+	r := gin.Default()
+
+	api := r.Group("/api/v1")
+	{
+		api.GET("/health", handlers.Health)
+		api.POST("/devices", handlers.DevicesRegister)
+
+		api.GET("/files", handlers.FilesList)
+		api.GET("/files/search", handlers.FilesSearch)
+		api.GET("/files/:id", handlers.FilesGet)
+		api.DELETE("/files/:id", handlers.FilesDelete)
+		api.GET("/files/folders", handlers.FoldersList)
+		api.POST("/files/upload", handlers.FilesUpload)
+
+		api.POST("/ocr/jobs", handlers.OcrJobsCreate)
+		api.GET("/ocr/jobs/:id", handlers.OcrJobsGet)
+
+		api.POST("/sync/ops", handlers.SyncOpsPush)
+		api.GET("/sync/permissions", handlers.SyncPermissionsGet)
+	}
+
+	return r
+
+}
+
 func main() {
 
-	err, _ := config.LoadApplicationConfig()
+	err, cfg := config.LoadApplicationConfig()
 
 	if err != nil {
 		log.Fatalln(err)
 	}
 
+	if err := newRouter().Run(fmt.Sprintf(":%d", cfg.Port)); err != nil {
+		log.Fatalln(err)
+	}
+
 }
diff --git a/backend/cmd/server/main_test.go b/backend/cmd/server/main_test.go
index 7ef862f..d2caeb3 100644
--- a/backend/cmd/server/main_test.go
+++ b/backend/cmd/server/main_test.go
@@ -37,4 +37,4 @@ func TestCreateDocument(t *testing.T) {
 
 	fmt.Println(document, directory)
 
-}
\ No newline at end of file
+}
diff --git a/backend/cmd/server/router_test.go b/backend/cmd/server/router_test.go
new file mode 100644
index 0000000..f844c63
--- /dev/null
+++ b/backend/cmd/server/router_test.go
@@ -0,0 +1,40 @@
+package main
+
+import (
+	"testing"
+)
+
+// expectedRoutes mirrors the endpoints in mobile/api/client.ts (the contract).
+// Paths are full (under /api/v1), methods match the client calls exactly.
+var expectedRoutes = []string{
+	"GET /api/v1/health",
+	"POST /api/v1/devices",
+
+	"GET /api/v1/files",
+	"GET /api/v1/files/:id",
+	"DELETE /api/v1/files/:id",
+	"GET /api/v1/files/search",
+	"GET /api/v1/files/folders",
+	"POST /api/v1/files/upload",
+
+	"POST /api/v1/ocr/jobs",
+	"GET /api/v1/ocr/jobs/:id",
+
+	"POST /api/v1/sync/ops",
+	"GET /api/v1/sync/permissions",
+}
+
+func TestRoutesMatchClientContract(t *testing.T) {
+
+	registered := map[string]bool{}
+	for _, route := range newRouter().Routes() {
+		registered[route.Method+" "+route.Path] = true
+	}
+
+	for _, want := range expectedRoutes {
+		if !registered[want] {
+			t.Errorf("missing route %q — must mirror mobile/api/client.ts", want)
+		}
+	}
+
+}
diff --git a/backend/config/config.go b/backend/config/config.go
index 02c96d2..f55da92 100644
--- a/backend/config/config.go
+++ b/backend/config/config.go
@@ -1,8 +1,6 @@
 package config
 
 import (
-	"fmt"
-	"log"
 	"os"
 	"strconv"
 
@@ -10,46 +8,52 @@ import (
 )
 
 type ApplicationConfig struct {
-	Port int64
+	Port          int
+	DatabaseURL   string
+	UploadDir     string
+	MaxFileSizeMB int64
+	OcrLang       string
+	AuthSecret    string
 }
 
 func LoadApplicationConfig() (error, *ApplicationConfig) {
 
-	err := godotenv.Load()
+	// .env optionnel — les défauts suffisent pour le dev local.
+	_ = godotenv.Load()
 
-	if err != nil {
-		log.Fatal("Error loading .env file")
-	}
-
-	err, portString := getVar("PORT", "8080", true)
+	port, err := getInt("PORT", 8080)
 	if err != nil {
 		return err, nil
 	}
 
-	port, err := strconv.ParseInt(portString, 10, 64)
+	maxSize, err := getInt("MAX_FILE_SIZE_MB", 50)
 	if err != nil {
 		return err, nil
 	}
 
 	return nil, &ApplicationConfig{
-		Port: port,
+		Port:          port,
+		DatabaseURL:   get("DATABASE_URL", "postgres://vaultdrop:vaultdrop@localhost:5432/vaultdrop?sslmode=disable"),
+		UploadDir:     get("UPLOAD_DIR", "./uploads"),
+		MaxFileSizeMB: int64(maxSize),
+		OcrLang:       get("OCR_LANG", "fra+eng"),
+		AuthSecret:    get("AUTH_SECRET", "dev-secret-change-me"),
 	}
 
 }
 
-func getVar(varName string, defaultValue string, isRequired bool) (error, string) {
-	varValue := os.Getenv(varName)
-
-	if varValue == "" {
-
-		if isRequired {
-			return fmt.Errorf("%s is missing and required : ", varName), ""
-		}
-
-		return nil, defaultValue
-
+func get(name string, defaultValue string) string {
+	value := os.Getenv(name)
+	if value == "" {
+		return defaultValue
 	}
+	return value
+}
 
-	return nil, varValue
-
+func getInt(name string, defaultValue int) (int, error) {
+	value := os.Getenv(name)
+	if value == "" {
+		return defaultValue, nil
+	}
+	return strconv.Atoi(value)
 }
diff --git a/backend/handlers/.gitkeep b/backend/handlers/.gitkeep
deleted file mode 100644
index 4dff090..0000000
--- a/backend/handlers/.gitkeep
+++ /dev/null
@@ -1 +0,0 @@
-# Gin HTTP handlers land here (bind the routes, current 501 stubs).
\ No newline at end of file
diff --git a/backend/handlers/devices.go b/backend/handlers/devices.go
new file mode 100644
index 0000000..e4ea106
--- /dev/null
+++ b/backend/handlers/devices.go
@@ -0,0 +1,8 @@
+package handlers
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/vaultdrop/backend/pkg/api"
+)
+
+func DevicesRegister(c *gin.Context) { api.NotImplemented(c) }
diff --git a/backend/handlers/files.go b/backend/handlers/files.go
new file mode 100644
index 0000000..ad1b6e5
--- /dev/null
+++ b/backend/handlers/files.go
@@ -0,0 +1,12 @@
+package handlers
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/vaultdrop/backend/pkg/api"
+)
+
+func FilesList(c *gin.Context)   { api.NotImplemented(c) }
+func FilesGet(c *gin.Context)    { api.NotImplemented(c) }
+func FilesDelete(c *gin.Context) { api.NotImplemented(c) }
+func FilesSearch(c *gin.Context) { api.NotImplemented(c) }
+func FilesUpload(c *gin.Context) { api.NotImplemented(c) }
diff --git a/backend/handlers/folders.go b/backend/handlers/folders.go
new file mode 100644
index 0000000..14a3623
--- /dev/null
+++ b/backend/handlers/folders.go
@@ -0,0 +1,8 @@
+package handlers
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/vaultdrop/backend/pkg/api"
+)
+
+func FoldersList(c *gin.Context) { api.NotImplemented(c) }
diff --git a/backend/handlers/health.go b/backend/handlers/health.go
new file mode 100644
index 0000000..13af2db
--- /dev/null
+++ b/backend/handlers/health.go
@@ -0,0 +1,10 @@
+package handlers
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/vaultdrop/backend/pkg/api"
+)
+
+func Health(c *gin.Context) {
+	api.OK(c, gin.H{"status": "healthy"})
+}
diff --git a/backend/handlers/ocr.go b/backend/handlers/ocr.go
new file mode 100644
index 0000000..9520364
--- /dev/null
+++ b/backend/handlers/ocr.go
@@ -0,0 +1,9 @@
+package handlers
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/vaultdrop/backend/pkg/api"
+)
+
+func OcrJobsCreate(c *gin.Context) { api.NotImplemented(c) }
+func OcrJobsGet(c *gin.Context)    { api.NotImplemented(c) }
diff --git a/backend/handlers/sync.go b/backend/handlers/sync.go
new file mode 100644
index 0000000..c5c7327
--- /dev/null
+++ b/backend/handlers/sync.go
@@ -0,0 +1,9 @@
+package handlers
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/vaultdrop/backend/pkg/api"
+)
+
+func SyncOpsPush(c *gin.Context)        { api.NotImplemented(c) }
+func SyncPermissionsGet(c *gin.Context) { api.NotImplemented(c) }
diff --git a/backend/ocr/engine.go b/backend/ocr/engine.go
index 3317f4f..f17fa4f 100644
--- a/backend/ocr/engine.go
+++ b/backend/ocr/engine.go
@@ -7,4 +7,4 @@ import "context"
 // swapping to a remote service later only changes the injection point.
 type Engine interface {
 	ExtractText(ctx context.Context, filePath string, lang string) (string, error)
-}
\ No newline at end of file
+}
diff --git a/backend/pkg/api/response.go b/backend/pkg/api/response.go
new file mode 100644
index 0000000..7083b3f
--- /dev/null
+++ b/backend/pkg/api/response.go
@@ -0,0 +1,32 @@
+package api
+
+import "github.com/gin-gonic/gin"
+
+const NotImplementedCode = "NOT_IMPLEMENTED"
+
+type Meta struct {
+	Page     int `json:"page"`
+	PageSize int `json:"pageSize"`
+	Total    int `json:"total"`
+}
+
+func OK(c *gin.Context, data any) {
+	c.JSON(200, gin.H{"data": data})
+}
+
+func OKList(c *gin.Context, data any, page, pageSize, total int) {
+	c.JSON(200, gin.H{
+		"data": data,
+		"meta": Meta{Page: page, PageSize: pageSize, Total: total},
+	})
+}
+
+func Error(c *gin.Context, status int, code, message string) {
+	c.JSON(status, gin.H{
+		"error": gin.H{"code": code, "message": message},
+	})
+}
+
+func NotImplemented(c *gin.Context) {
+	Error(c, 501, NotImplementedCode, "route not implemented yet")
+}