diff --git a/api/dependecyInjection.go b/api/dependecyInjection.go
index 62ac288..c866698 100644
--- a/api/dependecyInjection.go
+++ b/api/dependecyInjection.go
@@ -5,6 +5,7 @@ import (
 	domainImage "RenewCMS/internal/domain/image"
 	domainMail "RenewCMS/internal/domain/mail"
 	domainUser "RenewCMS/internal/domain/user"
+	"RenewCMS/internal/infrastructure/config"
 	"RenewCMS/internal/infrastructure/hashing"
 	"RenewCMS/internal/infrastructure/mailer"
 	"RenewCMS/internal/infrastructure/persistence/models"
@@ -43,8 +44,7 @@ type Repositories struct {
 	MailRepo    domainMail.Repository
 }
 
-func getDb() *gorm.DB {
-	dbName := os.Getenv("DB_FILE")
+func getDb(dbName string) *gorm.DB {
 	if err := os.MkdirAll(filepath.Dir(dbName), os.ModePerm); err != nil {
 		panic("Unable to create necessary subdirectories: " + err.Error())
 	}
@@ -60,20 +60,20 @@ func getDb() *gorm.DB {
 	return db
 }
 
-func getRepositories(db *gorm.DB) *Repositories {
+func getRepositories(db *gorm.DB, settings config.Settings) *Repositories {
 	return &Repositories{
 		ArticleRepo: persistence.NewArticleRepository(db),
 		UserRepo:    persistence.NewUserRepository(db),
-		ImageRepo:   persistence.NewImageRepository(db),
-		MailRepo:    mailer.NewMailRepository(),
+		ImageRepo:   persistence.NewImageRepository(db, settings.UploadDir),
+		MailRepo:    mailer.NewMailRepository(settings.Smtp),
 	}
 }
 
-func getUseCases(repos *Repositories) *UseCases {
+func getUseCases(repos *Repositories, settings config.Settings) *UseCases {
 	hasher := hashing.NewBcryptHasher()
 
 	return &UseCases{
-		Token:                   jwtauth.New("HS256", []byte(os.Getenv("JWT_SECRET")), nil),
+		Token:                   jwtauth.New("HS256", []byte(settings.JWTSecret), nil),
 		CreateArticleUseCase:    useCases.NewCreateArticleUseCase(repos.ArticleRepo),
 		GetArticleUseCase:       useCases.NewGetArticleUseCase(repos.ArticleRepo),
 		ListArticlesUseCase:     useCases.NewListArticlesUseCase(repos.ArticleRepo),
@@ -91,10 +91,10 @@ func getUseCases(repos *Repositories) *UseCases {
 	}
 }
 
-func InitContainer() (*UseCases, func() error) {
-	db := getDb()
-	repos := getRepositories(db)
-	return getUseCases(repos), closeDb(db)
+func InitContainer(settings config.Settings) (*UseCases, func() error) {
+	db := getDb(settings.DBFile)
+	repos := getRepositories(db, settings)
+	return getUseCases(repos, settings), closeDb(db)
 }
 
 func closeDb(db *gorm.DB) func() error {
diff --git a/api/handlers/auth/authHandler.go b/api/handlers/auth/authHandler.go
index 15e0ae7..c199b03 100644
--- a/api/handlers/auth/authHandler.go
+++ b/api/handlers/auth/authHandler.go
@@ -6,7 +6,6 @@ import (
 	"RenewCMS/internal/infrastructure/useCases"
 	"encoding/json"
 	"net/http"
-	"os"
 	"time"
 
 	"github.com/go-chi/jwtauth/v5"
@@ -18,6 +17,7 @@ type Handler struct {
 	ListUseCase         *useCases.ListUsersUseCase
 	CreateUseCase       *useCases.CreateUserUseCase
 	AuthenticateUseCase *useCases.AuthenticateUserUseCase
+	IsProduction        bool
 }
 
 type RegisterCredentials struct {
@@ -31,29 +31,26 @@ type LoginCredentials struct {
 	Password string `json:"password" validate:"required,min=8"`
 }
 
-func shouldCookieBeSecure() bool {
-	return os.Getenv("ENVIRONMENT") == "production"
-}
-
-func removeJwtCookie(w http.ResponseWriter) {
+func (h *Handler) removeJwtCookie(w http.ResponseWriter) {
 	http.SetCookie(w, &http.Cookie{
 		Name:     "jwt",
 		Value:    "",
 		Expires:  time.Now(),
 		MaxAge:   -1,
-		Secure:   shouldCookieBeSecure(),
+		Secure:   h.IsProduction,
 		HttpOnly: true,
 		Path:     "/",
 	})
 }
 
-func NewHandler(token *jwtauth.JWTAuth, get *useCases.GetUserUseCase, list *useCases.ListUsersUseCase, create *useCases.CreateUserUseCase, authenticate *useCases.AuthenticateUserUseCase) *Handler {
+func NewHandler(token *jwtauth.JWTAuth, get *useCases.GetUserUseCase, list *useCases.ListUsersUseCase, create *useCases.CreateUserUseCase, authenticate *useCases.AuthenticateUserUseCase, isProduction bool) *Handler {
 	return &Handler{
 		Token:               token,
 		GetUseCase:          get,
 		ListUseCase:         list,
 		CreateUseCase:       create,
 		AuthenticateUseCase: authenticate,
+		IsProduction:        isProduction,
 	}
 }
 
@@ -66,7 +63,7 @@ func (h *Handler) SetJwtCookie(w *http.ResponseWriter, userId uint32) error {
 		Name:     "jwt",
 		Value:    tokenString,
 		Expires:  time.Now().Add(24 * time.Hour),
-		Secure:   shouldCookieBeSecure(),
+		Secure:   h.IsProduction,
 		HttpOnly: true,
 		Path:     "/",
 	})
@@ -176,7 +173,7 @@ func (h *Handler) Register(w http.ResponseWriter, r *http.Request) {
 }
 
 func (h *Handler) Logout(w http.ResponseWriter, _ *http.Request) {
-	removeJwtCookie(w)
+	h.removeJwtCookie(w)
 	message, _ := json.Marshal(map[string]any{"message": "User logged out! HTTPonly jwt cookie deleted"})
 	_, _ = w.Write(message)
 }
diff --git a/api/router.go b/api/router.go
index 90f69ae..de9cce4 100644
--- a/api/router.go
+++ b/api/router.go
@@ -6,10 +6,9 @@ import (
 	"RenewCMS/api/handlers/frontend"
 	"RenewCMS/api/handlers/image"
 	"RenewCMS/api/middleware"
+	"RenewCMS/internal/infrastructure/config"
 	"encoding/json"
 	"net/http"
-	"os"
-	"strings"
 
 	"github.com/MadAppGang/httplog"
 	"github.com/go-chi/chi/v5"
@@ -18,8 +17,8 @@ import (
 	"github.com/go-chi/jwtauth/v5"
 )
 
-func enableLoggingIfDev(r *chi.Mux, routerName string) {
-	if os.Getenv("ENVIRONMENT") == "development" {
+func enableLoggingIfDev(r *chi.Mux, routerName string, environment string) {
+	if environment == "development" {
 		r.Use(httplog.LoggerWithName(routerName))
 	}
 }
@@ -51,10 +50,10 @@ func NewArticleRouter(container *UseCases) http.Handler {
 	return r
 }
 
-func NewAuthRouter(container *UseCases) http.Handler {
+func NewAuthRouter(container *UseCases, isProduction bool) http.Handler {
 	r := chi.NewRouter()
 
-	authHandler := auth.NewHandler(container.Token, container.GetUserUseCase, container.ListUsersUseCase, container.CreateUserUseCase, container.AuthenticateUserUseCase)
+	authHandler := auth.NewHandler(container.Token, container.GetUserUseCase, container.ListUsersUseCase, container.CreateUserUseCase, container.AuthenticateUserUseCase, isProduction)
 
 	r.Post("/register", authHandler.Register)
 	r.Post("/login", authHandler.Login)
@@ -62,10 +61,10 @@ func NewAuthRouter(container *UseCases) http.Handler {
 	return r
 }
 
-func InitBackendRoutes(container *UseCases) *chi.Mux {
+func InitBackendRoutes(container *UseCases, settings config.Settings) *chi.Mux {
 	r := chi.NewRouter()
 
-	enableLoggingIfDev(r, "backend")
+	enableLoggingIfDev(r, "backend", settings.Environment)
 
 	r.Use(chimiddleware.GetHead)
 	r.Use(middleware.JsonContentTypeMiddleware)
@@ -74,15 +73,15 @@ func InitBackendRoutes(container *UseCases) *chi.Mux {
 		r.Use(jwtauth.Verifier(container.Token))
 		r.Mount("/article", NewArticleRouter(container))
 	})
-	r.Mount("/auth", NewAuthRouter(container))
+	r.Mount("/auth", NewAuthRouter(container, settings.IsProduction()))
 
 	return r
 }
 
-func InitFrontendRoutes() *chi.Mux {
+func InitFrontendRoutes(environment string) *chi.Mux {
 	r := chi.NewRouter()
 
-	enableLoggingIfDev(r, "frontend")
+	enableLoggingIfDev(r, "frontend", environment)
 
 	r.Mount("/", frontend.NewFrontendRouter())
 
@@ -94,13 +93,12 @@ func GetHealth(w http.ResponseWriter, _ *http.Request) {
 	_, _ = w.Write([]byte("ok"))
 }
 
-func enableCorsIfConfigured(r *chi.Mux) {
-	origins := os.Getenv("CORS_ALLOWED_ORIGINS")
-	if origins == "" {
+func enableCorsIfConfigured(r *chi.Mux, origins []string) {
+	if len(origins) == 0 {
 		return
 	}
 	r.Use(cors.Handler(cors.Options{
-		AllowedOrigins:   strings.Split(origins, ";"),
+		AllowedOrigins:   origins,
 		AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
 		AllowedHeaders:   []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
 		ExposedHeaders:   []string{"Link"},
@@ -109,12 +107,12 @@ func enableCorsIfConfigured(r *chi.Mux) {
 	}))
 }
 
-func InitRoutes(container *UseCases) *chi.Mux {
-	backend := InitBackendRoutes(container)
-	frontend := InitFrontendRoutes()
+func InitRoutes(container *UseCases, settings config.Settings) *chi.Mux {
+	backend := InitBackendRoutes(container, settings)
+	frontend := InitFrontendRoutes(settings.Environment)
 
 	apiRouter := chi.NewRouter()
-	enableCorsIfConfigured(apiRouter)
+	enableCorsIfConfigured(apiRouter, settings.CorsAllowedOrigins)
 	apiRouter.Use(chimiddleware.GetHead)
 	apiRouter.Get("/healthz", GetHealth)
 	apiRouter.Mount("/v1", backend)
diff --git a/cmd/server/main.go b/cmd/server/main.go
index c9e1215..b1f48c9 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -3,6 +3,7 @@ package main
 import (
 	"RenewCMS/api"
 	validator "RenewCMS/api/pkg/validator"
+	"RenewCMS/internal/infrastructure/config"
 	"context"
 	"errors"
 	"fmt"
@@ -53,12 +54,17 @@ func main() {
 func run() error {
 	initEnvVariables()
 
-	container, closeDb := api.InitContainer()
+	settings, err := config.NewSettingsFromEnv()
+	if err != nil {
+		return err
+	}
+
+	container, closeDb := api.InitContainer(settings)
 	defer closeDatabase(closeDb)
 	validator.InitValidator()
 
-	server := newServer(api.InitRoutes(container))
-	return serveUntilStopped(server)
+	server := newServer(api.InitRoutes(container, settings), settings)
+	return serveUntilStopped(server, settings)
 }
 
 func initEnvVariables() {
@@ -98,9 +104,9 @@ func closeDatabase(closeDb func() error) {
 	}
 }
 
-func newServer(handler http.Handler) *http.Server {
+func newServer(handler http.Handler, settings config.Settings) *http.Server {
 	return &http.Server{
-		Addr:              ":" + os.Getenv("PORT"),
+		Addr:              ":" + settings.Port,
 		Handler:           handler,
 		ReadHeaderTimeout: readHeaderTimeout,
 		ReadTimeout:       readTimeout,
@@ -109,12 +115,12 @@ func newServer(handler http.Handler) *http.Server {
 	}
 }
 
-func serveUntilStopped(server *http.Server) error {
+func serveUntilStopped(server *http.Server, settings config.Settings) error {
 	stopSignal, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 	defer stop()
 
 	serverErr := make(chan error, 1)
-	go listen(server, serverErr)
+	go listen(server, serverErr, settings)
 
 	select {
 	case err := <-serverErr:
@@ -124,8 +130,8 @@ func serveUntilStopped(server *http.Server) error {
 	}
 }
 
-func listen(server *http.Server, serverErr chan<- error) {
-	log.Printf("RenewCMS %s (%s) listening on %s, public URL %s", version, os.Getenv("ENVIRONMENT"), server.Addr, os.Getenv("PUBLIC_URL"))
+func listen(server *http.Server, serverErr chan<- error, settings config.Settings) {
+	log.Printf("RenewCMS %s (%s) listening on %s, public URL %s", version, settings.Environment, server.Addr, settings.PublicURL)
 	err := server.ListenAndServe()
 	if errors.Is(err, http.ErrServerClosed) {
 		err = nil
diff --git a/features/runtime_settings_injection.feature b/features/runtime_settings_injection.feature
new file mode 100644
index 0000000..ea305f3
--- /dev/null
+++ b/features/runtime_settings_injection.feature
@@ -0,0 +1,120 @@
+Feature: Runtime settings are read once at startup
+
+  As a maintainer of RenewCMS
+  I want the environment, CORS origins, public URL, upload dir and SMTP
+  settings to be read from the process environment exactly once, in the
+  composition root, and handed down explicitly from there
+  So that no handler, router or repository reads an environment variable at
+    request or construction time, and changing the process environment after
+    startup can never change already-built behaviour
+
+  Background:
+    Given before this slice, os.Getenv is called outside cmd/server/main.go
+      in four places: api/router.go's enableLoggingIfDev reads ENVIRONMENT
+      on every router build, api/router.go's enableCorsIfConfigured reads
+      CORS_ALLOWED_ORIGINS on every router build,
+      api/handlers/auth.shouldCookieBeSecure reads ENVIRONMENT on every
+      Login/Register/Logout call, internal/infrastructure/mailer.MailRepository.Send
+      reads SMTP_EMAIL, SMTP_PASSWORD, SMTP_HOST and SMTP_PORT on every call,
+      and internal/infrastructure/persistence.ImageRepository.Create and
+      .Delete read UPLOAD_DIR on every call
+    And this slice introduces internal/infrastructure/config.Settings, a
+      plain struct with fields Environment, CorsAllowedOrigins ([]string),
+      PublicURL, UploadDir, JWTSecret, DBFile, Port and an Smtp sub-struct
+      (Email, Password, Host, Port)
+    And cmd/server/main.go's initEnvVariables still loads the .env file and
+      applies the same defaults and required-var checks as before, then
+      builds exactly one config.Settings value from the process environment,
+      before api.InitContainer or api.InitRoutes is ever called
+    And api.InitContainer and api.InitRoutes now take that config.Settings
+      value, and every downstream constructor receives its own slice of it
+      explicitly instead of reading os.Getenv: auth.NewHandler receives
+      whether the environment is production, mailer.NewMailRepository
+      receives the Smtp settings, persistence.NewImageRepository receives
+      the upload dir, and the router's logging and CORS setup receive the
+      environment string and the CORS origins list as parameters
+    And after this slice, os.Getenv (and os.LookupEnv) for ENVIRONMENT,
+      CORS_ALLOWED_ORIGINS, SMTP_EMAIL, SMTP_PASSWORD, SMTP_HOST, SMTP_PORT
+      and UPLOAD_DIR appears only inside cmd/server/main.go and
+      internal/infrastructure/config
+    And a component built from a config.Settings value keeps behaving
+      according to the values it was built with even if the process
+      environment changes afterwards, because it holds the captured values,
+      not the environment
+    And GET /healthz is mounted directly on the outer API router
+      (api/router.go), not under /v1, so the CORS middleware wraps it the
+      same way it wraps every route
+
+  Scenario Outline: The jwt cookie's Secure flag follows the injected environment, not the process environment
+    Given a config.Settings value with Environment "<injected environment>"
+    And the auth handler is built from that settings value
+    And the process environment variable ENVIRONMENT is set to "<process environment>"
+    When the client sends POST /v1/auth/login with valid credentials for an
+      existing, verified user
+    Then the response's Set-Cookie header for the "jwt" cookie has its
+      Secure attribute set to <secure expected>
+
+    Examples:
+      | injected environment | process environment | secure expected |
+      | production            | production           | true             |
+      | production            | development           | true             |
+      | development            | production           | false            |
+      | development            | development           | false            |
+
+  Scenario: CORS allows a request from an injected allowed origin
+    Given a config.Settings value with CorsAllowedOrigins
+      ["https://cms.example.com"]
+    And the API router is built from that settings value
+    When the client sends GET /healthz with header
+      Origin: https://cms.example.com
+    Then the response has header Access-Control-Allow-Origin:
+      https://cms.example.com
+
+  Scenario: CORS does not allow a request from an origin outside the injected list
+    Given a config.Settings value with CorsAllowedOrigins
+      ["https://cms.example.com"]
+    And the API router is built from that settings value
+    When the client sends GET /healthz with header
+      Origin: https://attacker.example.com
+    Then the response has no Access-Control-Allow-Origin header
+
+  Scenario: An empty injected origins list disables CORS entirely
+    Given a config.Settings value with CorsAllowedOrigins as an empty list
+    And the API router is built from that settings value
+    When the client sends GET /healthz with header
+      Origin: https://cms.example.com
+    Then the response has no Access-Control-Allow-Origin header
+
+  Scenario: An uploaded image is stored under the injected upload directory
+    Given a config.Settings value with UploadDir pointing at a fresh
+      directory created for this scenario
+    And the image repository is built from that settings value, over a
+      fresh in-memory database
+    And the process environment variable UPLOAD_DIR is unset or points at a
+      different directory
+    When internal/infrastructure/persistence.ImageRepository.Create is
+      called with a PNG file
+    Then the image file is written inside the injected upload directory,
+      not inside the process environment's UPLOAD_DIR
+    And the returned image's Path still starts with "/static/uploadedImages/"
+
+  Scenario: Changing the process environment after construction does not change already-built behaviour
+    Given a config.Settings value with Environment "production"
+    And the auth handler is built from that settings value
+    When the process environment variable ENVIRONMENT is then changed to
+      "development"
+    And the client sends POST /v1/auth/login with valid credentials for an
+      existing, verified user
+    Then the response's Set-Cookie header for the "jwt" cookie still has its
+      Secure attribute set to true
+
+  Scenario: The mailer is constructed from injected SMTP settings, not the environment
+    Given a config.Settings value with Smtp.Email "notify@example.com",
+      Smtp.Host "smtp.example.com" and Smtp.Port 587
+    And internal/infrastructure/mailer.NewMailRepository is called with that
+      Smtp settings value and no SMTP_* environment variable set
+    Then constructing the MailRepository does not read any SMTP_*
+      environment variable
+    And the maintainer verifies by manual test (see QA procedure) that an
+      actual send still uses those injected values, since a real SMTP
+      dialog is never exercised by the automated suite
diff --git a/features/runtime_settings_injection.qa.md b/features/runtime_settings_injection.qa.md
new file mode 100644
index 0000000..d52447f
--- /dev/null
+++ b/features/runtime_settings_injection.qa.md
@@ -0,0 +1,113 @@
+# QA procedure: runtime_settings_injection
+
+Package: `test` (black-box).
+
+## Setup shared by every case
+1. Call `validator.InitValidator()` once.
+2. For the secure-cookie and upload-directory cases, build only the pieces
+   under test directly (no real SQLite file), mirroring
+   `test/article_publishing_http_test.go` and siblings.
+3. For the CORS cases, build the **real** router construction path — see
+   "CORS" section below. A test-local reimplementation of the CORS wiring
+   (a helper that copies `enableCorsIfConfigured`'s logic instead of calling
+   it) is not acceptable: the point of these scenarios is to prove the
+   actual `api/router.go` wiring, driven by injected settings, behaves
+   correctly, not that some parallel logic does.
+4. Never set `t.Setenv` before constructing a component under test in a way
+   that the component is expected to read; the whole point of this suite is
+   that env is captured once elsewhere. Where a scenario needs to prove
+   the environment has no effect, set it with `t.Setenv` explicitly *after*
+   construction, and say so in the test's own scenario name (not as a code
+   comment).
+
+## Secure cookie flag (Scenario Outline + regression scenario)
+5. Build a `mockUserRepo` (reuse `test/user_test.go`'s fake) seeded with one
+   verified user and a known bcrypt hash via `hashing.NewBcryptHasher()`.
+6. Build `auth.NewHandler(token, getUseCase, listUseCase, createUseCase,
+   authenticateUseCase, <injected production flag>)` — this slice adds a
+   constructor parameter carrying the environment/production flag in place
+   of `shouldCookieBeSecure`'s `os.Getenv` call. Mount only `POST /login` on
+   a fresh `chi.NewRouter()`.
+7. For each row of the outline: optionally `t.Setenv("ENVIRONMENT", ...)`
+   with the process value from the table (this must have zero effect), then
+   send `POST /login` with valid JSON credentials for the seeded user via
+   `httptest.NewRequest` + `httptest.NewRecorder()`. Read the `Set-Cookie`
+   response header value with `rec.Result().Header.Values("Set-Cookie")`,
+   parse it with `http.ParseSetCookie(...)`, and assert `.Secure` equals the
+   table's expected value.
+8. For the "changing the process environment after construction" scenario,
+   build the handler once with the production flag fixed at construction
+   time, then call `t.Setenv("ENVIRONMENT", "development")`, then perform the
+   same login request and assert `Secure` is still `true`.
+
+## CORS
+9. Build a `*api.UseCases` (or whatever the composition-root container is
+   named after this slice) backed by the existing in-memory fakes
+   (`mockArticleRepo`, `mockUserRepo`, `mockImageRepo`, `mockMailRepo`, a
+   test `jwtauth.New("HS256", []byte("test-secret"), nil)`), then call the
+   real `api.InitRoutes(container, settings)` (or whichever exported
+   constructor this slice ends up exposing for the outer router, e.g. an
+   exported `NewApiRouter(container, settings)`) with a
+   `config.Settings{CorsAllowedOrigins: ...}` value. Do not hand-roll a
+   second `cors.Handler` call in the test; call the same construction path
+   `cmd/server/main.go` calls.
+10. For the allowed-origin case, build the router with
+    `CorsAllowedOrigins: []string{"https://cms.example.com"}`, send
+    `GET /healthz` with header `Origin: https://cms.example.com`, and assert
+    the response header `Access-Control-Allow-Origin` equals
+    `"https://cms.example.com"`.
+11. For the disallowed-origin case, same router, send the request with
+    `Origin: https://attacker.example.com`, and assert the response has no
+    `Access-Control-Allow-Origin` header (`rec.Result().Header.Get(...)`
+    returns `""`).
+12. For the empty-list case, build the router with `CorsAllowedOrigins: nil`
+    (or `[]string{}`), send a request to `GET /healthz` with any `Origin`
+    header, and assert the header is again absent.
+
+## Upload directory
+13. Reuse `openInMemoryDb(t)` and `models.Image{}` migration as
+    `test/image_extension_mapping_test.go` does, but construct the
+    repository as `persistence.NewImageRepository(db, uploadDir)` where
+    `uploadDir := t.TempDir()` — no `t.Setenv("UPLOAD_DIR", ...)` at all.
+    Additionally call `t.Setenv("UPLOAD_DIR", t.TempDir())` with a
+    *different* temp directory right before `Create`, to prove it has no
+    effect.
+14. Call `repo.Create(imageDomain.ImageInput{...})` with a PNG payload.
+    Assert no error; assert the returned `Path` starts with
+    `/static/uploadedImages/`; assert, via `os.Stat`, that the file exists
+    under the constructor's `uploadDir` and does **not** exist under the
+    `t.Setenv` directory from step 13.
+15. Update `test/image_extension_mapping_test.go` in the same slice to pass
+    `t.TempDir()` straight into `persistence.NewImageRepository(db,
+    uploadDir)` instead of `t.Setenv("UPLOAD_DIR", ...)`, since the
+    constructor signature changes.
+
+## Mailer
+16. Construct `mailer.NewMailRepository(config.SmtpSettings{Email:
+    "notify@example.com", Host: "smtp.example.com", Port: 587, Password:
+    "unused-in-test"})` with no `SMTP_*` environment variable set (do not
+    call `t.Setenv` for any `SMTP_*` name in this test). Assert construction
+    does not panic and does not error — this is the only automated
+    assertion available, since exercising `Send` requires a real SMTP dialog
+    that this suite deliberately never performs (matches
+    `test/mail_test.go`, which already tests `SendMailUseCase` against
+    `mockMailRepo`, not the real `MailRepository`).
+
+## Manual verification (not exercised by the Go test)
+- Real SMTP send: run `task dev` (or a built binary) with a real `.env`
+  populated with SMTP_EMAIL/SMTP_PASSWORD/SMTP_HOST/SMTP_PORT, trigger a
+  flow that calls `SendMailUseCase.SendMail`, and confirm the message
+  actually leaves via the injected host/port/credentials, and that changing
+  those env vars requires a process restart to take effect (there is no
+  live-reload).
+- Dev-only request logging: run the binary with `ENVIRONMENT=development`
+  vs `ENVIRONMENT=production` and confirm `httplog` output is present only
+  in the development case; this is not response-observable so it isn't
+  asserted by `httptest`.
+- Confirm `api/dependecyInjection.go`'s `getDb` and `getUseCases` consume
+  `DB_FILE` and `JWT_SECRET` from the same `config.Settings` value built in
+  `cmd/server/main.go`, rather than calling `os.Getenv` themselves — this
+  stays inside the composition root per CLAUDE.md and is not a behaviour
+  change, so it has no dedicated scenario, but review the diff to confirm
+  no stray `os.Getenv` remains there either.
+- SPA-visible behaviour: none: this slice has no SPA-facing change.
diff --git a/internal/infrastructure/config/settings.go b/internal/infrastructure/config/settings.go
new file mode 100644
index 0000000..124e9e2
--- /dev/null
+++ b/internal/infrastructure/config/settings.go
@@ -0,0 +1,59 @@
+package config
+
+import (
+	"os"
+	"strconv"
+	"strings"
+)
+
+type SmtpSettings struct {
+	Email    string
+	Password string
+	Host     string
+	Port     int
+}
+
+type Settings struct {
+	Environment        string
+	CorsAllowedOrigins []string
+	PublicURL          string
+	UploadDir          string
+	JWTSecret          string
+	DBFile             string
+	Port               string
+	Smtp               SmtpSettings
+}
+
+func (s Settings) IsProduction() bool {
+	return s.Environment == "production"
+}
+
+func NewSettingsFromEnv() (Settings, error) {
+	smtpPort, err := strconv.Atoi(os.Getenv("SMTP_PORT"))
+	if err != nil {
+		return Settings{}, err
+	}
+
+	return Settings{
+		Environment:        os.Getenv("ENVIRONMENT"),
+		CorsAllowedOrigins: parseCorsAllowedOrigins(os.Getenv("CORS_ALLOWED_ORIGINS")),
+		PublicURL:          os.Getenv("PUBLIC_URL"),
+		UploadDir:          os.Getenv("UPLOAD_DIR"),
+		JWTSecret:          os.Getenv("JWT_SECRET"),
+		DBFile:             os.Getenv("DB_FILE"),
+		Port:               os.Getenv("PORT"),
+		Smtp: SmtpSettings{
+			Email:    os.Getenv("SMTP_EMAIL"),
+			Password: os.Getenv("SMTP_PASSWORD"),
+			Host:     os.Getenv("SMTP_HOST"),
+			Port:     smtpPort,
+		},
+	}, nil
+}
+
+func parseCorsAllowedOrigins(raw string) []string {
+	if raw == "" {
+		return nil
+	}
+	return strings.Split(raw, ";")
+}
diff --git a/internal/infrastructure/mailer/mailRepository.go b/internal/infrastructure/mailer/mailRepository.go
index d5b29e2..6538ee4 100644
--- a/internal/infrastructure/mailer/mailRepository.go
+++ b/internal/infrastructure/mailer/mailRepository.go
@@ -2,30 +2,31 @@ package mailer
 
 import (
 	domain "RenewCMS/internal/domain/mail"
+	"RenewCMS/internal/infrastructure/config"
 	"bytes"
 	"embed"
 	"html/template"
 	"log"
-	"os"
-	"strconv"
 
 	"gopkg.in/gomail.v2"
 )
 
-type MailRepository struct{}
+type MailRepository struct {
+	smtp config.SmtpSettings
+}
 
 //go:embed templates/*
 var mailTemplateFiles embed.FS
 
-func NewMailRepository() *MailRepository {
-	return &MailRepository{}
+func NewMailRepository(smtp config.SmtpSettings) *MailRepository {
+	return &MailRepository{smtp: smtp}
 }
 
 func (m MailRepository) Send(receiverAddress string, templateName string, data any) error {
-	from := os.Getenv("SMTP_EMAIL")
-	password := os.Getenv("SMTP_PASSWORD")
-	smtpHost := os.Getenv("SMTP_HOST")
-	smtpPort, _ := strconv.Atoi(os.Getenv("SMTP_PORT"))
+	from := m.smtp.Email
+	password := m.smtp.Password
+	smtpHost := m.smtp.Host
+	smtpPort := m.smtp.Port
 
 	d := gomail.NewDialer(smtpHost, smtpPort, from, password)
 
diff --git a/internal/infrastructure/persistence/repositories/imageRepository.go b/internal/infrastructure/persistence/repositories/imageRepository.go
index d5329d9..d6bddc7 100644
--- a/internal/infrastructure/persistence/repositories/imageRepository.go
+++ b/internal/infrastructure/persistence/repositories/imageRepository.go
@@ -13,11 +13,12 @@ import (
 )
 
 type ImageRepository struct {
-	db *gorm.DB
+	db        *gorm.DB
+	uploadDir string
 }
 
-func NewImageRepository(db *gorm.DB) *ImageRepository {
-	return &ImageRepository{db}
+func NewImageRepository(db *gorm.DB, uploadDir string) *ImageRepository {
+	return &ImageRepository{db, uploadDir}
 }
 
 var contentTypeExtensions = map[string]string{
@@ -28,7 +29,7 @@ var contentTypeExtensions = map[string]string{
 }
 
 func (i ImageRepository) Create(input domain.ImageInput) (domain.Image, error) {
-	uploadDir := os.Getenv("UPLOAD_DIR")
+	uploadDir := i.uploadDir
 
 	fileBytes, err := io.ReadAll(input.Content)
 	if err != nil {
@@ -57,7 +58,7 @@ func (i ImageRepository) Create(input domain.ImageInput) (domain.Image, error) {
 }
 
 func (i ImageRepository) Delete(id uint32) error {
-	uploadDir := os.Getenv("UPLOAD_DIR")
+	uploadDir := i.uploadDir
 	var entityImage entity.Image
 	err := i.db.Model(&entity.Image{}).First(&entityImage, id).Error
 	if err != nil {
diff --git a/test/hasher_test.go b/test/hasher_test.go
index 71b63bd..7eaa0b2 100644
--- a/test/hasher_test.go
+++ b/test/hasher_test.go
@@ -218,6 +218,7 @@ func newHasherRouter(userRepo *mockUserRepo, hasher *stubHasher) *chi.Mux {
 		useCases.NewListUsersUseCase(userRepo),
 		useCases.NewCreateUserUseCase(userRepo, hasher),
 		useCases.NewAuthenticateUserUseCase(userRepo, hasher),
+		true,
 	)
 
 	r := chi.NewRouter()
@@ -237,6 +238,7 @@ func newRealHasherRouter(userRepo *mockUserRepo) *chi.Mux {
 		useCases.NewListUsersUseCase(userRepo),
 		useCases.NewCreateUserUseCase(userRepo, hasher),
 		useCases.NewAuthenticateUserUseCase(userRepo, hasher),
+		true,
 	)
 
 	r := chi.NewRouter()
diff --git a/test/image_extension_mapping_test.go b/test/image_extension_mapping_test.go
index 19e8e3c..b6c8d74 100644
--- a/test/image_extension_mapping_test.go
+++ b/test/image_extension_mapping_test.go
@@ -15,8 +15,7 @@ func TestImageRepositoryHasAnExtensionForEveryAllowedContentType(t *testing.T) {
 	if err := db.AutoMigrate(&models.Image{}); err != nil {
 		t.Fatalf("failed to migrate: %v", err)
 	}
-	repo := persistence.NewImageRepository(db)
-	t.Setenv("UPLOAD_DIR", t.TempDir())
+	repo := persistence.NewImageRepository(db, t.TempDir())
 
 	allowedContentTypes := imageDomain.AllowedContentTypes()
 	expectedContentTypes := []string{"image/jpeg", "image/png", "image/svg+xml", "image/webp"}
diff --git a/test/not_found_errors_test.go b/test/not_found_errors_test.go
index 83059e9..f765f14 100644
--- a/test/not_found_errors_test.go
+++ b/test/not_found_errors_test.go
@@ -138,6 +138,7 @@ func newNotFoundErrorsRouter(articleRepo *mockArticleRepo, userRepo *mockUserRep
 		useCases.NewListUsersUseCase(userRepo),
 		useCases.NewCreateUserUseCase(userRepo, hasher),
 		useCases.NewAuthenticateUserUseCase(userRepo, hasher),
+		true,
 	)
 
 	r := chi.NewRouter()
diff --git a/test/runtime_settings_from_env_test.go b/test/runtime_settings_from_env_test.go
new file mode 100644
index 0000000..b0ef581
--- /dev/null
+++ b/test/runtime_settings_from_env_test.go
@@ -0,0 +1,113 @@
+package test
+
+import (
+	"RenewCMS/internal/infrastructure/config"
+	"testing"
+)
+
+func setBaseSettingsEnv(t *testing.T) {
+	t.Helper()
+	t.Setenv("ENVIRONMENT", "production")
+	t.Setenv("PUBLIC_URL", "https://cms.example.com")
+	t.Setenv("UPLOAD_DIR", "./data/uploads")
+	t.Setenv("JWT_SECRET", "test-secret")
+	t.Setenv("DB_FILE", "./data/renewcms.db")
+	t.Setenv("PORT", "8080")
+	t.Setenv("SMTP_EMAIL", "notify@example.com")
+	t.Setenv("SMTP_PASSWORD", "hunter2")
+	t.Setenv("SMTP_HOST", "smtp.example.com")
+	t.Setenv("SMTP_PORT", "465")
+	t.Setenv("CORS_ALLOWED_ORIGINS", "")
+}
+
+func TestNewSettingsFromEnvReadsAllFields(t *testing.T) {
+	setBaseSettingsEnv(t)
+	t.Setenv("CORS_ALLOWED_ORIGINS", "https://cms.example.com;https://admin.example.com")
+
+	settings, err := config.NewSettingsFromEnv()
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+
+	if settings.Environment != "production" {
+		t.Errorf("expected Environment %q, got %q", "production", settings.Environment)
+	}
+	if settings.PublicURL != "https://cms.example.com" {
+		t.Errorf("expected PublicURL %q, got %q", "https://cms.example.com", settings.PublicURL)
+	}
+	if settings.UploadDir != "./data/uploads" {
+		t.Errorf("expected UploadDir %q, got %q", "./data/uploads", settings.UploadDir)
+	}
+	if settings.JWTSecret != "test-secret" {
+		t.Errorf("expected JWTSecret %q, got %q", "test-secret", settings.JWTSecret)
+	}
+	if settings.DBFile != "./data/renewcms.db" {
+		t.Errorf("expected DBFile %q, got %q", "./data/renewcms.db", settings.DBFile)
+	}
+	if settings.Port != "8080" {
+		t.Errorf("expected Port %q, got %q", "8080", settings.Port)
+	}
+	if settings.Smtp.Email != "notify@example.com" {
+		t.Errorf("expected Smtp.Email %q, got %q", "notify@example.com", settings.Smtp.Email)
+	}
+	if settings.Smtp.Password != "hunter2" {
+		t.Errorf("expected Smtp.Password %q, got %q", "hunter2", settings.Smtp.Password)
+	}
+	if settings.Smtp.Host != "smtp.example.com" {
+		t.Errorf("expected Smtp.Host %q, got %q", "smtp.example.com", settings.Smtp.Host)
+	}
+	if settings.Smtp.Port != 465 {
+		t.Errorf("expected Smtp.Port %d, got %d", 465, settings.Smtp.Port)
+	}
+	expectedOrigins := []string{"https://cms.example.com", "https://admin.example.com"}
+	if len(settings.CorsAllowedOrigins) != len(expectedOrigins) {
+		t.Fatalf("expected %d origins, got %v", len(expectedOrigins), settings.CorsAllowedOrigins)
+	}
+	for i, origin := range expectedOrigins {
+		if settings.CorsAllowedOrigins[i] != origin {
+			t.Errorf("expected origin %d to be %q, got %q", i, origin, settings.CorsAllowedOrigins[i])
+		}
+	}
+}
+
+func TestNewSettingsFromEnvEmptyCorsOriginsIsNil(t *testing.T) {
+	setBaseSettingsEnv(t)
+
+	settings, err := config.NewSettingsFromEnv()
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+	if settings.CorsAllowedOrigins != nil {
+		t.Errorf("expected nil CorsAllowedOrigins, got %v", settings.CorsAllowedOrigins)
+	}
+}
+
+func TestNewSettingsFromEnvSingleCorsOrigin(t *testing.T) {
+	setBaseSettingsEnv(t)
+	t.Setenv("CORS_ALLOWED_ORIGINS", "https://cms.example.com")
+
+	settings, err := config.NewSettingsFromEnv()
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+	if len(settings.CorsAllowedOrigins) != 1 || settings.CorsAllowedOrigins[0] != "https://cms.example.com" {
+		t.Errorf("expected a single origin %q, got %v", "https://cms.example.com", settings.CorsAllowedOrigins)
+	}
+}
+
+func TestNewSettingsFromEnvInvalidSmtpPortReturnsError(t *testing.T) {
+	setBaseSettingsEnv(t)
+	t.Setenv("SMTP_PORT", "not-a-number")
+
+	_, err := config.NewSettingsFromEnv()
+	if err == nil {
+		t.Fatal("expected an error for a non-numeric SMTP_PORT")
+	}
+}
+
+func TestSettingsIsProductionFalseForNonProductionEnvironment(t *testing.T) {
+	settings := config.Settings{Environment: "development"}
+	if settings.IsProduction() {
+		t.Error("expected IsProduction to be false for environment \"development\"")
+	}
+}
diff --git a/test/runtime_settings_injection_http_test.go b/test/runtime_settings_injection_http_test.go
new file mode 100644
index 0000000..7eb2071
--- /dev/null
+++ b/test/runtime_settings_injection_http_test.go
@@ -0,0 +1,246 @@
+package test
+
+import (
+	"RenewCMS/api"
+	"RenewCMS/api/handlers/auth"
+	validator "RenewCMS/api/pkg/validator"
+	domainUser "RenewCMS/internal/domain/user"
+	"RenewCMS/internal/infrastructure/config"
+	"RenewCMS/internal/infrastructure/hashing"
+	"RenewCMS/internal/infrastructure/mailer"
+	"RenewCMS/internal/infrastructure/persistence/models"
+	persistence "RenewCMS/internal/infrastructure/persistence/repositories"
+	"RenewCMS/internal/infrastructure/useCases"
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+
+	imageDomain "RenewCMS/internal/domain/image"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/jwtauth/v5"
+)
+
+func newSecureCookieAuthRouter(t *testing.T, isProduction bool) (*chi.Mux, *mockUserRepo) {
+	t.Helper()
+	token := jwtauth.New("HS256", []byte("test-secret"), nil)
+	userRepo := newMockUserRepo()
+	hasher := hashing.NewBcryptHasher()
+	hashed, err := hasher.Hash("hunter2example")
+	if err != nil {
+		t.Fatalf("failed to hash password: %v", err)
+	}
+	userRepo.users[1] = domainUser.User{ID: 1, Username: "alice", Password: hashed, IsVerified: true}
+
+	authHandler := auth.NewHandler(
+		token,
+		useCases.NewGetUserUseCase(userRepo),
+		useCases.NewListUsersUseCase(userRepo),
+		useCases.NewCreateUserUseCase(userRepo, hasher),
+		useCases.NewAuthenticateUserUseCase(userRepo, hasher),
+		isProduction,
+	)
+
+	r := chi.NewRouter()
+	r.Post("/login", authHandler.Login)
+	return r, userRepo
+}
+
+func performLoginRequest(t *testing.T, router *chi.Mux) *httptest.ResponseRecorder {
+	t.Helper()
+	body, err := json.Marshal(map[string]string{"username": "alice", "password": "hunter2example"})
+	if err != nil {
+		t.Fatalf("failed to marshal body: %v", err)
+	}
+	req := httptest.NewRequest(http.MethodPost, "/login", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+	return rec
+}
+
+func secureAttributeFromResponse(t *testing.T, rec *httptest.ResponseRecorder) bool {
+	t.Helper()
+	values := rec.Result().Header.Values("Set-Cookie")
+	for _, value := range values {
+		cookie, err := http.ParseSetCookie(value)
+		if err != nil {
+			t.Fatalf("failed to parse Set-Cookie header %q: %v", value, err)
+		}
+		if cookie.Name == "jwt" {
+			return cookie.Secure
+		}
+	}
+	t.Fatalf("expected a jwt Set-Cookie header, got %v", values)
+	return false
+}
+
+func TestRuntimeSettingsInjectionSecureCookie(t *testing.T) {
+	validator.InitValidator()
+
+	outline := []struct {
+		injectedEnvironment string
+		processEnvironment  string
+		secureExpected      bool
+	}{
+		{"production", "production", true},
+		{"production", "development", true},
+		{"development", "production", false},
+		{"development", "development", false},
+	}
+
+	for _, tc := range outline {
+		t.Run("Secure follows the injected environment "+tc.injectedEnvironment+"/"+tc.processEnvironment, func(t *testing.T) {
+			isProduction := tc.injectedEnvironment == "production"
+			router, _ := newSecureCookieAuthRouter(t, isProduction)
+			t.Setenv("ENVIRONMENT", tc.processEnvironment)
+
+			rec := performLoginRequest(t, router)
+			if rec.Code != http.StatusOK {
+				t.Fatalf("expected status 200, got %d, body %q", rec.Code, rec.Body.String())
+			}
+			if got := secureAttributeFromResponse(t, rec); got != tc.secureExpected {
+				t.Errorf("expected Secure=%v, got %v", tc.secureExpected, got)
+			}
+		})
+	}
+
+	t.Run("Changing the process environment after construction does not change already-built behaviour", func(t *testing.T) {
+		router, _ := newSecureCookieAuthRouter(t, true)
+		t.Setenv("ENVIRONMENT", "development")
+
+		rec := performLoginRequest(t, router)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("expected status 200, got %d, body %q", rec.Code, rec.Body.String())
+		}
+		if got := secureAttributeFromResponse(t, rec); !got {
+			t.Errorf("expected Secure=true, got %v", got)
+		}
+	})
+}
+
+func newRuntimeSettingsContainer(t *testing.T) *api.UseCases {
+	t.Helper()
+	articleRepo := newMockArticleRepo()
+	userRepo := newMockUserRepo()
+	imageRepo := newMockImageRepo()
+	mailRepo := newMockMailRepo()
+	hasher := hashing.NewBcryptHasher()
+	token := jwtauth.New("HS256", []byte("test-secret"), nil)
+
+	return &api.UseCases{
+		Token:                   token,
+		CreateArticleUseCase:    useCases.NewCreateArticleUseCase(articleRepo),
+		GetArticleUseCase:       useCases.NewGetArticleUseCase(articleRepo),
+		ListArticlesUseCase:     useCases.NewListArticlesUseCase(articleRepo),
+		UpdateArticleUseCase:    useCases.NewUpdateArticleUseCase(articleRepo),
+		DeleteArticleUseCase:    useCases.NewDeleteArticleUseCase(articleRepo, imageRepo),
+		GetUserUseCase:          useCases.NewGetUserUseCase(userRepo),
+		CreateUserUseCase:       useCases.NewCreateUserUseCase(userRepo, hasher),
+		UpdateUserUseCase:       useCases.NewUpdateUserUseCase(userRepo, hasher),
+		AuthenticateUserUseCase: useCases.NewAuthenticateUserUseCase(userRepo, hasher),
+		DeleteUserUseCase:       useCases.NewDeleteUserUseCase(userRepo),
+		ListUsersUseCase:        useCases.NewListUsersUseCase(userRepo),
+		SendMailUseCase:         useCases.NewSendMailUseCase(mailRepo),
+		CreateImageUseCase:      useCases.NewCreateImageUseCase(imageRepo),
+		DeleteImageUseCase:      useCases.NewDeleteImageUseCase(imageRepo),
+	}
+}
+
+func TestRuntimeSettingsInjectionCors(t *testing.T) {
+	validator.InitValidator()
+	container := newRuntimeSettingsContainer(t)
+
+	t.Run("CORS allows a request from an injected allowed origin", func(t *testing.T) {
+		settings := config.Settings{CorsAllowedOrigins: []string{"https://cms.example.com"}}
+		router := api.InitRoutes(container, settings)
+
+		req := httptest.NewRequest(http.MethodGet, "/healthz", nil)
+		req.Header.Set("Origin", "https://cms.example.com")
+		rec := httptest.NewRecorder()
+		router.ServeHTTP(rec, req)
+
+		if got := rec.Result().Header.Get("Access-Control-Allow-Origin"); got != "https://cms.example.com" {
+			t.Errorf("expected Access-Control-Allow-Origin %q, got %q", "https://cms.example.com", got)
+		}
+	})
+
+	t.Run("CORS does not allow a request from an origin outside the injected list", func(t *testing.T) {
+		settings := config.Settings{CorsAllowedOrigins: []string{"https://cms.example.com"}}
+		router := api.InitRoutes(container, settings)
+
+		req := httptest.NewRequest(http.MethodGet, "/healthz", nil)
+		req.Header.Set("Origin", "https://attacker.example.com")
+		rec := httptest.NewRecorder()
+		router.ServeHTTP(rec, req)
+
+		if got := rec.Result().Header.Get("Access-Control-Allow-Origin"); got != "" {
+			t.Errorf("expected no Access-Control-Allow-Origin header, got %q", got)
+		}
+	})
+
+	t.Run("An empty injected origins list disables CORS entirely", func(t *testing.T) {
+		settings := config.Settings{CorsAllowedOrigins: nil}
+		router := api.InitRoutes(container, settings)
+
+		req := httptest.NewRequest(http.MethodGet, "/healthz", nil)
+		req.Header.Set("Origin", "https://cms.example.com")
+		rec := httptest.NewRecorder()
+		router.ServeHTTP(rec, req)
+
+		if got := rec.Result().Header.Get("Access-Control-Allow-Origin"); got != "" {
+			t.Errorf("expected no Access-Control-Allow-Origin header, got %q", got)
+		}
+	})
+}
+
+func TestRuntimeSettingsInjectionUploadDirectory(t *testing.T) {
+	db := openInMemoryDb(t)
+	if err := db.AutoMigrate(&models.Image{}); err != nil {
+		t.Fatalf("failed to migrate: %v", err)
+	}
+	injectedUploadDir := t.TempDir()
+	repo := persistence.NewImageRepository(db, injectedUploadDir)
+
+	processUploadDir := t.TempDir()
+	t.Setenv("UPLOAD_DIR", processUploadDir)
+
+	result, err := repo.Create(imageDomain.ImageInput{
+		Content:     bytes.NewReader([]byte("fake-image-data")),
+		Filename:    "upload.png",
+		ContentType: "image/png",
+	})
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
+	}
+
+	if got := result.Path; len(got) < len("/static/uploadedImages/") || got[:len("/static/uploadedImages/")] != "/static/uploadedImages/" {
+		t.Errorf("expected Path to start with /static/uploadedImages/, got %q", got)
+	}
+
+	fileName := filepath.Base(result.Path)
+	if _, err := os.Stat(filepath.Join(injectedUploadDir, fileName)); err != nil {
+		t.Errorf("expected the file to exist under the injected upload dir: %v", err)
+	}
+	if _, err := os.Stat(filepath.Join(processUploadDir, fileName)); !os.IsNotExist(err) {
+		t.Errorf("expected the file to not exist under the process UPLOAD_DIR")
+	}
+}
+
+func TestRuntimeSettingsInjectionMailer(t *testing.T) {
+	smtp := config.SmtpSettings{
+		Email:    "notify@example.com",
+		Host:     "smtp.example.com",
+		Port:     587,
+		Password: "unused-in-test",
+	}
+
+	repo := mailer.NewMailRepository(smtp)
+	if repo == nil {
+		t.Fatalf("expected a non-nil MailRepository")
+	}
+}
diff --git a/test/write_not_found_errors_test.go b/test/write_not_found_errors_test.go
index 3cddd36..c275a0f 100644
--- a/test/write_not_found_errors_test.go
+++ b/test/write_not_found_errors_test.go
@@ -144,7 +144,7 @@ func TestTheImageRepositoryReportsAMissingImageAsADomainErrorOnDelete(t *testing
 	if err := db.Create(&models.Image{Path: "/static/uploadedImages/one.png"}).Error; err != nil {
 		t.Fatalf("failed to seed image: %v", err)
 	}
-	repo := persistence.NewImageRepository(db)
+	repo := persistence.NewImageRepository(db, t.TempDir())
 
 	err := repo.Delete(9)
 	assertWriteResultIsImageNotFound(t, err)