diff --git a/internal/api/v1/scheme_test.go b/internal/api/v1/scheme_test.go
new file mode 100644
index 0000000..e74ce67
--- /dev/null
+++ b/internal/api/v1/scheme_test.go
@@ -0,0 +1,20 @@
+package v1
+
+import (
+	"crypto/tls"
+	"net/http"
+	"testing"
+)
+
+func TestScheme(t *testing.T) {
+	if got := scheme(&http.Request{TLS: &tls.ConnectionState{}}); got != "https" {
+		t.Errorf("TLS request scheme = %q, want https", got)
+	}
+	r := &http.Request{Header: http.Header{"X-Forwarded-Proto": {"https"}}}
+	if got := scheme(r); got != "https" {
+		t.Errorf("X-Forwarded-Proto scheme = %q, want https", got)
+	}
+	if got := scheme(&http.Request{Header: http.Header{}}); got != "http" {
+		t.Errorf("default scheme = %q, want http", got)
+	}
+}
diff --git a/internal/api/v2/errorpaths_test.go b/internal/api/v2/errorpaths_test.go
new file mode 100644
index 0000000..abedb70
--- /dev/null
+++ b/internal/api/v2/errorpaths_test.go
@@ -0,0 +1,130 @@
+package v2
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"strings"
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/internal/database"
+	"git.unkin.net/unkin/artifactapi/internal/testsupport"
+)
+
+var testDSN string
+
+func TestMain(m *testing.M) {
+	ctx := context.Background()
+	dsn, terminate, err := testsupport.StartPostgres(ctx)
+	if err != nil {
+		os.Exit(m.Run())
+	}
+	testDSN = dsn
+	code := m.Run()
+	terminate()
+	if code != 0 {
+		os.Exit(code)
+	}
+}
+
+// closedDB returns a DB whose pool has been closed, so every query fails —
+// used to drive the handlers' error branches.
+func closedDB(t *testing.T) *database.DB {
+	t.Helper()
+	if testDSN == "" {
+		t.Skip("Docker unavailable")
+	}
+	db, err := database.New(testDSN)
+	if err != nil {
+		t.Fatalf("new db: %v", err)
+	}
+	db.Close()
+	return db
+}
+
+func do(t *testing.T, h http.Handler, method, path, body string) int {
+	t.Helper()
+	var r io.Reader
+	if body != "" {
+		r = strings.NewReader(body)
+	}
+	req := httptest.NewRequest(method, path, r)
+	w := httptest.NewRecorder()
+	h.ServeHTTP(w, req)
+	return w.Code
+}
+
+func TestRemotesErrorPaths(t *testing.T) {
+	h := NewRemotesHandler(closedDB(t)).Routes()
+	if c := do(t, h, "GET", "/", ""); c != 500 {
+		t.Errorf("list with dead db = %d, want 500", c)
+	}
+	if c := do(t, h, "POST", "/", `{"name":"x","package_type":"generic","repo_type":"remote","base_url":"https://x"}`); c != 500 {
+		t.Errorf("create with dead db = %d, want 500", c)
+	}
+	if c := do(t, h, "PUT", "/x", `{"package_type":"generic","base_url":"https://x"}`); c != 500 {
+		t.Errorf("update with dead db = %d, want 500", c)
+	}
+	if c := do(t, h, "GET", "/x", ""); c != 404 {
+		t.Errorf("get missing = %d, want 404", c)
+	}
+	if c := do(t, h, "DELETE", "/x", ""); c != 500 {
+		t.Errorf("delete with dead db = %d, want 500", c)
+	}
+	// Bad request bodies never reach the db.
+	if c := do(t, h, "POST", "/", `not json`); c != 400 {
+		t.Errorf("invalid json = %d, want 400", c)
+	}
+}
+
+func TestVirtualsErrorPaths(t *testing.T) {
+	h := NewVirtualsHandler(closedDB(t)).Routes()
+	if c := do(t, h, "GET", "/", ""); c != 500 {
+		t.Errorf("list = %d, want 500", c)
+	}
+	if c := do(t, h, "GET", "/x", ""); c != 404 {
+		t.Errorf("get missing = %d, want 404", c)
+	}
+	if c := do(t, h, "POST", "/", `{"name":"v","package_type":"helm","members":["a"]}`); c != 500 {
+		t.Errorf("create = %d, want 500", c)
+	}
+	if c := do(t, h, "PUT", "/v", `{"package_type":"helm","members":["a"]}`); c != 500 {
+		t.Errorf("update = %d, want 500", c)
+	}
+	if c := do(t, h, "DELETE", "/v", ""); c != 500 {
+		t.Errorf("delete = %d, want 500", c)
+	}
+}
+
+func TestStatsErrorPaths(t *testing.T) {
+	h := NewStatsHandler(closedDB(t)).Routes()
+	for _, p := range []string{"/", "/top-remotes", "/top-files-by-hits", "/top-files-by-bandwidth"} {
+		if c := do(t, h, "GET", p, ""); c != 500 {
+			t.Errorf("stats %s = %d, want 500", p, c)
+		}
+	}
+}
+
+func TestLocalErrorPaths(t *testing.T) {
+	h := NewLocalHandler(closedDB(t), nil).Routes()
+	// GetRemote fails on the closed db -> not found.
+	if c := do(t, h, "PUT", "/x/files/a.bin", "data"); c != 404 {
+		t.Errorf("upload unknown repo = %d, want 404", c)
+	}
+	// download / remove hit the db and 500.
+	if c := do(t, h, "GET", "/x/files/a.bin", ""); c != 500 {
+		t.Errorf("download = %d, want 500", c)
+	}
+	if c := do(t, h, "DELETE", "/x/files/a.bin", ""); c != 500 {
+		t.Errorf("remove = %d, want 500", c)
+	}
+}
+
+func TestLocalHandlerDBAccessor(t *testing.T) {
+	db := closedDB(t)
+	if NewLocalHandler(db, nil).DB() != db {
+		t.Error("DB() should return the handler's database")
+	}
+}
diff --git a/internal/api/v2/local_fault_test.go b/internal/api/v2/local_fault_test.go
new file mode 100644
index 0000000..3159411
--- /dev/null
+++ b/internal/api/v2/local_fault_test.go
@@ -0,0 +1,88 @@
+package v2
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/go-chi/chi/v5"
+
+	"git.unkin.net/unkin/artifactapi/internal/database"
+	"git.unkin.net/unkin/artifactapi/internal/storage"
+	"git.unkin.net/unkin/artifactapi/internal/testsupport"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+// TestLocalUploadStoreFailure covers the upload handlers' store-error branches
+// by killing the object store after a successful upload.
+func TestLocalUploadStoreFailure(t *testing.T) {
+	if testDSN == "" {
+		t.Skip("Docker unavailable")
+	}
+	ctx := context.Background()
+	db, err := database.New(testDSN)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	conn, termMinio, err := testsupport.StartMinio(ctx)
+	if err != nil {
+		t.Skip("minio unavailable")
+	}
+	var store *storage.S3
+	for i := 0; i < 20; i++ {
+		if store, err = storage.NewS3(conn.Endpoint, conn.AccessKey, conn.SecretKey, "fault", false, ""); err == nil {
+			break
+		}
+		time.Sleep(500 * time.Millisecond)
+	}
+	if err != nil {
+		termMinio()
+		t.Fatal(err)
+	}
+
+	for _, pt := range []models.PackageType{models.PackageGeneric, models.PackagePyPI} {
+		if err := db.CreateRemote(ctx, &models.Remote{Name: "fault-" + string(pt), PackageType: pt, RepoType: models.RepoTypeLocal}); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	h := NewLocalHandler(db, store)
+	router := chi.NewRouter()
+	router.Route("/remotes/{name}/files", func(r chi.Router) {
+		r.Put("/*", h.Routes().ServeHTTP)
+	})
+	srv := httptest.NewServer(router)
+	defer srv.Close()
+
+	put := func(name, path, body string) int {
+		rq, _ := http.NewRequest("PUT", srv.URL+"/remotes/"+name+"/files/"+path, strings.NewReader(body))
+		resp, err := http.DefaultClient.Do(rq)
+		if err != nil {
+			t.Fatalf("put: %v", err)
+		}
+		resp.Body.Close()
+		return resp.StatusCode
+	}
+
+	// Sanity: uploads succeed while the store is up.
+	if c := put("fault-generic", "ok.bin", "data"); c != 201 {
+		t.Fatalf("generic upload while up = %d", c)
+	}
+	if c := put("fault-pypi", "foo-1.0-py3-none-any.whl", "wheel"); c != 201 {
+		t.Fatalf("pypi upload while up = %d", c)
+	}
+
+	// Kill the store; subsequent CAS.Store calls fail -> 500.
+	termMinio()
+	if c := put("fault-generic", "after.bin", "data"); c != 500 {
+		t.Errorf("generic upload after store down = %d, want 500", c)
+	}
+	if c := put("fault-pypi", "bar-1.0-py3-none-any.whl", "wheel"); c != 500 {
+		t.Errorf("pypi upload after store down = %d, want 500", c)
+	}
+}
diff --git a/internal/auth/basic_test.go b/internal/auth/basic_test.go
new file mode 100644
index 0000000..dd089d3
--- /dev/null
+++ b/internal/auth/basic_test.go
@@ -0,0 +1,23 @@
+package auth
+
+import (
+	"encoding/base64"
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func TestBasicHeaders(t *testing.T) {
+	h := BasicHeaders(models.Remote{Username: "alice", Password: "secret"})
+	got := h.Get("Authorization")
+	want := "Basic " + base64.StdEncoding.EncodeToString([]byte("alice:secret"))
+	if got != want {
+		t.Errorf("Authorization = %q, want %q", got, want)
+	}
+}
+
+func TestBasicHeadersNoUser(t *testing.T) {
+	if h := BasicHeaders(models.Remote{}); h.Get("Authorization") != "" {
+		t.Error("expected no Authorization header without a username")
+	}
+}
diff --git a/internal/cache/cache_test.go b/internal/cache/cache_test.go
new file mode 100644
index 0000000..5edbf41
--- /dev/null
+++ b/internal/cache/cache_test.go
@@ -0,0 +1,133 @@
+package cache
+
+import (
+	"context"
+	"os"
+	"testing"
+	"time"
+
+	"git.unkin.net/unkin/artifactapi/internal/testsupport"
+)
+
+var testRedis *Redis
+
+func TestMain(m *testing.M) {
+	ctx := context.Background()
+	url, terminate, err := testsupport.StartRedis(ctx)
+	if err != nil {
+		os.Exit(m.Run())
+	}
+	r, err := NewRedis(url)
+	if err != nil {
+		terminate()
+		panic(err)
+	}
+	testRedis = r
+	code := m.Run()
+	r.Close()
+	terminate()
+	if code != 0 {
+		os.Exit(code)
+	}
+}
+
+func requireRedis(t *testing.T) {
+	t.Helper()
+	if testRedis == nil {
+		t.Skip("Docker unavailable; skipping cache integration test")
+	}
+}
+
+func TestNewRedisInvalid(t *testing.T) {
+	if _, err := NewRedis("://bad-url"); err == nil {
+		t.Error("expected error for invalid redis URL")
+	}
+}
+
+func TestTTL(t *testing.T) {
+	requireRedis(t)
+	ctx := context.Background()
+	if fresh, _ := testRedis.CheckTTL(ctx, "r", "missing"); fresh {
+		t.Error("missing key should not be fresh")
+	}
+	if err := testRedis.SetTTL(ctx, "r", "p", time.Minute); err != nil {
+		t.Fatal(err)
+	}
+	if fresh, err := testRedis.CheckTTL(ctx, "r", "p"); err != nil || !fresh {
+		t.Errorf("expected fresh after SetTTL: %v %v", fresh, err)
+	}
+}
+
+func TestLock(t *testing.T) {
+	requireRedis(t)
+	ctx := context.Background()
+	ok, err := testRedis.AcquireLock(ctx, "r", "lockpath", time.Minute)
+	if err != nil || !ok {
+		t.Fatalf("first acquire should succeed: %v %v", ok, err)
+	}
+	if ok, _ := testRedis.AcquireLock(ctx, "r", "lockpath", time.Minute); ok {
+		t.Error("second acquire should fail while held")
+	}
+	if err := testRedis.ReleaseLock(ctx, "r", "lockpath"); err != nil {
+		t.Fatal(err)
+	}
+	if ok, _ := testRedis.AcquireLock(ctx, "r", "lockpath", time.Minute); !ok {
+		t.Error("acquire should succeed after release")
+	}
+}
+
+func TestETagAndToken(t *testing.T) {
+	requireRedis(t)
+	ctx := context.Background()
+	if v, _ := testRedis.GetETag(ctx, "r", "missing"); v != "" {
+		t.Error("missing etag should be empty")
+	}
+	testRedis.SetETag(ctx, "r", "p", `"abc"`, time.Minute)
+	if v, _ := testRedis.GetETag(ctx, "r", "p"); v != `"abc"` {
+		t.Errorf("etag = %q", v)
+	}
+
+	if v, _ := testRedis.GetToken(ctx, "missing"); v != "" {
+		t.Error("missing token should be empty")
+	}
+	testRedis.SetToken(ctx, "key", "tok", time.Minute)
+	if v, _ := testRedis.GetToken(ctx, "key"); v != "tok" {
+		t.Errorf("token = %q", v)
+	}
+}
+
+func TestCircuit(t *testing.T) {
+	requireRedis(t)
+	ctx := context.Background()
+	if n, _ := testRedis.GetCircuitFailures(ctx, "cr"); n != 0 {
+		t.Errorf("initial failures = %d", n)
+	}
+	n1, err := testRedis.IncrCircuitFailure(ctx, "cr", time.Minute)
+	if err != nil || n1 != 1 {
+		t.Fatalf("first incr = %d %v", n1, err)
+	}
+	n2, _ := testRedis.IncrCircuitFailure(ctx, "cr", time.Minute)
+	if n2 != 2 {
+		t.Errorf("second incr = %d", n2)
+	}
+	if n, _ := testRedis.GetCircuitFailures(ctx, "cr"); n != 2 {
+		t.Errorf("get failures = %d", n)
+	}
+	testRedis.ResetCircuit(ctx, "cr")
+	if n, _ := testRedis.GetCircuitFailures(ctx, "cr"); n != 0 {
+		t.Errorf("failures after reset = %d", n)
+	}
+}
+
+func TestFlushRemote(t *testing.T) {
+	requireRedis(t)
+	ctx := context.Background()
+	testRedis.SetTTL(ctx, "flushme", "a", time.Hour)
+	testRedis.SetETag(ctx, "flushme", "a", "x", time.Hour)
+	if err := testRedis.FlushRemote(ctx, "flushme"); err != nil {
+		t.Fatal(err)
+	}
+	if fresh, _ := testRedis.CheckTTL(ctx, "flushme", "a"); fresh {
+		t.Error("expected keys flushed")
+	}
+}
diff --git a/internal/config/env_test.go b/internal/config/env_test.go
new file mode 100644
index 0000000..179d314
--- /dev/null
+++ b/internal/config/env_test.go
@@ -0,0 +1,66 @@
+package config
+
+import (
+	"os"
+	"testing"
+)
+
+func TestLoadDefaults(t *testing.T) {
+	// Unset the vars Load reads so the fallback defaults are exercised.
+	for _, k := range []string{
+		"LISTEN_ADDR", "DBHOST", "DBPORT", "DBUSER", "DBPASS", "DBNAME", "DBSSL",
+		"REDIS_URL", "MINIO_ENDPOINT", "MINIO_ACCESS_KEY", "MINIO_SECRET_KEY",
+		"MINIO_BUCKET", "MINIO_SECURE", "MINIO_REGION",
+	} {
+		old, ok := os.LookupEnv(k)
+		os.Unsetenv(k)
+		if ok {
+			t.Cleanup(func() { os.Setenv(k, old) })
+		}
+	}
+
+	cfg, err := Load()
+	if err != nil {
+		t.Fatalf("load: %v", err)
+	}
+	if cfg.ListenAddr != ":8000" || cfg.DBPort != 5432 || cfg.DBUser != "artifacts" {
+		t.Errorf("unexpected defaults: %+v", cfg)
+	}
+	if cfg.RedisURL != "redis://localhost:6379" || cfg.S3Bucket != "artifacts" || cfg.S3Secure {
+		t.Errorf("unexpected defaults: %+v", cfg)
+	}
+}
+
+func TestLoadOverrides(t *testing.T) {
+	t.Setenv("LISTEN_ADDR", ":9999")
+	t.Setenv("DBHOST", "db.example.com")
+	t.Setenv("DBPORT", "6000")
+	t.Setenv("DBUSER", "u")
+	t.Setenv("DBPASS", "pw")
+	t.Setenv("DBNAME", "n")
+	t.Setenv("DBSSL", "require")
+	t.Setenv("MINIO_SECURE", "true")
+	t.Setenv("MINIO_REGION", "us-east-1")
+
+	cfg, err := Load()
+	if err != nil {
+		t.Fatalf("load: %v", err)
+	}
+	if cfg.ListenAddr != ":9999" || cfg.DBHost != "db.example.com" || cfg.DBPort != 6000 {
+		t.Errorf("overrides not applied: %+v", cfg)
+	}
+	if !cfg.S3Secure {
+		t.Error("MINIO_SECURE=true not parsed")
+	}
+	want := "postgres://u:pw@db.example.com:6000/n?sslmode=require"
+	if got := cfg.DatabaseDSN(); got != want {
+		t.Errorf("DSN = %q, want %q", got, want)
+	}
+}
+
+func TestLoadInvalidPort(t *testing.T) {
+	t.Setenv("DBPORT", "not-a-number")
+	if _, err := Load(); err == nil {
+		t.Error("expected error for invalid DBPORT")
+	}
+}
diff --git a/internal/database/database_test.go b/internal/database/database_test.go
new file mode 100644
index 0000000..af3746e
--- /dev/null
+++ b/internal/database/database_test.go
@@ -0,0 +1,334 @@
+package database
+
+import (
+	"context"
+	"os"
+	"testing"
+	"time"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	"git.unkin.net/unkin/artifactapi/internal/testsupport"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+var (
+	testDB  *DB
+	testDSN string
+)
+
+func TestMain(m *testing.M) {
+	c := context.Background()
+	dsn, terminate, err := testsupport.StartPostgres(c)
+	if err != nil {
+		// Docker unavailable: run anyway so tests self-skip via requireDB.
+		os.Exit(m.Run())
+	}
+	testDSN = dsn
+	db, err := New(dsn)
+	if err != nil {
+		terminate()
+		panic(err)
+	}
+	testDB = db
+
+	code := m.Run()
+
+	db.Close()
+	terminate()
+	// Return normally on success so the coverage profile is flushed; os.Exit
+	// would truncate it.
+	if code != 0 {
+		os.Exit(code)
+	}
+}
+
+func requireDB(t *testing.T) {
+	t.Helper()
+	if testDB == nil {
+		t.Skip("Docker unavailable; skipping database integration test")
+	}
+}
+
+func ctx() context.Context { return context.Background() }
+
+func seedRemote(t *testing.T, name string) {
+	t.Helper()
+	if err := testDB.CreateRemote(ctx(), &models.Remote{
+		Name: name, PackageType: models.PackageGeneric, RepoType: models.RepoTypeRemote,
+		BaseURL: "https://example.com", MutableTTL: 3600,
+	}); err != nil {
+		t.Fatalf("seed remote: %v", err)
+	}
+}
+
+// seedBlob inserts a blob and returns its full content hash (sha256:<hash>),
+// matching the reference convention used by artifacts and local files.
+func seedBlob(t *testing.T, hash string) string {
+	t.Helper()
+	full := "sha256:" + hash
+	if err := testDB.UpsertBlob(ctx(), full, "blobs/sha256/"+hash, 10, "application/octet-stream"); err != nil {
+		t.Fatalf("seed blob: %v", err)
+	}
+	return full
+}
+
+func TestRemotesCRUD(t *testing.T) {
+	requireDB(t)
+	seedRemote(t, "r-crud")
+	got, err := testDB.GetRemote(ctx(), "r-crud")
+	if err != nil || got.BaseURL != "https://example.com" {
+		t.Fatalf("get: %v %v", got, err)
+	}
+	got.BaseURL = "https://updated.example.com"
+	if err := testDB.UpdateRemote(ctx(), got); err != nil {
+		t.Fatalf("update: %v", err)
+	}
+	got, _ = testDB.GetRemote(ctx(), "r-crud")
+	if got.BaseURL != "https://updated.example.com" {
+		t.Errorf("update not applied: %v", got.BaseURL)
+	}
+	list, err := testDB.ListRemotes(ctx())
+	if err != nil || len(list) == 0 {
+		t.Fatalf("list: %v %v", len(list), err)
+	}
+	if err := testDB.DeleteRemote(ctx(), "r-crud"); err != nil {
+		t.Fatalf("delete: %v", err)
+	}
+	if _, err := testDB.GetRemote(ctx(), "r-crud"); err == nil {
+		t.Error("expected error after delete")
+	}
+}
+
+func TestArtifactsAndBlobs(t *testing.T) {
+	requireDB(t)
+	seedRemote(t, "r-art")
+	seedBlob(t, "aaaa")
+	hash := "sha256:aaaa"
+	if err := testDB.UpsertBlob(ctx(), hash, "blobs/sha256/aaaa", 10, "text/plain"); err != nil {
+		t.Fatal(err)
+	}
+	if err := testDB.UpsertArtifact(ctx(), "r-art", "path/a.txt", hash, "etag1"); err != nil {
+		t.Fatal(err)
+	}
+	// Upsert again to exercise the ON CONFLICT update branch.
+	if err := testDB.UpsertArtifact(ctx(), "r-art", "path/a.txt", hash, "etag2"); err != nil {
+		t.Fatal(err)
+	}
+	art, err := testDB.GetArtifact(ctx(), "r-art", "path/a.txt")
+	if err != nil || art.ContentHash != hash {
+		t.Fatalf("get artifact: %v %v", art, err)
+	}
+	if err := testDB.TouchArtifactAccess(ctx(), "r-art", "path/a.txt"); err != nil {
+		t.Fatal(err)
+	}
+	arts, err := testDB.ListArtifacts(ctx(), "r-art", 10, 0)
+	if err != nil || len(arts) != 1 {
+		t.Fatalf("list artifacts: %v %v", len(arts), err)
+	}
+	if err := testDB.InsertAccessLog(ctx(), "r-art", "path/a.txt", true, 10, 5, "1.2.3.4"); err != nil {
+		t.Fatal(err)
+	}
+	if err := testDB.InsertAccessLogBatch(ctx(), []AccessLogEntry{
+		{RemoteName: "r-art", Path: "b", CacheHit: false, SizeBytes: 20, UpstreamMS: 3},
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if err := testDB.InsertAccessLogBatch(ctx(), nil); err != nil {
+		t.Fatalf("empty batch should be a no-op: %v", err)
+	}
+	if err := testDB.DeleteArtifact(ctx(), "r-art", "path/a.txt"); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestOrphanAndColdCleanup(t *testing.T) {
+	requireDB(t)
+	seedBlob(t, "orphanhash")
+	// A blob with no artifact/local_file reference is orphaned, but only past
+	// the grace period.
+	if got, _ := testDB.FindOrphanedBlobs(ctx(), time.Hour); containsHash(got, "sha256:orphanhash") {
+		t.Error("fresh orphan should be excluded by grace period")
+	}
+	orphans, err := testDB.FindOrphanedBlobs(ctx(), -time.Hour) // cutoff in the future => include fresh
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !containsHash(orphans, "sha256:orphanhash") {
+		t.Error("expected orphan to be found with zero grace")
+	}
+	if err := testDB.DeleteBlob(ctx(), "sha256:orphanhash"); err != nil {
+		t.Fatal(err)
+	}
+
+	seedRemote(t, "r-cold")
+	seedBlob(t, "coldhash")
+	testDB.UpsertArtifact(ctx(), "r-cold", "cold.txt", "sha256:coldhash", "")
+	n, err := testDB.DeleteColdArtifacts(ctx(), "r-cold", -time.Hour) // negative => everything is "cold"
+	if err != nil || n < 1 {
+		t.Fatalf("delete cold: n=%d err=%v", n, err)
+	}
+}
+
+func containsHash(blobs []models.Blob, hash string) bool {
+	for _, b := range blobs {
+		if b.ContentHash == hash {
+			return true
+		}
+	}
+	return false
+}
+
+func TestLocalFiles(t *testing.T) {
+	requireDB(t)
+	seedRemote(t, "r-local")
+	seedBlob(t, "localhash")
+	hash := "sha256:localhash"
+	if err := testDB.CreateLocalFile(ctx(), "r-local", "foo/foo-1.0.whl", hash); err != nil {
+		t.Fatal(err)
+	}
+	// Duplicate create must be rejected.
+	if err := testDB.CreateLocalFile(ctx(), "r-local", "foo/foo-1.0.whl", hash); err == nil {
+		t.Error("expected duplicate local file error")
+	}
+	f, err := testDB.GetLocalFile(ctx(), "r-local", "foo/foo-1.0.whl")
+	if err != nil || f == nil {
+		t.Fatalf("get local file: %v %v", f, err)
+	}
+	if files, err := testDB.ListLocalFiles(ctx(), "r-local", 10, 0); err != nil || len(files) != 1 {
+		t.Fatalf("list: %v %v", len(files), err)
+	}
+	if files, err := testDB.ListLocalFilesByPrefix(ctx(), "r-local", "foo/"); err != nil || len(files) != 1 {
+		t.Fatalf("list by prefix: %v %v", len(files), err)
+	}
+	if entries, err := testDB.ListFilesByPrefix(ctx(), "r-local", "foo/"); err != nil || len(entries) != 1 {
+		t.Fatalf("provider list by prefix: %v %v", len(entries), err)
+	}
+	if pkgs, err := testDB.ListLocalFilePackages(ctx(), "r-local"); err != nil || len(pkgs) == 0 {
+		t.Fatalf("list packages: %v %v", pkgs, err)
+	}
+	if pkgs, err := testDB.ListPackages(ctx(), "r-local"); err != nil || len(pkgs) == 0 {
+		t.Fatalf("provider list packages: %v %v", pkgs, err)
+	}
+	if err := testDB.DeleteLocalFile(ctx(), "r-local", "foo/foo-1.0.whl"); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestVirtualsCRUD(t *testing.T) {
+	requireDB(t)
+	if err := testDB.CreateVirtual(ctx(), &models.Virtual{
+		Name: "v-crud", PackageType: models.PackageHelm, Members: []string{"a", "b"},
+	}); err != nil {
+		t.Fatal(err)
+	}
+	v, err := testDB.GetVirtual(ctx(), "v-crud")
+	if err != nil || len(v.Members) != 2 {
+		t.Fatalf("get virtual: %v %v", v, err)
+	}
+	v.Members = []string{"a"}
+	if err := testDB.UpdateVirtual(ctx(), v); err != nil {
+		t.Fatal(err)
+	}
+	if vs, err := testDB.ListVirtuals(ctx()); err != nil || len(vs) == 0 {
+		t.Fatalf("list virtuals: %v %v", len(vs), err)
+	}
+	if err := testDB.DeleteVirtual(ctx(), "v-crud"); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestStats(t *testing.T) {
+	requireDB(t)
+	seedRemote(t, "r-stats")
+	seedBlob(t, "statshash")
+	testDB.UpsertArtifact(ctx(), "r-stats", "s.txt", "sha256:statshash", "")
+	testDB.InsertAccessLog(ctx(), "r-stats", "s.txt", true, 100, 2, "")
+
+	if _, err := testDB.GetOverviewStats(ctx()); err != nil {
+		t.Fatalf("overview: %v", err)
+	}
+	if _, err := testDB.GetTopRemotes(ctx(), 5); err != nil {
+		t.Fatalf("top remotes: %v", err)
+	}
+	if _, err := testDB.GetTopFilesByHits(ctx(), 5); err != nil {
+		t.Fatalf("top files by hits: %v", err)
+	}
+	if _, err := testDB.GetTopFilesByBandwidth(ctx(), 5); err != nil {
+		t.Fatalf("top files by bandwidth: %v", err)
+	}
+}
+
+func TestDatabaseErrorPaths(t *testing.T) {
+	requireDB(t)
+	bad, err := New(testDSN)
+	if err != nil {
+		t.Fatal(err)
+	}
+	bad.Close() // every query now fails
+	ctx := context.Background()
+
+	if _, err := bad.ListRemotes(ctx); err == nil {
+		t.Error("ListRemotes should error on closed db")
+	}
+	if _, err := bad.ListVirtuals(ctx); err == nil {
+		t.Error("ListVirtuals should error")
+	}
+	if _, err := bad.ListArtifacts(ctx, "r", 10, 0); err == nil {
+		t.Error("ListArtifacts should error")
+	}
+	if _, err := bad.ListLocalFiles(ctx, "r", 10, 0); err == nil {
+		t.Error("ListLocalFiles should error")
+	}
+	if _, err := bad.ListLocalFilesByPrefix(ctx, "r", "p"); err == nil {
+		t.Error("ListLocalFilesByPrefix should error")
+	}
+	if _, err := bad.ListLocalFilePackages(ctx, "r"); err == nil {
+		t.Error("ListLocalFilePackages should error")
+	}
+	if _, err := bad.ListFilesByPrefix(ctx, "r", "p"); err == nil {
+		t.Error("ListFilesByPrefix should error")
+	}
+	if _, err := bad.ListPackages(ctx, "r"); err == nil {
+		t.Error("ListPackages should error")
+	}
+	if _, err := bad.FindOrphanedBlobs(ctx, 0); err == nil {
+		t.Error("FindOrphanedBlobs should error")
+	}
+	if _, err := bad.GetOverviewStats(ctx); err == nil {
+		t.Error("GetOverviewStats should error")
+	}
+	if _, err := bad.GetTopRemotes(ctx, 5); err == nil {
+		t.Error("GetTopRemotes should error")
+	}
+	if _, err := bad.GetTopFilesByHits(ctx, 5); err == nil {
+		t.Error("GetTopFilesByHits should error")
+	}
+	if _, err := bad.GetTopFilesByBandwidth(ctx, 5); err == nil {
+		t.Error("GetTopFilesByBandwidth should error")
+	}
+	if _, err := bad.ListRPMMetadataEntries(ctx, "r"); err == nil {
+		t.Error("ListRPMMetadataEntries should error")
+	}
+}
+
+func TestRPMMetadata(t *testing.T) {
+	requireDB(t)
+	seedRemote(t, "r-rpm")
+	meta := &provider.RPMMetadata{
+		RepoName: "r-rpm", FilePath: "Packages/x.rpm", ContentHash: "sha256:rpm",
+		Name: "x", Version: "1.0", Release: "1", Arch: "noarch",
+		Requires: []provider.RPMDep{{Name: "libc"}},
+		Provides: []provider.RPMDep{{Name: "x"}},
+		Files:    []provider.RPMFile{},
+	}
+	if err := testDB.InsertRPMMetadata(ctx(), meta); err != nil {
+		t.Fatal(err)
+	}
+	entries, err := testDB.ListRPMMetadataEntries(ctx(), "r-rpm")
+	if err != nil || len(entries) != 1 {
+		t.Fatalf("list rpm entries: %v %v", len(entries), err)
+	}
+	if rows, err := testDB.ListRPMMetadata(ctx(), "r-rpm"); err != nil || len(rows) != 1 {
+		t.Fatalf("list rpm rows: %v %v", len(rows), err)
+	}
+}
diff --git a/internal/gc/gc_integration_test.go b/internal/gc/gc_integration_test.go
new file mode 100644
index 0000000..fa5b413
--- /dev/null
+++ b/internal/gc/gc_integration_test.go
@@ -0,0 +1,114 @@
+package gc
+
+import (
+	"bytes"
+	"context"
+	"os"
+	"testing"
+	"time"
+
+	"git.unkin.net/unkin/artifactapi/internal/database"
+	"git.unkin.net/unkin/artifactapi/internal/storage"
+	"git.unkin.net/unkin/artifactapi/internal/testsupport"
+)
+
+var (
+	testDB    *database.DB
+	testStore *storage.S3
+)
+
+func TestMain(m *testing.M) {
+	ctx := context.Background()
+	dsn, termPG, err := testsupport.StartPostgres(ctx)
+	if err != nil {
+		os.Exit(m.Run())
+	}
+	minio, termMinio, err := testsupport.StartMinio(ctx)
+	if err != nil {
+		termPG()
+		os.Exit(m.Run())
+	}
+	db, err := database.New(dsn)
+	if err != nil {
+		panic(err)
+	}
+	var s3 *storage.S3
+	for i := 0; i < 20; i++ {
+		if s3, err = storage.NewS3(minio.Endpoint, minio.AccessKey, minio.SecretKey, "gc-test", false, ""); err == nil {
+			break
+		}
+		time.Sleep(500 * time.Millisecond)
+	}
+	if err != nil {
+		panic(err)
+	}
+	testDB = db
+	testStore = s3
+
+	code := m.Run()
+	db.Close()
+	termMinio()
+	termPG()
+	if code != 0 {
+		os.Exit(code)
+	}
+}
+
+func TestSweepDeletesOldOrphan(t *testing.T) {
+	if testDB == nil {
+		t.Skip("Docker unavailable")
+	}
+	ctx := context.Background()
+	hash := "sha256:gcorphan"
+	key := storage.BlobKey("gcorphan")
+
+	if err := testStore.Upload(ctx, key, bytes.NewReader([]byte("orphan")), 6, "application/octet-stream"); err != nil {
+		t.Fatal(err)
+	}
+	if err := testDB.UpsertBlob(ctx, hash, key, 6, "application/octet-stream"); err != nil {
+		t.Fatal(err)
+	}
+	// Age the blob past the grace period.
+	if _, err := testDB.Pool.Exec(ctx, `UPDATE blobs SET created_at = now() - interval '2 hours' WHERE content_hash = $1`, hash); err != nil {
+		t.Fatal(err)
+	}
+
+	c := New(testDB, testStore, time.Hour)
+	c.sweep(ctx)
+
+	if exists, _ := testStore.Exists(ctx, key); exists {
+		t.Error("expected orphan object deleted from store")
+	}
+	orphans, _ := testDB.FindOrphanedBlobs(ctx, 0)
+	for _, b := range orphans {
+		if b.ContentHash == hash {
+			t.Error("expected orphan blob row deleted")
+		}
+	}
+}
+
+func TestSweepNoOrphans(t *testing.T) {
+	if testDB == nil {
+		t.Skip("Docker unavailable")
+	}
+	// A sweep with nothing to collect should be a clean no-op.
+	New(testDB, testStore, time.Hour).sweep(context.Background())
+}
+
+func TestRunStopsOnContextCancel(t *testing.T) {
+	if testDB == nil {
+		t.Skip("Docker unavailable")
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan struct{})
+	go func() {
+		New(testDB, testStore, time.Hour).Run(ctx)
+		close(done)
+	}()
+	cancel()
+	select {
+	case <-done:
+	case <-time.After(5 * time.Second):
+		t.Fatal("Run did not return after context cancel")
+	}
+}
diff --git a/internal/provider/alpine/alpine_test.go b/internal/provider/alpine/alpine_test.go
new file mode 100644
index 0000000..a90c880
--- /dev/null
+++ b/internal/provider/alpine/alpine_test.go
@@ -0,0 +1,60 @@
+package alpine
+
+import (
+	"context"
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func TestType(t *testing.T) {
+	if (&Provider{}).Type() != models.PackageAlpine {
+		t.Fatal("wrong type")
+	}
+}
+
+func TestClassify(t *testing.T) {
+	p := &Provider{}
+	if p.Classify("v3.19/main/x86_64/APKINDEX.tar.gz") != provider.Mutable {
+		t.Error("APKINDEX should be mutable")
+	}
+	if p.Classify("v3.19/main/x86_64/curl-8.0-r0.apk") != provider.Immutable {
+		t.Error("apk should be immutable")
+	}
+}
+
+func TestContentType(t *testing.T) {
+	p := &Provider{}
+	cases := map[string]string{
+		"pkg.apk":          "application/vnd.android.package-archive",
+		"APKINDEX.tar.gz":  "application/gzip",
+		"something.random": "application/octet-stream",
+	}
+	for path, want := range cases {
+		if got := p.ContentType(path); got != want {
+			t.Errorf("ContentType(%q) = %q, want %q", path, got, want)
+		}
+	}
+}
+
+func TestUpstreamURL(t *testing.T) {
+	p := &Provider{}
+	got := p.UpstreamURL(models.Remote{BaseURL: "https://dl-cdn.alpinelinux.org/alpine/"}, "/v3.19/main/x86_64/curl.apk")
+	if got != "https://dl-cdn.alpinelinux.org/alpine/v3.19/main/x86_64/curl.apk" {
+		t.Errorf("got %q", got)
+	}
+}
+
+func TestRewriteResponse(t *testing.T) {
+	if out, err := (&Provider{}).RewriteResponse([]byte("x"), models.Remote{}, "http://proxy"); out != nil || err != nil {
+		t.Error("alpine never rewrites")
+	}
+}
+
+func TestAuthHeaders(t *testing.T) {
+	h, _ := (&Provider{}).AuthHeaders(context.Background(), models.Remote{Username: "u", Password: "p"})
+	if h.Get("Authorization") == "" {
+		t.Error("expected auth header")
+	}
+}
diff --git a/internal/provider/docker/docker_extra_test.go b/internal/provider/docker/docker_extra_test.go
new file mode 100644
index 0000000..e07f3e6
--- /dev/null
+++ b/internal/provider/docker/docker_extra_test.go
@@ -0,0 +1,53 @@
+package docker
+
+import (
+	"context"
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func TestDockerClassifyBranches(t *testing.T) {
+	p := &Provider{}
+	if p.Classify("library/nginx/tags/list") != provider.Mutable {
+		t.Error("tags/list should be mutable")
+	}
+	if p.Classify("library/nginx/manifests/latest") != provider.Mutable {
+		t.Error("tag manifest should be mutable")
+	}
+	if p.Classify("library/nginx/manifests/sha256:abcdef") != provider.Immutable {
+		t.Error("digest manifest should be immutable")
+	}
+	if p.Classify("library/nginx/blobs/sha256:abc") != provider.Immutable {
+		t.Error("blob should be immutable")
+	}
+}
+
+func TestDockerContentType(t *testing.T) {
+	p := &Provider{}
+	if p.ContentType("x/blobs/sha256:abc") != "application/octet-stream" {
+		t.Error("blob content type")
+	}
+	if p.ContentType("x/manifests/latest") != "application/vnd.docker.distribution.manifest.v2+json" {
+		t.Error("manifest content type")
+	}
+	if p.ContentType("x/tags/list") != "application/json" {
+		t.Error("default content type")
+	}
+}
+
+func TestDockerRewriteAndAuth(t *testing.T) {
+	p := &Provider{}
+	if out, err := p.RewriteResponse([]byte("x"), models.Remote{}, "http://p"); out != nil || err != nil {
+		t.Error("docker never rewrites")
+	}
+	h, _ := p.AuthHeaders(context.Background(), models.Remote{Username: "u", Password: "p"})
+	if h.Get("Authorization") == "" {
+		t.Error("expected basic auth header")
+	}
+	h, _ = p.AuthHeaders(context.Background(), models.Remote{})
+	if h.Get("Authorization") != "" {
+		t.Error("no creds, no header")
+	}
+}
diff --git a/internal/provider/generic/generic_extra_test.go b/internal/provider/generic/generic_extra_test.go
new file mode 100644
index 0000000..601d0f6
--- /dev/null
+++ b/internal/provider/generic/generic_extra_test.go
@@ -0,0 +1,13 @@
+package generic
+
+import (
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func TestGenericRewriteResponse(t *testing.T) {
+	if out, err := (&Provider{}).RewriteResponse([]byte("x"), models.Remote{}, "http://p"); out != nil || err != nil {
+		t.Error("generic never rewrites")
+	}
+}
diff --git a/internal/provider/goproxy/goproxy_extra_test.go b/internal/provider/goproxy/goproxy_extra_test.go
new file mode 100644
index 0000000..eb2f3cf
--- /dev/null
+++ b/internal/provider/goproxy/goproxy_extra_test.go
@@ -0,0 +1,27 @@
+package goproxy
+
+import (
+	"context"
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func TestGoProxyURLAuthRewrite(t *testing.T) {
+	p := &Provider{}
+	if got := p.UpstreamURL(models.Remote{BaseURL: "https://proxy.golang.org/"}, "/mod/@v/list"); got != "https://proxy.golang.org/mod/@v/list" {
+		t.Errorf("upstream url %q", got)
+	}
+	if out, err := p.RewriteResponse([]byte("x"), models.Remote{}, "http://p"); out != nil || err != nil {
+		t.Error("goproxy never rewrites")
+	}
+	if h, _ := p.AuthHeaders(context.Background(), models.Remote{Username: "u", Password: "p"}); h.Get("Authorization") == "" {
+		t.Error("expected basic auth header")
+	}
+	if got := p.ContentType("mod/@v/v1.0.0.info"); got != "application/json" {
+		t.Errorf("info content type %q", got)
+	}
+	if got := p.ContentType("mod/@v/v1.0.0.mod"); got != "text/plain" {
+		t.Errorf("mod content type %q", got)
+	}
+}
diff --git a/internal/provider/helm/helm_extra_test.go b/internal/provider/helm/helm_extra_test.go
new file mode 100644
index 0000000..2f93783
--- /dev/null
+++ b/internal/provider/helm/helm_extra_test.go
@@ -0,0 +1,18 @@
+package helm
+
+import "testing"
+
+func TestHelmContentTypeBranches(t *testing.T) {
+	p := &Provider{}
+	for path, want := range map[string]string{
+		"charts/x-1.0.0.tgz": "application/gzip",
+		"x.tar.gz":           "application/gzip",
+		"index.yaml":         "text/yaml",
+		"x.yml":              "text/yaml",
+		"other":              "application/octet-stream",
+	} {
+		if got := p.ContentType(path); got != want {
+			t.Errorf("ContentType(%q)=%q want %q", path, got, want)
+		}
+	}
+}
diff --git a/internal/provider/npm/npm_test.go b/internal/provider/npm/npm_test.go
new file mode 100644
index 0000000..5073e19
--- /dev/null
+++ b/internal/provider/npm/npm_test.go
@@ -0,0 +1,78 @@
+package npm
+
+import (
+	"context"
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func TestType(t *testing.T) {
+	if (&Provider{}).Type() != models.PackageNPM {
+		t.Fatal("wrong type")
+	}
+}
+
+func TestClassify(t *testing.T) {
+	p := &Provider{}
+	if p.Classify("pkg/-/pkg-1.0.0.tgz") != provider.Immutable {
+		t.Error("tgz should be immutable")
+	}
+	if p.Classify("pkg") != provider.Mutable {
+		t.Error("metadata should be mutable")
+	}
+}
+
+func TestContentType(t *testing.T) {
+	p := &Provider{}
+	if p.ContentType("pkg/-/pkg-1.0.0.tgz") != "application/gzip" {
+		t.Error("tgz content type")
+	}
+	if p.ContentType("pkg") != "application/json" {
+		t.Error("metadata content type")
+	}
+}
+
+func TestUpstreamURL(t *testing.T) {
+	p := &Provider{}
+	got := p.UpstreamURL(models.Remote{BaseURL: "https://registry.npmjs.org/"}, "/pkg")
+	if got != "https://registry.npmjs.org/pkg" {
+		t.Errorf("got %q", got)
+	}
+}
+
+func TestRewriteResponse(t *testing.T) {
+	p := &Provider{}
+	remote := models.Remote{Name: "npmjs", BaseURL: "https://registry.npmjs.org"}
+
+	if out, _ := p.RewriteResponse([]byte(`{"a":1}`), remote, ""); out != nil {
+		t.Error("empty proxyBaseURL should be a no-op")
+	}
+	if out, _ := p.RewriteResponse([]byte("not json"), remote, "http://proxy"); out != nil {
+		t.Error("invalid json should be a no-op")
+	}
+	body := []byte(`{"tarball":"https://registry.npmjs.org/pkg/-/pkg-1.0.0.tgz"}`)
+	out, err := p.RewriteResponse(body, remote, "http://proxy")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(out) != `{"tarball":"http://proxy/api/v1/remote/npmjs/pkg/-/pkg-1.0.0.tgz"}` {
+		t.Errorf("rewrite: %s", out)
+	}
+	if out, _ := p.RewriteResponse([]byte(`{"x":"unrelated"}`), remote, "http://proxy"); out != nil {
+		t.Error("no matching base URL should be a no-op")
+	}
+}
+
+func TestAuthHeaders(t *testing.T) {
+	p := &Provider{}
+	h, _ := p.AuthHeaders(context.Background(), models.Remote{Username: "u", Password: "pw"})
+	if h.Get("Authorization") == "" {
+		t.Error("expected auth header when credentials set")
+	}
+	h, _ = p.AuthHeaders(context.Background(), models.Remote{})
+	if h.Get("Authorization") != "" {
+		t.Error("expected no auth header without credentials")
+	}
+}
diff --git a/internal/provider/puppet/puppet_test.go b/internal/provider/puppet/puppet_test.go
new file mode 100644
index 0000000..33b76a3
--- /dev/null
+++ b/internal/provider/puppet/puppet_test.go
@@ -0,0 +1,78 @@
+package puppet
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func TestType(t *testing.T) {
+	if (&Provider{}).Type() != models.PackagePuppet {
+		t.Fatal("wrong type")
+	}
+}
+
+func TestClassify(t *testing.T) {
+	p := &Provider{}
+	if p.Classify("v3/modules/puppetlabs-stdlib") != provider.Mutable {
+		t.Error("modules should be mutable")
+	}
+	if p.Classify("v3/releases?module=x") != provider.Mutable {
+		t.Error("releases should be mutable")
+	}
+	if p.Classify("v3/files/puppetlabs-stdlib-1.0.0.tar.gz") != provider.Immutable {
+		t.Error("files should be immutable")
+	}
+}
+
+func TestContentType(t *testing.T) {
+	p := &Provider{}
+	if p.ContentType("x/mod-1.0.0.tar.gz") != "application/gzip" {
+		t.Error("tar.gz")
+	}
+	if p.ContentType("v3/modules/x") != "application/json" {
+		t.Error("v3 json")
+	}
+	if p.ContentType("other") != "application/octet-stream" {
+		t.Error("default")
+	}
+}
+
+func TestUpstreamURL(t *testing.T) {
+	got := (&Provider{}).UpstreamURL(models.Remote{BaseURL: "https://forgeapi.puppet.com/"}, "/v3/modules/x")
+	if got != "https://forgeapi.puppet.com/v3/modules/x" {
+		t.Errorf("got %q", got)
+	}
+}
+
+func TestRewriteResponse(t *testing.T) {
+	p := &Provider{}
+	remote := models.Remote{Name: "forge", BaseURL: "https://forgeapi.puppet.com"}
+
+	if out, _ := p.RewriteResponse([]byte("x"), remote, ""); out != nil {
+		t.Error("empty proxyBaseURL is a no-op")
+	}
+
+	body := []byte(`{"file_uri":"/v3/files/mod.tar.gz","home":"https://forgeapi.puppet.com/x"}`)
+	out, err := p.RewriteResponse(body, remote, "http://proxy")
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := string(out)
+	if !strings.Contains(s, "http://proxy/api/v1/remote/forge/v3/files/mod.tar.gz") {
+		t.Errorf("v3/files not rewritten: %s", s)
+	}
+	if !strings.Contains(s, "http://proxy/api/v1/remote/forge/x") {
+		t.Errorf("base URL not rewritten: %s", s)
+	}
+}
+
+func TestAuthHeaders(t *testing.T) {
+	h, _ := (&Provider{}).AuthHeaders(context.Background(), models.Remote{})
+	if h.Get("Authorization") != "" {
+		t.Error("no credentials, no header")
+	}
+}
diff --git a/internal/provider/pypi/pypi_test.go b/internal/provider/pypi/pypi_test.go
new file mode 100644
index 0000000..ecabe0e
--- /dev/null
+++ b/internal/provider/pypi/pypi_test.go
@@ -0,0 +1,177 @@
+package pypi
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+// fakeFileStore is an in-memory provider.FileStore for exercising local index
+// generation without a database.
+type fakeFileStore struct {
+	packages []string
+	files    map[string][]provider.FileEntry
+}
+
+func (f *fakeFileStore) ListPackages(_ context.Context, _ string) ([]string, error) {
+	return f.packages, nil
+}
+
+func (f *fakeFileStore) ListFilesByPrefix(_ context.Context, _, prefix string) ([]provider.FileEntry, error) {
+	return f.files[prefix], nil
+}
+
+func TestTypeClassifyContentType(t *testing.T) {
+	p := &Provider{}
+	if p.Type() != models.PackagePyPI {
+		t.Fatal("type")
+	}
+	if p.Classify("simple/foo/") != provider.Mutable {
+		t.Error("simple index should be mutable")
+	}
+	if p.Classify("packages/foo-1.0.whl") != provider.Immutable {
+		t.Error("wheel should be immutable")
+	}
+	cases := map[string]string{
+		"foo-1.0-py3-none-any.whl": "application/zip",
+		"foo-1.0.zip":              "application/zip",
+		"foo-1.0.tar.gz":           "application/gzip",
+		"simple/foo/":              "text/html",
+		"weird":                    "application/octet-stream",
+	}
+	for path, want := range cases {
+		if got := p.ContentType(path); got != want {
+			t.Errorf("ContentType(%q)=%q want %q", path, got, want)
+		}
+	}
+}
+
+func TestUpstreamURL(t *testing.T) {
+	p := &Provider{}
+	if got := p.UpstreamURL(models.Remote{BaseURL: "https://files.example.com"}, "packages/foo.whl"); got != "https://files.example.com/packages/foo.whl" {
+		t.Errorf("got %q", got)
+	}
+	if got := p.UpstreamURL(models.Remote{BaseURL: "https://x"}, "simple/foo/"); got != "https://pypi.org/simple/foo/" {
+		t.Errorf("simple should hit pypi.org, got %q", got)
+	}
+}
+
+func TestValidateUpload(t *testing.T) {
+	p := &Provider{}
+	sp, ct, err := p.ValidateUpload("numpy-1.26.0-cp311-cp311-linux_x86_64.whl")
+	if err != nil || sp != "numpy/numpy-1.26.0-cp311-cp311-linux_x86_64.whl" || ct != "application/zip" {
+		t.Errorf("wheel: sp=%q ct=%q err=%v", sp, ct, err)
+	}
+	sp, ct, err = p.ValidateUpload("requests-2.31.0.tar.gz")
+	if err != nil || sp != "requests/requests-2.31.0.tar.gz" || ct != "application/gzip" {
+		t.Errorf("sdist: sp=%q ct=%q err=%v", sp, ct, err)
+	}
+	if _, _, err := p.ValidateUpload("not-a-package.txt"); err == nil {
+		t.Error("expected error for bad extension")
+	}
+}
+
+func TestPackageNameParsing(t *testing.T) {
+	if got := packageFromWheel("Foo_Bar-1.0-py3-none-any.whl"); got != "foo-bar" {
+		t.Errorf("wheel name = %q", got)
+	}
+	if got := packageFromWheel("noseparator.whl"); got != "" {
+		t.Errorf("expected empty for unparseable wheel, got %q", got)
+	}
+	if got := packageFromSdist("My.Pkg-2.0.tar.gz"); got != "my-pkg" {
+		t.Errorf("sdist name = %q", got)
+	}
+	if got := packageFromSdist("noseparator.zip"); got != "" {
+		t.Errorf("expected empty, got %q", got)
+	}
+}
+
+func TestUploadResponse(t *testing.T) {
+	resp := (&Provider{}).UploadResponse("foo/foo-1.0.whl", "sha256:abc", 123)
+	if resp["filename"] != "foo-1.0.whl" || resp["package"] != "foo" || resp["content_hash"] != "sha256:abc" {
+		t.Errorf("unexpected upload response: %v", resp)
+	}
+}
+
+func TestRewriteResponse(t *testing.T) {
+	p := &Provider{}
+	if out, _ := p.RewriteResponse([]byte("x"), models.Remote{Name: "pypi"}, ""); out != nil {
+		t.Error("empty proxyBaseURL is a no-op")
+	}
+	body := []byte(`<a href="https://files.pythonhosted.org/packages/foo.whl">foo.whl</a>`)
+	out, err := p.RewriteResponse(body, models.Remote{Name: "pypi"}, "http://proxy")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(string(out), "http://proxy/api/v1/remote/pypi/") {
+		t.Errorf("not rewritten: %s", out)
+	}
+}
+
+func TestGenerateLocalIndex(t *testing.T) {
+	p := &Provider{}
+	fs := &fakeFileStore{
+		packages: []string{"foo", "bar"},
+		files: map[string][]provider.FileEntry{
+			"foo/": {{FilePath: "foo/foo-1.0-py3-none-any.whl", ContentHash: "sha256:aaa"}},
+		},
+	}
+	list, err := p.GenerateLocalIndex(context.Background(), fs, "local", "simple/")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(string(list), "foo") || !strings.Contains(string(list), "bar") {
+		t.Errorf("package list missing entries: %s", list)
+	}
+
+	files, err := p.GenerateLocalIndex(context.Background(), fs, "local", "simple/foo/")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(string(files), "foo-1.0-py3-none-any.whl") {
+		t.Errorf("file list missing wheel: %s", files)
+	}
+
+	if _, err := p.GenerateLocalIndex(context.Background(), fs, "local", "notsimple"); err == nil {
+		t.Error("expected error for non-simple path")
+	}
+}
+
+func TestServeLocalIndexHTTP(t *testing.T) {
+	p := &Provider{}
+	fs := &fakeFileStore{
+		packages: []string{"foo"},
+		files: map[string][]provider.FileEntry{
+			"foo/": {{FilePath: "foo/foo-1.0-py3-none-any.whl", ContentHash: "sha256:aaa"}},
+		},
+	}
+	serve := func(path string) (*httptest.ResponseRecorder, bool) {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest(http.MethodGet, "/"+path, nil)
+		handled := p.ServeLocalIndex(w, r, fs, "local", path)
+		return w, handled
+	}
+
+	if w, ok := serve("simple/"); !ok || w.Code != 200 || !strings.Contains(w.Body.String(), "foo") {
+		t.Errorf("simple index: handled=%v code=%d body=%s", ok, w.Code, w.Body.String())
+	}
+	if w, ok := serve("simple/foo/"); !ok || w.Code != 200 || !strings.Contains(w.Body.String(), "foo-1.0-py3-none-any.whl") {
+		t.Errorf("package index: handled=%v code=%d body=%s", ok, w.Code, w.Body.String())
+	}
+	// Non-simple paths are not handled.
+	if _, ok := serve("packages/foo.whl"); ok {
+		t.Error("non-index path should not be handled")
+	}
+}
+
+func TestAuthHeaders(t *testing.T) {
+	h, _ := (&Provider{}).AuthHeaders(context.Background(), models.Remote{Username: "u", Password: "p"})
+	if h.Get("Authorization") == "" {
+		t.Error("expected auth header")
+	}
+}
diff --git a/internal/provider/rpm/rpm_meta_test.go b/internal/provider/rpm/rpm_meta_test.go
new file mode 100644
index 0000000..1aa3c2f
--- /dev/null
+++ b/internal/provider/rpm/rpm_meta_test.go
@@ -0,0 +1,276 @@
+package rpm
+
+import (
+	"bytes"
+	"compress/gzip"
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	"git.unkin.net/unkin/artifactapi/internal/testsupport"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+type fakeBlobReader struct{ data []byte }
+
+func (f fakeBlobReader) Download(_ context.Context, _ string) (io.ReadCloser, int64, error) {
+	return io.NopCloser(bytes.NewReader(f.data)), int64(len(f.data)), nil
+}
+
+type fakeMetaStore struct{ inserted *provider.RPMMetadata }
+
+func (f *fakeMetaStore) InsertRPMMetadata(_ context.Context, m *provider.RPMMetadata) error {
+	f.inserted = m
+	return nil
+}
+
+type fakeRPMReader struct{ metas []provider.RPMMetadata }
+
+func (f fakeRPMReader) ListRPMMetadataEntries(_ context.Context, _ string) ([]provider.RPMMetadata, error) {
+	return f.metas, nil
+}
+func (f fakeRPMReader) ListFilesByPrefix(_ context.Context, _, _ string) ([]provider.FileEntry, error) {
+	return nil, nil
+}
+func (f fakeRPMReader) ListPackages(_ context.Context, _ string) ([]string, error) { return nil, nil }
+
+func TestRPMPureFuncs(t *testing.T) {
+	p := &Provider{}
+	if p.Type() != models.PackageRPM {
+		t.Error("type")
+	}
+	if p.Classify("repodata/repomd.xml") != provider.Mutable {
+		t.Error("repomd should be mutable")
+	}
+	if p.Classify("Packages/foo.rpm") != provider.Immutable {
+		t.Error("rpm should be immutable")
+	}
+	if p.ContentType("x.rpm") != "application/x-rpm" {
+		t.Error("rpm content type")
+	}
+	if got := p.UpstreamURL(models.Remote{BaseURL: "https://mirror/"}, "/Packages/x.rpm"); got != "https://mirror/Packages/x.rpm" {
+		t.Errorf("upstream url %q", got)
+	}
+	if out, _ := p.RewriteResponse(nil, models.Remote{}, "http://p"); out != nil {
+		t.Error("rpm never rewrites")
+	}
+	h, _ := p.AuthHeaders(context.Background(), models.Remote{Username: "u", Password: "p"})
+	if h.Get("Authorization") == "" {
+		t.Error("auth header")
+	}
+}
+
+func TestRPMValidateUpload(t *testing.T) {
+	p := &Provider{}
+	sp, ct, err := p.ValidateUpload("dir/foo-1.0.noarch.rpm")
+	if err != nil || sp != "Packages/foo-1.0.noarch.rpm" || ct != "application/x-rpm" {
+		t.Errorf("sp=%q ct=%q err=%v", sp, ct, err)
+	}
+	if _, _, err := p.ValidateUpload("foo.txt"); err == nil {
+		t.Error("expected error for non-rpm")
+	}
+	resp := p.UploadResponse("Packages/foo.rpm", "sha256:abc", 10)
+	if resp["content_hash"] != "sha256:abc" {
+		t.Errorf("upload response %v", resp)
+	}
+}
+
+func TestRPMAfterUpload(t *testing.T) {
+	data := testsupport.MinimalRPM("e2e-testpkg", "1.0", "1", "noarch")
+	store := &fakeMetaStore{}
+	(&Provider{}).AfterUpload(context.Background(), "myrepo", "Packages/e2e-testpkg-1.0-1.noarch.rpm",
+		"sha256:deadbeef", fakeBlobReader{data: data}, store)
+
+	m := store.inserted
+	if m == nil {
+		t.Fatal("no metadata inserted")
+	}
+	if m.Name != "e2e-testpkg" || m.Version != "1.0" || m.Release != "1" || m.Arch != "noarch" {
+		t.Errorf("unexpected metadata: %+v", m)
+	}
+	if m.RPMSize != int64(len(data)) {
+		t.Errorf("RPMSize = %d, want %d", m.RPMSize, len(data))
+	}
+	if len(m.Provides) == 0 {
+		t.Error("expected the package to provide itself")
+	}
+}
+
+type errBlobReader struct{}
+
+func (errBlobReader) Download(_ context.Context, _ string) (io.ReadCloser, int64, error) {
+	return nil, 0, io.ErrUnexpectedEOF
+}
+
+func TestRPMAfterUploadErrors(t *testing.T) {
+	// Download failure: no metadata inserted, no panic.
+	store := &fakeMetaStore{}
+	(&Provider{}).AfterUpload(context.Background(), "r", "p", "sha256:x", errBlobReader{}, store)
+	if store.inserted != nil {
+		t.Error("no metadata should be inserted on download error")
+	}
+	// Parse failure: garbage bytes are not a valid RPM.
+	store2 := &fakeMetaStore{}
+	(&Provider{}).AfterUpload(context.Background(), "r", "p", "sha256:x", fakeBlobReader{data: []byte("not an rpm")}, store2)
+	if store2.inserted != nil {
+		t.Error("no metadata should be inserted on parse error")
+	}
+}
+
+func TestRPMServeRepodata(t *testing.T) {
+	p := &Provider{}
+	reader := fakeRPMReader{metas: []provider.RPMMetadata{{
+		Name: "e2e-testpkg", Version: "1.0", Release: "1", Arch: "noarch",
+		Summary:     "test & <special>",
+		ContentHash: "sha256:abc",
+		Requires:    []provider.RPMDep{{Name: "libc", Flags: "GE", Version: "2.0"}},
+		Provides:    []provider.RPMDep{{Name: "e2e-testpkg"}},
+		Files:       []provider.RPMFile{{Path: "/usr/share/e2e/README", Type: "file"}},
+		Changelogs:  []provider.RPMChangelog{{Author: "e2e", Date: 1, Text: "init"}},
+	}}}
+
+	serve := func(path string) *httptest.ResponseRecorder {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest(http.MethodGet, "/"+path, nil)
+		if !p.ServeLocalIndex(w, r, reader, "myrepo", path) {
+			t.Fatalf("ServeLocalIndex returned false for %q", path)
+		}
+		return w
+	}
+
+	if w := serve("repodata/repomd.xml"); w.Code != 200 || !strings.Contains(w.Body.String(), "<repomd") {
+		t.Errorf("repomd: code=%d body=%s", w.Code, w.Body.String())
+	}
+	for _, name := range []string{"repodata/h-primary.xml.gz", "repodata/h-filelists.xml.gz", "repodata/h-other.xml.gz"} {
+		w := serve(name)
+		if w.Code != 200 {
+			t.Errorf("%s: code %d", name, w.Code)
+		}
+		if _, err := gzip.NewReader(bytes.NewReader(w.Body.Bytes())); err != nil {
+			t.Errorf("%s: not gzip: %v", name, err)
+		}
+	}
+	// Unknown repodata file -> 404.
+	if w := serve("repodata/bogus"); w.Code != http.StatusNotFound {
+		t.Errorf("bogus repodata: code %d", w.Code)
+	}
+	// Non-repodata path -> not handled.
+	w := httptest.NewRecorder()
+	r := httptest.NewRequest(http.MethodGet, "/Packages/x.rpm", nil)
+	if p.ServeLocalIndex(w, r, reader, "myrepo", "Packages/x.rpm") {
+		t.Error("expected ServeLocalIndex false for non-repodata path")
+	}
+}
+
+type errRPMReader struct{}
+
+func (errRPMReader) ListRPMMetadataEntries(context.Context, string) ([]provider.RPMMetadata, error) {
+	return nil, io.ErrUnexpectedEOF
+}
+func (errRPMReader) ListFilesByPrefix(context.Context, string, string) ([]provider.FileEntry, error) {
+	return nil, nil
+}
+func (errRPMReader) ListPackages(context.Context, string) ([]string, error) { return nil, nil }
+
+func TestRPMServeMetadataError(t *testing.T) {
+	p := &Provider{}
+	for _, path := range []string{"repodata/repomd.xml", "repodata/h-primary.xml.gz", "repodata/h-filelists.xml.gz", "repodata/h-other.xml.gz"} {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest(http.MethodGet, "/"+path, nil)
+		p.ServeLocalIndex(w, r, errRPMReader{}, "repo", path)
+		if w.Code != 500 {
+			t.Errorf("%s with failing reader = %d, want 500", path, w.Code)
+		}
+	}
+}
+
+func TestRPMFullMetadataXML(t *testing.T) {
+	// A fully-populated entry exercises every optional-field branch in the
+	// primary/filelists/other XML generators.
+	metas := []provider.RPMMetadata{{
+		Name: "full", Epoch: 1, Version: "2.0", Release: "3", Arch: "x86_64",
+		Summary: "s", Description: "d", License: "MIT", Vendor: "acme",
+		Group: "System", BuildHost: "build.example.com", SourceRPM: "full-2.0.src.rpm",
+		URL: "https://example.com", Packager: "pkgr", ContentHash: "sha256:abc",
+		RPMSize: 100, InstalledSize: 200,
+		Requires:   []provider.RPMDep{{Name: "libc", Flags: "GE", Epoch: "0", Version: "2.0", Release: "1"}},
+		Provides:   []provider.RPMDep{{Name: "full", Flags: "EQ", Version: "2.0"}},
+		Files:      []provider.RPMFile{{Path: "/usr/bin/full", Type: "file"}, {Path: "/etc/full", Type: "dir"}},
+		Changelogs: []provider.RPMChangelog{{Author: "a", Date: 100, Text: "changed"}},
+	}}
+	for _, gen := range []func([]provider.RPMMetadata) []byte{generatePrimaryXMLGZ, generateFilelistsXMLGZ, generateOtherXMLGZ} {
+		zr, err := gzip.NewReader(bytes.NewReader(gen(metas)))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if _, err := io.ReadAll(zr); err != nil {
+			t.Error(err)
+		}
+	}
+}
+
+func TestRPMPrimaryXMLContents(t *testing.T) {
+	// Exercise xmlEscape and dependency entry writing through the gzip'd XML.
+	metas := []provider.RPMMetadata{{
+		Name: "pkg", Version: "1", Release: "1", Arch: "x86_64", Summary: "a & b",
+		Requires: []provider.RPMDep{{Name: "dep", Flags: "EQ", Version: "1.0", Epoch: "0"}},
+	}}
+	gz := generatePrimaryXMLGZ(metas)
+	zr, err := gzip.NewReader(bytes.NewReader(gz))
+	if err != nil {
+		t.Fatal(err)
+	}
+	out, _ := io.ReadAll(zr)
+	s := string(out)
+	if !strings.Contains(s, "a &amp; b") {
+		t.Errorf("summary not xml-escaped: %s", s)
+	}
+	if !strings.Contains(s, "<name>pkg</name>") {
+		t.Errorf("package name missing: %s", s)
+	}
+}
+
+func TestRPMContentTypeAndHelpers(t *testing.T) {
+	p := &Provider{}
+	for path, want := range map[string]string{
+		"x.rpm":                     "application/x-rpm",
+		"repodata/repomd.xml":       "application/xml",
+		"repodata/h-primary.xml.gz": "application/xml",
+		"repodata/h-primary.xml.xz": "application/xml",
+		"Packages/other":            "application/octet-stream",
+	} {
+		if got := p.ContentType(path); got != want {
+			t.Errorf("ContentType(%q)=%q want %q", path, got, want)
+		}
+	}
+
+	for flag, want := range map[int]string{
+		0x08 | 0x04: "GE",
+		0x02 | 0x04: "LE",
+		0x08:        "GT",
+		0x02:        "LT",
+		0x04:        "EQ",
+		0x00:        "",
+	} {
+		if got := rpmFlagString(flag); got != want {
+			t.Errorf("rpmFlagString(%d)=%q want %q", flag, got, want)
+		}
+	}
+
+	if firstGroup(nil) != "Unspecified" {
+		t.Error("empty groups should be Unspecified")
+	}
+	if firstGroup([]string{"System", "Base"}) != "System" {
+		t.Error("firstGroup should return the first")
+	}
+}
+
+func TestGenerateLocalIndexUnsupported(t *testing.T) {
+	if _, err := (&Provider{}).GenerateLocalIndex(context.Background(), fakeRPMReader{}, "r", "simple/"); err == nil {
+		t.Error("expected unsupported error")
+	}
+}
diff --git a/internal/proxy/classifier_extra_test.go b/internal/proxy/classifier_extra_test.go
new file mode 100644
index 0000000..dd5403a
--- /dev/null
+++ b/internal/proxy/classifier_extra_test.go
@@ -0,0 +1,52 @@
+package proxy
+
+import (
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	_ "git.unkin.net/unkin/artifactapi/internal/provider/generic"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func TestClassifierBranches(t *testing.T) {
+	gp, err := provider.Get(models.PackageGeneric)
+	if err != nil {
+		t.Fatal(err)
+	}
+	c := NewClassifier(gp)
+
+	if c.Classify(models.Remote{Blocklist: []string{`\.exe$`}}, "x.exe") != ClassDenied {
+		t.Error("blocklist match should be denied")
+	}
+	// Allowlist present but path doesn't match -> denied.
+	allow := models.Remote{Patterns: []string{`^allowed/`}}
+	if c.Classify(allow, "other/x") != ClassDenied {
+		t.Error("non-allowlisted path should be denied")
+	}
+	if c.Classify(allow, "allowed/x") != ClassImmutable {
+		t.Error("allowlisted generic path should be immutable")
+	}
+	if c.Classify(models.Remote{MutablePatterns: []string{`index$`}}, "a/index") != ClassMutable {
+		t.Error("mutable pattern override failed")
+	}
+	if c.Classify(models.Remote{ImmutablePatterns: []string{`\.bin$`}}, "a.bin") != ClassImmutable {
+		t.Error("immutable pattern failed")
+	}
+	// An invalid regex is skipped (not treated as a match) rather than denying.
+	if c.Classify(models.Remote{Blocklist: []string{`[invalid`}}, "anything") == ClassDenied {
+		t.Error("invalid blocklist regex should be skipped, not deny everything")
+	}
+}
+
+func TestClassificationString(t *testing.T) {
+	for c, want := range map[Classification]string{
+		ClassImmutable:     "immutable",
+		ClassMutable:       "mutable",
+		ClassDenied:        "denied",
+		Classification(99): "unknown",
+	} {
+		if c.String() != want {
+			t.Errorf("Classification(%d).String() = %q, want %q", c, c.String(), want)
+		}
+	}
+}
diff --git a/internal/proxy/engine_test.go b/internal/proxy/engine_test.go
new file mode 100644
index 0000000..87ce690
--- /dev/null
+++ b/internal/proxy/engine_test.go
@@ -0,0 +1,557 @@
+package proxy
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+	"time"
+
+	"git.unkin.net/unkin/artifactapi/internal/cache"
+	"git.unkin.net/unkin/artifactapi/internal/database"
+	"git.unkin.net/unkin/artifactapi/internal/provider"
+	_ "git.unkin.net/unkin/artifactapi/internal/provider/generic"
+	_ "git.unkin.net/unkin/artifactapi/internal/provider/npm"
+	"git.unkin.net/unkin/artifactapi/internal/storage"
+	"git.unkin.net/unkin/artifactapi/internal/testsupport"
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+var (
+	testEngine *Engine
+	testCache  *cache.Redis
+	testDB     *database.DB
+	upstream   *httptest.Server
+)
+
+func TestMain(m *testing.M) {
+	ctx := context.Background()
+	dsn, termPG, err := testsupport.StartPostgres(ctx)
+	if err != nil {
+		os.Exit(m.Run())
+	}
+	redisURL, termRedis, err := testsupport.StartRedis(ctx)
+	if err != nil {
+		termPG()
+		os.Exit(m.Run())
+	}
+	minio, termMinio, err := testsupport.StartMinio(ctx)
+	if err != nil {
+		termPG()
+		termRedis()
+		os.Exit(m.Run())
+	}
+
+	db, err := database.New(dsn)
+	if err != nil {
+		panic(err)
+	}
+	redis, err := cache.NewRedis(redisURL)
+	if err != nil {
+		panic(err)
+	}
+	var s3 *storage.S3
+	for i := 0; i < 20; i++ {
+		if s3, err = storage.NewS3(minio.Endpoint, minio.AccessKey, minio.SecretKey, "proxy-test", false, ""); err == nil {
+			break
+		}
+		time.Sleep(500 * time.Millisecond)
+	}
+	if err != nil {
+		panic(err)
+	}
+
+	testCache = redis
+	testDB = db
+	testEngine = NewEngine(db, redis, s3)
+	upstream = httptest.NewServer(http.HandlerFunc(mockUpstream))
+
+	code := m.Run()
+
+	upstream.Close()
+	db.Close()
+	termMinio()
+	termRedis()
+	termPG()
+	if code != 0 {
+		os.Exit(code)
+	}
+}
+
+func mockUpstream(w http.ResponseWriter, r *http.Request) {
+	switch r.URL.Path {
+	case "/blob.bin":
+		w.Header().Set("Content-Type", "application/octet-stream")
+		w.Write([]byte("immutable blob"))
+	case "/pkg": // npm metadata: mutable, supports revalidation
+		if r.Method == http.MethodHead && r.Header.Get("If-None-Match") == `"v1"` {
+			w.WriteHeader(http.StatusNotModified)
+			return
+		}
+		w.Header().Set("ETag", `"v1"`)
+		w.Write([]byte(`{"name":"pkg"}`))
+	case "/protected.bin": // requires a bearer token obtained from /token
+		if r.Header.Get("Authorization") != "Bearer minted-token" {
+			w.Header().Set("Www-Authenticate", `Bearer realm="`+upstream.URL+`/token",service="reg",scope="repo:pull"`)
+			w.WriteHeader(http.StatusUnauthorized)
+			return
+		}
+		w.Write([]byte("protected payload"))
+	case "/protected2.bin": // same challenge as /protected.bin
+		if r.Header.Get("Authorization") != "Bearer minted-token" {
+			w.Header().Set("Www-Authenticate", `Bearer realm="`+upstream.URL+`/token",service="reg",scope="repo:pull"`)
+			w.WriteHeader(http.StatusUnauthorized)
+			return
+		}
+		w.Write([]byte("protected payload 2"))
+	case "/token":
+		w.Write([]byte(`{"token":"minted-token","expires_in":300}`))
+	case "/token-at":
+		w.Write([]byte(`{"access_token":"at-token"}`))
+	case "/token-500":
+		w.WriteHeader(http.StatusInternalServerError)
+	case "/err500":
+		w.WriteHeader(http.StatusInternalServerError)
+	case "/noauth": // 401 with an unusable challenge (no realm)
+		w.Header().Set("Www-Authenticate", `Bearer service="reg"`)
+		w.WriteHeader(http.StatusUnauthorized)
+	default:
+		http.NotFound(w, r)
+	}
+}
+
+func requireStack(t *testing.T) {
+	t.Helper()
+	if testEngine == nil {
+		t.Skip("Docker unavailable; skipping proxy engine test")
+	}
+}
+
+func genericRemote(name string) models.Remote {
+	return models.Remote{Name: name, PackageType: models.PackageGeneric, RepoType: models.RepoTypeRemote, BaseURL: upstream.URL, StaleOnError: true}
+}
+
+// seed inserts the remote so artifact rows (FK to remotes) can be stored.
+func seed(t *testing.T, r models.Remote) models.Remote {
+	t.Helper()
+	rr := r
+	if err := testDB.CreateRemote(context.Background(), &rr); err != nil {
+		t.Fatalf("seed remote %s: %v", r.Name, err)
+	}
+	return r
+}
+
+func prov(t *testing.T, pt models.PackageType) provider.Provider {
+	p, err := provider.Get(pt)
+	if err != nil {
+		t.Fatalf("provider %s: %v", pt, err)
+	}
+	return p
+}
+
+func readAll(t *testing.T, res *FetchResult) string {
+	t.Helper()
+	defer res.Reader.Close()
+	b, _ := io.ReadAll(res.Reader)
+	return string(b)
+}
+
+func TestFetchImmutableMissThenHit(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	r := seed(t, genericRemote("eng-imm"))
+	p := prov(t, models.PackageGeneric)
+
+	res, err := testEngine.Fetch(ctx, r, "blob.bin", p)
+	if err != nil {
+		t.Fatalf("fetch: %v", err)
+	}
+	if res.Source != "remote" || readAll(t, res) != "immutable blob" {
+		t.Errorf("miss: source=%s", res.Source)
+	}
+	res, err = testEngine.Fetch(ctx, r, "blob.bin", p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if res.Source != "cache" || readAll(t, res) != "immutable blob" {
+		t.Errorf("hit: source=%s", res.Source)
+	}
+}
+
+func TestFetchDenied(t *testing.T) {
+	requireStack(t)
+	r := genericRemote("eng-deny")
+	r.Blocklist = []string{`\.secret$`}
+	_, err := testEngine.Fetch(context.Background(), r, "x.secret", prov(t, models.PackageGeneric))
+	var pe *ProxyError
+	if err == nil || !asProxyError(err, &pe) || pe.Status != http.StatusForbidden {
+		t.Errorf("expected 403 ProxyError, got %v", err)
+	}
+}
+
+func TestHead(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	r := seed(t, genericRemote("eng-head"))
+	p := prov(t, models.PackageGeneric)
+
+	// Uncached HEAD hits upstream.
+	h, err := testEngine.Head(ctx, r, "blob.bin", p)
+	if err != nil || h.Source != "remote" {
+		t.Fatalf("head uncached: %+v %v", h, err)
+	}
+	// Populate the cache, then HEAD should be served from metadata.
+	res, _ := testEngine.Fetch(ctx, r, "blob.bin", p)
+	res.Reader.Close()
+	h, err = testEngine.Head(ctx, r, "blob.bin", p)
+	if err != nil || h.Source != "cache" {
+		t.Errorf("head cached: %+v %v", h, err)
+	}
+	// Denied HEAD.
+	r.Blocklist = []string{".*"}
+	if _, err := testEngine.Head(ctx, r, "blob.bin", p); err == nil {
+		t.Error("expected denied head error")
+	}
+}
+
+func TestStaleOnError(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	r := seed(t, genericRemote("eng-stale"))
+	p := prov(t, models.PackageGeneric)
+
+	if _, err := testEngine.Fetch(ctx, r, "blob.bin", p); err != nil {
+		t.Fatal(err)
+	}
+	// Drop cache freshness so the next fetch goes upstream, then point at a
+	// dead upstream: stale-on-error must serve the stored copy.
+	testCache.FlushRemote(ctx, "eng-stale")
+	r.BaseURL = "http://127.0.0.1:1"
+	res, err := testEngine.Fetch(ctx, r, "blob.bin", p)
+	if err != nil {
+		t.Fatalf("expected stale serve, got %v", err)
+	}
+	if res.Source != "cache" || readAll(t, res) != "immutable blob" {
+		t.Errorf("stale: source=%s", res.Source)
+	}
+}
+
+func TestCircuitOpenServesStale(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	r := seed(t, genericRemote("eng-circuit"))
+	p := prov(t, models.PackageGeneric)
+	if _, err := testEngine.Fetch(ctx, r, "blob.bin", p); err != nil {
+		t.Fatal(err)
+	}
+	testCache.FlushRemote(ctx, "eng-circuit")
+	for i := 0; i < 6; i++ {
+		testEngine.circuit.RecordFailure(ctx, "eng-circuit")
+	}
+	res, err := testEngine.Fetch(ctx, r, "blob.bin", p)
+	if err != nil {
+		t.Fatalf("circuit-open should serve stale: %v", err)
+	}
+	if res.Source != "cache" {
+		t.Errorf("expected stale from open circuit, got %s", res.Source)
+	}
+	res.Reader.Close()
+}
+
+func TestMutableRevalidation(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	r := seed(t, models.Remote{Name: "eng-npm", PackageType: models.PackageNPM, RepoType: models.RepoTypeRemote, BaseURL: upstream.URL, CheckMutable: true, MutableTTL: 3600, StaleOnError: true})
+	p := prov(t, models.PackageNPM)
+
+	res, err := testEngine.Fetch(ctx, r, "pkg", p)
+	if err != nil {
+		t.Fatalf("initial mutable fetch: %v", err)
+	}
+	res.Reader.Close()
+
+	// Expire only the freshness marker; the ETag persists, forcing a
+	// conditional revalidation that the upstream answers with 304.
+	testCache.SetTTL(ctx, "eng-npm", "pkg", time.Millisecond)
+	time.Sleep(10 * time.Millisecond)
+	res, err = testEngine.Fetch(ctx, r, "pkg", p)
+	if err != nil {
+		t.Fatalf("revalidation fetch: %v", err)
+	}
+	if res.Source != "cache" {
+		t.Errorf("revalidated response should come from cache, got %s", res.Source)
+	}
+	res.Reader.Close()
+}
+
+func TestBearerTokenFlow(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	r := seed(t, genericRemote("eng-bearer"))
+	p := prov(t, models.PackageGeneric)
+
+	// GET: 401 challenge -> token endpoint -> retry with bearer -> 200.
+	res, err := testEngine.Fetch(ctx, r, "protected.bin", p)
+	if err != nil {
+		t.Fatalf("bearer fetch: %v", err)
+	}
+	if readAll(t, res) != "protected payload" {
+		t.Error("bearer-protected content mismatch")
+	}
+
+	// A second protected path with the same challenge reuses the cached token.
+	res2, err := testEngine.Fetch(ctx, r, "protected2.bin", p)
+	if err != nil {
+		t.Fatalf("second bearer fetch: %v", err)
+	}
+	if readAll(t, res2) != "protected payload 2" {
+		t.Error("second bearer content mismatch")
+	}
+
+	// HEAD path also negotiates a bearer token (uncached).
+	testCache.FlushRemote(ctx, "eng-bearer")
+	testDB.DeleteArtifact(ctx, "eng-bearer", "protected.bin")
+	if h, err := testEngine.Head(ctx, r, "protected.bin", p); err != nil || h.Source != "cache" && h.Source != "remote" {
+		t.Fatalf("bearer head: %+v %v", h, err)
+	}
+}
+
+func TestFetchUpstreamError(t *testing.T) {
+	requireStack(t)
+	r := seed(t, genericRemote("eng-404"))
+	// Upstream 404 (no cached copy, stale-on-error can't help) -> ProxyError.
+	_, err := testEngine.Fetch(context.Background(), r, "missing", prov(t, models.PackageGeneric))
+	var pe *ProxyError
+	if err == nil || !asProxyError(err, &pe) || pe.Status != http.StatusNotFound {
+		t.Errorf("expected 404 ProxyError, got %v", err)
+	}
+	// HEAD of a missing upstream path also errors.
+	if _, err := testEngine.Head(context.Background(), r, "missing", prov(t, models.PackageGeneric)); err == nil {
+		t.Error("expected head error for missing path")
+	}
+}
+
+func TestFetchUpstreamStatusErrors(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	p := prov(t, models.PackageGeneric)
+
+	r := seed(t, genericRemote("eng-500"))
+	_, err := testEngine.Fetch(ctx, r, "err500", p)
+	var pe *ProxyError
+	if err == nil || !asProxyError(err, &pe) || pe.Status != http.StatusInternalServerError {
+		t.Errorf("expected 500 ProxyError, got %v", err)
+	}
+
+	r = seed(t, genericRemote("eng-noauth"))
+	_, err = testEngine.Fetch(ctx, r, "noauth", p)
+	if err == nil || !asProxyError(err, &pe) || pe.Status != http.StatusUnauthorized {
+		t.Errorf("expected 401 ProxyError, got %v", err)
+	}
+}
+
+func TestBearerTokenParsing(t *testing.T) {
+	// Non-Bearer challenges and missing realms are rejected.
+	if _, _, err := fetchBearerToken(context.Background(), "Basic realm=x", models.Remote{}); err == nil {
+		t.Error("expected error for non-Bearer challenge")
+	}
+	if _, _, err := fetchBearerToken(context.Background(), `Bearer service="reg"`, models.Remote{}); err == nil {
+		t.Error("expected error for missing realm")
+	}
+}
+
+func TestWaitForStoreCoalesces(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	r := seed(t, genericRemote("eng-herd"))
+	p := prov(t, models.PackageGeneric)
+
+	// Fire concurrent cold-cache fetches: only one holds the lock, the others
+	// wait on the store (waitForStore) and pick up the result.
+	const n = 4
+	done := make(chan string, n)
+	for i := 0; i < n; i++ {
+		go func() {
+			res, err := testEngine.Fetch(ctx, r, "blob.bin", p)
+			if err != nil {
+				done <- "err:" + err.Error()
+				return
+			}
+			done <- readAll(t, res)
+		}()
+	}
+	for i := 0; i < n; i++ {
+		if got := <-done; got != "immutable blob" {
+			t.Errorf("concurrent fetch got %q", got)
+		}
+	}
+}
+
+func TestRevalidationUpstreamError(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	r := seed(t, models.Remote{Name: "eng-reval-err", PackageType: models.PackageNPM, RepoType: models.RepoTypeRemote, BaseURL: upstream.URL, CheckMutable: true, MutableTTL: 3600, StaleOnError: true})
+	p := prov(t, models.PackageNPM)
+
+	res, err := testEngine.Fetch(ctx, r, "pkg", p)
+	if err != nil {
+		t.Fatalf("initial fetch: %v", err)
+	}
+	res.Reader.Close()
+
+	// Expire freshness but keep the ETag, then break the upstream: the
+	// conditional HEAD (checkUpstream) errors, and stale-on-error serves the
+	// stored index.
+	testCache.SetTTL(ctx, "eng-reval-err", "pkg", time.Millisecond)
+	time.Sleep(10 * time.Millisecond)
+	r.BaseURL = "http://127.0.0.1:1"
+	res, err = testEngine.Fetch(ctx, r, "pkg", p)
+	if err != nil {
+		t.Fatalf("expected stale serve on revalidation error, got %v", err)
+	}
+	if res.Source != "cache" {
+		t.Errorf("expected stale cache source, got %s", res.Source)
+	}
+	res.Reader.Close()
+}
+
+func TestTTLFor(t *testing.T) {
+	e := &Engine{}
+	if got := e.ttlFor(models.Remote{ImmutableTTL: 100}, ClassImmutable); got != 100*time.Second {
+		t.Errorf("immutable ttl = %v", got)
+	}
+	if got := e.ttlFor(models.Remote{ImmutableTTL: 0}, ClassImmutable); got != 0 {
+		t.Errorf("immutable ttl=0 (forever) = %v", got)
+	}
+	if got := e.ttlFor(models.Remote{MutableTTL: 50}, ClassMutable); got != 50*time.Second {
+		t.Errorf("mutable ttl = %v", got)
+	}
+}
+
+func TestHeadUpstreamStatusError(t *testing.T) {
+	requireStack(t)
+	r := seed(t, genericRemote("eng-head500"))
+	if _, err := testEngine.Head(context.Background(), r, "err500", prov(t, models.PackageGeneric)); err == nil {
+		t.Error("expected error for HEAD of 500 upstream")
+	}
+}
+
+func TestHeadCachedIndex(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	r := seed(t, models.Remote{Name: "eng-headidx", PackageType: models.PackageNPM, RepoType: models.RepoTypeRemote, BaseURL: upstream.URL, CheckMutable: true, MutableTTL: 3600})
+	p := prov(t, models.PackageNPM)
+	// Cache the mutable index, then HEAD is answered from the stored index.
+	res, err := testEngine.Fetch(ctx, r, "pkg", p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	res.Reader.Close()
+	h, err := testEngine.Head(ctx, r, "pkg", p)
+	if err != nil || h.Source != "cache" {
+		t.Errorf("head of cached index: %+v %v", h, err)
+	}
+}
+
+func TestFetchBearerTokenVariants(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+
+	// access_token field + service/scope params + basic auth on the token req.
+	tok, _, err := fetchBearerToken(ctx, `Bearer realm="`+upstream.URL+`/token-at",service="reg",scope="repo:pull"`, models.Remote{Username: "u", Password: "p"})
+	if err != nil || tok != "at-token" {
+		t.Errorf("access_token variant: tok=%q err=%v", tok, err)
+	}
+	// Token endpoint error status.
+	if _, _, err := fetchBearerToken(ctx, `Bearer realm="`+upstream.URL+`/token-500"`, models.Remote{}); err == nil {
+		t.Error("expected error for 500 token endpoint")
+	}
+}
+
+func TestCheckUpstreamChanged(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	r := genericRemote("eng-check")
+	// A non-matching ETag yields a normal 200 (not 304): not modified is false.
+	notModified, err := testEngine.checkUpstream(ctx, r, "pkg", `"stale-etag"`, prov(t, models.PackageNPM))
+	if err != nil {
+		t.Fatalf("checkUpstream: %v", err)
+	}
+	if notModified {
+		t.Error("mismatched etag should report modified (notModified=false)")
+	}
+}
+
+func TestUpstreamErrorUnwrap(t *testing.T) {
+	base := context.DeadlineExceeded
+	ue := &UpstreamError{Err: base}
+	if ue.Unwrap() != base {
+		t.Error("Unwrap should return the wrapped error")
+	}
+	if !isNetworkError(ue) {
+		t.Error("UpstreamError should be a network error")
+	}
+	if isNetworkError(context.Canceled) {
+		t.Error("plain error should not be a network error")
+	}
+}
+
+func TestImmutableBlobDedup(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	p := prov(t, models.PackageGeneric)
+	// Two remotes serving identical content: the second store hits the
+	// already-exists branch (blob content is deduplicated).
+	for _, name := range []string{"eng-dedup-a", "eng-dedup-b"} {
+		r := seed(t, genericRemote(name))
+		res, err := testEngine.Fetch(ctx, r, "blob.bin", p)
+		if err != nil {
+			t.Fatalf("%s fetch: %v", name, err)
+		}
+		if readAll(t, res) != "immutable blob" {
+			t.Errorf("%s content mismatch", name)
+		}
+	}
+}
+
+func TestCircuitBreakerStates(t *testing.T) {
+	requireStack(t)
+	ctx := context.Background()
+	cb := NewCircuitBreaker(testCache)
+	const key = "cb-states"
+	testCache.ResetCircuit(ctx, key)
+
+	if cb.IsOpen(ctx, key) {
+		t.Error("fresh breaker should be closed")
+	}
+	if cb.Health(ctx, key).Status != "healthy" {
+		t.Error("fresh breaker should be healthy")
+	}
+	cb.RecordFailure(ctx, key)
+	if s := cb.Health(ctx, key).Status; s != "degraded" {
+		t.Errorf("one failure should be degraded, got %q", s)
+	}
+	for i := 0; i < 6; i++ {
+		cb.RecordFailure(ctx, key)
+	}
+	if !cb.IsOpen(ctx, key) {
+		t.Error("breaker should be open after threshold failures")
+	}
+	if s := cb.Health(ctx, key).Status; s != "down" {
+		t.Errorf("open breaker should be down, got %q", s)
+	}
+	cb.RecordSuccess(ctx, key)
+	if cb.IsOpen(ctx, key) {
+		t.Error("breaker should close after success")
+	}
+}
+
+func asProxyError(err error, target **ProxyError) bool {
+	pe, ok := err.(*ProxyError)
+	if ok {
+		*target = pe
+	}
+	return ok
+}
diff --git a/internal/server/server_test.go b/internal/server/server_test.go
new file mode 100644
index 0000000..62b7bcf
--- /dev/null
+++ b/internal/server/server_test.go
@@ -0,0 +1,620 @@
+package server
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"git.unkin.net/unkin/artifactapi/internal/config"
+	"git.unkin.net/unkin/artifactapi/internal/testsupport"
+)
+
+var (
+	testTS   *httptest.Server // the artifactapi router
+	upstream *httptest.Server // mock upstream the proxy fetches from
+	testSrv  *Server
+)
+
+func TestMain(m *testing.M) {
+	ctx := context.Background()
+
+	dsn, termPG, err := testsupport.StartPostgres(ctx)
+	if err != nil {
+		os.Exit(m.Run())
+	}
+	defer termPG()
+	redisURL, termRedis, err := testsupport.StartRedis(ctx)
+	if err != nil {
+		termPG()
+		os.Exit(m.Run())
+	}
+	defer termRedis()
+	minio, termMinio, err := testsupport.StartMinio(ctx)
+	if err != nil {
+		termPG()
+		termRedis()
+		os.Exit(m.Run())
+	}
+	defer termMinio()
+
+	u, _ := url.Parse(dsn)
+	port, _ := strconv.Atoi(u.Port())
+	cfg := &config.Config{
+		ListenAddr:  ":0",
+		DBHost:      u.Hostname(),
+		DBPort:      port,
+		DBUser:      "artifacts",
+		DBPass:      "artifacts123",
+		DBName:      "artifacts",
+		DBSSL:       "disable",
+		RedisURL:    redisURL,
+		S3Endpoint:  minio.Endpoint,
+		S3AccessKey: minio.AccessKey,
+		S3SecretKey: minio.SecretKey,
+		S3Bucket:    "server-test",
+	}
+
+	var srv *Server
+	for i := 0; i < 20; i++ { // tolerate MinIO reporting ready before bucket ops succeed
+		if srv, err = New(cfg, "test-version"); err == nil {
+			break
+		}
+		time.Sleep(500 * time.Millisecond)
+	}
+	if err != nil {
+		panic(err)
+	}
+	testSrv = srv
+	testTS = httptest.NewServer(srv.router)
+	upstream = httptest.NewServer(http.HandlerFunc(mockUpstream))
+
+	code := m.Run()
+
+	testTS.Close()
+	upstream.Close()
+	termMinio()
+	termRedis()
+	termPG()
+	if code != 0 {
+		os.Exit(code)
+	}
+}
+
+func mockUpstream(w http.ResponseWriter, r *http.Request) {
+	switch r.URL.Path {
+	case "/data/file.bin":
+		w.Write([]byte("upstream blob payload"))
+	case "/helm-a/index.yaml":
+		w.Write([]byte("apiVersion: v1\nentries:\n  alpha:\n    - name: alpha\n      version: 1.0.0\n      urls: [charts/alpha-1.0.0.tgz]\n"))
+	case "/helm-b/index.yaml":
+		w.Write([]byte("apiVersion: v1\nentries:\n  beta:\n    - name: beta\n      version: 2.0.0\n      urls: [charts/beta-2.0.0.tgz]\n"))
+	default:
+		http.NotFound(w, r)
+	}
+}
+
+func requireStack(t *testing.T) {
+	t.Helper()
+	if testTS == nil {
+		t.Skip("Docker unavailable; skipping server integration test")
+	}
+}
+
+func req(t *testing.T, method, path string, body string) (*http.Response, []byte) {
+	t.Helper()
+	var r io.Reader
+	if body != "" {
+		r = strings.NewReader(body)
+	}
+	rq, _ := http.NewRequest(method, testTS.URL+path, r)
+	if body != "" {
+		rq.Header.Set("Content-Type", "application/json")
+	}
+	resp, err := http.DefaultClient.Do(rq)
+	if err != nil {
+		t.Fatalf("%s %s: %v", method, path, err)
+	}
+	defer resp.Body.Close()
+	b, _ := io.ReadAll(resp.Body)
+	return resp, b
+}
+
+func TestServerHealthAndRoot(t *testing.T) {
+	requireStack(t)
+	if resp, _ := req(t, "GET", "/health", ""); resp.StatusCode != 200 {
+		t.Errorf("health: %d", resp.StatusCode)
+	}
+	if resp, b := req(t, "GET", "/", ""); resp.StatusCode != 200 || !strings.Contains(string(b), "test-version") {
+		t.Errorf("root: %d %s", resp.StatusCode, b)
+	}
+	if resp, _ := req(t, "GET", "/api/v2/health", ""); resp.StatusCode != 200 {
+		t.Errorf("health v2: %d", resp.StatusCode)
+	}
+}
+
+func TestServerRemoteAndProxy(t *testing.T) {
+	requireStack(t)
+	create := fmt.Sprintf(`{"name":"srv-remote","package_type":"generic","repo_type":"remote","base_url":%q,"stale_on_error":true}`, upstream.URL)
+	if resp, b := req(t, "POST", "/api/v2/remotes", create); resp.StatusCode != 201 {
+		t.Fatalf("create remote: %d %s", resp.StatusCode, b)
+	}
+	defer req(t, "DELETE", "/api/v2/remotes/srv-remote", "")
+
+	if resp, _ := req(t, "GET", "/api/v2/remotes/srv-remote", ""); resp.StatusCode != 200 {
+		t.Errorf("get remote: %d", resp.StatusCode)
+	}
+	if resp, _ := req(t, "GET", "/api/v2/remotes", ""); resp.StatusCode != 200 {
+		t.Errorf("list remotes: %d", resp.StatusCode)
+	}
+
+	// Proxy fetch: miss then hit.
+	resp, b := req(t, "GET", "/api/v1/remote/srv-remote/data/file.bin", "")
+	if resp.StatusCode != 200 || string(b) != "upstream blob payload" {
+		t.Fatalf("proxy miss: %d %s", resp.StatusCode, b)
+	}
+	if src := resp.Header.Get("X-Artifact-Source"); src != "remote" {
+		t.Errorf("expected remote source, got %q", src)
+	}
+	resp, _ = req(t, "GET", "/api/v1/remote/srv-remote/data/file.bin", "")
+	if resp.Header.Get("X-Artifact-Source") != "cache" {
+		t.Errorf("second fetch should be cache: %q", resp.Header.Get("X-Artifact-Source"))
+	}
+
+	// Objects listing + stats now that we have an artifact.
+	if resp, _ := req(t, "GET", "/api/v2/remotes/srv-remote/objects", ""); resp.StatusCode != 200 {
+		t.Errorf("objects: %d", resp.StatusCode)
+	}
+	if resp, _ := req(t, "GET", "/api/v2/stats", ""); resp.StatusCode != 200 {
+		t.Errorf("stats: %d", resp.StatusCode)
+	}
+	for _, p := range []string{"/api/v2/stats/top-remotes", "/api/v2/stats/top-files-by-hits", "/api/v2/stats/top-files-by-bandwidth"} {
+		if resp, _ := req(t, "GET", p, ""); resp.StatusCode != 200 {
+			t.Errorf("%s: %d", p, resp.StatusCode)
+		}
+	}
+}
+
+func TestServerLocalUpload(t *testing.T) {
+	requireStack(t)
+	if resp, b := req(t, "POST", "/api/v2/remotes", `{"name":"srv-local","package_type":"generic","repo_type":"local"}`); resp.StatusCode != 201 {
+		t.Fatalf("create local: %d %s", resp.StatusCode, b)
+	}
+	defer req(t, "DELETE", "/api/v2/remotes/srv-local", "")
+
+	rq, _ := http.NewRequest("PUT", testTS.URL+"/api/v2/remotes/srv-local/files/dir/hello.bin", strings.NewReader("local payload"))
+	rq.Header.Set("Content-Type", "text/plain") // exercise the content-type branch
+	resp, err := http.DefaultClient.Do(rq)
+	if err != nil || resp.StatusCode != 201 {
+		t.Fatalf("upload: %v %d", err, resp.StatusCode)
+	}
+	resp.Body.Close()
+
+	resp, b := req(t, "GET", "/api/v1/local/srv-local/dir/hello.bin", "")
+	if resp.StatusCode != 200 || string(b) != "local payload" {
+		t.Errorf("download local: %d %s", resp.StatusCode, b)
+	}
+	// Also download via the v2 files endpoint.
+	if resp, b := req(t, "GET", "/api/v2/remotes/srv-local/files/dir/hello.bin", ""); resp.StatusCode != 200 || string(b) != "local payload" {
+		t.Errorf("v2 download: %d %s", resp.StatusCode, b)
+	}
+}
+
+func TestServerVirtualMerge(t *testing.T) {
+	requireStack(t)
+	for _, m := range []string{"a", "b"} {
+		body := fmt.Sprintf(`{"name":"srv-helm-%s","package_type":"helm","repo_type":"remote","base_url":"%s/helm-%s","stale_on_error":true}`, m, upstream.URL, m)
+		if resp, b := req(t, "POST", "/api/v2/remotes", body); resp.StatusCode != 201 {
+			t.Fatalf("create helm-%s: %d %s", m, resp.StatusCode, b)
+		}
+		defer req(t, "DELETE", "/api/v2/remotes/srv-helm-"+m, "")
+	}
+	if resp, b := req(t, "POST", "/api/v2/virtuals", `{"name":"srv-vh","package_type":"helm","members":["srv-helm-a","srv-helm-b"]}`); resp.StatusCode != 201 {
+		t.Fatalf("create virtual: %d %s", resp.StatusCode, b)
+	}
+	defer req(t, "DELETE", "/api/v2/virtuals/srv-vh", "")
+
+	resp, b := req(t, "GET", "/api/v1/virtual/srv-vh/index.yaml", "")
+	if resp.StatusCode != 200 {
+		t.Fatalf("virtual fetch: %d %s", resp.StatusCode, b)
+	}
+	s := string(b)
+	if !strings.Contains(s, "alpha") || !strings.Contains(s, "beta") {
+		t.Errorf("merged index missing charts: %s", s)
+	}
+}
+
+func TestServerProbe(t *testing.T) {
+	requireStack(t)
+	create := fmt.Sprintf(`{"name":"srv-probe","package_type":"generic","repo_type":"remote","base_url":%q,"stale_on_error":true}`, upstream.URL)
+	req(t, "POST", "/api/v2/remotes", create)
+	defer req(t, "DELETE", "/api/v2/remotes/srv-probe", "")
+
+	// Reachable path -> status 200 in the probe body.
+	if resp, b := req(t, "POST", "/api/v2/probe", `{"remote":"srv-probe","path":"data/file.bin"}`); resp.StatusCode != 200 || !strings.Contains(string(b), `"status":200`) {
+		t.Errorf("probe reachable: %d %s", resp.StatusCode, b)
+	}
+	// Missing upstream path -> upstream error reported (502) in the body.
+	if resp, b := req(t, "POST", "/api/v2/probe", `{"remote":"srv-probe","path":"missing"}`); resp.StatusCode != 200 || !strings.Contains(string(b), `"status":502`) {
+		t.Errorf("probe missing: %d %s", resp.StatusCode, b)
+	}
+	// Unknown remote -> 404 in the body.
+	if resp, b := req(t, "POST", "/api/v2/probe", `{"remote":"nope","path":"x"}`); resp.StatusCode != 200 || !strings.Contains(string(b), `"status":404`) {
+		t.Errorf("probe unknown: %d %s", resp.StatusCode, b)
+	}
+	// Bad requests.
+	if resp, _ := req(t, "POST", "/api/v2/probe", `{}`); resp.StatusCode != 400 {
+		t.Errorf("probe missing fields: %d", resp.StatusCode)
+	}
+	if resp, _ := req(t, "POST", "/api/v2/probe", `not json`); resp.StatusCode != 400 {
+		t.Errorf("probe invalid json: %d", resp.StatusCode)
+	}
+}
+
+func put(t *testing.T, path string, body []byte) (*http.Response, []byte) {
+	t.Helper()
+	rq, _ := http.NewRequest("PUT", testTS.URL+path, bytes.NewReader(body))
+	resp, err := http.DefaultClient.Do(rq)
+	if err != nil {
+		t.Fatalf("PUT %s: %v", path, err)
+	}
+	defer resp.Body.Close()
+	b, _ := io.ReadAll(resp.Body)
+	return resp, b
+}
+
+func TestServerLocalPyPI(t *testing.T) {
+	requireStack(t)
+	if resp, b := req(t, "POST", "/api/v2/remotes", `{"name":"srv-pypi","package_type":"pypi","repo_type":"local"}`); resp.StatusCode != 201 {
+		t.Fatalf("create pypi local: %d %s", resp.StatusCode, b)
+	}
+	defer req(t, "DELETE", "/api/v2/remotes/srv-pypi", "")
+
+	if resp, b := put(t, "/api/v2/remotes/srv-pypi/files/foo-1.0-py3-none-any.whl", []byte("wheel bytes")); resp.StatusCode != 201 {
+		t.Fatalf("upload wheel: %d %s", resp.StatusCode, b)
+	}
+	// Re-uploading the same file is rejected.
+	if resp, _ := put(t, "/api/v2/remotes/srv-pypi/files/foo-1.0-py3-none-any.whl", []byte("again")); resp.StatusCode != 409 {
+		t.Errorf("expected 409 on overwrite, got %d", resp.StatusCode)
+	}
+	// Invalid pypi filename rejected.
+	if resp, _ := put(t, "/api/v2/remotes/srv-pypi/files/not-a-package.txt", []byte("x")); resp.StatusCode != 400 {
+		t.Errorf("expected 400 for bad filename, got %d", resp.StatusCode)
+	}
+
+	if resp, b := req(t, "GET", "/api/v1/local/srv-pypi/simple/", ""); resp.StatusCode != 200 || !strings.Contains(string(b), "foo") {
+		t.Errorf("simple index: %d %s", resp.StatusCode, b)
+	}
+	if resp, b := req(t, "GET", "/api/v1/local/srv-pypi/simple/foo/", ""); resp.StatusCode != 200 || !strings.Contains(string(b), "foo-1.0-py3-none-any.whl") {
+		t.Errorf("package index: %d %s", resp.StatusCode, b)
+	}
+}
+
+func TestServerLocalRPMRepodata(t *testing.T) {
+	requireStack(t)
+	rpm := testsupport.MinimalRPM("e2e-testpkg", "1.0", "1", "noarch")
+	if resp, b := req(t, "POST", "/api/v2/remotes", `{"name":"srv-rpm","package_type":"rpm","repo_type":"local"}`); resp.StatusCode != 201 {
+		t.Fatalf("create rpm local: %d %s", resp.StatusCode, b)
+	}
+	defer req(t, "DELETE", "/api/v2/remotes/srv-rpm", "")
+
+	if resp, b := put(t, "/api/v2/remotes/srv-rpm/files/e2e-testpkg-1.0-1.noarch.rpm", rpm); resp.StatusCode != 201 {
+		t.Fatalf("upload rpm: %d %s", resp.StatusCode, b)
+	}
+
+	// repodata is generated asynchronously; poll for it.
+	var body []byte
+	for i := 0; i < 40; i++ {
+		var resp *http.Response
+		resp, body = req(t, "GET", "/api/v1/local/srv-rpm/repodata/repomd.xml", "")
+		if resp.StatusCode == 200 && strings.Contains(string(body), "<repomd") {
+			return
+		}
+		time.Sleep(250 * time.Millisecond)
+	}
+	t.Errorf("repomd.xml not generated: %s", body)
+}
+
+func TestServerObjectEviction(t *testing.T) {
+	requireStack(t)
+	create := fmt.Sprintf(`{"name":"srv-evict","package_type":"generic","repo_type":"remote","base_url":%q,"stale_on_error":true}`, upstream.URL)
+	req(t, "POST", "/api/v2/remotes", create)
+	defer req(t, "DELETE", "/api/v2/remotes/srv-evict", "")
+
+	resp, _ := req(t, "GET", "/api/v1/remote/srv-evict/data/file.bin", "")
+	resp.Body.Close()
+	if resp, _ := req(t, "DELETE", "/api/v2/remotes/srv-evict/objects/data/file.bin", ""); resp.StatusCode >= 400 {
+		t.Errorf("evict object: %d", resp.StatusCode)
+	}
+}
+
+func TestServerValidationErrors(t *testing.T) {
+	requireStack(t)
+	if resp, _ := req(t, "POST", "/api/v2/remotes", `{"name":"bad","package_type":"bogus","base_url":"https://x"}`); resp.StatusCode != 400 {
+		t.Errorf("invalid package type: %d", resp.StatusCode)
+	}
+	if resp, _ := req(t, "POST", "/api/v2/remotes", `{"name":"bad","package_type":"generic","repo_type":"remote"}`); resp.StatusCode != 400 {
+		t.Errorf("missing base_url: %d", resp.StatusCode)
+	}
+	if resp, _ := req(t, "POST", "/api/v2/remotes", `not json`); resp.StatusCode != 400 {
+		t.Errorf("invalid json: %d", resp.StatusCode)
+	}
+	// Invalid regex pattern -> 400 from ValidatePatterns.
+	if resp, _ := req(t, "POST", "/api/v2/remotes", `{"name":"badre","package_type":"generic","repo_type":"remote","base_url":"https://x","blocklist":["[unterminated"]}`); resp.StatusCode != 400 {
+		t.Errorf("invalid regex: %d", resp.StatusCode)
+	}
+}
+
+func TestServerDockerAndHead(t *testing.T) {
+	requireStack(t)
+	create := fmt.Sprintf(`{"name":"srv-docker","package_type":"generic","repo_type":"remote","base_url":%q,"stale_on_error":true}`, upstream.URL)
+	req(t, "POST", "/api/v2/remotes", create)
+	defer req(t, "DELETE", "/api/v2/remotes/srv-docker", "")
+
+	// Docker registry ping.
+	if resp, _ := req(t, "GET", "/v2/", ""); resp.StatusCode != 200 {
+		t.Errorf("docker ping: %d", resp.StatusCode)
+	}
+	// HEAD through the docker route resolves metadata (uncached -> upstream).
+	rq, _ := http.NewRequest("HEAD", testTS.URL+"/v2/srv-docker/data/file.bin", nil)
+	resp, err := http.DefaultClient.Do(rq)
+	if err != nil {
+		t.Fatalf("head: %v", err)
+	}
+	resp.Body.Close()
+	if resp.StatusCode != 200 {
+		t.Errorf("head status: %d", resp.StatusCode)
+	}
+}
+
+func TestServerRemoteUpdateAndVirtualCRUD(t *testing.T) {
+	requireStack(t)
+	req(t, "POST", "/api/v2/remotes", `{"name":"srv-upd","package_type":"helm","repo_type":"remote","base_url":"https://a.example.com","stale_on_error":true}`)
+	defer req(t, "DELETE", "/api/v2/remotes/srv-upd", "")
+	if resp, b := req(t, "PUT", "/api/v2/remotes/srv-upd", `{"package_type":"helm","base_url":"https://b.example.com","stale_on_error":true}`); resp.StatusCode != 200 {
+		t.Errorf("update remote: %d %s", resp.StatusCode, b)
+	}
+
+	req(t, "POST", "/api/v2/virtuals", `{"name":"srv-v2","package_type":"helm","members":["srv-upd"]}`)
+	defer req(t, "DELETE", "/api/v2/virtuals/srv-v2", "")
+	if resp, _ := req(t, "GET", "/api/v2/virtuals/srv-v2", ""); resp.StatusCode != 200 {
+		t.Errorf("get virtual: %d", resp.StatusCode)
+	}
+	if resp, _ := req(t, "GET", "/api/v2/virtuals", ""); resp.StatusCode != 200 {
+		t.Errorf("list virtuals: %d", resp.StatusCode)
+	}
+	if resp, b := req(t, "PUT", "/api/v2/virtuals/srv-v2", `{"package_type":"helm","members":["srv-upd"]}`); resp.StatusCode != 200 {
+		t.Errorf("update virtual: %d %s", resp.StatusCode, b)
+	}
+}
+
+func TestServerLocalRemoveAndMissing(t *testing.T) {
+	requireStack(t)
+	req(t, "POST", "/api/v2/remotes", `{"name":"srv-rm","package_type":"generic","repo_type":"local"}`)
+	defer req(t, "DELETE", "/api/v2/remotes/srv-rm", "")
+
+	put(t, "/api/v2/remotes/srv-rm/files/a/b.bin", []byte("payload"))
+	if resp, _ := req(t, "DELETE", "/api/v2/remotes/srv-rm/files/a/b.bin", ""); resp.StatusCode >= 400 {
+		t.Errorf("delete local file: %d", resp.StatusCode)
+	}
+	if resp, _ := req(t, "GET", "/api/v1/local/srv-rm/a/b.bin", ""); resp.StatusCode != 404 {
+		t.Errorf("expected 404 for removed file, got %d", resp.StatusCode)
+	}
+}
+
+func TestServerLocalUploadErrors(t *testing.T) {
+	requireStack(t)
+	// Uploading to a remote-type repo is rejected.
+	create := fmt.Sprintf(`{"name":"srv-uerr","package_type":"generic","repo_type":"remote","base_url":%q,"stale_on_error":true}`, upstream.URL)
+	req(t, "POST", "/api/v2/remotes", create)
+	defer req(t, "DELETE", "/api/v2/remotes/srv-uerr", "")
+	if resp, _ := put(t, "/api/v2/remotes/srv-uerr/files/x.bin", []byte("x")); resp.StatusCode != 400 {
+		t.Errorf("upload to remote repo should be 400, got %d", resp.StatusCode)
+	}
+
+	// Duplicate generic upload is a conflict.
+	req(t, "POST", "/api/v2/remotes", `{"name":"srv-dup","package_type":"generic","repo_type":"local"}`)
+	defer req(t, "DELETE", "/api/v2/remotes/srv-dup", "")
+	put(t, "/api/v2/remotes/srv-dup/files/dup.bin", []byte("one"))
+	if resp, _ := put(t, "/api/v2/remotes/srv-dup/files/dup.bin", []byte("two")); resp.StatusCode != 409 {
+		t.Errorf("duplicate upload should be 409, got %d", resp.StatusCode)
+	}
+
+	// Download of a missing local file is 404.
+	if resp, _ := req(t, "GET", "/api/v1/local/srv-dup/does/not/exist", ""); resp.StatusCode != 404 {
+		t.Errorf("missing local download should be 404, got %d", resp.StatusCode)
+	}
+	// Unknown virtual is 404.
+	if resp, _ := req(t, "GET", "/api/v1/virtual/nope/index.yaml", ""); resp.StatusCode != 404 {
+		t.Errorf("unknown virtual should be 404, got %d", resp.StatusCode)
+	}
+}
+
+func TestServerEvents(t *testing.T) {
+	requireStack(t)
+	client := &http.Client{Timeout: 800 * time.Millisecond}
+	resp, err := client.Get(testTS.URL + "/api/v2/events")
+	if err == nil {
+		resp.Body.Close()
+		if resp.StatusCode != 200 {
+			t.Errorf("events status: %d", resp.StatusCode)
+		}
+	}
+	// A timeout is expected for a streaming endpoint; the handler still ran.
+}
+
+func TestRunOnListener(t *testing.T) {
+	requireStack(t)
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	errc := make(chan error, 1)
+	go func() { errc <- testSrv.RunOnListener(ctx, ln) }()
+
+	base := "http://" + ln.Addr().String()
+	ok := false
+	for i := 0; i < 50; i++ {
+		if resp, e := http.Get(base + "/health"); e == nil {
+			resp.Body.Close()
+			ok = resp.StatusCode == 200
+			break
+		}
+		time.Sleep(20 * time.Millisecond)
+	}
+	if !ok {
+		t.Error("server did not serve /health")
+	}
+	cancel()
+	select {
+	case err := <-errc:
+		if err != nil {
+			t.Errorf("RunOnListener returned error: %v", err)
+		}
+	case <-time.After(12 * time.Second):
+		t.Fatal("RunOnListener did not shut down")
+	}
+}
+
+func TestRun(t *testing.T) {
+	requireStack(t)
+	ctx, cancel := context.WithCancel(context.Background())
+	errc := make(chan error, 1)
+	go func() { errc <- testSrv.Run(ctx) }()
+	time.Sleep(300 * time.Millisecond) // let it bind and start serving
+	cancel()
+	select {
+	case err := <-errc:
+		if err != nil {
+			t.Errorf("Run returned error: %v", err)
+		}
+	case <-time.After(12 * time.Second):
+		t.Fatal("Run did not shut down")
+	}
+}
+
+func TestServerVirtualUnreachableMembers(t *testing.T) {
+	requireStack(t)
+	// A virtual whose only member does not exist -> no members reachable.
+	req(t, "POST", "/api/v2/virtuals", `{"name":"srv-vbad","package_type":"helm","members":["nonexistent-member"]}`)
+	defer req(t, "DELETE", "/api/v2/virtuals/srv-vbad", "")
+	if resp, _ := req(t, "GET", "/api/v1/virtual/srv-vbad/index.yaml", ""); resp.StatusCode != 502 {
+		t.Errorf("virtual with dead members = %d, want 502", resp.StatusCode)
+	}
+}
+
+func TestServerVirtualLocalPyPIMerge(t *testing.T) {
+	requireStack(t)
+	for _, n := range []string{"a", "b"} {
+		req(t, "POST", "/api/v2/remotes", `{"name":"srv-pm-`+n+`","package_type":"pypi","repo_type":"local"}`)
+		defer req(t, "DELETE", "/api/v2/remotes/srv-pm-"+n, "")
+	}
+	put(t, "/api/v2/remotes/srv-pm-a/files/foo-1.0-py3-none-any.whl", []byte("foo"))
+	put(t, "/api/v2/remotes/srv-pm-b/files/bar-2.0-py3-none-any.whl", []byte("bar"))
+	req(t, "POST", "/api/v2/virtuals", `{"name":"srv-pmv","package_type":"pypi","members":["srv-pm-a","srv-pm-b"]}`)
+	defer req(t, "DELETE", "/api/v2/virtuals/srv-pmv", "")
+
+	resp, b := req(t, "GET", "/api/v1/virtual/srv-pmv/simple/", "")
+	if resp.StatusCode != 200 {
+		t.Fatalf("virtual pypi index: %d %s", resp.StatusCode, b)
+	}
+	if s := string(b); !strings.Contains(s, "foo") || !strings.Contains(s, "bar") {
+		t.Errorf("merged local pypi index missing packages: %s", s)
+	}
+}
+
+func TestServerProxyErrors(t *testing.T) {
+	requireStack(t)
+	// Blocklisted path -> 403 propagated through handleProxy.
+	block := fmt.Sprintf(`{"name":"srv-block","package_type":"generic","repo_type":"remote","base_url":%q,"blocklist":["\\.secret$"],"stale_on_error":true}`, upstream.URL)
+	req(t, "POST", "/api/v2/remotes", block)
+	defer req(t, "DELETE", "/api/v2/remotes/srv-block", "")
+	if resp, _ := req(t, "GET", "/api/v1/remote/srv-block/x.secret", ""); resp.StatusCode != 403 {
+		t.Errorf("blocklisted GET = %d, want 403", resp.StatusCode)
+	}
+	rq, _ := http.NewRequest("HEAD", testTS.URL+"/v2/srv-block/x.secret", nil)
+	if resp, err := http.DefaultClient.Do(rq); err == nil {
+		resp.Body.Close()
+		if resp.StatusCode != 403 {
+			t.Errorf("blocklisted HEAD = %d, want 403", resp.StatusCode)
+		}
+	}
+
+	// Unreachable upstream, no stale copy -> 502 bad gateway.
+	dead := `{"name":"srv-dead","package_type":"generic","repo_type":"remote","base_url":"http://127.0.0.1:1","stale_on_error":false}`
+	req(t, "POST", "/api/v2/remotes", dead)
+	defer req(t, "DELETE", "/api/v2/remotes/srv-dead", "")
+	if resp, _ := req(t, "GET", "/api/v1/remote/srv-dead/x", ""); resp.StatusCode != 502 {
+		t.Errorf("dead upstream GET = %d, want 502", resp.StatusCode)
+	}
+}
+
+func TestServerLocalMissingBlob(t *testing.T) {
+	requireStack(t)
+	req(t, "POST", "/api/v2/remotes", `{"name":"srv-ghost","package_type":"generic","repo_type":"local"}`)
+	defer req(t, "DELETE", "/api/v2/remotes/srv-ghost", "")
+
+	ctx := context.Background()
+	// A local file whose blob object is absent from the store.
+	testSrv.db.UpsertBlob(ctx, "sha256:ghost", "blobs/sha256/ghost-missing", 5, "text/plain")
+	if err := testSrv.db.CreateLocalFile(ctx, "srv-ghost", "ghost.bin", "sha256:ghost"); err != nil {
+		t.Fatalf("create local file: %v", err)
+	}
+
+	if resp, _ := req(t, "GET", "/api/v1/local/srv-ghost/ghost.bin", ""); resp.StatusCode != 500 {
+		t.Errorf("v1 download missing blob = %d, want 500", resp.StatusCode)
+	}
+	if resp, _ := req(t, "GET", "/api/v2/remotes/srv-ghost/files/ghost.bin", ""); resp.StatusCode != 500 {
+		t.Errorf("v2 download missing blob = %d, want 500", resp.StatusCode)
+	}
+}
+
+func TestServerBogusProviderType(t *testing.T) {
+	requireStack(t)
+	// Insert a remote with an unregistered package type directly, bypassing
+	// validation, to exercise the provider-not-found branches.
+	_, err := testSrv.db.Pool.Exec(context.Background(),
+		`INSERT INTO remotes (name, package_type, repo_type, base_url) VALUES ($1,'bogus','remote','https://x')`, "srv-bogus")
+	if err != nil {
+		t.Fatalf("insert bogus remote: %v", err)
+	}
+	defer testSrv.db.Pool.Exec(context.Background(), `DELETE FROM remotes WHERE name='srv-bogus'`)
+
+	if resp, _ := req(t, "GET", "/api/v1/remote/srv-bogus/x", ""); resp.StatusCode != 500 {
+		t.Errorf("bogus provider GET = %d, want 500", resp.StatusCode)
+	}
+	rq, _ := http.NewRequest("HEAD", testTS.URL+"/v2/srv-bogus/x", nil)
+	if resp, err := http.DefaultClient.Do(rq); err == nil {
+		resp.Body.Close()
+		if resp.StatusCode != 500 {
+			t.Errorf("bogus provider HEAD = %d, want 500", resp.StatusCode)
+		}
+	}
+	if resp, b := req(t, "POST", "/api/v2/probe", `{"remote":"srv-bogus","path":"x"}`); resp.StatusCode != 200 || !strings.Contains(string(b), `"status":500`) {
+		t.Errorf("bogus provider probe: %d %s", resp.StatusCode, b)
+	}
+}
+
+func TestServerNotFound(t *testing.T) {
+	requireStack(t)
+	if resp, _ := req(t, "GET", "/api/v2/remotes/does-not-exist", ""); resp.StatusCode != 404 {
+		t.Errorf("expected 404, got %d", resp.StatusCode)
+	}
+	if resp, _ := req(t, "GET", "/api/v1/remote/nope/x", ""); resp.StatusCode != 404 {
+		t.Errorf("expected 404 for unknown remote, got %d", resp.StatusCode)
+	}
+	// Unknown local repo -> 404 in handleLocal.
+	if resp, _ := req(t, "GET", "/api/v1/local/nope/x", ""); resp.StatusCode != 404 {
+		t.Errorf("expected 404 for unknown local repo, got %d", resp.StatusCode)
+	}
+}
diff --git a/internal/storage/storage_test.go b/internal/storage/storage_test.go
new file mode 100644
index 0000000..0379900
--- /dev/null
+++ b/internal/storage/storage_test.go
@@ -0,0 +1,160 @@
+package storage
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"git.unkin.net/unkin/artifactapi/internal/testsupport"
+)
+
+var (
+	testS3       *S3
+	testEndpoint string
+)
+
+func TestMain(m *testing.M) {
+	ctx := context.Background()
+	conn, terminate, err := testsupport.StartMinio(ctx)
+	if err != nil {
+		os.Exit(m.Run())
+	}
+	var s3 *S3
+	for i := 0; i < 20; i++ { // MinIO can report ready before bucket ops succeed
+		if s3, err = NewS3(conn.Endpoint, conn.AccessKey, conn.SecretKey, "test-bucket", false, ""); err == nil {
+			break
+		}
+		time.Sleep(500 * time.Millisecond)
+	}
+	if err != nil {
+		terminate()
+		panic(err)
+	}
+	testS3 = s3
+	testEndpoint = conn.Endpoint
+	code := m.Run()
+	terminate()
+	if code != 0 {
+		os.Exit(code)
+	}
+}
+
+func requireS3(t *testing.T) {
+	t.Helper()
+	if testS3 == nil {
+		t.Skip("Docker unavailable; skipping storage integration test")
+	}
+}
+
+func TestKeys(t *testing.T) {
+	if BlobKey("abc") != "blobs/sha256/abc" {
+		t.Error("BlobKey")
+	}
+	if IndexKey("remote", "path/to/x") != "indexes/remote/path/to/x" {
+		t.Error("IndexKey")
+	}
+}
+
+func TestS3RoundTrip(t *testing.T) {
+	requireS3(t)
+	ctx := context.Background()
+	key := "blobs/sha256/test1"
+	content := []byte("hello storage")
+
+	if err := testS3.Upload(ctx, key, bytes.NewReader(content), int64(len(content)), "text/plain"); err != nil {
+		t.Fatalf("upload: %v", err)
+	}
+
+	exists, err := testS3.Exists(ctx, key)
+	if err != nil || !exists {
+		t.Fatalf("exists after upload: %v %v", exists, err)
+	}
+
+	reader, info, err := testS3.Download(ctx, key)
+	if err != nil {
+		t.Fatalf("download: %v", err)
+	}
+	got, _ := io.ReadAll(reader)
+	reader.Close()
+	if !bytes.Equal(got, content) {
+		t.Errorf("content mismatch: %q", got)
+	}
+	if info.Size != int64(len(content)) || info.ContentType != "text/plain" {
+		t.Errorf("stat info wrong: size=%d ct=%s", info.Size, info.ContentType)
+	}
+
+	if _, err := testS3.Stat(ctx, key); err != nil {
+		t.Errorf("stat: %v", err)
+	}
+
+	if err := testS3.Delete(ctx, key); err != nil {
+		t.Fatalf("delete: %v", err)
+	}
+	if exists, _ := testS3.Exists(ctx, key); exists {
+		t.Error("expected object gone after delete")
+	}
+}
+
+func TestNewS3ExistingBucket(t *testing.T) {
+	requireS3(t)
+	// The bucket already exists from TestMain, so ensureBucket takes the
+	// "already present" path.
+	if _, err := NewS3(testEndpoint, "minioadmin", "minioadmin", "test-bucket", false, ""); err != nil {
+		t.Fatalf("second NewS3: %v", err)
+	}
+}
+
+func TestS3DownloadMissing(t *testing.T) {
+	requireS3(t)
+	if _, _, err := testS3.Download(context.Background(), "does/not/exist"); err == nil {
+		t.Error("expected error downloading missing key")
+	}
+	if _, err := testS3.Stat(context.Background(), "does/not/exist"); err == nil {
+		t.Error("expected error stat-ing missing key")
+	}
+	if exists, err := testS3.Exists(context.Background(), "does/not/exist"); err != nil || exists {
+		t.Errorf("Exists(missing) = %v, %v; want false, nil", exists, err)
+	}
+}
+
+func TestCASStore(t *testing.T) {
+	requireS3(t)
+	ctx := context.Background()
+	cas := NewCAS(testS3)
+	content := "content-addressed payload"
+
+	res, err := cas.Store(ctx, strings.NewReader(content), "text/plain")
+	if err != nil {
+		t.Fatalf("store: %v", err)
+	}
+	if res.AlreadyExists {
+		t.Error("first store should not report AlreadyExists")
+	}
+	if res.SizeBytes != int64(len(content)) || !strings.HasPrefix(res.ContentHash, "sha256:") {
+		t.Errorf("unexpected result: %+v", res)
+	}
+
+	// Storing identical content again is deduplicated.
+	res2, err := cas.Store(ctx, strings.NewReader(content), "text/plain")
+	if err != nil {
+		t.Fatalf("store again: %v", err)
+	}
+	if !res2.AlreadyExists || res2.ContentHash != res.ContentHash {
+		t.Errorf("second store should dedup: %+v", res2)
+	}
+
+	// The stored blob is retrievable.
+	reader, _, err := testS3.Download(ctx, res.S3Key)
+	if err != nil {
+		t.Fatalf("download stored blob: %v", err)
+	}
+	got, _ := io.ReadAll(reader)
+	reader.Close()
+	if string(got) != content {
+		t.Errorf("stored content mismatch: %q", got)
+	}
+}
diff --git a/internal/testsupport/containers.go b/internal/testsupport/containers.go
new file mode 100644
index 0000000..0727571
--- /dev/null
+++ b/internal/testsupport/containers.go
@@ -0,0 +1,101 @@
+// Package testsupport starts throwaway backing containers (Postgres, Redis,
+// MinIO) for integration-style unit tests. It is only ever imported from
+// *_test.go files, so it never reaches the production binary. Each Start*
+// function returns a connection detail plus a terminate func; callers wire
+// them up in a TestMain and skip the package's tests when Docker is absent.
+package testsupport
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/testcontainers/testcontainers-go"
+	tcpostgres "github.com/testcontainers/testcontainers-go/modules/postgres"
+	tcredis "github.com/testcontainers/testcontainers-go/modules/redis"
+	"github.com/testcontainers/testcontainers-go/wait"
+)
+
+func init() {
+	// The Ryuk reaper container cannot start in this environment; each Start*
+	// returns an explicit terminate func for cleanup instead.
+	if _, ok := os.LookupEnv("TESTCONTAINERS_RYUK_DISABLED"); !ok {
+		os.Setenv("TESTCONTAINERS_RYUK_DISABLED", "true")
+	}
+}
+
+// StartPostgres launches postgres:17-alpine and returns its DSN.
+func StartPostgres(ctx context.Context) (dsn string, terminate func(), err error) {
+	c, err := tcpostgres.Run(ctx,
+		"postgres:17-alpine",
+		tcpostgres.WithDatabase("artifacts"),
+		tcpostgres.WithUsername("artifacts"),
+		tcpostgres.WithPassword("artifacts123"),
+		testcontainers.WithWaitStrategy(
+			// Postgres opens the port, runs init scripts, then restarts, so wait
+			// for the readiness log to appear twice to avoid connection resets.
+			wait.ForLog("database system is ready to accept connections").
+				WithOccurrence(2).
+				WithStartupTimeout(60*time.Second),
+		),
+	)
+	if err != nil {
+		return "", nil, err
+	}
+	host, _ := c.Host(ctx)
+	port, _ := c.MappedPort(ctx, "5432/tcp")
+	dsn = fmt.Sprintf("postgres://artifacts:artifacts123@%s:%s/artifacts?sslmode=disable", host, port.Port())
+	return dsn, func() { _ = c.Terminate(ctx) }, nil
+}
+
+// StartRedis launches redis:7-alpine and returns its URL.
+func StartRedis(ctx context.Context) (url string, terminate func(), err error) {
+	c, err := tcredis.Run(ctx,
+		"redis:7-alpine",
+		testcontainers.WithWaitStrategy(
+			wait.ForListeningPort("6379/tcp").WithStartupTimeout(60*time.Second),
+		),
+	)
+	if err != nil {
+		return "", nil, err
+	}
+	host, _ := c.Host(ctx)
+	port, _ := c.MappedPort(ctx, "6379/tcp")
+	url = fmt.Sprintf("redis://%s:%s", host, port.Port())
+	return url, func() { _ = c.Terminate(ctx) }, nil
+}
+
+// MinioConn holds MinIO connection details.
+type MinioConn struct {
+	Endpoint  string
+	AccessKey string
+	SecretKey string
+}
+
+// StartMinio launches minio and returns its connection details.
+func StartMinio(ctx context.Context) (conn MinioConn, terminate func(), err error) {
+	c, err := testcontainers.GenericContainer(ctx, testcontainers.GenericContainerRequest{
+		ContainerRequest: testcontainers.ContainerRequest{
+			Image:        "minio/minio:latest",
+			ExposedPorts: []string{"9000/tcp"},
+			Cmd:          []string{"server", "/data"},
+			Env: map[string]string{
+				"MINIO_ROOT_USER":     "minioadmin",
+				"MINIO_ROOT_PASSWORD": "minioadmin",
+			},
+			WaitingFor: wait.ForHTTP("/minio/health/ready").WithPort("9000/tcp").WithStartupTimeout(60 * time.Second),
+		},
+		Started: true,
+	})
+	if err != nil {
+		return MinioConn{}, nil, err
+	}
+	host, _ := c.Host(ctx)
+	port, _ := c.MappedPort(ctx, "9000/tcp")
+	return MinioConn{
+		Endpoint:  fmt.Sprintf("%s:%s", host, port.Port()),
+		AccessKey: "minioadmin",
+		SecretKey: "minioadmin",
+	}, func() { _ = c.Terminate(ctx) }, nil
+}
diff --git a/internal/testsupport/rpm.go b/internal/testsupport/rpm.go
new file mode 100644
index 0000000..49f37bb
--- /dev/null
+++ b/internal/testsupport/rpm.go
@@ -0,0 +1,59 @@
+package testsupport
+
+import (
+	"bytes"
+	"encoding/binary"
+)
+
+// MinimalRPM builds a valid-enough RPM package in pure Go (no committed binary
+// fixture, no external rpmbuild). It carries just the header tags the provider
+// reads: name/version/release/arch plus a single self Provides entry, which is
+// enough for cavaliergopher/rpm to parse and for repodata generation.
+func MinimalRPM(name, version, release, arch string) []byte {
+	type tag struct {
+		id, typ, count uint32
+		data           []byte
+	}
+	cstr := func(s string) []byte { return append([]byte(s), 0) }
+	tags := []tag{
+		{1000, 6, 1, cstr(name)},         // RPMTAG_NAME (STRING)
+		{1001, 6, 1, cstr(version)},      // RPMTAG_VERSION
+		{1002, 6, 1, cstr(release)},      // RPMTAG_RELEASE
+		{1022, 6, 1, cstr(arch)},         // RPMTAG_ARCH
+		{1047, 8, 1, cstr(name)},         // RPMTAG_PROVIDENAME (STRING_ARRAY)
+		{1112, 4, 1, []byte{0, 0, 0, 0}}, // RPMTAG_PROVIDEFLAGS (INT32)
+		{1113, 8, 1, cstr(version)},      // RPMTAG_PROVIDEVERSION (STRING_ARRAY)
+	}
+
+	buildHeader := func(entries []tag) []byte {
+		var index, store bytes.Buffer
+		for _, e := range entries {
+			off := uint32(store.Len())
+			for _, v := range []uint32{e.id, e.typ, off, e.count} {
+				binary.Write(&index, binary.BigEndian, v)
+			}
+			store.Write(e.data)
+		}
+		var b bytes.Buffer
+		b.Write([]byte{0x8e, 0xad, 0xe8, 0x01, 0, 0, 0, 0}) // header magic + reserved
+		binary.Write(&b, binary.BigEndian, uint32(len(entries)))
+		binary.Write(&b, binary.BigEndian, uint32(store.Len()))
+		b.Write(index.Bytes())
+		b.Write(store.Bytes())
+		return b.Bytes()
+	}
+
+	lead := make([]byte, 96)
+	copy(lead[0:4], []byte{0xed, 0xab, 0xee, 0xdb}) // lead magic
+	lead[4] = 3                                     // major version
+	binary.BigEndian.PutUint16(lead[8:10], 1)       // archnum
+	copy(lead[10:76], name)                         // name (66 bytes, null-padded)
+	binary.BigEndian.PutUint16(lead[76:78], 1)      // osnum
+	binary.BigEndian.PutUint16(lead[78:80], 5)      // signature type
+
+	var out bytes.Buffer
+	out.Write(lead)
+	out.Write(buildHeader(nil)) // empty signature header (16 bytes, 8-aligned)
+	out.Write(buildHeader(tags))
+	return out.Bytes()
+}
diff --git a/internal/virtual/merger_test.go b/internal/virtual/merger_test.go
new file mode 100644
index 0000000..2e117fe
--- /dev/null
+++ b/internal/virtual/merger_test.go
@@ -0,0 +1,155 @@
+package virtual
+
+import (
+	"strings"
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func TestRegisterGetMerger(t *testing.T) {
+	if _, err := GetMerger(models.PackageHelm); err != nil {
+		t.Errorf("helm merger should be registered: %v", err)
+	}
+	if _, err := GetMerger(models.PackagePyPI); err != nil {
+		t.Errorf("pypi merger should be registered: %v", err)
+	}
+	if _, err := GetMerger(models.PackageType("nope")); err == nil {
+		t.Error("expected error for unknown merger")
+	}
+}
+
+func TestPyPIMerge(t *testing.T) {
+	m := &PyPIMerger{}
+	members := []MemberIndex{
+		{RemoteName: "a", RepoType: models.RepoTypeRemote, Body: []byte(`<a href="pkg/foo-1.0.whl">foo-1.0.whl</a>`)},
+		{RemoteName: "b", RepoType: models.RepoTypeLocal, Body: []byte(`<a href="/bar-2.0.whl">bar-2.0.whl</a>`)},
+	}
+	out, err := m.MergeIndexes(members, "http://proxy")
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := string(out)
+	if !strings.Contains(s, "foo-1.0.whl") || !strings.Contains(s, "bar-2.0.whl") {
+		t.Errorf("merged index missing entries: %s", s)
+	}
+	if !strings.Contains(s, "http://proxy/api/v1/remote/a/pkg/foo-1.0.whl") {
+		t.Errorf("remote href not rewritten: %s", s)
+	}
+	if !strings.Contains(s, "http://proxy/api/v1/local/b/bar-2.0.whl") {
+		t.Errorf("local href not rewritten: %s", s)
+	}
+
+	// Sorted output: foo before... entries sorted by link text.
+	if strings.Index(s, "bar-2.0.whl") > strings.Index(s, "foo-1.0.whl") {
+		t.Error("entries should be sorted by text")
+	}
+
+	// Duplicate link texts across members are de-duplicated.
+	dup := []MemberIndex{
+		{RemoteName: "a", Body: []byte(`<a href="x">dup</a>`)},
+		{RemoteName: "b", Body: []byte(`<a href="y">dup</a>`)},
+	}
+	out, _ = m.MergeIndexes(dup, "")
+	if strings.Count(string(out), ">dup</a>") != 1 {
+		t.Errorf("duplicate not de-duplicated: %s", out)
+	}
+}
+
+func TestPyPIMergeNoProxyAndBadLinks(t *testing.T) {
+	m := &PyPIMerger{}
+	members := []MemberIndex{{
+		RemoteName: "a",
+		Body:       []byte("<a href=\"foo.whl\">foo.whl</a>\n<a>no href</a>\n<span>not a link</span>"),
+	}}
+	// No proxy base URL: hrefs are left as-is.
+	out, err := m.MergeIndexes(members, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := string(out)
+	if !strings.Contains(s, ">foo.whl</a>") {
+		t.Errorf("missing link: %s", s)
+	}
+}
+
+func TestHelmMerge(t *testing.T) {
+	m := &HelmMerger{}
+	memberA := `apiVersion: v1
+entries:
+  alpha:
+    - name: alpha
+      version: 1.0.0
+      urls:
+        - charts/alpha-1.0.0.tgz
+`
+	memberB := `apiVersion: v1
+entries:
+  beta:
+    - name: beta
+      version: 2.0.0
+      urls:
+        - https://charts.example.com/beta-2.0.0.tgz
+  gamma:
+    - name: gamma
+      version: 3.0.0
+      urls:
+        - https://other-host.example.net/gamma-3.0.0.tgz
+`
+	members := []MemberIndex{
+		{RemoteName: "a", RepoType: models.RepoTypeLocal, BaseURL: "https://charts.example.com", Body: []byte(memberA)},
+		{RemoteName: "b", RepoType: models.RepoTypeRemote, BaseURL: "https://charts.example.com", Body: []byte(memberB)},
+	}
+	out, err := m.MergeIndexes(members, "http://proxy")
+	if err != nil {
+		t.Fatal(err)
+	}
+	s := string(out)
+	for _, chart := range []string{"alpha", "beta", "gamma"} {
+		if !strings.Contains(s, chart) {
+			t.Errorf("merged index missing chart %q: %s", chart, s)
+		}
+	}
+	// Relative URL from a local member is rewritten under /local/.
+	if !strings.Contains(s, "http://proxy/api/v1/local/a/charts/alpha-1.0.0.tgz") {
+		t.Errorf("relative local url not rewritten: %s", s)
+	}
+	// Same-host absolute URL from a remote member is rewritten under /remote/.
+	if !strings.Contains(s, "http://proxy/api/v1/remote/b/beta-2.0.0.tgz") {
+		t.Errorf("same-host absolute url not rewritten: %s", s)
+	}
+	// Cross-host absolute URL is left untouched.
+	if !strings.Contains(s, "https://other-host.example.net/gamma-3.0.0.tgz") {
+		t.Errorf("cross-host url should be preserved: %s", s)
+	}
+}
+
+func TestHelmMergeDedup(t *testing.T) {
+	m := &HelmMerger{}
+	body := `apiVersion: v1
+entries:
+  alpha:
+    - name: alpha
+      version: 1.0.0
+      urls: [charts/alpha-1.0.0.tgz]
+`
+	members := []MemberIndex{
+		{RemoteName: "a", BaseURL: "https://x", Body: []byte(body)},
+		{RemoteName: "b", BaseURL: "https://x", Body: []byte(body)},
+	}
+	out, _ := m.MergeIndexes(members, "")
+	if strings.Count(string(out), "version: 1.0.0") != 1 {
+		t.Errorf("duplicate chart version not de-duplicated: %s", out)
+	}
+}
+
+func TestHelmMergeInvalidYAML(t *testing.T) {
+	m := &HelmMerger{}
+	out, err := m.MergeIndexes([]MemberIndex{{RemoteName: "a", Body: []byte("::: not yaml :::")}}, "")
+	if err != nil {
+		t.Fatalf("invalid member yaml should be skipped, not error: %v", err)
+	}
+	if !strings.Contains(string(out), "apiVersion") {
+		t.Errorf("expected a valid empty merged index: %s", out)
+	}
+}
diff --git a/pkg/client/client_test.go b/pkg/client/client_test.go
new file mode 100644
index 0000000..62f9fd5
--- /dev/null
+++ b/pkg/client/client_test.go
@@ -0,0 +1,145 @@
+package client
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"git.unkin.net/unkin/artifactapi/pkg/models"
+)
+
+func testServer(t *testing.T, h http.HandlerFunc) *Client {
+	t.Helper()
+	srv := httptest.NewServer(h)
+	t.Cleanup(srv.Close)
+	return New(srv.URL)
+}
+
+func TestRemotesRoundTrip(t *testing.T) {
+	var gotMethod, gotPath string
+	c := testServer(t, func(w http.ResponseWriter, r *http.Request) {
+		gotMethod, gotPath = r.Method, r.URL.Path
+		switch {
+		case r.Method == http.MethodGet && r.URL.Path == "/api/v2/remotes":
+			w.Write([]byte(`[{"name":"a"},{"name":"b"}]`))
+		case r.Method == http.MethodGet && r.URL.Path == "/api/v2/remotes/a":
+			w.Write([]byte(`{"name":"a"}`))
+		case r.Method == http.MethodDelete:
+			w.WriteHeader(http.StatusNoContent)
+		default:
+			w.WriteHeader(http.StatusCreated)
+			w.Write([]byte(`{"name":"a"}`))
+		}
+	})
+	ctx := context.Background()
+
+	remotes, err := c.ListRemotes(ctx)
+	if err != nil || len(remotes) != 2 {
+		t.Fatalf("ListRemotes: %v %v", remotes, err)
+	}
+	if r, err := c.GetRemote(ctx, "a"); err != nil || r.Name != "a" {
+		t.Fatalf("GetRemote: %v %v", r, err)
+	}
+	if err := c.CreateRemote(ctx, &models.Remote{Name: "a", PackageType: models.PackageGeneric}); err != nil {
+		t.Fatalf("CreateRemote: %v", err)
+	}
+	if err := c.UpdateRemote(ctx, &models.Remote{Name: "a"}); err != nil {
+		t.Fatalf("UpdateRemote: %v", err)
+	}
+	if err := c.DeleteRemote(ctx, "a"); err != nil {
+		t.Fatalf("DeleteRemote: %v", err)
+	}
+	if gotMethod != http.MethodDelete || gotPath != "/api/v2/remotes/a" {
+		t.Errorf("last call = %s %s", gotMethod, gotPath)
+	}
+}
+
+func TestVirtualsRoundTrip(t *testing.T) {
+	c := testServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case r.Method == http.MethodGet && strings.HasSuffix(r.URL.Path, "/virtuals"):
+			w.Write([]byte(`[{"name":"v"}]`))
+		case r.Method == http.MethodGet:
+			w.Write([]byte(`{"name":"v"}`))
+		case r.Method == http.MethodDelete:
+			w.WriteHeader(http.StatusNoContent)
+		default:
+			w.WriteHeader(http.StatusCreated)
+			w.Write([]byte(`{"name":"v"}`))
+		}
+	})
+	ctx := context.Background()
+	if vs, err := c.ListVirtuals(ctx); err != nil || len(vs) != 1 {
+		t.Fatalf("ListVirtuals: %v %v", vs, err)
+	}
+	if v, err := c.GetVirtual(ctx, "v"); err != nil || v.Name != "v" {
+		t.Fatalf("GetVirtual: %v %v", v, err)
+	}
+	if err := c.CreateVirtual(ctx, &models.Virtual{Name: "v"}); err != nil {
+		t.Fatalf("CreateVirtual: %v", err)
+	}
+	if err := c.UpdateVirtual(ctx, &models.Virtual{Name: "v"}); err != nil {
+		t.Fatalf("UpdateVirtual: %v", err)
+	}
+	if err := c.DeleteVirtual(ctx, "v"); err != nil {
+		t.Fatalf("DeleteVirtual: %v", err)
+	}
+}
+
+func TestStatsHealthObjects(t *testing.T) {
+	c := testServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case strings.HasSuffix(r.URL.Path, "/stats"):
+			w.Write([]byte(`{"total_remotes":3}`))
+		case strings.HasSuffix(r.URL.Path, "/health"):
+			w.Write([]byte(`{"status":"ok"}`))
+		case r.Method == http.MethodDelete:
+			w.WriteHeader(http.StatusNoContent)
+		default:
+			w.Write([]byte(`[{"path":"p"}]`))
+		}
+	})
+	ctx := context.Background()
+	if _, err := c.Stats(ctx); err != nil {
+		t.Fatalf("Stats: %v", err)
+	}
+	if _, err := c.Health(ctx); err != nil {
+		t.Fatalf("Health: %v", err)
+	}
+	if objs, err := c.ListObjects(ctx, "r", 1, 50); err != nil || len(objs) != 1 {
+		t.Fatalf("ListObjects: %v %v", objs, err)
+	}
+	if err := c.EvictObject(ctx, "r", "some/path"); err != nil {
+		t.Fatalf("EvictObject: %v", err)
+	}
+}
+
+func TestErrorResponses(t *testing.T) {
+	c := testServer(t, func(w http.ResponseWriter, r *http.Request) {
+		http.Error(w, "boom", http.StatusInternalServerError)
+	})
+	ctx := context.Background()
+	_, err := c.GetRemote(ctx, "x")
+	if err == nil || !strings.Contains(err.Error(), "api error 500") {
+		t.Errorf("expected api error, got %v", err)
+	}
+}
+
+func TestDecodeError(t *testing.T) {
+	c := testServer(t, func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte(`not json`))
+	})
+	if _, err := c.ListRemotes(context.Background()); err == nil || !strings.Contains(err.Error(), "decode") {
+		t.Errorf("expected decode error, got %v", err)
+	}
+}
+
+func TestRequestError(t *testing.T) {
+	// Invalid base URL triggers request construction failure.
+	c := New("http://[::1]:namedport")
+	if err := c.DeleteRemote(context.Background(), "x"); err == nil {
+		t.Error("expected request error for invalid URL")
+	}
+}
diff --git a/pkg/models/repotype_test.go b/pkg/models/repotype_test.go
new file mode 100644
index 0000000..bedcc52
--- /dev/null
+++ b/pkg/models/repotype_test.go
@@ -0,0 +1,18 @@
+package models
+
+import "testing"
+
+func TestRepoType(t *testing.T) {
+	if RepoTypeRemote.String() != "remote" || RepoTypeLocal.String() != "local" {
+		t.Error("RepoType.String")
+	}
+	if !RepoTypeRemote.Valid() || RepoType("bogus").Valid() {
+		t.Error("RepoType.Valid")
+	}
+	if rt, err := ParseRepoType("local"); err != nil || rt != RepoTypeLocal {
+		t.Errorf("ParseRepoType(local) = %v %v", rt, err)
+	}
+	if _, err := ParseRepoType("nope"); err == nil {
+		t.Error("ParseRepoType should reject unknown")
+	}
+}