diff --git a/build/blob/ref.go b/build/blob/ref.go
index 9a033fcb..dc7bdcef 100644
--- a/build/blob/ref.go
+++ b/build/blob/ref.go
@@ -2,6 +2,8 @@ package blob
 
 import (
 	"cmp"
+	"path"
+	"path/filepath"
 	"strings"
 )
 
@@ -11,26 +13,31 @@ import (
 //
 // Users or Ref must check Valid before using it.
 type Ref struct {
-	name  string
-	tag   string
-	build string
+	domain string
+	name   string
+	tag    string
+	build  string
 }
 
 // WithBuild returns a copy of r with the provided build. If the provided
 // build is empty, it returns the short, unqualified copy of r.
 func (r Ref) WithBuild(build string) Ref {
 	if build == "" {
-		return Ref{r.name, r.tag, ""}
+		return Ref{r.domain, r.name, r.tag, ""}
 	}
 	if !isValidPart(build) {
 		return Ref{}
 	}
-	return makeRef(r.name, r.tag, build)
+	return makeRef(r.domain, r.name, r.tag, build)
 }
 
 // String returns the fully qualified ref string.
 func (r Ref) String() string {
 	var b strings.Builder
+	if r.domain != "" {
+		b.WriteString(r.domain)
+		b.WriteString("/")
+	}
 	b.WriteString(r.name)
 	if r.tag != "" {
 		b.WriteString(":")
@@ -49,7 +56,7 @@ func (r Ref) Full() string {
 	if !r.Valid() {
 		return ""
 	}
-	return makeRef(r.name, r.tag, cmp.Or(r.build, "!(MISSING BUILD)")).String()
+	return makeRef(r.domain, r.name, r.tag, cmp.Or(r.build, "!(MISSING BUILD)")).String()
 }
 
 // Short returns the short ref string which does not include the build.
@@ -65,9 +72,18 @@ func (r Ref) FullyQualified() bool {
 	return r.name != "" && r.tag != "" && r.build != ""
 }
 
-func (r Ref) Name() string  { return r.name }
-func (r Ref) Tag() string   { return r.tag }
-func (r Ref) Build() string { return r.build }
+func (r Ref) Path() string {
+	return path.Join(r.domain, r.name, r.tag, r.build)
+}
+
+func (r Ref) Filepath() string {
+	return filepath.Join(r.domain, r.name, r.tag, r.build)
+}
+
+func (r Ref) Domain() string { return r.domain }
+func (r Ref) Name() string   { return r.name }
+func (r Ref) Tag() string    { return r.tag }
+func (r Ref) Build() string  { return r.build }
 
 // ParseRef parses a ref string into a Ref. A ref string is a name, an
 // optional tag, and an optional build, separated by colons and pluses.
@@ -107,12 +123,14 @@ func ParseRef(s string) Ref {
 	if expectBuild && !isValidPart(build) {
 		return Ref{}
 	}
-	return makeRef(name, tag, build)
+
+	const TODO = "registry.ollama.ai"
+	return makeRef(TODO, name, tag, build)
 }
 
 // makeRef makes a ref, skipping validation.
-func makeRef(name, tag, build string) Ref {
-	return Ref{name, cmp.Or(tag, "latest"), strings.ToUpper(build)}
+func makeRef(domain, name, tag, build string) Ref {
+	return Ref{domain, name, cmp.Or(tag, "latest"), strings.ToUpper(build)}
 }
 
 // isValidPart returns true if given part is valid ascii [a-zA-Z0-9_\.-]
diff --git a/build/blob/ref_test.go b/build/blob/ref_test.go
index b49d39df..1322022f 100644
--- a/build/blob/ref_test.go
+++ b/build/blob/ref_test.go
@@ -12,24 +12,24 @@ func TestParseRef(t *testing.T) {
 		in   string
 		want Ref
 	}{
-		{"mistral:latest", Ref{"mistral", "latest", ""}},
-		{"mistral", Ref{"mistral", "latest", ""}},
-		{"mistral:30B", Ref{"mistral", "30B", ""}},
-		{"mistral:7b", Ref{"mistral", "7b", ""}},
-		{"mistral:7b+Q4_0", Ref{"mistral", "7b", "Q4_0"}},
-		{"mistral+KQED", Ref{"mistral", "latest", "KQED"}},
-		{"mistral.x-3:7b+Q4_0", Ref{"mistral.x-3", "7b", "Q4_0"}},
+		{"mistral:latest", Ref{"registry.ollama.ai", "mistral", "latest", ""}},
+		{"mistral", Ref{"registry.ollama.ai", "mistral", "latest", ""}},
+		{"mistral:30B", Ref{"registry.ollama.ai", "mistral", "30B", ""}},
+		{"mistral:7b", Ref{"registry.ollama.ai", "mistral", "7b", ""}},
+		{"mistral:7b+Q4_0", Ref{"registry.ollama.ai", "mistral", "7b", "Q4_0"}},
+		{"mistral+KQED", Ref{"registry.ollama.ai", "mistral", "latest", "KQED"}},
+		{"mistral.x-3:7b+Q4_0", Ref{"registry.ollama.ai", "mistral.x-3", "7b", "Q4_0"}},
 
 		// lowecase build
-		{"mistral:7b+q4_0", Ref{"mistral", "7b", "Q4_0"}},
+		{"mistral:7b+q4_0", Ref{"registry.ollama.ai", "mistral", "7b", "Q4_0"}},
 
 		// Invalid
-		{"mistral:7b+Q4_0:latest", Ref{"", "", ""}},
-		{"mi tral", Ref{"", "", ""}},
-		{"llama2:+", Ref{"", "", ""}},
+		{"mistral:7b+Q4_0:latest", Ref{"", "", "", ""}},
+		{"mi tral", Ref{"", "", "", ""}},
+		{"llama2:+", Ref{"", "", "", ""}},
 
 		// too long
-		{refTooLong, Ref{"", "", ""}},
+		{refTooLong, Ref{"", "", "", ""}},
 	}
 	for _, tt := range cases {
 		t.Run(tt.in, func(t *testing.T) {
@@ -48,11 +48,11 @@ func TestRefFull(t *testing.T) {
 		wantFull  string
 	}{
 		{"", "", ""},
-		{"mistral:7b+x", "mistral:7b", "mistral:7b+X"},
-		{"mistral:7b+Q4_0", "mistral:7b", "mistral:7b+Q4_0"},
-		{"mistral:latest", "mistral:latest", "mistral:latest+!(MISSING BUILD)"},
-		{"mistral", "mistral:latest", "mistral:latest+!(MISSING BUILD)"},
-		{"mistral:30b", "mistral:30b", "mistral:30b+!(MISSING BUILD)"},
+		{"mistral:7b+x", "registry.ollama.ai/mistral:7b", "registry.ollama.ai/mistral:7b+X"},
+		{"mistral:7b+Q4_0", "registry.ollama.ai/mistral:7b", "registry.ollama.ai/mistral:7b+Q4_0"},
+		{"mistral:latest", "registry.ollama.ai/mistral:latest", "registry.ollama.ai/mistral:latest+!(MISSING BUILD)"},
+		{"mistral", "registry.ollama.ai/mistral:latest", "registry.ollama.ai/mistral:latest+!(MISSING BUILD)"},
+		{"mistral:30b", "registry.ollama.ai/mistral:30b", "registry.ollama.ai/mistral:30b+!(MISSING BUILD)"},
 	}
 
 	for _, tt := range cases {
diff --git a/build/build.go b/build/build.go
index 21491102..f66138db 100644
--- a/build/build.go
+++ b/build/build.go
@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"io/fs"
 	"os"
-	"path"
 
 	"bllamo.com/build/blob"
 	"bllamo.com/build/internal/blobstore"
@@ -22,10 +21,6 @@ var (
 	ErrNotFound               = errors.New("not found")
 )
 
-func ManifestKey(domain string, ref blob.Ref) string {
-	return path.Join("manifests", domain, ref.Name(), ref.Tag(), ref.Build())
-}
-
 type mediaType string
 
 // Known media types
diff --git a/build/internal/blobstore/blob.go b/build/internal/blobstore/blob.go
index e5981416..3c29538a 100644
--- a/build/internal/blobstore/blob.go
+++ b/build/internal/blobstore/blob.go
@@ -1,7 +1,3 @@
-// Copyright 2017 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
 // Package blobstore implements a blob store.
 package blobstore
 
@@ -228,8 +224,7 @@ func (s *Store) refFileName(ref blob.Ref) (string, error) {
 	if !ref.FullyQualified() {
 		return "", fmt.Errorf("ref not fully qualified: %q", ref)
 	}
-	const cheatTODO = "registry.ollama.ai/library"
-	return filepath.Join(s.dir, "manifests", cheatTODO, ref.Name(), ref.Tag(), ref.Build()), nil
+	return filepath.Join(s.dir, "manifests", ref.Domain(), ref.Name(), ref.Tag(), ref.Build()), nil
 }
 
 // Get looks up the blob ID in the store,
diff --git a/registry/server.go b/registry/server.go
index b22042bb..f22d0b1f 100644
--- a/registry/server.go
+++ b/registry/server.go
@@ -1,4 +1,4 @@
-// Package implements an Ollama registry client and server
+// Package implements an Ollama registry client and server package registry
 package registry
 
 import (
@@ -8,9 +8,10 @@ import (
 	"errors"
 	"log"
 	"net/http"
+	"os"
+	"path"
 	"time"
 
-	"bllamo.com/build"
 	"bllamo.com/build/blob"
 	"bllamo.com/client/ollama"
 	"bllamo.com/oweb"
@@ -19,6 +20,13 @@ import (
 	"github.com/minio/minio-go/v7/pkg/credentials"
 )
 
+// TODO(bmizerany): move all env things to package envkobs?
+var defaultLibrary = cmp.Or(os.Getenv("OLLAMA_REGISTRY"), "registry.ollama.ai/library")
+
+func DefaultLibrary() string {
+	return defaultLibrary
+}
+
 type Server struct{}
 
 func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@@ -80,7 +88,8 @@ func (s *Server) handlePush(w http.ResponseWriter, r *http.Request) error {
 		}
 		if !pushed {
 			const expires = 1 * time.Hour
-			signedURL, err := mc.PresignedPutObject(r.Context(), "test", l.Digest, expires)
+			key := path.Join("blobs", l.Digest)
+			signedURL, err := mc.PresignedPutObject(r.Context(), "test", key, expires)
 			if err != nil {
 				return err
 			}
@@ -95,9 +104,10 @@ func (s *Server) handlePush(w http.ResponseWriter, r *http.Request) error {
 	}
 
 	if len(requirements) == 0 {
-		const cheatTODO = "registry.ollama.ai/library"
-		key := build.ManifestKey(cheatTODO, ref)
-		_, err := mc.PutObject(r.Context(), "test", key, bytes.NewReader(pr.Manifest), int64(len(pr.Manifest)), minio.PutObjectOptions{})
+		// Commit the manifest
+		body := bytes.NewReader(pr.Manifest)
+		path := path.Join("manifests", ref.Path())
+		_, err := mc.PutObject(r.Context(), "test", path, body, int64(len(pr.Manifest)), minio.PutObjectOptions{})
 		if err != nil {
 			return err
 		}
@@ -122,7 +132,8 @@ func (s *Server) statObject(ctx context.Context, digest string) (pushed bool, er
 	}
 
 	// HEAD the object
-	_, err = mc.StatObject(ctx, "test", digest, minio.StatObjectOptions{})
+	path := path.Join("blobs", digest)
+	_, err = mc.StatObject(ctx, "test", path, minio.StatObjectOptions{})
 	if err != nil {
 		if isNoSuchKey(err) {
 			err = nil
diff --git a/registry/server_test.go b/registry/server_test.go
index 79c1875b..0e268c76 100644
--- a/registry/server_test.go
+++ b/registry/server_test.go
@@ -2,6 +2,7 @@ package registry
 
 import (
 	"context"
+	"encoding/json"
 	"net/http/httptest"
 	"os/exec"
 	"strings"
@@ -57,6 +58,50 @@ func TestPush(t *testing.T) {
 	if len(got) != 0 {
 		t.Fatalf("unexpected requirements: % #v", pretty.Formatter(got))
 	}
+
+	mc, err := minio.New("localhost:9000", &minio.Options{
+		Creds:  credentials.NewStaticV4("minioadmin", "minioadmin", ""),
+		Secure: false,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var paths []string
+	keys := mc.ListObjects(context.Background(), "test", minio.ListObjectsOptions{
+		Recursive: true,
+	})
+	for k := range keys {
+		paths = append(paths, k.Key)
+	}
+
+	t.Logf("paths: %v", paths)
+
+	diff.Test(t, t.Errorf, paths, []string{
+		"blobs/sha256-1",
+		"blobs/sha256-2",
+		"blobs/sha256-3",
+		"manifests/registry.ollama.ai/x/latest/Y",
+	})
+
+	obj, err := mc.GetObject(context.Background(), "test", "manifests/registry.ollama.ai/x/latest/Y", minio.GetObjectOptions{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer obj.Close()
+
+	var gotM apitype.Manifest
+	if err := json.NewDecoder(obj).Decode(&gotM); err != nil {
+		t.Fatal(err)
+	}
+
+	diff.Test(t, t.Errorf, gotM, apitype.Manifest{
+		Layers: []apitype.Layer{
+			{Digest: "sha256-1", Size: 1},
+			{Digest: "sha256-2", Size: 2},
+			{Digest: "sha256-3", Size: 3},
+		},
+	})
 }
 
 func startMinio(t *testing.T) {