diff --git a/modules/mesh-build-go/buildstep/blob.go b/modules/mesh-build-go/buildstep/blob.go
deleted file mode 100644
index 127c6ace..00000000
--- a/modules/mesh-build-go/buildstep/blob.go
+++ /dev/null
@@ -1,170 +0,0 @@
-package buildstep
-
-import (
-	"bytes"
-	"context"
-	"crypto/sha256"
-	"encoding/hex"
-	"errors"
-	"fmt"
-	"io"
-	"net/http"
-	"net/url"
-	"strings"
-	"syscall"
-	"time"
-)
-
-// RegistryWait is how long a push waits for an artifact store that refuses connections, longer than its nightly
-// collection holds it still (about a minute and a half, issue 457); RegistryFirstPause is the first pause, doubling
-// to RegistryMostPause. Variables so a test shortens them.
-var (
-	RegistryWait       = 5 * time.Minute
-	RegistryFirstPause = time.Second
-	RegistryMostPause  = 10 * time.Second
-)
-
-// BlobReference is where a pushed bundle or archive is, as a done key names it and the controller delivers from
-// (novox/hq ADR 0498 clause 1): artifact-store://<module>/<artifact>/blobs/<digest>, the store's address left out
-// (issue 102).
-func BlobReference(module, artifact, digest string) string {
-	return "artifact-store://" + module + "/" + artifact + "/blobs/" + digest
-}
-
-// PushBlob puts body into the artifact store at registry (host:port) as a blob of repository (<module>/<artifact>) by
-// its digest (`sha256:` and hex), from the build module's own process, after the build step ended (novox/hq ADR 0498
-// clauses 1 and 2): a blob the store already holds is done without an upload; otherwise it is uploaded (POST
-// blobs/uploads/, then PUT with the digest). A store refusing connections is waited out up to RegistryWait; any other
-// refusal fails, naming the store's status and its own words, for the caller's `not stored:` error. Bytes that are not
-// their digest are refused before anything is sent.
-func PushBlob(ctx context.Context, client *http.Client, registry, repository, digest string, body []byte) error {
-	sum := sha256.Sum256(body)
-	if got := "sha256:" + hex.EncodeToString(sum[:]); got != digest {
-		return fmt.Errorf("the blob is %s, not the digest %s it was to be pushed as", got, digest)
-	}
-	if client == nil {
-		client = http.DefaultClient
-	}
-	base := "http://" + registry + "/v2/" + repository + "/blobs/"
-	var present bool
-	if err := waitForStore(ctx, registry, func() error {
-		var err error
-		present, err = blobPresent(ctx, client, base+digest)
-		return err
-	}); err != nil {
-		return err
-	}
-	if present {
-		return nil
-	}
-	var location string
-	if err := waitForStore(ctx, registry, func() error {
-		var err error
-		location, err = startUpload(ctx, client, base+"uploads/")
-		return err
-	}); err != nil {
-		return err
-	}
-	target, err := url.Parse(base)
-	if err != nil {
-		return err
-	}
-	loc, err := target.Parse(location)
-	if err != nil {
-		return fmt.Errorf("the store answered the upload's location %q, which is not a URL: %w", location, err)
-	}
-	q := loc.Query()
-	q.Set("digest", digest)
-	loc.RawQuery = q.Encode()
-	req, err := http.NewRequestWithContext(ctx, http.MethodPut, loc.String(), bytes.NewReader(body))
-	if err != nil {
-		return err
-	}
-	req.Header.Set("Content-Type", "application/octet-stream")
-	resp, err := client.Do(req)
-	if err != nil {
-		return fmt.Errorf("putting %s of %s: %w", digest, repository, err)
-	}
-	defer resp.Body.Close()
-	if resp.StatusCode != http.StatusCreated {
-		return storeSaid(resp, "putting "+digest+" of "+repository)
-	}
-	return nil
-}
-
-func blobPresent(ctx context.Context, client *http.Client, at string) (bool, error) {
-	req, err := http.NewRequestWithContext(ctx, http.MethodHead, at, nil)
-	if err != nil {
-		return false, err
-	}
-	resp, err := client.Do(req)
-	if err != nil {
-		return false, err
-	}
-	resp.Body.Close()
-	switch resp.StatusCode {
-	case http.StatusOK:
-		return true, nil
-	case http.StatusNotFound:
-		return false, nil
-	}
-	return false, fmt.Errorf("asking the store for %s: it answered %s", at, resp.Status)
-}
-
-func startUpload(ctx context.Context, client *http.Client, at string) (string, error) {
-	req, err := http.NewRequestWithContext(ctx, http.MethodPost, at, nil)
-	if err != nil {
-		return "", err
-	}
-	resp, err := client.Do(req)
-	if err != nil {
-		return "", err
-	}
-	defer resp.Body.Close()
-	if resp.StatusCode != http.StatusAccepted {
-		return "", storeSaid(resp, "starting an upload at "+at)
-	}
-	location := resp.Header.Get("Location")
-	if location == "" {
-		return "", fmt.Errorf("starting an upload at %s: the store named no location", at)
-	}
-	return location, nil
-}
-
-// storeSaid is the store's refusal: its status and the first of its own words.
-func storeSaid(resp *http.Response, what string) error {
-	words, _ := io.ReadAll(io.LimitReader(resp.Body, 2048))
-	return fmt.Errorf("%s: the store answered %s: %s", what, resp.Status, strings.TrimSpace(string(words)))
-}
-
-// refused is whether an error is a connection refused.
-func refused(err error) bool {
-	return err != nil && (errors.Is(err, syscall.ECONNREFUSED) || strings.Contains(err.Error(), "connection refused"))
-}
-
-// waitForStore runs try, and while it fails because the store refuses connections, tries again with a growing pause
-// until RegistryWait has passed. A refusal is the one error waited for: nothing was sent, so trying again does nothing
-// twice.
-func waitForStore(ctx context.Context, registry string, try func() error) error {
-	err := try()
-	if !refused(err) {
-		return err
-	}
-	started, pause := time.Now(), RegistryFirstPause
-	for {
-		left := RegistryWait - time.Since(started)
-		if left <= 0 {
-			return fmt.Errorf("the artifact store at %s refused every connection for %s, longer than its nightly collection holds it still, so it is down, not paused: %w",
-				registry, time.Since(started).Round(time.Millisecond), err)
-		}
-		select {
-		case <-ctx.Done():
-			return fmt.Errorf("stopped while waiting for the artifact store at %s: %w (last: %v)", registry, ctx.Err(), err)
-		case <-time.After(min(pause, left)):
-		}
-		pause = min(pause*2, RegistryMostPause)
-		if err = try(); !refused(err) {
-			return err
-		}
-	}
-}
diff --git a/modules/mesh-build-go/buildstep/blob_test.go b/modules/mesh-build-go/buildstep/blob_test.go
deleted file mode 100644
index b77afb0c..00000000
--- a/modules/mesh-build-go/buildstep/blob_test.go
+++ /dev/null
@@ -1,151 +0,0 @@
-package buildstep
-
-import (
-	"context"
-	"crypto/sha256"
-	"encoding/hex"
-	"io"
-	"net"
-	"net/http"
-	"net/http/httptest"
-	"strings"
-	"sync"
-	"testing"
-	"time"
-
-	"git.novox.be/novox/mesh-sdk/go/delivery"
-)
-
-func digestOfBytes(b []byte) string {
-	h := sha256.Sum256(b)
-	return "sha256:" + hex.EncodeToString(h[:])
-}
-
-// registry is an artifact store as far as a blob push needs one: HEAD a blob, start an upload, PUT it with its digest.
-type registry struct {
-	mu    sync.Mutex
-	blobs map[string][]byte
-	calls []string
-	put   int // the status a PUT answers, 201 when 0
-}
-
-func (r *registry) ServeHTTP(w http.ResponseWriter, req *http.Request) {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	r.calls = append(r.calls, req.Method+" "+req.URL.Path)
-	switch {
-	case req.Method == http.MethodHead && strings.Contains(req.URL.Path, "/blobs/sha256:"):
-		if _, ok := r.blobs[req.URL.Path[strings.LastIndex(req.URL.Path, "/")+1:]]; ok {
-			w.WriteHeader(http.StatusOK)
-			return
-		}
-		w.WriteHeader(http.StatusNotFound)
-	case req.Method == http.MethodPost && strings.HasSuffix(req.URL.Path, "/blobs/uploads/"):
-		w.Header().Set("Location", strings.TrimSuffix(req.URL.Path, "/")+"/u1?state=x")
-		w.WriteHeader(http.StatusAccepted)
-	case req.Method == http.MethodPut && strings.Contains(req.URL.Path, "/blobs/uploads/u1"):
-		if r.put != 0 {
-			w.WriteHeader(r.put)
-			_, _ = io.WriteString(w, `{"errors":[{"code":"DIGEST_INVALID","message":"provided digest did not match uploaded content"}]}`)
-			return
-		}
-		body, _ := io.ReadAll(req.Body)
-		d := req.URL.Query().Get("digest")
-		if req.URL.Query().Get("state") != "x" || d != digestOfBytes(body) {
-			w.WriteHeader(http.StatusBadRequest)
-			return
-		}
-		r.blobs[d] = body
-		w.WriteHeader(http.StatusCreated)
-	default:
-		w.WriteHeader(http.StatusMethodNotAllowed)
-	}
-}
-
-// A done build's bundle or archive is pushed to the artifact store by its build module (novox/hq ADR 0498 clauses 1
-// and 2): a blob the store already holds is done with no upload; one it lacks is uploaded by digest; its reference is
-// the artifact-store form the builder's key and the controller check.
-func TestABlobIsPushedOnceByItsDigest(t *testing.T) {
-	reg := &registry{blobs: map[string][]byte{}}
-	srv := httptest.NewServer(reg)
-	defer srv.Close()
-	addr := strings.TrimPrefix(srv.URL, "http://")
-	body := []byte("the packed bundle")
-	d := digestOfBytes(body)
-	if err := PushBlob(context.Background(), srv.Client(), addr, "mail/code", d, body); err != nil {
-		t.Fatal(err)
-	}
-	if string(reg.blobs[d]) != string(body) {
-		t.Fatalf("the store holds %q", reg.blobs[d])
-	}
-	reg.calls = nil
-	if err := PushBlob(context.Background(), srv.Client(), addr, "mail/code", d, body); err != nil {
-		t.Fatal(err)
-	}
-	if len(reg.calls) != 1 || !strings.HasPrefix(reg.calls[0], "HEAD ") {
-		t.Fatalf("a blob the store holds was uploaded again: %v", reg.calls)
-	}
-	ref := BlobReference("mail", "code", d)
-	if ref != "artifact-store://mail/code/blobs/"+d {
-		t.Fatalf("BlobReference = %q", ref)
-	}
-	b := delivery.BuilderBuild{State: delivery.BuildDone, Manifest: strings.Repeat("4", 64),
-		Artifacts: []delivery.BuiltArtifact{{Name: "code", Kind: "bundle", Digest: d, Reference: ref}}}
-	if _, err := delivery.EncodeBuilderBuild(b); err != nil {
-		t.Fatalf("the key refuses the reference BlobReference gives: %v", err)
-	}
-}
-
-// A store that refuses the upload fails the push naming the store's own words; bytes that are not the digest are
-// refused before anything is sent.
-func TestAPushTheStoreRefusesSaysTheStoresWords(t *testing.T) {
-	reg := &registry{blobs: map[string][]byte{}, put: http.StatusBadRequest}
-	srv := httptest.NewServer(reg)
-	defer srv.Close()
-	addr := strings.TrimPrefix(srv.URL, "http://")
-	body := []byte("x")
-	err := PushBlob(context.Background(), srv.Client(), addr, "mail/code", digestOfBytes(body), body)
-	if err == nil || !strings.Contains(err.Error(), "provided digest did not match") || !strings.Contains(err.Error(), "400") {
-		t.Fatalf("a refused upload said %v", err)
-	}
-	reg.calls = nil
-	err = PushBlob(context.Background(), srv.Client(), addr, "mail/code", digestOfBytes([]byte("other")), body)
-	if err == nil || len(reg.calls) != 0 {
-		t.Fatalf("bytes that are not their digest: %v, calls %v", err, reg.calls)
-	}
-}
-
-// A store refusing connections (its nightly collection holds it still) is waited out, up to RegistryWait (issue 457).
-func TestAPushWaitsOutAStoreRefusingConnections(t *testing.T) {
-	l, err := net.Listen("tcp", "127.0.0.1:0")
-	if err != nil {
-		t.Fatal(err)
-	}
-	addr := l.Addr().String()
-	l.Close() // refusing now
-	reg := &registry{blobs: map[string][]byte{}}
-	go func() {
-		time.Sleep(300 * time.Millisecond)
-		l2, err := net.Listen("tcp", addr)
-		if err != nil {
-			return
-		}
-		_ = http.Serve(l2, reg)
-	}()
-	beforeWait, beforePause := RegistryWait, RegistryFirstPause
-	RegistryWait, RegistryFirstPause = 3*time.Second, 100*time.Millisecond
-	defer func() { RegistryWait, RegistryFirstPause = beforeWait, beforePause }()
-	body := []byte("late")
-	if err := PushBlob(context.Background(), http.DefaultClient, addr, "mail/code", digestOfBytes(body), body); err != nil {
-		t.Fatalf("a store that came back was not waited for: %v", err)
-	}
-
-	l3, _ := net.Listen("tcp", "127.0.0.1:0")
-	gone := l3.Addr().String()
-	l3.Close()
-	RegistryWait = 300 * time.Millisecond
-	err = PushBlob(context.Background(), http.DefaultClient, gone, "mail/code", digestOfBytes(body), body)
-	if err == nil || !strings.Contains(err.Error(), "refused every connection") {
-		t.Fatalf("a store that stayed down said %v", err)
-	}
-}
diff --git a/modules/mesh-build-go/cmd/mesh-build-go/store_integration_test.go b/modules/mesh-build-go/cmd/mesh-build-go/store_integration_test.go
index 7692a545..a9212974 100644
--- a/modules/mesh-build-go/cmd/mesh-build-go/store_integration_test.go
+++ b/modules/mesh-build-go/cmd/mesh-build-go/store_integration_test.go
@@ -3,13 +3,16 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"crypto/sha256"
 	"encoding/hex"
 	"encoding/json"
+	"fmt"
 	"io"
 	"net/http"
 	"net/http/httptest"
+	"net/url"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -23,8 +26,6 @@ import (
 	registry "git.novox.be/novox/mesh-contracts/go/seats/containerimageregistry"
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
 	"git.novox.be/novox/mesh-sdk/go/delivery"
-
-	"git.novox.be/novox/mesh-catalog/modules/mesh-build-go/buildstep"
 )
 
 // realStore starts the artifact store's own program (the distribution registry, modules/distribution) inside this
@@ -53,7 +54,7 @@ func realStore(t *testing.T, m *Module) string {
 		defer s.mu.Unlock()
 		for k, b := range s.blobs {
 			name, digest, _ := strings.Cut(k, "@")
-			if err := buildstep.PushBlob(context.Background(), http.DefaultClient, addr, name, digest, b); err != nil {
+			if err := uploadBlob(srv.URL, name, digest, b); err != nil {
 				return nil, err
 			}
 			delete(s.blobs, k)
@@ -63,6 +64,36 @@ func realStore(t *testing.T, m *Module) string {
 	return addr
 }
 
+// uploadBlob is the holder's own write into its store: an upload opened, then its bytes put by their digest (the
+// distribution protocol's two requests), as distribution stores a part it took whole.
+func uploadBlob(base, name, digest string, body []byte) error {
+	resp, err := http.Post(base+"/v2/"+name+"/blobs/uploads/", "", nil)
+	if err != nil {
+		return err
+	}
+	resp.Body.Close()
+	loc, err := url.Parse(resp.Header.Get("Location"))
+	if err != nil || resp.StatusCode != http.StatusAccepted {
+		return fmt.Errorf("the store opened no upload of %s: %s %v", digest, resp.Status, err)
+	}
+	b, _ := url.Parse(base)
+	u := b.ResolveReference(loc)
+	q := u.Query()
+	q.Set("digest", digest)
+	u.RawQuery = q.Encode()
+	req, _ := http.NewRequest(http.MethodPut, u.String(), bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/octet-stream")
+	put, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	put.Body.Close()
+	if put.StatusCode != http.StatusCreated {
+		return fmt.Errorf("the store did not take %s: %s", digest, put.Status)
+	}
+	return nil
+}
+
 // resolve reads a done artifact's reference from the store as a node-engine does (catalogue.Routed): the seat's form
 // oci-artifact-registry/<module>/<artifact>@<digest> is <store>/v2/<module>/<artifact>/blobs/<digest> (ADR 0605 §9).
 func resolve(t *testing.T, addr string, a delivery.BuiltArtifact) []byte {