diff --git a/cmd/mesh-builder/main.go b/cmd/mesh-builder/main.go
index 5ec294a..c4fa5e1 100644
--- a/cmd/mesh-builder/main.go
+++ b/cmd/mesh-builder/main.go
@@ -24,6 +24,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"net/url"
 	"os"
 	"os/signal"
 	"strings"
@@ -202,6 +203,7 @@ func answer(ctx context.Context, channel *amqp.Channel, publisher builder.Publis
 		// not after a clone that then fails at npm ci.
 		built, err = builder.Build(ctx, builder.Command, publisher,
 			request.Repository, request.Path, request.Ref, workspace, request.Held, npmrc,
+			forgeFrom(),
 			func(step, message string) {
 				fmt.Fprintf(os.Stderr, "  [%s] %s\n", step, message)
 			})
@@ -367,6 +369,53 @@ func packagesFrom() (builder.Npmrc, error) {
 	return builder.Npmrc{Scope: scope, Registry: registry, Token: secret}, nil
 }
 
+// forgeFrom is the git credential this builder may offer a clone, composed from the same binding
+// and sealed secret its package-registry half already reads: the forge that answers npm is the
+// forge that hosts the repositories, and its provisioner applies one password to one user for
+// both. Anything missing means no credential, and every clone stays anonymous — which is all a
+// mesh of public repositories ever needs.
+//
+// The URL names the binding's own address — the machine the mesh says the forge is on — so a
+// private repository is registered and built by that address, and a clone of anything else is
+// never shown this credential (git's credential store matches the whole origin).
+func forgeFrom() builder.GitCredential {
+	path := strings.TrimSpace(os.Getenv("MESH_PACKAGE_BINDING"))
+	if path == "" {
+		return builder.GitCredential{}
+	}
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return builder.GitCredential{}
+	}
+	var told struct {
+		At     string         `json:"at"`
+		As     string         `json:"as"`
+		Serves map[string]any `json:"serves"`
+	}
+	if err := json.Unmarshal(raw, &told); err != nil || told.At == "" || told.As == "" {
+		return builder.GitCredential{}
+	}
+	secret := strings.TrimSpace(os.Getenv("MESH_NPM_TOKEN"))
+	if file := strings.TrimSpace(os.Getenv("MESH_NPM_TOKEN_FILE")); file != "" {
+		if raw, err := os.ReadFile(file); err == nil {
+			secret = strings.TrimSpace(string(raw))
+		}
+	}
+	if secret == "" {
+		return builder.GitCredential{}
+	}
+	scheme := "https"
+	if s, ok := told.Serves["scheme"]; ok {
+		scheme = fmt.Sprintf("%v", s)
+	}
+	host := told.At
+	if port, ok := told.Serves["port"]; ok {
+		host = fmt.Sprintf("%s:%v", told.At, port)
+	}
+	made := url.URL{Scheme: scheme, User: url.UserPassword(told.As, secret), Host: host}
+	return builder.GitCredential{URL: made.String()}
+}
+
 func short(commit string) string {
 	if len(commit) > 8 {
 		return commit[:8]
diff --git a/cmd/mesh-builder/once.go b/cmd/mesh-builder/once.go
index 1ea9da7..97b2ef1 100644
--- a/cmd/mesh-builder/once.go
+++ b/cmd/mesh-builder/once.go
@@ -89,6 +89,7 @@ func buildOnce(ctx context.Context, args []string) error {
 		return err
 	}
 	built, buildErr := builder.Build(ctx, builder.Command, publisher, repository, *path, *ref, where, bases, npmrc,
+		forgeFrom(),
 		func(step, message string) { fmt.Fprintf(os.Stderr, "  [%s] %s\n", step, message) })
 	if buildErr != nil {
 		return buildErr
diff --git a/internal/builder/builder.go b/internal/builder/builder.go
index 222878d..3aa56f3 100644
--- a/internal/builder/builder.go
+++ b/internal/builder/builder.go
@@ -63,6 +63,19 @@ type Result struct {
 	Built []catalogue.Built
 }
 
+// GitCredential is the forge credential a clone may present when the server asks for one.
+//
+// **Offered, never pushed.** It is written as a git credential-store file and named to git with
+// `-c credential.helper=store`, so git itself decides when it applies: only on an authentication
+// challenge, and only for the URL it was written for — scheme, host and port included. A public
+// repository clones exactly as before, and a repository on any other host is never shown it.
+type GitCredential struct {
+	// URL is the credential-store line — scheme://user:password@host[:port] — naming the one
+	// server this credential belongs to. Empty means the builder holds none and every clone is
+	// anonymous, as it always was.
+	URL string
+}
+
 // Build clones a repository at a ref, reads its manifest, produces what it declares, publishes
 // each, and returns the manifest the mesh should hold.
 //
@@ -70,7 +83,8 @@ type Result struct {
 // archive failed would otherwise leave half of itself in the store under a digest the mesh never
 // records — reachable, unreferenced, and indistinguishable from something in use.
 func Build(ctx context.Context, run Runner, publish Publisher,
-	repository, path, ref, workspace string, held map[string]string, npmrc Npmrc, log Log) (Result, error) {
+	repository, path, ref, workspace string, held map[string]string, npmrc Npmrc,
+	forge GitCredential, log Log) (Result, error) {
 
 	say := logging(log)
 	say("clone", "%s%s at %s", repository, describePath(path), refOrHead(ref))
@@ -80,6 +94,15 @@ func Build(ctx context.Context, run Runner, publish Publisher,
 	if err := os.MkdirAll(workspace, 0o755); err != nil {
 		return Result{}, err
 	}
+	// The credential is a file git reads, never an argument: a URL carrying a password in argv
+	// would be readable by anything that can list processes for as long as a clone runs.
+	credentials := ""
+	if forge.URL != "" {
+		credentials = filepath.Join(workspace, "git-credentials")
+		if err := os.WriteFile(credentials, []byte(forge.URL+"\n"), 0o600); err != nil {
+			return Result{}, err
+		}
+	}
 	tree := filepath.Join(workspace, "source")
 	if err := os.RemoveAll(tree); err != nil {
 		return Result{}, err
@@ -87,7 +110,7 @@ func Build(ctx context.Context, run Runner, publish Publisher,
 	// A fresh clone every time rather than a fetch into a tree that is already there. A build
 	// that reuses a working tree can succeed because of something a previous build left behind,
 	// and that is a build nobody can reproduce.
-	if _, err := run(ctx, workspace, "git", "clone", "--quiet", repository, tree); err != nil {
+	if _, err := run(ctx, workspace, "git", cloneWith(credentials, "clone", "--quiet", repository, tree)...); err != nil {
 		say("clone", "FAILED: %v", err)
 		return Result{}, fmt.Errorf("cannot clone %s: %w", repository, err)
 	}
@@ -177,7 +200,7 @@ func Build(ctx context.Context, run Runner, publish Publisher,
 		sort.Slice(artifacts, func(i, j int) bool { return artifacts[i].Name < artifacts[j].Name })
 		for _, a := range artifacts {
 			say("artifact", "%s (%s%s) — starting", a.Name, a.Kind, langSuffix(a))
-			made, err := one(ctx, run, publish, manifest.Module, within, workspace, commit, a, args, held, npmrcPath, say)
+			made, err := one(ctx, run, publish, manifest.Module, within, workspace, commit, credentials, a, args, held, npmrcPath, say)
 			if err != nil {
 				say("artifact", "%s FAILED: %v", a.Name, err)
 				return Result{}, err
@@ -213,14 +236,14 @@ func logging(log Log) func(step, format string, args ...any) {
 // contextFrom clones an image artifact's own build context, when it names one apart from this
 // module's own repository — a fresh tree, the same way the module's own is, keyed by artifact
 // name so two artifacts of one module naming different contexts do not collide.
-func contextFrom(ctx context.Context, run Runner, workspace, artifact string,
+func contextFrom(ctx context.Context, run Runner, workspace, artifact, credentials string,
 	from catalogue.ArtifactContext, say func(step, format string, args ...any)) (string, error) {
 	say("context", "cloning %s at %s for %s", from.Repository, refOrHead(from.Ref), artifact)
 	dir := filepath.Join(workspace, "context-"+artifact)
 	if err := os.RemoveAll(dir); err != nil {
 		return "", err
 	}
-	if _, err := run(ctx, workspace, "git", "clone", "--quiet", from.Repository, dir); err != nil {
+	if _, err := run(ctx, workspace, "git", cloneWith(credentials, "clone", "--quiet", from.Repository, dir)...); err != nil {
 		return "", fmt.Errorf("cannot clone %s: %w", from.Repository, err)
 	}
 	if from.Ref != "" {
@@ -232,6 +255,21 @@ func contextFrom(ctx context.Context, run Runner, workspace, artifact string,
 	return dir, nil
 }
 
+// cloneWith is a git invocation that may offer a stored credential.
+//
+// The first `-c credential.helper=` clears every helper the environment might carry, so exactly
+// one place answers an authentication challenge: the file the builder wrote. Without a file, the
+// invocation is exactly what it always was.
+func cloneWith(credentials string, rest ...string) []string {
+	if credentials == "" {
+		return rest
+	}
+	return append([]string{
+		"-c", "credential.helper=",
+		"-c", "credential.helper=store --file=" + credentials,
+	}, rest...)
+}
+
 func describePath(path string) string {
 	if path == "" {
 		return ""
@@ -355,7 +393,7 @@ func wantsPackages(manifest catalogue.Manifest, within string) bool {
 }
 
 func one(ctx context.Context, run Runner, publish Publisher,
-	module, tree, workspace, commit string, a catalogue.Artifact, args []string,
+	module, tree, workspace, commit, credentials string, a catalogue.Artifact, args []string,
 	held map[string]string, npmrc string, say func(step, format string, args ...any)) (catalogue.Built, error) {
 
 	switch a.Kind {
@@ -433,7 +471,7 @@ func one(ctx context.Context, run Runner, publish Publisher,
 		recipePath := a.From
 		buildDir := tree
 		if a.Context != nil {
-			cloned, err := contextFrom(ctx, run, workspace, a.Name, *a.Context, say)
+			cloned, err := contextFrom(ctx, run, workspace, a.Name, credentials, *a.Context, say)
 			if err != nil {
 				return catalogue.Built{}, fmt.Errorf("%s: %s's context: %w", module, a.Name, err)
 			}
diff --git a/internal/builder/builder_test.go b/internal/builder/builder_test.go
index 175295e..0dbd714 100644
--- a/internal/builder/builder_test.go
+++ b/internal/builder/builder_test.go
@@ -42,8 +42,17 @@ func (r *recorded) run(_ context.Context, dir, name string, args ...string) (str
 	line := name + " " + strings.Join(args, " ")
 	r.ran = append(r.ran, line)
 	r.dirs = append(r.dirs, dir)
+	// A clone may carry `-c` configuration in front of the verb — the credential store — so the
+	// verb is found rather than assumed first.
+	isClone := false
+	for _, a := range args {
+		if a == "clone" {
+			isClone = true
+			break
+		}
+	}
 	switch {
-	case name == "git" && len(args) > 0 && args[0] == "clone":
+	case name == "git" && isClone:
 		repository := args[len(args)-2]
 		tree := args[len(args)-1]
 		if err := os.MkdirAll(tree, 0o755); err != nil {
@@ -119,7 +128,7 @@ func TestABuildProducesAManifestThePinsAreIn(t *testing.T) {
 	r, workspace := aRepository(t, withBoth, map[string]string{
 		"Dockerfile": "FROM scratch", "files/theme.conf": "dark",
 	})
-	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/meshboard.git", "", "", workspace, nil, Npmrc{}, nil)
+	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/meshboard.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -145,7 +154,7 @@ func TestTwoBuildsOfOneCommitProduceOneDigest(t *testing.T) {
 		})
 		// A year apart, so a packer carrying timestamps cannot accidentally agree.
 		r.stamped = time.Date(2020+i, time.March, 3, 4, 5, 6, 0, time.UTC)
-		got, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, nil)
+		got, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -165,7 +174,7 @@ func TestNothingIsPublishedUntilEverythingIsBuilt(t *testing.T) {
 	// unreferenced, and indistinguishable from something in use.
 	r, workspace := aRepository(t, withBoth, map[string]string{"Dockerfile": "FROM scratch"})
 	// `files` is missing, so packing the archive fails — after the image would have been pushed.
-	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, nil)
+	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err == nil {
 		t.Fatal("a build with a missing input succeeded")
 	}
@@ -177,7 +186,7 @@ func TestNothingIsPublishedUntilEverythingIsBuilt(t *testing.T) {
 func TestARepositoryWithNoManifestSaysSo(t *testing.T) {
 	workspace := t.TempDir()
 	r := &recorded{contents: map[string]string{"README.md": "nothing to see"}}
-	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, nil)
+	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err == nil {
 		t.Fatal("a repository with nothing saying what it is was built")
 	}
@@ -190,7 +199,7 @@ func TestAModuleThatBuildsNothingStillProducesAManifest(t *testing.T) {
 	// Most of what a person installs is configuration.
 	r, workspace := aRepository(t, `{"module":"shell","version":"1","resources":[
 		{"id":"rc","type":"file","path":"/etc/zsh/zshrc","content":"setopt"}]}`, nil)
-	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/shell.git", "", "", workspace, nil, Npmrc{}, nil)
+	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/shell.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -220,7 +229,7 @@ func TestTheTreeIsFreshEveryTime(t *testing.T) {
 	if err := os.WriteFile(leftover, []byte("stale"), 0o644); err != nil {
 		t.Fatal(err)
 	}
-	if _, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, nil); err != nil {
+	if _, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil); err != nil {
 		t.Fatal(err)
 	}
 	if _, err := os.Stat(leftover); err == nil {
@@ -233,7 +242,7 @@ func TestABuildThatCannotPushFails(t *testing.T) {
 		"Dockerfile": "FROM scratch", "files/a": "b",
 	})
 	r.failPush = true
-	if _, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, nil); err == nil {
+	if _, err := Build(context.Background(), r.run, r, "https://forge.invalid/x.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil); err == nil {
 		t.Fatal("a build that could publish nothing reported success")
 	}
 }
@@ -247,7 +256,7 @@ func TestAnUpstreamImageIsMirroredRatherThanBuilt(t *testing.T) {
 	  "resources":[{"id":"db","type":"container","name":"mesh-postgres","artifact":"store"}]}`
 
 	r, workspace := aRepository(t, mirrors, nil)
-	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/postgres.git", "", "", workspace, nil, Npmrc{}, nil)
+	got, err := Build(context.Background(), r.run, r, "https://forge.invalid/postgres.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -313,7 +322,7 @@ func TestAModuleIsBuiltFromItsPathWithinTheRepository(t *testing.T) {
 		"modules/other/" + ManifestName: `{"module":"other","version":"1"}`,
 	}}
 	got, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/catalogue.git", "modules/shell", "", t.TempDir(), nil, Npmrc{}, nil)
+		"https://forge.invalid/catalogue.git", "modules/shell", "", t.TempDir(), nil, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -332,7 +341,7 @@ func TestAPathThatLeavesTheRepositoryIsRefused(t *testing.T) {
 	for _, escaping := range []string{"../../etc", "/etc"} {
 		r := &recorded{contents: map[string]string{ManifestName: withBoth}}
 		_, err := Build(context.Background(), r.run, r,
-			"https://forge.invalid/x.git", escaping, "", t.TempDir(), nil, Npmrc{}, nil)
+			"https://forge.invalid/x.git", escaping, "", t.TempDir(), nil, Npmrc{}, GitCredential{}, nil)
 		if err == nil {
 			t.Fatalf("%q was accepted as a module's path", escaping)
 		}
@@ -369,7 +378,7 @@ func TestAnArtifactWithItsOwnContextIsBuiltFromThere(t *testing.T) {
 		},
 	}
 	_, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/catalogue.git", "", "", t.TempDir(), nil, Npmrc{}, nil)
+		"https://forge.invalid/catalogue.git", "", "", t.TempDir(), nil, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -411,3 +420,99 @@ func TestAnArtifactWithItsOwnContextIsBuiltFromThere(t *testing.T) {
 		t.Errorf("the build was not given a context: %s", build)
 	}
 }
+
+// The forge credential is offered through git's own credential store — a file, never argv — and
+// git decides when it applies. What is checked: the clone names the store, the secret never
+// appears in a command line, and the file holds exactly the URL at 0600.
+func TestABuildOffersTheForgesCredentialThroughGitsOwnStore(t *testing.T) {
+	r, workspace := aRepository(t, withBoth, map[string]string{
+		"Dockerfile": "FROM scratch", "files/theme.conf": "dark",
+	})
+	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/meshboard.git", "", "",
+		workspace, nil, Npmrc{},
+		GitCredential{URL: "http://mesh_novox_builder:sw0rdfi5h@forge.invalid:20000"}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	stored := filepath.Join(workspace, "git-credentials")
+	clone := r.ran[0]
+	if !strings.Contains(clone, "credential.helper=store --file="+stored) {
+		t.Fatalf("the clone does not name the credential store: %s", clone)
+	}
+	for _, line := range r.ran {
+		if strings.Contains(line, "sw0rdfi5h") {
+			t.Fatalf("the secret is in a command line, readable by anything that can list processes: %s", line)
+		}
+	}
+	raw, err := os.ReadFile(stored)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.TrimSpace(string(raw)) != "http://mesh_novox_builder:sw0rdfi5h@forge.invalid:20000" {
+		t.Fatalf("the store does not hold the credential as given: %q", raw)
+	}
+	info, err := os.Stat(stored)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if info.Mode().Perm() != 0o600 {
+		t.Fatalf("the credential file is readable beyond its owner: %v", info.Mode())
+	}
+}
+
+// Without a credential, a clone is exactly the invocation it always was, and no credential file
+// appears — the builder a mesh of public repositories runs is unchanged.
+func TestABuildWithNoCredentialClonesExactlyAsBefore(t *testing.T) {
+	r, workspace := aRepository(t, withBoth, map[string]string{
+		"Dockerfile": "FROM scratch", "files/theme.conf": "dark",
+	})
+	_, err := Build(context.Background(), r.run, r, "https://forge.invalid/meshboard.git", "", "",
+		workspace, nil, Npmrc{}, GitCredential{}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.HasPrefix(r.ran[0], "git clone --quiet ") {
+		t.Fatalf("a credential-less clone grew flags: %s", r.ran[0])
+	}
+	if _, err := os.Stat(filepath.Join(workspace, "git-credentials")); !os.IsNotExist(err) {
+		t.Fatal("a credential file was written with no credential to put in it")
+	}
+}
+
+// An artifact's own context is cloned with the same offer: a private module whose context is a
+// second private repository on the same forge builds, and the secret still never reaches argv.
+func TestAContextCloneCarriesTheSameCredentialStore(t *testing.T) {
+	const withContext = `{"module":"route-proxy","version":"1",
+	  "build":{"artifacts":[
+	    {"name":"server","kind":"image","from":"Dockerfile",
+	     "context":{"repository":"https://forge.invalid/source.git","ref":"main"}}]}}`
+	r := &recorded{
+		contents: map[string]string{
+			ManifestName: withContext,
+			"Dockerfile": "FROM scratch\nCOPY go.mod ./\n",
+		},
+		secondary: map[string]map[string]string{
+			"https://forge.invalid/source.git": {"go.mod": "module route-proxy\n"},
+		},
+	}
+	workspace := t.TempDir()
+	_, err := Build(context.Background(), r.run, r,
+		"https://forge.invalid/catalogue.git", "", "", workspace, nil, Npmrc{},
+		GitCredential{URL: "https://builder:s3cret@forge.invalid"}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	stored := filepath.Join(workspace, "git-credentials")
+	var contextClone string
+	for _, line := range r.ran {
+		if strings.Contains(line, "clone") && strings.Contains(line, "source.git") {
+			contextClone = line
+		}
+	}
+	if contextClone == "" {
+		t.Fatalf("the context was never cloned: %v", r.ran)
+	}
+	if !strings.Contains(contextClone, "credential.helper=store --file="+stored) {
+		t.Fatalf("the context clone does not name the credential store: %s", contextClone)
+	}
+}
diff --git a/internal/builder/bundle_test.go b/internal/builder/bundle_test.go
index 5cf8846..da718fd 100644
--- a/internal/builder/bundle_test.go
+++ b/internal/builder/bundle_test.go
@@ -54,7 +54,7 @@ func TestABundleIsCompiledAndPackedWithNoDockerfile(t *testing.T) {
 	held := map[string]string{"mesh-tools/build": "registry.invalid/mesh-tools/build@sha256:" + strings.Repeat("b", 64)}
 
 	got, err := Build(context.Background(), compiling{r}.run, r,
-		"https://forge.invalid/greeter.git", "", "", workspace, held, Npmrc{}, nil)
+		"https://forge.invalid/greeter.git", "", "", workspace, held, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatalf("a module with a language and no Dockerfile did not build: %v", err)
 	}
@@ -91,7 +91,7 @@ func TestABundleWhoseToolchainIsNotHeldIsRefusedFirst(t *testing.T) {
 	r, workspace := aRepository(t, aBundle, map[string]string{"index.ts": "console.log(1)"})
 
 	_, err := Build(context.Background(), compiling{r}.run, r,
-		"https://forge.invalid/greeter.git", "", "", workspace, nil, Npmrc{}, nil)
+		"https://forge.invalid/greeter.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err == nil {
 		t.Fatal("a bundle was built with no toolchain to compile it in")
 	}
@@ -112,7 +112,7 @@ func TestABundleInAnUnknownLanguageIsRefused(t *testing.T) {
 
 	_, err := Build(context.Background(), compiling{r}.run, r,
 		"https://forge.invalid/greeter.git", "", "", workspace,
-		map[string]string{"mesh-tools/build": "registry.invalid/x@sha256:" + strings.Repeat("c", 64)}, Npmrc{}, nil)
+		map[string]string{"mesh-tools/build": "registry.invalid/x@sha256:" + strings.Repeat("c", 64)}, Npmrc{}, GitCredential{}, nil)
 	if err == nil {
 		t.Fatal("a language nothing can compile was accepted")
 	}
@@ -140,7 +140,7 @@ func TestTwoBundlesInOneModuleArePackedSeparately(t *testing.T) {
 	held := map[string]string{"mesh-tools/build": "registry.invalid/mesh-tools/build@sha256:" + strings.Repeat("b", 64)}
 
 	got, err := Build(context.Background(), compiling{r}.run, r,
-		"https://forge.invalid/greeter.git", "", "", workspace, held, Npmrc{}, nil)
+		"https://forge.invalid/greeter.git", "", "", workspace, held, Npmrc{}, GitCredential{}, nil)
 	if err != nil {
 		t.Fatalf("a module with two bundles did not build: %v", err)
 	}
diff --git a/internal/builder/packages_test.go b/internal/builder/packages_test.go
index 8a8ae8c..a87f19f 100644
--- a/internal/builder/packages_test.go
+++ b/internal/builder/packages_test.go
@@ -71,7 +71,7 @@ func TestAnImageBuildGetsTheCredentialInTheContextAndHostNetwork(t *testing.T) {
 	r, workspace := aRepository(t, withBoth, map[string]string{"Dockerfile": "FROM scratch\nCOPY .npmrc ./", "files/x": "y"})
 	n := Npmrc{Scope: "@novox", Registry: "https://forge.invalid/api/packages/novox/npm/", Token: "t"}
 	if _, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/meshboard.git", "", "", workspace, nil, n, nil); err != nil {
+		"https://forge.invalid/meshboard.git", "", "", workspace, nil, n, GitCredential{}, nil); err != nil {
 		t.Fatalf("the build failed: %v", err)
 	}
 
@@ -101,7 +101,7 @@ func TestAnImageBuildGetsTheCredentialInTheContextAndHostNetwork(t *testing.T) {
 func TestAnImageBuildWithoutACredentialGetsNoHostNetwork(t *testing.T) {
 	r, workspace := aRepository(t, withBoth, map[string]string{"Dockerfile": "FROM scratch", "files/x": "y"})
 	if _, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/meshboard.git", "", "", workspace, nil, Npmrc{}, nil); err != nil {
+		"https://forge.invalid/meshboard.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil); err != nil {
 		t.Fatalf("the build failed: %v", err)
 	}
 	for _, line := range r.ran {
@@ -127,7 +127,7 @@ func TestAPackageIsBuiltOnAPublicBaseAndPublishedByVersion(t *testing.T) {
 	})
 	n := Npmrc{Scope: "@novox", Registry: "https://forge.invalid/api/packages/novox/npm/", Token: "t"}
 	got, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/mesh-sdk.git", "", "", workspace, nil, n, nil)
+		"https://forge.invalid/mesh-sdk.git", "", "", workspace, nil, n, GitCredential{}, nil)
 	if err != nil {
 		t.Fatalf("the package did not build: %v", err)
 	}
@@ -159,7 +159,7 @@ func TestAPackageWithNoRegistryIsRefused(t *testing.T) {
 		"package.json": `{"name":"@novox/mesh-sdk","version":"0.1.0"}`,
 	})
 	_, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/mesh-sdk.git", "", "", workspace, nil, Npmrc{}, nil)
+		"https://forge.invalid/mesh-sdk.git", "", "", workspace, nil, Npmrc{}, GitCredential{}, nil)
 	if err == nil {
 		t.Fatal("a package built with no registry to publish to, silently")
 	}
@@ -206,7 +206,7 @@ func TestAnImageThatDoesNotAskForTheCredentialDoesNotGetIt(t *testing.T) {
 	r, workspace := aRepository(t, withBoth, map[string]string{"Dockerfile": "FROM scratch\nCOPY . .", "files/x": "y"})
 	n := Npmrc{Scope: "@novox", Registry: "https://forge.invalid/api/packages/novox/npm/", Token: "t"}
 	if _, err := Build(context.Background(), r.run, r,
-		"https://forge.invalid/meshboard.git", "", "", workspace, nil, n, nil); err != nil {
+		"https://forge.invalid/meshboard.git", "", "", workspace, nil, n, GitCredential{}, nil); err != nil {
 		t.Fatalf("the build failed: %v", err)
 	}
 	for _, line := range r.ran {