diff --git a/node-tools/internal/console/firstviews.go b/node-tools/internal/console/firstviews.go
index 4a36fe1..16f44e6 100644
--- a/node-tools/internal/console/firstviews.go
+++ b/node-tools/internal/console/firstviews.go
@@ -6,6 +6,7 @@ import (
 	"log"
 	"strings"
 
+	"git.novox.be/novox/mesh-sdk/go/process"
 	"git.novox.be/novox/mesh-sdk/go/views"
 )
 
@@ -20,6 +21,10 @@ type FirstViewer interface {
 // state and since when.
 type entryLister interface{ Entries() any }
 
+// ownBuilder is a FirstViewer that also says the build the tool runner itself was started with (design 47 G §205, §424):
+// mesh_first_views names it, or says `own build unknown` and why.
+type ownBuilder interface{ OwnBuild() process.Build }
+
 // firstViewsAnswer is mesh_first_views and mesh_first_view_again.
 func (s *Surface) firstViewsAnswer(ctx context.Context, name string, args map[string]any) map[string]any {
 	fv, ok := s.src.(FirstViewer)
@@ -29,6 +34,9 @@ func (s *Surface) firstViewsAnswer(ctx context.Context, name string, args map[st
 	}
 	if name == verbFirstViews {
 		out := map[string]any{"first views": fv.Status()}
+		if ob, ok := fv.(ownBuilder); ok {
+			out["own build"] = ob.OwnBuild().String()
+		}
 		if el, ok := fv.(entryLister); ok {
 			out["entries"] = el.Entries()
 		}
diff --git a/node-tools/internal/console/firstviews_test.go b/node-tools/internal/console/firstviews_test.go
index abd7af9..5192c3a 100644
--- a/node-tools/internal/console/firstviews_test.go
+++ b/node-tools/internal/console/firstviews_test.go
@@ -7,6 +7,7 @@ import (
 	"strings"
 	"testing"
 
+	"git.novox.be/novox/mesh-sdk/go/process"
 	"git.novox.be/novox/mesh-sdk/go/views"
 )
 
@@ -14,12 +15,16 @@ import (
 type viewer struct {
 	busSource
 	asked []string
+	build process.Build
 }
 
 func (v *viewer) Status() []views.Status {
 	return []views.Status{{Owner: "mesh-delivery-assigner", Tool: "assignments", State: "assignments", Revision: 4, Asks: 1}}
 }
 
+// OwnBuild is the build the viewer was started with.
+func (v *viewer) OwnBuild() process.Build { return v.build }
+
 // Entries are the entries by fingerprint the viewer keeps (design 47 G A-103).
 func (v *viewer) Entries() any { return []string{"fp:a asked"} }
 
@@ -41,6 +46,13 @@ func TestTheConsoleShowsAndAsksAgainTheRunnersFirstViews(t *testing.T) {
 	if got := text(s.discover(context.Background(), "mesh_first_views", nil)); !strings.Contains(got, "mesh-delivery-assigner") || !strings.Contains(got, "assignments") || !strings.Contains(got, "fp:a asked") {
 		t.Errorf("mesh_first_views shows %s", got)
 	}
+	// The tool runner's own build is named, or said unknown with the reason (design 47 G §205, §424).
+	for build, want := range map[string]string{"abcd1234": "abcd1234", "": "own build unknown"} {
+		v.build = process.ReadOwnBuild(func(string) string { return build })
+		if got := text(s.discover(context.Background(), "mesh_first_views", nil)); !strings.Contains(got, `own build`) || !strings.Contains(got, want) {
+			t.Errorf("mesh_first_views with the build %q shows %s", build, got)
+		}
+	}
 	got := s.discover(context.Background(), "mesh_first_view_again", map[string]any{"why": "doubted"})
 	if len(v.asked) != 1 || v.asked[0] != "doubted" || !strings.Contains(text(got), "asked again") {
 		t.Errorf("mesh_first_view_again asked %v and answered %s", v.asked, text(got))
diff --git a/node-tools/internal/firstview/firstview.go b/node-tools/internal/firstview/firstview.go
index 706c5d7..21f4a2f 100644
--- a/node-tools/internal/firstview/firstview.go
+++ b/node-tools/internal/firstview/firstview.go
@@ -27,6 +27,7 @@ import (
 
 	stdio "git.novox.be/novox/mesh-sdk/go"
 	"git.novox.be/novox/mesh-sdk/go/keys"
+	"git.novox.be/novox/mesh-sdk/go/process"
 	"git.novox.be/novox/mesh-sdk/go/views"
 
 	"github.com/novox/mesh-tools/node-tools/internal/bus"
@@ -86,6 +87,9 @@ type Deps struct {
 	Findings FindingWriter
 	// StartFindings starts that writer, and its stop ends it; nil starts none.
 	StartFindings func(ctx context.Context) (stop func(), err error)
+	// Build is the build this process was started with (process.OwnBuild, read once at the start): its fingerprint, or
+	// why it is unknown (design 47 G §205, §424).
+	Build process.Build
 	// Node is the machine the runner is on, named in its findings' subject.
 	Node string
 	// Bound and Wait are the follower's (zero: two minutes, five seconds).
@@ -108,7 +112,7 @@ func Start(parent context.Context, conn *bus.Conn, logf func(string, ...any)) (*
 // state adapter, JetStream and node are this connection's, in this one place (design 47 G A-16, A-27).
 func DepsOf(conn *bus.Conn, logf func(string, ...any)) Deps {
 	me := conn.Module()
-	d := Deps{Module: me, Node: conn.Node(),
+	d := Deps{Module: me, Node: conn.Node(), Build: process.OwnBuild(),
 		Ask: func(address string, body any) (json.RawMessage, error) {
 			got, err := conn.Ask(address, body, "")
 			return got.Result, err
@@ -287,6 +291,10 @@ func (v *Views) Status() []views.Status {
 	return out
 }
 
+// OwnBuild is the build the tool runner was started with: the fingerprint of the want its node-engine applied, or why it is
+// unknown (`own build unknown: started without MESH_FINGERPRINT`).
+func (v *Views) OwnBuild() process.Build { return v.deps.Build }
+
 // Entries are the entries by fingerprint the catalog half's follower keeps, with their state and since when (design 47 G A-103).
 func (v *Views) Entries() any {
 	if v.branches == nil {