diff --git a/go/buscalls/buscalls.go b/go/buscalls/buscalls.go
index b39dada2..6db4fc6c 100644
--- a/go/buscalls/buscalls.go
+++ b/go/buscalls/buscalls.go
@@ -44,6 +44,8 @@ const (
 	LedgerHistory = "mesh/ledger.history"
 	LedgerWatch   = "mesh/ledger.watch"
 	LedgerQuery   = "mesh/ledger.query"
+	// LedgerFill is one ledger's fill against its cap, answered as a Fill (design 47 G §462).
+	LedgerFill = "mesh/ledger.fill"
 	// The ledger's repairs, which the tool runner also serves as tools of every module owning a ledger, its own
 	// ledgers only (design 25 § 12.5).
 	LedgerRebuild  = "mesh/ledger.rebuild"
@@ -364,7 +366,7 @@ type ReindexRequest struct {
 	Index  string `json:"index"`
 }
 
-// LedgerRequest names a ledger: lag.
+// LedgerRequest names a ledger: lag, fill.
 type LedgerRequest struct {
 	Ledger string `json:"ledger"`
 }
diff --git a/go/packages_list_test.go b/go/packages_list_test.go
index c2823dc7..c4246809 100644
--- a/go/packages_list_test.go
+++ b/go/packages_list_test.go
@@ -301,6 +301,13 @@ func TestMeshSDKHoldsOnlyWhatEveryModuleShares(t *testing.T) {
 	if string(entry) != `{"instance":"listing/a17","sequence":3}` {
 		t.Errorf("an index entry is %s", entry)
 	}
+	// G §462: a ledger's fill is one call, answered as one buscalls.Fill.
+	if buscalls.LedgerFill != "mesh/ledger.fill" {
+		t.Errorf("a ledger's fill call is %q", buscalls.LedgerFill)
+	}
+	if raw, _ := json.Marshal(buscalls.Fill{Count: 3, Bytes: 10, MaxBytes: 100}); string(raw) != `{"count":3,"bytes":10,"max_bytes":100}` {
+		t.Errorf("a fill is %s", raw)
+	}
 	// A tool's answer reads the same whatever wraps it (buscalls.Unwrap, the lead's ruling 2026-11-04 13:12).
 	for _, c := range []struct {
 		name, raw, answer, said string