diff --git a/cmd/mesh-controller/seats_test.go b/cmd/mesh-controller/seats_test.go
index 5273127b..27b201d1 100644
--- a/cmd/mesh-controller/seats_test.go
+++ b/cmd/mesh-controller/seats_test.go
@@ -93,3 +93,27 @@ func TestTheSeatsListingShowsEachSeatsPaths(t *testing.T) {
 		}
 	}
 }
+
+// 1718/AC2: a manifest claiming node-files that serves upload and download passes the controller's module
+// check, judged by the mesh-sdk it vendors; a verb outside the contract is still refused.
+func TestAFilesHolderServingUploadAndDownloadCanHoldTheSeat(t *testing.T) {
+	seat, ok := catalogue.SeatNamed(catalogue.FilesSeat)
+	if !ok {
+		t.Fatal("node-files is not a seat")
+	}
+	serves := []string{"upload", "download"}
+	for _, v := range seat.Serves {
+		if v.Name != "upload" && v.Name != "download" {
+			serves = append(serves, v.Name)
+		}
+	}
+	holder := catalogue.Manifest{Module: "mesh-files", Version: "1", Claims: []catalogue.Claim{{
+		Name: catalogue.FilesSeat, Scope: catalogue.ScopeNode, Serves: serves}}}
+	if err := catalogue.CanHold(holder, seat); err != nil { // 1718/AC2
+		t.Fatalf("a holder serving upload and download is refused: %v", err)
+	}
+	holder.Claims[0].Serves = append(append([]string{}, serves...), "teleport")
+	if err := catalogue.CanHold(holder, seat); err == nil || !strings.Contains(err.Error(), "does not promise") {
+		t.Fatalf("a verb outside the contract must be refused with 'does not promise': %v", err)
+	}
+}
diff --git a/go.mod b/go.mod
index 2c0bb303..dd814bad 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module github.com/novox/mesh-controller
 go 1.26.0
 
 require (
-	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021130958-85b5a2687e6a
+	git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021144048-d4deecdb380b
 	github.com/jackc/pgx/v5 v5.10.0
 	github.com/nats-io/nats-server/v2 v2.11.17
 	github.com/nats-io/nats.go v1.54.0
diff --git a/go.sum b/go.sum
index 6b818e32..e67f5187 100644
--- a/go.sum
+++ b/go.sum
@@ -1,7 +1,7 @@
 git.novox.be/novox/mesh-host v0.0.0-20261018171808-9d9e3a46c4f5 h1:E5stfIeCN6uYgA9TCv+4K8JgaURg3zQppvUgJLaDMP4=
 git.novox.be/novox/mesh-host v0.0.0-20261018171808-9d9e3a46c4f5/go.mod h1:4wyoCr6IIIIarEUuROThWDj7DAvJvIidqMjWcpSnOwE=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021130958-85b5a2687e6a h1:CVTQBD4vxbGQ+TW9MWAut/ABQN6nvAZ1VTqojNpvGUE=
-git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021130958-85b5a2687e6a/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021144048-d4deecdb380b h1:5UlQ8ytlHNgqlm5AbwJEnZwuf1EWUiNyXX2hcOV9Yro=
+git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021144048-d4deecdb380b/go.mod h1:ouERNpZizzwZ0HLEtAypsY9FR20FyUgUYRni6J7kVCY=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op h1:Z/MZK75wC/NSrkgqeNIa7jexam9uWzhLmFTSCPI/kn0=
 github.com/antithesishq/antithesis-sdk-go v0.7.0-default-no-op/go.mod h1:FQyySiasQQM8735Ddel3MRojmy4dA1IqCeyJ5jmPMbI=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
diff --git a/testdata/beside/CAPTURED b/testdata/beside/CAPTURED
index 7d76163f..786b4ff3 100644
--- a/testdata/beside/CAPTURED
+++ b/testdata/beside/CAPTURED
@@ -9,7 +9,7 @@ a second place to clean besides the catalogue itself.
 
 mesh-catalog  e0bc919d4945bb5f13f971f74643a0b714cf45da  modules/*/module.json, modules/nats/Dockerfile
 mesh-host     9d9e3a46c4f5943cfffb413d962ce48b75e2fd39  examples/foundation-first-node.lock
-mesh-sdk      85b5a2687e6a8d0854dd8e53ed68f98e0e9d3c1b  conformance/events/module-event.json
+mesh-sdk      d4deecdb380b69358aae2fdaedcfcc06e1571d42  conformance/events/module-event.json
 
 To move them, from this repository's root, with the two repositories checked out beside it:
 
diff --git a/vendor/git.novox.be/novox/mesh-sdk/go/catalogue/files.go b/vendor/git.novox.be/novox/mesh-sdk/go/catalogue/files.go
index f1356ed1..a1231a34 100644
--- a/vendor/git.novox.be/novox/mesh-sdk/go/catalogue/files.go
+++ b/vendor/git.novox.be/novox/mesh-sdk/go/catalogue/files.go
@@ -74,6 +74,22 @@ func filesVerbs() []Verb {
 			map[string]string{"path": "an absolute path", "owner": "an account's name or number",
 				"group": "a group's name or number (optional)", "recursive": "\"true\": also everything under a directory"},
 			[]string{"path", "owner"}, []string{"group", "recursive"}, "chown", "chgrp"),
+		Verb{Name: "upload", Description: "Send one file of this node into a bucket of the object store, over a short signed link " +
+			"and never over the bus; answers the key (the file's SHA-256 when none is given), the size and the SHA-256. " +
+			"At most 100 MiB. A place a secret is kept, a known credential file, or a link to one is refused by name, " +
+			"before anything is sent. Read " + filesAsAccount + ".",
+			Input: schema(map[string]string{"path": "an absolute path to a file", "bucket": "the bucket the file goes into",
+				"key": "the object's key (optional; the file's SHA-256 when not given)"}, []string{"path", "bucket"})},
+		// download is a plain Verb, not through write(): write() types its optional arguments as true/false
+		// switches, which a hash and a reason are not (issue 1719).
+		Verb{Name: "download", Description: "Write one object of a bucket to a file of this node, over a short signed link and " +
+			"never over the bus; the old file goes to the node's trash. At most 100 MiB. The bytes must hash to sha256, or to " +
+			"the key when the key is a SHA-256; otherwise no file is written. Refuses a path a module owns " +
+			"unless override names a reason; done as the node's operator account, through sudo -n where its rights do not reach.",
+			Input: schema(map[string]string{"bucket": "the bucket", "key": "the object's key", "path": "an absolute path",
+				"sha256":   "the SHA-256 the bytes must have (optional; the key when that is a SHA-256)",
+				"reason":   "why the file is changed, for the audit trail",
+				"override": overrideWord}, []string{"bucket", "key", "path", "reason"})},
 		Verb{Name: "trash", Description: "What the node's trash holds: each deleted or replaced item with its id, " +
 			"original path and when it went.",
 			Input: schema(map[string]string{}, nil), Replaces: []string{"ls ~/.local/share/Trash"}},
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 127b9a13..c0114ffc 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -1,4 +1,4 @@
-# git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021130958-85b5a2687e6a
+# git.novox.be/novox/mesh-sdk/go v0.1.14-0.20261021144048-d4deecdb380b
 ## explicit; go 1.26.0
 git.novox.be/novox/mesh-sdk/go/asks
 git.novox.be/novox/mesh-sdk/go/catalogue