diff --git a/modules/gitea/index.ts b/modules/gitea/index.ts
index fe80595e..012399ad 100644
--- a/modules/gitea/index.ts
+++ b/modules/gitea/index.ts
@@ -20,8 +20,8 @@
 // writes it (check.ts; ADR 0521, R4e finding R2-1). No tool writes mesh/check (finding K1), and no event: the watch hands
 // over the latest value of every key whenever this module starts.
 //
-// Consumes node-build-agent.started — a build machine took an ask — and says, on the head a pending check is of,
-// which machine builds it since when (novox/hq issue 446). This module is the one writer of mesh/merge-gate.
+// This module is the one writer of mesh/merge-gate. It hears no build seat's event: since R4g a check's steps are asks
+// on the build seats' streams, whose backlog the delivery view shows (novox/hq ADR 0525 §9; issue 1887).
 //
 // **A trunk's move puts every open verdict into it out of date** (novox/hq ADR 0323 §4, trunk.ts): each pass reads the
 // head of every trunk an open pull request merges into, and when one moved, the merge check statuses of every open pull
@@ -53,7 +53,7 @@ import { mergeTool } from "./merge.js";
 import { GiteaAdmin, GiteaClient, movedSince } from "./client.js";
 import { CHECK_CONTEXT, CHECK_STATUS, REPO_CHECK_CONTEXT, commentFor, composedGate, groupGateStatus, headsToAnnounce, maintained,
   requiredOf, statusesFor, writesGate, type Announced, type Checked, repoCheckFacts, reposToLook } from "./pulls.js";
-import { GateWriter, clonedAs, type BuildStarted } from "./gate.js";
+import { GateWriter } from "./gate.js";
 import { HOOK_PATH, HOOK_PORT, Pace, claimHead, ensureSystemHook, eventsTool, keptSecret, receiver, type ForgeEvent } from "./webhook.js";
 import { keepSiblings, noteComposed, noteVerdict, readSiblings, siblingsFile, siblingsOf, weighSiblings } from "./siblings.js";
 import { bindInBackground } from "./bind.js";
@@ -504,23 +504,6 @@ registerModuleTools("gitea", () => [eventsTool(pace), ...(gitea ? [commitStatusT
   gates,
 }), mergeTool(gitea, { gates })] : [])]);
 
-// **A build machine took an ask** (the build seat's `started`, novox/hq ADR 0157): said on the head it checks, when
-// the head is an open pull request's this module announced. Any other build — a branch, a merge's — says nothing.
-async function buildStarted(event: { body: unknown }): Promise<void> {
-  const b = (event.body ?? {}) as BuildStarted;
-  const ref = String(b.ref ?? "").toLowerCase();
-  if (!/^[0-9a-f]{40}$/.test(ref)) return;
-  for (const [key, sha] of Object.entries(heads)) {
-    if (sha.toLowerCase() !== ref) continue;
-    const [owner, rest] = key.split("/");
-    const repo = rest?.split("#")[0] ?? "";
-    if (owner && repo && clonedAs(b.repository, owner, repo)) {
-      await gates.started(owner, repo, sha, b);
-      return;
-    }
-  }
-}
-
 /** What the forge's event asks of the announcer at once (issue 729): a new head is announced, and a merge. */
 async function actOn(client: GiteaClient, event: ForgeEvent): Promise<void> {
   const b = event.body as { owner?: string; repo?: string; number?: number };
@@ -628,7 +611,6 @@ if (gitea) {
       }
       return setVerdict(client, event);
     })],
-    ["node-build-agent.started", () => on("node-build-agent.started", buildStarted)],
   ], () => console.log("[gitea] watching for new repositories and merged pull requests"));
   // The checker's mesh/check, from its owed state (check.ts; ADR 0521): a read not granted yet is said once and asked again,
   // apart from the binds above, so neither waits for the other.
diff --git a/modules/gitea/module.json b/modules/gitea/module.json
index 279529fb..26bcdfad 100644
--- a/modules/gitea/module.json
+++ b/modules/gitea/module.json
@@ -86,8 +86,7 @@
     "forge.other"
   ],
   "consumes": [
-    "mesh-controller.checked",
-    "node-build-agent.started"
+    "mesh-controller.checked"
   ],
   "listens": [
     {
diff --git a/modules/mesh-catalog/heard.ts b/modules/mesh-catalog/heard.ts
index 4dab234f..eaa8f882 100644
--- a/modules/mesh-catalog/heard.ts
+++ b/modules/mesh-catalog/heard.ts
@@ -47,12 +47,8 @@ export interface Built {
 
 /** The events a build outcome reaches this module on: the build seat's, as it happens, and the control plane's replay. */
 export const BUILD_EVENTS = [
-  // **The build seat that builds now** (novox/hq ADR 0190). Until issue 712 the catalogue heard only the
-  // retired seat below, so every build after the handover reached the graph only through the replay this
-  // module asks for when it starts: a merge built and pushed stayed out of the catalogue until its next start.
-  "node-build-agent.built",
-  // The retired build role, while a machine still serves it (ADR 0190's handover). Goes with the seat row.
-  "mesh-build-machine.built",
+  // The build seat node-build-agent and the retired mesh-build-machine went with build-agent (novox/hq ADR 0524 §5,
+  // ADR 0525 §10): no build seat says `built` since R4g, so what the mesh holds is asked when this module starts.
   // What the mesh already held, when this module asks what it missed (novox/hq ADR 0134).
   "mesh-controller.built-before",
 ] as const;
diff --git a/modules/mesh-catalog/module.json b/modules/mesh-catalog/module.json
index 8d8c6599..b8f45096 100644
--- a/modules/mesh-catalog/module.json
+++ b/modules/mesh-catalog/module.json
@@ -26,8 +26,6 @@
     "postgres-database": "${dir:state}/database.secret"
   },
   "consumes": [
-    "node-build-agent.built",
-    "mesh-build-machine.built",
     "mesh-controller.built-before"
   ],
   "emits": [
diff --git a/modules/mesh-catalog/test/heard.test.ts b/modules/mesh-catalog/test/heard.test.ts
index e00daa1b..84b91ac4 100644
--- a/modules/mesh-catalog/test/heard.test.ts
+++ b/modules/mesh-catalog/test/heard.test.ts
@@ -20,8 +20,10 @@ const walkBuild = {
   made: [{ name: "code", kind: "bundle", reference: "artifact-store://mailu/code/blobs/sha256:d041" }],
 };
 
-test("the catalogue hears the build seat that builds now, not only the retired one (issue 712)", async () => {
-  assert.ok(BUILD_EVENTS.includes("node-build-agent.built"));
+test("the catalogue hears no retired build seat, and what the mesh held (issue 712, issue 1887 E2)", async () => {
+  for (const retired of ["node-build-agent.built", "mesh-build-machine.built"]) {
+    assert.ok(!(BUILD_EVENTS as readonly string[]).includes(retired), `${retired} is still heard`);
+  }
   assert.ok(BUILD_EVENTS.includes("mesh-controller.built-before"));
   // Subscribing is not enough: the mesh grants and routes only what the manifest consumes.
   const manifest = JSON.parse(await readFile(new URL("../module.json", import.meta.url), "utf8"));
diff --git a/modules/nats/cmd/nats-tools/server_test.go b/modules/nats/cmd/nats-tools/server_test.go
index acff8f8f..8ade21ea 100644
--- a/modules/nats/cmd/nats-tools/server_test.go
+++ b/modules/nats/cmd/nats-tools/server_test.go
@@ -96,9 +96,9 @@ func TestAConsumerWithSeveralFiltersIsHandedEveryMessage(t *testing.T) {
 		FilterSubjects: []string{
 			"mesh.mod.mesh-catalog.event.upgraded",
 			"mesh.mod.mesh-catalog.event.catching-up",
-			"mesh.seat.node-build-agent.event.built",
+			"mesh.seat.node-backup.event.done",
 			"mesh.mod.gitea.event.pull.merged",
-			"mesh.seat.mesh-build-machine.event.built",
+			"mesh.seat.node-power.event.slept",
 			"mesh.mod.*.event.provisioner.failing",
 			"mesh.mod.*.event.provisioner.recovered",
 		},
@@ -128,7 +128,7 @@ func TestAConsumerWithSeveralFiltersIsHandedEveryMessage(t *testing.T) {
 		}
 	}()
 
-	followed := []string{"mesh.mod.gitea.event.pull.merged", "mesh.seat.node-build-agent.event.built",
+	followed := []string{"mesh.mod.gitea.event.pull.merged", "mesh.seat.node-backup.event.done",
 		"mesh.mod.postgres.event.provisioner.recovered", "mesh.mod.mesh-catalog.event.catching-up"}
 	var mu sync.Mutex
 	var sent []uint64
@@ -153,7 +153,7 @@ func TestAConsumerWithSeveralFiltersIsHandedEveryMessage(t *testing.T) {
 						mu.Unlock()
 					}
 				} else {
-					_, _ = pjs.Publish(fmt.Sprintf("mesh.seat.node-build-agent.event.log.build-%d-%d", w, i/50), make([]byte, 200))
+					_, _ = pjs.Publish(fmt.Sprintf("mesh.seat.node-backup.event.log.run-%d-%d", w, i/50), make([]byte, 200))
 				}
 				if rand.Intn(100) == 0 {
 					time.Sleep(time.Duration(rand.Intn(300)) * time.Millisecond)