diff --git a/merge-check.sh b/merge-check.sh
index 22a189c..c6e04de 100644
--- a/merge-check.sh
+++ b/merge-check.sh
@@ -1,28 +1,33 @@
 #!/bin/sh
 # mesh-check-toolchain: typescript
+# mesh-check-also: go replays/merge-check.sh
 #
 # The lab's own check (novox/hq ADR 0237 as amended): the second layer of a pull request's merge check,
-# `mesh/repo-check`, run by the build seat in the mesh's TypeScript toolchain — and by hand.
+# `mesh/repo-check`, run by the build seat — and by hand.
 #
 # The mesh builds no module from the lab, so no gate runs for its pull requests (`mesh/merge-gate` says the
-# change touches no module of the graph); this is all that is checked before a change to it merges:
+# change touches no module of the graph); this is all that is checked before a change to it merges. The lab
+# is in two languages, and each part runs in its own toolchain's container (novox/hq issue 302):
 #
-#   1. installed from the lock file, and type-checked, sources and tests;
-#   2. the unit suite.
+#   - this script, in the TypeScript toolchain: installed from the lock file, type-checked, sources and
+#     tests, and the unit suite;
+#   - replays/merge-check.sh, in the Go toolchain, declared on the line above: the replays register and its
+#     prover formatted, vetted and compiled, and the register's own tests.
 #
 # **Said, never passed silently**: the integration suite raises a lab on a workstation, and the replays
-# (replays/, Go) raise containers through the container runtime — neither is given to code nobody has
-# approved, and this toolchain holds no Go compiler. The replays run from the lab's main, reviewed, in every
-# gate of a core change; a change to them is proven by `go run ./replays/cmd/prove` by hand before it merges.
+# raise containers through the container runtime — neither is given to code nobody has approved. The
+# replays run from the lab's main, reviewed, in every gate of a core change; a change to them is proven by
+# `go run ./replays/cmd/prove` by hand before it merges.
 set -eu
 
 npm ci --no-audit --no-fund --loglevel=error
 npm run typecheck
 npm test
 
+# By hand, with Go at hand, the Go part runs here too; on the build seat it runs in the Go toolchain.
 if command -v go >/dev/null 2>&1; then
-	(cd replays && test -z "$(gofmt -l .)" && go vet ./...)
+	sh replays/merge-check.sh
 else
-	echo "NOT CHECKED HERE: replays/ (Go) — the TypeScript toolchain holds no Go compiler"
+	echo "replays/ (Go) is checked by replays/merge-check.sh, which the build seat runs in the Go toolchain"
 fi
 echo "NOT RUN HERE: the integration suite and the replays — they need a lab and the container runtime"
diff --git a/replays/merge-check.sh b/replays/merge-check.sh
new file mode 100644
index 0000000..fe63253
--- /dev/null
+++ b/replays/merge-check.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+# mesh-check-toolchain: go
+#
+# The Go part of the lab's own check (novox/hq issue 302): the replays register and its prover, run by the
+# build seat in the mesh's Go toolchain, its own container, because the lab's merge-check.sh declares it
+# (`# mesh-check-also: go replays/merge-check.sh`) — and by hand, from anywhere:
+# `sh replays/merge-check.sh`.
+#
+#   1. formatted and vetted — the register, the replays and the prover compile, tests included;
+#   2. the tests that need nothing but Go and git: every replay registered whole (TestEveryReplayIsWhole),
+#      and the bed's reading of what a change touches.
+#
+# **Said, never passed silently**: the replays themselves raise containers and a bus of the release the mesh
+# runs; this container holds no container runtime, so they are not run here. They run from the lab's main,
+# reviewed, in the gate of every core change, and a change to one is proven by `go run ./cmd/prove` before
+# it merges.
+set -eu
+cd "$(dirname "$0")"
+
+unformatted=$(gofmt -l .)
+if [ -n "$unformatted" ]; then
+	echo "not gofmt'd:"
+	echo "$unformatted"
+	exit 1
+fi
+go vet ./...
+go test -count=1 -run '^(TestEveryReplayIsWhole|TestTheBedProvesWhatTheChangeTouches)$' .
+echo "NOT RUN HERE: the replays themselves — they raise containers, and this container holds no container runtime"
diff --git a/replays/register.go b/replays/register.go
index 32a6c41..e868ebb 100644
--- a/replays/register.go
+++ b/replays/register.go
@@ -114,6 +114,24 @@ var Register = []Replay{
 		Asserts: "a merge adding a module asks the build seat for it, at the branch merged into, and opens no plan",
 		Package: "./cmd/mesh-controller", Test: "TestReplay300", Files: []string{"cmd/mesh-controller/replays_test.go"},
 		Home: "mesh-controller", HomeRef: "7597294ff86383c171b8bec3920b5472fbce00e9"},
+	// The push a recorded build waits for, counted as a repair (2026-10-07): a test in the controller, in
+	// the fix's own commit, recording two such pushes as the seat's push records them.
+	{ID: "R301", Issue: 301, Kind: InRepository, Repository: "mesh-controller", Fix: "e92a3fe",
+		What: "the operator's pushes of new builds whose upgrade policy is record — the resolver, the network " +
+			"managers, the packet filter — were counted as repairs, and S15 wanted a healer for each cause",
+		Asserts: "a push that moves only recorded builds, recorded as the push records it, wants no healer " +
+			"however often its cause is given",
+		Package: "./cmd/mesh-controller", Test: "TestReplay301", Files: []string{"cmd/mesh-controller/replays_test.go"}},
+	// The lab's Go replays never compiled before a lab merge (2026-10-07): the build agent ran a repository's
+	// check in one toolchain. Before the fix there was no part to run, so the commit before is held to fail
+	// by not having it.
+	{ID: "R302", Issue: 302, Kind: Gate, Repository: "mesh-controller", Fix: "98ef7ba",
+		What: "mesh-lab's replays register merged with NOT CHECKED HERE: its check ran in the TypeScript " +
+			"toolchain, which holds no Go compiler",
+		Asserts: "a repository in two languages has each declared part of its own check run in that part's " +
+			"toolchain, and the layer passes only when every part does",
+		Package: "./internal/builder", Test: "TestARepositoryInTwoLanguagesIsCheckedInBoth",
+		Files: []string{"internal/builder/check_test.go"}},
 	// Not a core incident, and the first of its kind: a module's. The crash loop was found by a person
 	// reading the agent server's log for another reason (issue 268); research 032 measured it, and ADR
 	// 0240 makes the node-engine judge it and the gate fail it.