diff --git a/infra/build-server/provision.sh b/infra/build-server/provision.sh
index 909a45d7..37458e9e 100755
--- a/infra/build-server/provision.sh
+++ b/infra/build-server/provision.sh
@@ -57,7 +57,7 @@ WORKTREES="${WORKTREES:-}"
 SLOTS_GIVEN="${SLOTS:-}"; SLOTS="${SLOTS:-2}"   # 2 since main's ruling of 6 October 2026 (20:3x UK); remote-run.sh gives 90 jobs alone, 45 beside another
 P2P_PORTS="${P2P_PORTS:-26611 26811 26621}"   # 26621: the Devnet 2 seed on build-1 (blocked by ufw until 7 Oct 2026 16:40 BST; the fleet lane found it closed from outside)
 BOX_HOSTNAME="${BOX_HOSTNAME:-igneum-build-1}"
-case "$BOX_HOSTNAME" in *-2) [ -n "$SLOTS_GIVEN" ] || SLOTS=3 ;; esac   # build-2: three slots (main, 7 Oct 2026; the bounded runs take one 32-core band each)
+case "$BOX_HOSTNAME" in *-2|*-4) [ -n "$SLOTS_GIVEN" ] || SLOTS=3 ;; esac   # build-2 and build-4 (AX162-1, 96 threads): three slots (main, 7 Oct 2026; the bounded runs take one 32-core band each)
 WORKERS_HOST="${WORKERS_HOST:-build.igneum.network}"   # the dashboard feed's HTTPS name (A record in deSEC, 6 Oct 2026)
 SSH_PUBKEY="${SSH_PUBKEY:-}"
 BUILD_USER=build
@@ -75,7 +75,7 @@ RUNNER_LABELS="${RUNNER_LABELS:-igneum-build-1,ci-red}"     # added to the defau
                                                             # holds the red watcher's record file and poster. A second box: BOX_HOSTNAME=igneum-build-2
                                                             # RUNNER_LABELS=igneum-build-1,igneum-build-2 RUNNER_CPUS=0-31 RUNNER_JOBS=32 (register.sh --host)
 RUNNER_CPUS="${RUNNER_CPUS:-}"                              # AllowedCPUs for the runner's service when set (a second box is bounded like a suite: 32 cores, nice 10)
-case "$BOX_HOSTNAME" in *-2|*-3) [ -n "$RUNNER_CPUS" ] || RUNNER_CPUS="0-31" ;; esac   # build-2 and build-3 join the pool (label igneum-build-1) bounded to 32 cores at Nice 10 (main, 7 Oct 2026)
+case "$BOX_HOSTNAME" in *-2|*-3|*-4) [ -n "$RUNNER_CPUS" ] || RUNNER_CPUS="0-31" ;; esac   # build-2, build-3 and build-4 join the pool (label igneum-build-1) bounded to 32 cores at Nice 10 (main, 7 Oct 2026)
 RUNNER_JOBS="${RUNNER_JOBS:-48}"                            # cargo jobs for a CI job: half the box, the agents' builds keep the rest
 RUNNER_TOKEN="${RUNNER_TOKEN:-}"                            # a registration token (1 h), from infra/build-server/runner/register.sh over stdin; never logged
 RUNNER_SCCACHE_PORT="${RUNNER_SCCACHE_PORT:-4227}"          # the runner's own sccache server; 4226 is the build user's