diff --git a/.claude/plans/infrahouse-keyring-convergence.md b/.claude/plans/infrahouse-keyring-convergence.md
index a46e5a7..5779071 100644
--- a/.claude/plans/infrahouse-keyring-convergence.md
+++ b/.claude/plans/infrahouse-keyring-convergence.md
@@ -88,15 +88,19 @@ Test node: `jumphost-sincere-crawdad.rmdbkn.ci-cd.infrahouse.com`
 > note. `gpg --show-keys` "lists every key in the bundle" check deferred until then.
 
 **1b. Cut a release** (once the live test looks good)
-- [ ] Merge to `main` → CD publishes the `.deb` to the APT repo (dev picks it up on next Puppet run)
+- [x] Merge to `main` → CD publishes the `.deb` to the APT repo (dev picks it up on next Puppet run)
+  — PR [#278](https://github.com/infrahouse/puppet-code/pull/278) **merged**.
 
-**1c. Zero-bootstrap check via instance-refresh**
-- [ ] `instance-refresh` the dev jumphost ASG so a brand-new instance provisions from scratch
-- [ ] On the fresh instance confirm cloud-init first-boot + Puppet convergence agree; keyring valid,
-  `apt-get update` clean — i.e. Puppet bootstraps an instance from zero, not just an existing one
+**1c. Zero-bootstrap check via instance-refresh** — done 2026-07-04 on fresh instance `ip-10-1-100-168`.
+- [x] Brand-new instance provisioned from scratch off the released `.deb`
+- [x] cloud-init first-boot + Puppet convergence agree: script deployed, `Exec[…::converge]` no-op
+  (keyring already == bundle), source list byte-identical (no rewrite), no spurious apt refresh
+- [x] `keyring == published bundle` (`curl … | cmp` → converged), `apt-get update` clean
+  (`Hit … noble InRelease`, no `EXPKEYSIG`) — Puppet bootstraps an instance from zero
 
 ### Phase 2: Sandbox
-- [ ] Promote: copy the change into `environments/sandbox/modules/profile`
+- [x] Promote: copy the change into `environments/sandbox/modules/profile` (byte-identical to dev:
+  `infrahouse_repo.pp` + `files/converge-infrahouse-keyring.sh` + `base.pp` include). PR pending.
 - [ ] Cut a release (merge → CD)
 - [ ] Watch sandbox nodes across roles: keyring converges, `apt-get update` clean, no drift
 
diff --git a/debian/changelog b/debian/changelog
index 2c8f995..8e1980a 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+puppet-code (0.1.0-1build312) noble; urgency=medium
+
+  * commit event. see changes history in git log
+
+ -- root <packager@infrahouse.com>  Sat, 04 Jul 2026 00:47:05 +0000
+
 puppet-code (0.1.0-1build311) noble; urgency=medium
 
   * commit event. see changes history in git log
diff --git a/environments/sandbox/modules/profile/files/converge-infrahouse-keyring.sh b/environments/sandbox/modules/profile/files/converge-infrahouse-keyring.sh
new file mode 100644
index 0000000..d16d476
--- /dev/null
+++ b/environments/sandbox/modules/profile/files/converge-infrahouse-keyring.sh
@@ -0,0 +1,72 @@
+#!/bin/bash
+#
+# Managed by Puppet (profile::infrahouse_repo). Do not edit locally.
+#
+# Converge /etc/apt/keyrings/infrahouse.gpg from the published InfraHouse
+# signing-key bundle so that long-lived instances pick up rotated GPG keys
+# without being reprovisioned. Trust is anchored on the TLS channel to
+# release-<codename>.infrahouse.com (no fingerprint pinning), consistent with
+# cloud-init. The (possibly concatenated multi-key) armored bundle is fetched
+# each run and dearmored into the keyring.
+#
+# Usage:
+#   converge-infrahouse-keyring.sh check <codename>
+#       exit 0 if the installed keyring already matches the published bundle,
+#       exit 1 otherwise (including when the bundle cannot be fetched, so the
+#       caller re-runs 'apply' and surfaces the underlying error).
+#   converge-infrahouse-keyring.sh apply <codename>
+#       fetch + dearmor + install the keyring atomically. A fetch/dearmor
+#       failure leaves the existing keyring intact. Refreshing apt is left to
+#       the Puppet-managed 'apt-get update' that this exec notifies.
+#
+set -euo pipefail
+
+export PATH=/usr/sbin:/usr/bin:/sbin:/bin
+
+KEYRING=/etc/apt/keyrings/infrahouse.gpg
+
+usage() {
+  echo "usage: $0 {check|apply} <codename>" >&2
+  exit 2
+}
+
+[ "$#" -eq 2 ] || usage
+action=$1
+codename=$2
+url="https://release-${codename}.infrahouse.com/DEB-GPG-KEY-release-${codename}.infrahouse.com"
+
+# Fetch the armored bundle over TLS and dearmor it into $1. Returns non-zero
+# without touching $KEYRING on any failure (fetch, dearmor, or empty result).
+fetch_dearmored() {
+  local out=$1 armored
+  armored=$(mktemp)
+  # shellcheck disable=SC2064
+  trap "rm -f '${armored}'" RETURN
+  curl --fail --silent --show-error --location \
+    --retry 3 --retry-delay 2 --max-time 30 \
+    --output "${armored}" "${url}"
+  gpg --dearmor <"${armored}" >"${out}"
+  # Refuse to install an empty/garbage keyring.
+  test -s "${out}"
+}
+
+candidate=$(mktemp)
+trap 'rm -f "${candidate}"' EXIT
+
+case "${action}" in
+  check)
+    fetch_dearmored "${candidate}" || exit 1
+    # 0 = already converged, 1 = differs or keyring missing.
+    cmp -s "${candidate}" "${KEYRING}"
+    ;;
+  apply)
+    fetch_dearmored "${candidate}"
+    if cmp -s "${candidate}" "${KEYRING}"; then
+      exit 0
+    fi
+    install -D -o root -g root -m 0644 "${candidate}" "${KEYRING}"
+    ;;
+  *)
+    usage
+    ;;
+esac
\ No newline at end of file
diff --git a/environments/sandbox/modules/profile/manifests/base.pp b/environments/sandbox/modules/profile/manifests/base.pp
index 5790001..1f84f07 100644
--- a/environments/sandbox/modules/profile/manifests/base.pp
+++ b/environments/sandbox/modules/profile/manifests/base.pp
@@ -5,6 +5,7 @@
 
   include 'profile::ntp'
   include 'profile::repos'
+  include 'profile::infrahouse_repo'
   include 'profile::packages'
   include 'profile::infrahouse_toolkit'
   include 'profile::puppet_apply'
diff --git a/environments/sandbox/modules/profile/manifests/infrahouse_repo.pp b/environments/sandbox/modules/profile/manifests/infrahouse_repo.pp
new file mode 100644
index 0000000..ee65810
--- /dev/null
+++ b/environments/sandbox/modules/profile/manifests/infrahouse_repo.pp
@@ -0,0 +1,67 @@
+# @summary: Converges the InfraHouse APT repository (source list + signing key).
+#
+# cloud-init seeds both `/etc/apt/sources.list.d/50-infrahouse.list` and
+# `/etc/apt/keyrings/infrahouse.gpg` at **first boot only** — it must, because the
+# InfraHouse toolkit (ih-secrets) has to be installable before Puppet ever runs.
+# This class **converges** both on every Puppet run so long-lived instances pick
+# up a rotated signing key (the urgent case: the key expires) or a changed repo
+# line without being reprovisioned.
+#
+# Ownership is intentionally shared: cloud-init writes the seed, Puppet keeps it
+# in sync. The rendered source line is kept byte-identical to cloud-init's seed so
+# the two never fight. Trust is anchored on the TLS channel to
+# release-<codename>.infrahouse.com (no fingerprint pinning), consistent with
+# cloud-init. On a fetch failure the previously installed keyring is left intact.
+#
+# @param codename APT codename whose repo/bundle to converge; derived from the
+#   node's OS facts by default.
+class profile::infrahouse_repo (
+  String[1] $codename = $facts['os']['distro']['codename'],
+) {
+  $script      = '/usr/local/sbin/converge-infrahouse-keyring.sh'
+  $keyring     = '/etc/apt/keyrings/infrahouse.gpg'
+  $source_list = '/etc/apt/sources.list.d/50-infrahouse.list'
+
+  stdlib::ensure_packages(['curl', 'gnupg', 'ca-certificates'])
+
+  file { $script:
+    ensure => file,
+    owner  => 'root',
+    group  => 'root',
+    mode   => '0755',
+    source => 'puppet:///modules/profile/converge-infrahouse-keyring.sh',
+  }
+
+  # Converge the keyring: 'check' short-circuits when already in sync, so steady
+  # state is a no-op and the shared 'apt-get update' only fires on a key change.
+  exec { 'profile::infrahouse_repo::converge':
+    command => "${script} apply ${codename}",
+    unless  => "${script} check ${codename}",
+    path    => ['/usr/bin', '/usr/sbin', '/bin', '/sbin'],
+    require => [
+      File[$script],
+      Package['curl'],
+      Package['gnupg'],
+    ],
+    notify  => Exec['profile::infrahouse_repo::apt_update'],
+  }
+
+  # Converge the repo line. Kept byte-identical to cloud-init's first-boot seed;
+  # $codename fills both the host (release-<codename>) and the suite.
+  file { $source_list:
+    ensure  => file,
+    owner   => 'root',
+    group   => 'root',
+    mode    => '0644',
+    content => "deb [signed-by=${keyring}] https://release-${codename}.infrahouse.com/ ${codename} main\n",
+    require => Exec['profile::infrahouse_repo::converge'],
+    notify  => Exec['profile::infrahouse_repo::apt_update'],
+  }
+
+  # Single refresh point for both the keyring and the source list.
+  exec { 'profile::infrahouse_repo::apt_update':
+    command     => 'apt-get update',
+    path        => ['/usr/bin', '/usr/sbin', '/bin', '/sbin'],
+    refreshonly => true,
+  }
+}
\ No newline at end of file