diff --git a/.github/agent-guides/validation.md b/.github/agent-guides/validation.md
index 933194e..e81ddd2 100644
--- a/.github/agent-guides/validation.md
+++ b/.github/agent-guides/validation.md
@@ -27,6 +27,14 @@ required; this fixture never proves live token generation or project association
 
 **Explicit manifests recovery:** Default-off `enable-signed-recovery` requests only the original version alias, with signed promotion and caller pinning required before any legacy write. Verify the original catalogue identity and all original source/version/run claims, restore only authenticated missing versions, treat matching versions as no-ops, refuse contradictory or ambiguous reads, and always preserve `latest`. Keep recovery boundary, interruption/readback controls and native Flux/registry/cryptographic tests in required CI. The native key fixture proves signed claims and registry bytes, not production OIDC. Cross-repository publisher identity migration remains #242; complete recovery rollout remains #425.
 
+The configuration caller guard approves the publisher workflow and both copied helpers by Git
+blob and regular-file mode, while retaining the exact workflow identity, full commit reference,
+publication opt-ins and artifact target. Releases with unchanged approved contents need no test-pin
+edit; changed contents require review before updating the recorded blobs. Missing commits are read
+through a disposable object store. The promotion suite exercises unchanged and changed releases,
+helper changes, modes and input refusals. This source check does not replace the deployed verifier's
+separate approved-revision gate.
+
 **Explicit application recovery:** The same default-off mode verifies both original signatures with all nine paired publication claims before reading both version aliases. Any conflict or unknown read prevents all writes; only missing aliases are restored, with digest readback and matching retries producing no writes. Keep `.github/tests/test-app-recovery.sh` and the native single-platform Buildx/Flux proof required. Never rebuild, re-sign or move `latest` during recovery. Registry writes have no compare-and-set or cross-repository transaction; the shared queue and final readback cannot fence unrelated writers.
 
 **Prebuilt WebApp publication:** Default-off `enable-prebuilt-webapp` requires
diff --git a/.github/scripts/check-manifests-caller.sh b/.github/scripts/check-manifests-caller.sh
new file mode 100644
index 0000000..8ab3c6b
--- /dev/null
+++ b/.github/scripts/check-manifests-caller.sh
@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+# Approve publisher contents, so an unrelated release does not require a pin edit here.
+set -euo pipefail
+fail() { echo "FAIL: configuration caller: $*" >&2; exit 1; }
+[[ "$#" == 1 ]] || fail 'expected one caller workflow'
+caller="$1"
+encoded_ref="$(yq -o=json -I=0 '.jobs["publish-manifests"].uses // ""' "$caller")" ||
+  fail 'cannot read publisher reference'
+ref_pattern='^"devantler-tech/\.github/\.github/workflows/publish-manifests\.yaml@([0-9a-f]{40})"$'
+[[ "$encoded_ref" =~ $ref_pattern ]] || fail 'expected a full immutable publisher reference'
+revision="${BASH_REMATCH[1]}"
+[[ "$revision" != 0000000000000000000000000000000000000000 ]] ||
+  fail 'expected a full immutable publisher reference'
+yq -e '
+  (.jobs["publish-manifests"].with["enable-caller-pin"] == true) and
+  (.jobs["publish-manifests"].with["enable-signed-promotion"] == true) and
+  (.jobs["publish-manifests"].with["oci-name"] == "devantler-tech/github-config")
+  ' "$caller" >/dev/null || fail 'expected verified-promotion inputs'
+
+# The workflow pins every external action and copies exactly these two source helpers.
+# All three files are unchanged between the previously approved v10.0.3 and v12.0.1.
+# A new release carrying these contents passes; a workflow/helper change requires review
+# and an explicit blob update. File modes are part of the approval too.
+reviewed_workflow_blob='ce9a9897b154486218478734a02c61e5ac3ea479'
+reviewed_absence_blob='3566e4067e953a1d9cb34e6a50a0f9b72a5d8bc8'
+reviewed_recovery_blob='48dc38f60ddebf90b0976758df9f1983bbb86bfd'
+source_remote='https://github.com/devantler-tech/.github.git'
+object_store=()
+read_object() { git --no-replace-objects ${object_store[@]+"${object_store[@]}"} "$@"; }
+if ! read_object cat-file -e "$revision" 2>/dev/null; then
+  scratch="$(mktemp -d)"
+  trap 'rm -rf "$scratch"' EXIT
+  git init --quiet --bare "$scratch/source.git"
+  object_store=(--git-dir "$scratch/source.git")
+  bounded=()
+  if command -v timeout >/dev/null 2>&1; then bounded=(timeout 2m); fi
+  ${bounded[@]+"${bounded[@]}"} git --no-replace-objects "${object_store[@]}" \
+    -c http.lowSpeedLimit=1000 -c http.lowSpeedTime=60 \
+    fetch --quiet --no-tags --depth=1 --filter=blob:none "$source_remote" "$revision" 2>/dev/null ||
+    fail 'publisher reference stays unverified: cannot read source commit'
+fi
+[[ "$(read_object cat-file -t "$revision" 2>/dev/null)" == commit ]] ||
+  fail 'publisher reference stays unverified: not a commit'
+while IFS=' ' read -r expected path; do
+  actual="$(read_object ls-tree "$revision" -- "$path")" ||
+    fail "publisher reference stays unverified: cannot read $path"
+  [[ "$actual" == "100644 blob $expected"$'\t'"$path" ]] ||
+    fail "unreviewed publisher content at $revision: $path; review its contents and mode before updating the approved blob"
+done <<EOF
+$reviewed_workflow_blob .github/workflows/publish-manifests.yaml
+$reviewed_absence_blob .github/scripts/require-unpublished-version.sh
+$reviewed_recovery_blob .github/scripts/recover-manifests-version.sh
+EOF
+echo 'ok configuration caller pins the reviewed publisher and helper contents with verified promotion'
diff --git a/.github/tests/fixtures/manifests-caller-contract.sh b/.github/tests/fixtures/manifests-caller-contract.sh
new file mode 100644
index 0000000..918793a
--- /dev/null
+++ b/.github/tests/fixtures/manifests-caller-contract.sh
@@ -0,0 +1,113 @@
+#!/usr/bin/env bash
+# Exercise the real caller guard with independent local Git histories.
+set -euo pipefail
+root="$(cd "$(dirname "$0")/../../.." && pwd)"
+guard="$root/.github/scripts/check-manifests-caller.sh"
+work="$(mktemp -d)"
+trap 'rm -rf "$work"' EXIT
+fail() { echo "FAIL: manifests caller fixture: $*" >&2; exit 1; }
+fixture_git() {
+  git -C "$work/source" -c user.name=fixture -c user.email=fixture@example.invalid \
+    -c commit.gpgsign=false -c gc.auto=0 -c maintenance.auto=false "$@"
+}
+git init --quiet "$work/source"
+mkdir -p "$work/source/.github/workflows" "$work/source/.github/scripts"
+workflow='.github/workflows/publish-manifests.yaml'
+absence='.github/scripts/require-unpublished-version.sh'
+recovery='.github/scripts/recover-manifests-version.sh'
+for path in "$workflow" "$absence" "$recovery"; do
+  printf 'independently reviewed fixture: %s\n' "$path" >"$work/source/$path"
+  fixture_git add -- "$path"
+done
+fixture_git commit --quiet -m reviewed
+reviewed="$(fixture_git rev-parse HEAD)"
+workflow_blob="$(fixture_git rev-parse "HEAD:$workflow")"
+absence_blob="$(fixture_git rev-parse "HEAD:$absence")"
+recovery_blob="$(fixture_git rev-parse "HEAD:$recovery")"
+printf 'unrelated release\n' >"$work/source/RELEASE"
+fixture_git add -- RELEASE
+fixture_git commit --quiet -m release
+release="$(fixture_git rev-parse HEAD)"
+for path in "$workflow" "$absence" "$recovery"; do
+  printf 'unreviewed change\n' >>"$work/source/$path"
+  fixture_git add -- "$path"
+  fixture_git commit --quiet -m changed
+  case "$path" in
+    "$workflow") changed_workflow="$(fixture_git rev-parse HEAD)" ;;
+    "$absence") changed_absence="$(fixture_git rev-parse HEAD)" ;;
+    "$recovery") changed_recovery="$(fixture_git rev-parse HEAD)" ;;
+  esac
+  fixture_git checkout --quiet "$release" -- "$path"
+  fixture_git commit --quiet -m restore
+done
+fixture_git update-index --chmod=+x "$workflow"
+fixture_git commit --quiet -m mode
+changed_mode="$(fixture_git rev-parse HEAD)"
+fixture_git config uploadpack.allowFilter true
+fixture_git config uploadpack.allowAnySHA1InWant true
+make_guard() {
+  sed -e "s|^reviewed_workflow_blob='.*'$|reviewed_workflow_blob='$workflow_blob'|" \
+    -e "s|^reviewed_absence_blob='.*'$|reviewed_absence_blob='$absence_blob'|" \
+    -e "s|^reviewed_recovery_blob='.*'$|reviewed_recovery_blob='$recovery_blob'|" \
+    -e "s|^source_remote='.*'$|source_remote='$1'|" "$guard" >"$2"
+}
+make_guard "$work/unavailable" "$work/offline.sh"
+make_guard "file://$work/source" "$work/fetching.sh"
+yq -o=json '.' "$root/.github/workflows/cd.yaml" >"$work/baseline.json"
+prefix='devantler-tech/.github/.github/workflows/publish-manifests.yaml'
+mutate() {
+  jq --arg prefix "$prefix" --arg reviewed "$reviewed" --arg release "$release" \
+    --arg workflow "$changed_workflow" --arg absence "$changed_absence" \
+    --arg recovery "$changed_recovery" --arg mode "$changed_mode" \
+    '.jobs["publish-manifests"].uses = ($prefix + "@" + $reviewed) | '"$1" \
+    "$work/baseline.json" >"$work/caller.json"
+}
+run_guard() { (cd "$2"; bash "$1" "$work/caller.json"); }
+for revision in reviewed release; do
+  mutate ".jobs[\"publish-manifests\"].uses = (\$prefix + \"@\" + \$$revision)"
+  run_guard "$work/offline.sh" "$work/source" >"$work/result" 2>&1 || {
+    cat "$work/result" >&2
+    fail "rejected $revision content"
+  }
+done
+git init --quiet "$work/consumer"
+# shellcheck disable=SC2016 # jq variables, not shell expansion.
+mutate '.jobs["publish-manifests"].uses = ($prefix + "@" + $release)'
+run_guard "$work/fetching.sh" "$work/consumer" >"$work/result" 2>&1 || {
+  cat "$work/result" >&2
+  fail 'rejected fetched unchanged release'
+}
+[[ ! -e "$work/consumer/.git/shallow" && ! -s "$work/consumer/.git/FETCH_HEAD" &&
+   -z "$(git -C "$work/consumer" remote)" ]] || fail 'fetch changed consumer Git state'
+while IFS=$'\t' read -r label mutation diagnostic; do
+  mutate "$mutation"
+  if run_guard "$work/offline.sh" "$work/source" >"$work/result" 2>&1; then
+    fail "accepted $label"
+  fi
+  grep -qF -- "$diagnostic" "$work/result" || {
+    cat "$work/result" >&2
+    fail "$label failed for the wrong reason"
+  }
+done <<'CASES'
+mutable ref	.jobs["publish-manifests"].uses=$prefix+"@main"	full immutable publisher reference
+short ref	.jobs["publish-manifests"].uses=$prefix+"@"+$reviewed[0:12]	full immutable publisher reference
+zero ref	.jobs["publish-manifests"].uses=$prefix+"@0000000000000000000000000000000000000000"	full immutable publisher reference
+trailing newline	.jobs["publish-manifests"].uses=$prefix+"@"+$reviewed+"\n"	full immutable publisher reference
+lookalike owner	.jobs["publish-manifests"].uses="outside/.github/.github/workflows/publish-manifests.yaml@"+$reviewed	full immutable publisher reference
+lookalike path	.jobs["publish-manifests"].uses="devantler-tech/.github/.github/workflows/publish-manifestsXyaml@"+$reviewed	full immutable publisher reference
+missing pin verification	del(.jobs["publish-manifests"].with["enable-caller-pin"])	verified-promotion inputs
+disabled promotion	.jobs["publish-manifests"].with["enable-signed-promotion"]=false	verified-promotion inputs
+wrong artifact	.jobs["publish-manifests"].with["oci-name"]="devantler-tech/other"	verified-promotion inputs
+changed workflow	.jobs["publish-manifests"].uses=$prefix+"@"+$workflow	unreviewed publisher content
+changed absence helper	.jobs["publish-manifests"].uses=$prefix+"@"+$absence	unreviewed publisher content
+changed recovery helper	.jobs["publish-manifests"].uses=$prefix+"@"+$recovery	unreviewed publisher content
+changed file mode	.jobs["publish-manifests"].uses=$prefix+"@"+$mode	unreviewed publisher content
+unreadable revision	.jobs["publish-manifests"].uses=$prefix+"@0123456789abcdef0123456789abcdef01234567"	reference stays unverified
+CASES
+# shellcheck disable=SC2016 # jq variables, not shell expansion.
+mutate '.jobs["publish-manifests"].uses=$prefix+"@"+$absence'
+if run_guard "$work/fetching.sh" "$work/consumer" >"$work/result" 2>&1; then
+  fail 'accepted fetched changed helper'
+fi
+grep -qF 'unreviewed publisher content' "$work/result" || fail 'fetched content refusal had the wrong cause'
+echo 'ok caller accepts unchanged releases and refuses unreviewed workflow/helper bytes, modes and unsafe inputs'
diff --git a/.github/tests/test-publish-manifests-promotion.sh b/.github/tests/test-publish-manifests-promotion.sh
index eb8bf05..45d7ce3 100644
--- a/.github/tests/test-publish-manifests-promotion.sh
+++ b/.github/tests/test-publish-manifests-promotion.sh
@@ -4,18 +4,13 @@
 set -euo pipefail
 # The live configuration caller must opt in only through a SHA-pinned publisher.
 validate_caller() {
-  yq -e '
-  (.jobs["publish-manifests"].uses ==
-    "devantler-tech/.github/.github/workflows/publish-manifests.yaml@0f390329b590404c02565b27a263ee841fa02bce") and
-  (.jobs["publish-manifests"].with["enable-caller-pin"] == true) and
-  (.jobs["publish-manifests"].with["enable-signed-promotion"] == true) and
-  (.jobs["publish-manifests"].with["oci-name"] == "devantler-tech/github-config")
-  ' "$1" >/dev/null
+  bash .github/scripts/check-manifests-caller.sh "$1"
 }
 validate_caller .github/workflows/cd.yaml || {
   echo 'FAIL: configuration publication requires a SHA-pinned, verified-promotion caller' >&2
   exit 1
 }
+bash .github/tests/fixtures/manifests-caller-contract.sh
 scratch="$(mktemp -d)"
 trap 'rm -rf "$scratch"' EXIT
 mkdir -p "$scratch/bin"
diff --git a/.github/workflows/cd.yaml b/.github/workflows/cd.yaml
index cfb54fb..6dd0a36 100644
--- a/.github/workflows/cd.yaml
+++ b/.github/workflows/cd.yaml
@@ -38,7 +38,7 @@ jobs:
     # ecosystem, no cooldown for devantler-tech/*).
     # Keep the ref a 40-hex commit: it is part of the cosign subject the platform
     # verifies, so its shape is load-bearing here.
-    uses: devantler-tech/.github/.github/workflows/publish-manifests.yaml@0f390329b590404c02565b27a263ee841fa02bce # v10.0.3
+    uses: devantler-tech/.github/.github/workflows/publish-manifests.yaml@6f1dee9557a939cc24ca2c562ea775d05e01564d # v12.0.1
     with:
       oci-name: devantler-tech/github-config
       # Without this, a ref the platform verifier does not accept fails nothing