diff --git a/.github/workflows/squabble-action.yml b/.github/workflows/squabble-action.yml
index 5393d82..00c27f6 100644
--- a/.github/workflows/squabble-action.yml
+++ b/.github/workflows/squabble-action.yml
@@ -67,6 +67,9 @@ jobs:
           GH_TOKEN: ${{ github.token }}
         run: bash tests/squabble_action_test.sh
 
+      - name: Estate gate census (read-only hermetic fixtures)
+        run: bash tests/estate_gate_census_test.sh
+
       - name: Install, as the action's install step does
         id: install
         env:
diff --git a/docs/ESTATE-GATE-CENSUS.adoc b/docs/ESTATE-GATE-CENSUS.adoc
new file mode 100644
index 0000000..5f429f9
--- /dev/null
+++ b/docs/ESTATE-GATE-CENSUS.adoc
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: CC-BY-SA-4.0
+= Read-only estate gate census
+
+The gate census inventories named Squabbler workflow files and probes the
+corresponding GitHub Actions run and readable repository rulesets. It is
+standalone: it does not call Hypatia and does not mutate GitHub repositories.
+
+== Running
+
+[source,shell]
+----
+bash scripts/estate-gate-census.sh --repo example/project
+bash scripts/estate-gate-census.sh --owner example --output /tmp/squabble-census.jsonl
+bash tests/estate_gate_census_test.sh
+----
+
+The owner form uses paginated `gh repo list --limit 10000`, excluding
+archived repositories and forks. Provide a `gh` identity with read access
+to the repositories, workflow runs and rulesets, plus `jq`.
+
+== Reading results
+
+Each output line is JSON. `filename_absent` means no workflow *filename*
+matches Squabble; it **does not** establish that no embedded integration
+exists in an unrelated workflow file. `named_workflow_found` establishes
+only that a candidate workflow exists. `role=action_selftest` distinguishes
+Squabble installer/consumer tests from `role=gate_candidate`; neither
+role alone establishes enforcement. `run.status` is the latest
+default-branch run status; `startup_failure` with `zero_jobs` is explicitly
+not green. A successful run is not evidence that its job is required.
+
+`policy.rulesets` distinguishes `required_by_ruleset`,
+`not_matched_in_readable_first_page` and `unknown`. Required-check comparison uses
+the **actual emitted job name**, not the guessed name of a workflow file.
+`policy.bypass` contains the effective-looking bypass actors from the
+matching repository ruleset. Classic branch protection is not inspected
+and is always marked `not_inspected`; an apparent absence from readable
+rulesets must not be promoted into an assertion of absent enforcement.
+GitHub access errors always produce an unknown state rather than a pass.
+
+== Known limits
+
+This is a bounded inventory instrument, not an authorisation to amend
+branch protections, grant workflow access, merge pull requests or enable
+autonomous repairs. It checks named workflow files rather than searching
+every workflow body, uses the first page of each Actions job/ruleset query,
+and inspects default-branch runs rather than all pull-request events. A
+full first page of rulesets or a missing emitted job name is not a
+verified absence of required checks.
+For an estate-wide enforcement decision, follow up with full pagination,
+classic-branch-protection reads using Administration:read, PR-event
+producibility checks, check-source identity and a separate human-reviewed
+ruleset diff. No filename or status count substitutes for those checks.
+
+The command exits nonzero if it cannot enumerate a requested owner;
+per-repository access failure is retained as an `unknown` row to allow
+the inventory to proceed and show gaps explicitly.
diff --git a/scripts/estate-gate-census.sh b/scripts/estate-gate-census.sh
new file mode 100644
index 0000000..7bda001
--- /dev/null
+++ b/scripts/estate-gate-census.sh
@@ -0,0 +1,102 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: MPL-2.0
+# Read-only squabbler deployment census. Unknown is NEVER a clean verdict.
+set -euo pipefail
+command -v gh >/dev/null && command -v jq >/dev/null || exit 2
+tmp="$(mktemp)"
+trap 'rm -f "$tmp"' EXIT
+out=""
+while (($#)); do
+  case "$1" in
+    --owner)
+      gh repo list "$2" --limit 10000 --json nameWithOwner,isArchived,isFork \
+        | jq -r '.[] | select(.isArchived != true and .isFork != true) | .nameWithOwner' >> "$tmp" || exit 3
+      shift 2 ;;
+    --repo) printf '%s\n' "$2" >> "$tmp"; shift 2 ;;
+    --output) out="$2"; shift 2 ;;
+    -h|--help) echo "Usage: $0 [--owner OWNER]... [--repo OWNER/REPO]... [--output JSONL]"; exit 0 ;;
+    *) echo "Bad argument: $1" >&2; exit 2 ;;
+  esac
+done
+# api <endpoint> — print the gh API response when jq -e accepts it.
+# Returns 1 on request or validation failure, including a final false or null
+# value; callers convert these failures to unknown evidence. Write errors propagate.
+api() {
+  local data
+  data="$(gh api "$1" 2>/dev/null)" || return 1
+  jq -e . >/dev/null 2>&1 <<< "$data" || return 1
+  printf '%s\n' "$data"
+}
+if [[ -n "$out" ]]; then mkdir -p "$(dirname "$out")"; : > "$out"; fi
+# emit <row> — write a newline-terminated row to stdout or append it to $out
+# when non-empty. Write errors propagate.
+emit() {
+  if [[ -n "$out" ]]; then printf '%s\n' "$1" >> "$out"
+  else printf '%s\n' "$1"; fi
+}
+sort -u "$tmp" | while IFS= read -r repo; do
+  [[ -n "$repo" ]] || continue
+  [[ "$repo" =~ ^[A-Za-z0-9_.-]+/[A-Za-z0-9_.-]+$ ]] || exit 2
+  meta="$(api "repos/$repo")" || {
+    emit "$(jq -nc --arg r "$repo" '{repo:$r,state:"unknown",reason:"metadata_unreadable"}')"; continue
+  }
+  branch="$(jq -r '.default_branch // empty' <<<"$meta")"
+  if [[ -z "$branch" ]]; then
+    emit "$(jq -nc --arg r "$repo" '{repo:$r,state:"unknown",reason:"default_branch_missing"}')"; continue
+  fi
+  ref="$(jq -rn --arg x "$branch" '$x|@uri')"
+  workflows="$(api "repos/$repo/contents/.github/workflows?ref=$ref")" || {
+    emit "$(jq -nc --arg r "$repo" '{repo:$r,state:"unknown",reason:"workflow_listing_unavailable"}')"; continue
+  }
+  if ! jq -e 'type == "array"' <<<"$workflows" >/dev/null; then
+    emit "$(jq -nc --arg r "$repo" '{repo:$r,state:"unknown",reason:"bad_listing"}')"; continue
+  fi
+  names="$(jq -r '.[] | select(.type=="file" and (.name|test("squabbl.*[.]ya?ml$";"i"))) | .name' <<<"$workflows")"
+  if [[ -z "$names" ]]; then
+    emit "$(jq -nc --arg r "$repo" '{repo:$r,state:"filename_absent",note:"embedded_callers_not_examined"}')"; continue
+  fi
+  rules="$(api "repos/$repo/rulesets?includes_parents=true")" || rules=""
+  while IFS= read -r name; do
+    [[ -n "$name" ]] || continue
+    role=gate_candidate
+    if [[ "$name" == *squabble-action* ]]; then role=action_selftest; fi
+    rid=""; status=unknown; job=""; job_status=unknown
+    runs="$(api "repos/$repo/actions/workflows/$name/runs?branch=$ref&per_page=10")" || runs=""
+    if [[ -n "$runs" ]] && jq -e '.workflow_runs|type=="array"' <<<"$runs" >/dev/null; then
+      rid="$(jq -r '.workflow_runs[0].id // empty' <<<"$runs")"
+      status="$(jq -r '.workflow_runs[0].conclusion // .workflow_runs[0].status // "no_run"' <<<"$runs")"
+      if [[ -n "$rid" ]]; then
+        jobs="$(api "repos/$repo/actions/runs/$rid/jobs?per_page=100")" || jobs=""
+        if [[ -n "$jobs" ]] && jq -e '.jobs|type=="array"' <<<"$jobs" >/dev/null; then
+          job="$(jq -r '[.jobs[]|select((.name//"")|test("squabbl";"i"))|.name]|first//empty' <<<"$jobs")"
+          if [[ -n "$job" ]]; then
+            job_status="$(jq -r --arg j "$job" '[.jobs[]|select(.name==$j)|.conclusion//.status]|first//"unknown"' <<<"$jobs")"
+          elif [[ "$status" == "startup_failure" ]]; then job_status=zero_jobs; fi
+        fi
+      fi
+    fi
+    required=unknown; bypass=unknown
+    if [[ -n "$job" && -n "$rules" ]] && jq -e 'type=="array"' <<<"$rules" >/dev/null; then
+      # A single page is not a complete negative. Keep incomplete data explicit.
+      required=not_matched_in_readable_first_page; bypass='[]'
+      if [[ "$(jq -r 'length' <<<"$rules")" -ge 30 ]]; then
+        required=unknown; bypass=unknown
+      fi
+      ids="$(jq -r '.[]|select(.enforcement=="active")|.id' <<<"$rules")"
+      while IFS= read -r id; do
+        [[ -n "$id" ]] || continue
+        detail="$(api "repos/$repo/rulesets/$id")" || { required=unknown; bypass=unknown; break; }
+        if [[ -n "$job" ]] && jq -e --arg j "$job" \
+          '[.rules[]?|select(.type=="required_status_checks")|.parameters.required_status_checks[]?|.context]|index($j)!=null' \
+          <<<"$detail" >/dev/null; then
+          required=required_by_ruleset
+          bypass="$(jq -c '[.bypass_actors[]?|{actor_type,actor_id,bypass_mode}]' <<<"$detail")"
+        fi
+      done <<<"$ids"
+    fi
+    emit "$(jq -nc --arg r "$repo" --arg wf "$name" --arg id "$rid" \
+      --arg state "$status" --arg job "$job" --arg js "$job_status" \
+      --arg req "$required" --arg by "$bypass" --arg role "$role" \
+      '{repo:$r,state:"named_workflow_found",role:$role,workflow:$wf,run:{id:$id,status:$state,job:$job,job_conclusion:$js},policy:{rulesets:$req,bypass:$by,classic_protection:"not_inspected"}}')"
+  done <<<"$names"
+done
diff --git a/tests/estate_gate_census_test.sh b/tests/estate_gate_census_test.sh
new file mode 100644
index 0000000..60cbc87
--- /dev/null
+++ b/tests/estate_gate_census_test.sh
@@ -0,0 +1,59 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: MPL-2.0
+set -euo pipefail
+root="$(cd "$(dirname "$0")/.." && pwd)"
+tmp="$(mktemp -d)"
+trap 'rm -rf "$tmp"' EXIT
+mkdir -p "$tmp/bin"
+cat > "$tmp/bin/gh" <<'MOCK'
+#!/usr/bin/env bash
+set -euo pipefail
+[[ "$1" == api ]] || exit 2
+case "$2" in
+  repos/example/pass|repos/example/startup|repos/example/absent|repos/example/selftest)
+    printf '%s\n' '{"default_branch":"main","archived":false}';;
+  'repos/example/pass/contents/.github/workflows?ref=main')
+    printf '%s\n' '[{"name":"cicd-squabbler.yml","type":"file"}]';;
+  'repos/example/startup/contents/.github/workflows?ref=main')
+    printf '%s\n' '[{"name":"squabble.yml","type":"file"}]';;
+  'repos/example/selftest/contents/.github/workflows?ref=main')
+    printf '%s\n' '[{"name":"squabble-action.yml","type":"file"}]';;
+  'repos/example/absent/contents/.github/workflows?ref=main')
+    printf '%s\n' '[{"name":"ci.yml","type":"file"}]';;
+  'repos/example/pass/actions/workflows/cicd-squabbler.yml/runs?branch=main&per_page=10')
+    printf '%s\n' '{"workflow_runs":[{"id":7,"conclusion":"success"}]}';;
+  'repos/example/startup/actions/workflows/squabble.yml/runs?branch=main&per_page=10')
+    printf '%s\n' '{"workflow_runs":[{"id":8,"conclusion":"startup_failure"}]}';;
+  'repos/example/pass/actions/runs/7/jobs?per_page=100')
+    printf '%s\n' '{"jobs":[{"name":"Squabble chains (hard gate)","conclusion":"success"}]}';;
+  'repos/example/selftest/actions/workflows/squabble-action.yml/runs?branch=main&per_page=10')
+    printf '%s\n' '{"workflow_runs":[{"id":9,"conclusion":"success"}]}';;
+  'repos/example/selftest/actions/runs/9/jobs?per_page=100')
+    printf '%s\n' '{"jobs":[{"name":"squabble action test","conclusion":"success"}]}';;
+  'repos/example/selftest/rulesets?includes_parents=true')
+    printf '%s\n' '[]';;
+  'repos/example/startup/actions/runs/8/jobs?per_page=100')
+    printf '%s\n' '{"jobs":[]}';;
+  'repos/example/pass/rulesets?includes_parents=true')
+    printf '%s\n' '[{"id":3,"enforcement":"active"}]';;
+  'repos/example/startup/rulesets?includes_parents=true')
+    printf '%s\n' '[]';;
+  repos/example/pass/rulesets/3)
+    printf '%s\n' '{"rules":[{"type":"required_status_checks","parameters":{"required_status_checks":[{"context":"Squabble chains (hard gate)"}]}}],"bypass_actors":[{"actor_type":"RepositoryRole","actor_id":5,"bypass_mode":"always"}]}';;
+  *) echo "unexpected mocked API call: $2" >&2; exit 1;;
+esac
+MOCK
+chmod +x "$tmp/bin/gh"
+bash -n "$root/scripts/estate-gate-census.sh"
+PATH="$tmp/bin:$PATH" bash "$root/scripts/estate-gate-census.sh" \
+  --repo example/pass --repo example/startup --repo example/absent --repo example/selftest --output "$tmp/rows.jsonl"
+[[ "$(wc -l < "$tmp/rows.jsonl")" -eq 4 ]]
+jq -e -s '
+  (map(select(.repo=="example/pass"))[0] | .run.job_conclusion=="success" and
+   .policy.rulesets=="required_by_ruleset" and (.policy.bypass | contains("always"))) and
+  (map(select(.repo=="example/startup"))[0] | .run.status=="startup_failure" and
+   .run.job_conclusion=="zero_jobs") and
+  (map(select(.repo=="example/absent"))[0] | .state=="filename_absent") and
+  (map(select(.repo=="example/selftest"))[0] | .role=="action_selftest")
+' "$tmp/rows.jsonl" >/dev/null
+echo "estate gate census: hermetic cases passed"