diff --git a/.claude/repo-standard-conformance.sh b/.claude/repo-standard-conformance.sh
index 38b5980..5bbec04 100644
--- a/.claude/repo-standard-conformance.sh
+++ b/.claude/repo-standard-conformance.sh
@@ -98,6 +98,7 @@ jq -r --arg stamp "$stamp" --arg human "$human" '
   "  callers:     \(.totals.caller.present) present · \(.totals.caller.absent) absent · \(.totals.caller.unreadable) unreadable   pinned \(.totals.pinned)",
   "  test lane:   \(.totals.test_lane.present) present · \(.totals.test_lane.absent) absent · \(.totals.test_lane["n/a"]) n/a · \(.totals.test_lane.unmeasured) unmeasured",
   "  runs:        \(.totals.standard_run.green) green · \(.totals.standard_run.red) red · \(.totals.standard_run.other) other · \(.totals.standard_run.none) none · \(.totals.standard_run.unreadable) unreadable",
+  "  gate:        \(.totals.gated // "?") gated · \(.totals.arming_lane // "?") arming lane · \(.totals.gate_ready // "?") dark-factory ready",
   "  findings:    \(.totals.findings) across \(.totals.with_findings) repos    gaps: \(.totals.gaps)"
 ' <<<"$body"
 
diff --git a/scripts/repo-standard-conformance.mjs b/scripts/repo-standard-conformance.mjs
index 30bb333..c029e9a 100644
--- a/scripts/repo-standard-conformance.mjs
+++ b/scripts/repo-standard-conformance.mjs
@@ -236,7 +236,7 @@ export function runtimeExpectation(rootNames, configured) {
  * ({conclusion, url, sha, at} | {unreadable} | null); `fleet` is the per-repo
  * slice of ci.json or null when the feed was unavailable.
  */
-export function classifyRepo({ repo, archived = false, defaultBranch = "main", files, filesError = null, root, rootError = null, run = null, fleet = null, headSha = null, tier = null }) {
+export function classifyRepo({ repo, archived = false, defaultBranch = "main", files, filesError = null, root, rootError = null, run = null, fleet = null, headSha = null, tier = null, rules }) {
   const findings = [];
   const gaps = [];
   const row = { repo: `${ORG}/${repo}`, archived, default_branch: defaultBranch, tier };
@@ -306,6 +306,36 @@ export function classifyRepo({ repo, archived = false, defaultBranch = "main", f
     if (red) findings.push("standard-run-red");
   }
 
+  // The dark-factory arrangement (.github-private#913 step 4): three facts, all
+  // observed here — what the default branch REQUIRES, whether the org's arming
+  // lane is present, and the conjunction that makes a green PR land unattended.
+  // `allow_auto_merge` is deliberately NOT one of them: GitHub returns it only to
+  // an admin-rights caller and this lane mints nothing; it is declared and applied
+  // in infra github-admin/repositories.tf, and this row does not guess at it.
+  // `rules` not passed at all (the unit surface) means not under measurement —
+  // `dark_factory: null`, no finding, no gap. The sweep always passes it.
+  const basenames = files ? files.map((f) => f.path.split("/").pop()) : null;
+  const arming = basenames ? (basenames.includes("auto-merge.yml") ? "auto-merge.yml" : null) : null;
+  const legacy = basenames ? basenames.includes("dependabot-auto-merge.yml") : null;
+  if (rules === undefined) row.dark_factory = null;
+  else if (!rules.read) {
+    row.dark_factory = { required_checks: null, rulesets: null, arming_lane: arming, legacy_arming: legacy, gate_ready: null };
+    gaps.push(`rules-unreadable:${rules.reason}`);
+  } else {
+    const req = rules.contexts;
+    const gated = req.length > 0;
+    const hasTest = req.includes("standard / test");
+    const hasClaim = req.includes("pr-claim / pr-claim");
+    row.dark_factory = { required_checks: req, rulesets: rules.rulesets, arming_lane: arming, legacy_arming: legacy, gate_ready: hasTest && hasClaim && arming === "auto-merge.yml" };
+    // Green gates nothing: a caller whose contexts nothing on the default branch
+    // requires is the fail-open case #913 names — the check runs and decides nothing.
+    if (row.caller.state === "present" && !gated) findings.push("gate-absent");
+    // Green waits for a person: something is required, and nothing arms the merge.
+    // A legacy dependabot-auto-merge.yml does not count — its precondition is false
+    // by construction (.github-private#929). Unreadable workflows are already a gap.
+    if (gated && basenames && arming === null) findings.push("arming-lane-absent");
+  }
+
   row.fleet = fleet;
   row.findings = findings;
   row.gaps = gaps;
@@ -333,8 +363,17 @@ export function summarize(rows) {
     with_findings: 0,
     findings: 0,
     gaps: 0,
+    // the dark factory: any required check at all · the org arming lane present · both plus the standard required
+    gated: 0,
+    arming_lane: 0,
+    gate_ready: 0,
   };
   for (const r of rows) {
+    if (r.dark_factory) {
+      if (r.dark_factory.required_checks?.length) t.gated++;
+      if (r.dark_factory.arming_lane) t.arming_lane++;
+      if (r.dark_factory.gate_ready === true) t.gate_ready++;
+    }
     t.caller[r.caller.state]++;
     if (r.caller.state === "present" && r.caller.pinned) t.pinned++;
     t.test_lane[r.test_lane]++;
@@ -390,6 +429,7 @@ export function renderSummary(snap, limit = 25) {
   lines.push(`| standard run green / red / other / none / unreadable | ${t.standard_run.green} / ${t.standard_run.red} / ${t.standard_run.other} / ${t.standard_run.none} / ${t.standard_run.unreadable} |`);
   lines.push(`| runtime mismatch (reported) | ${t.runtime_mismatch} |`);
   lines.push(`| repo-specific workflows (reported) | ${t.extra_workflows} |`);
+  lines.push(`| gated / arming lane / dark-factory ready | ${t.gated} / ${t.arming_lane} / ${t.gate_ready} |`);
   lines.push(`| repos with findings | ${t.with_findings} (${t.findings} findings) |`);
   lines.push(`| measurement gaps | ${t.gaps} |`);
   lines.push("");
@@ -455,13 +495,34 @@ export function parseYaml(text) {
   return Bun.YAML.parse(text);
 }
 
+/**
+ * The default branch's rules, reduced to what a PR must satisfy to merge: the
+ * `required_status_checks` contexts and the rulesets that require them. Public
+ * on a public repo, so the lane's own token reads it (#913 step 1 read desk's
+ * this way). Anything but a 200 array is `unreadable` with the status — a
+ * failed read is never an empty gate.
+ */
+export function readRules(res) {
+  if (res.status !== 200 || !Array.isArray(res.body)) return { read: false, reason: `${res.status}` };
+  const contexts = new Set();
+  const rulesets = new Set();
+  for (const rule of res.body) {
+    if (rule?.type !== "required_status_checks") continue;
+    if (rule.ruleset_id != null) rulesets.add(rule.ruleset_id);
+    for (const c of rule.parameters?.required_status_checks ?? []) if (typeof c?.context === "string") contexts.add(c.context);
+  }
+  return { read: true, contexts: [...contexts].sort(), rulesets: [...rulesets].sort((a, b) => a - b) };
+}
+
 async function fetchRepo({ fetchImpl, token, name, defaultBranch, parse, log }) {
   const full = `${ORG}/${name}`;
-  const [wfList, rootList, props] = await Promise.all([
+  const [wfList, rootList, props, rulesRes] = await Promise.all([
     api(fetchImpl, token, `/repos/${full}/contents/.github/workflows?ref=${encodeURIComponent(defaultBranch)}`),
     api(fetchImpl, token, `/repos/${full}/contents/?ref=${encodeURIComponent(defaultBranch)}`),
     api(fetchImpl, token, `/repos/${full}/properties/values`),
+    api(fetchImpl, token, `/repos/${full}/rules/branches/${encodeURIComponent(defaultBranch)}`),
   ]);
+  const rules = readRules(rulesRes);
 
   let files = null;
   let filesError = null;
@@ -507,7 +568,7 @@ async function fetchRepo({ fetchImpl, token, name, defaultBranch, parse, log })
   }
 
   log(`  ${full}: caller ${caller.state}${files ? ` (${files.length} workflows)` : ""}`);
-  return { name, files, filesError, root, rootError, run, tier };
+  return { name, files, filesError, root, rootError, run, tier, rules };
 }
 
 export async function fetchFleet(fetchImpl) {
diff --git a/scripts/repo-standard-conformance.test.mjs b/scripts/repo-standard-conformance.test.mjs
index ae9fc23..62dde04 100644
--- a/scripts/repo-standard-conformance.test.mjs
+++ b/scripts/repo-standard-conformance.test.mjs
@@ -33,6 +33,7 @@ import {
   runtimeExpectation,
   summarize,
   sweep,
+  readRules,
 } from "./repo-standard-conformance.mjs";
 
 // ── fixtures: real callers ───────────────────────────────────────────────────
@@ -346,6 +347,101 @@ test("classifyRepo: a workflow that does not parse is recorded on the row, not d
 
 // ── denominator, summary, snapshot ───────────────────────────────────────────
 
+// ── the dark-factory arrangement (.github-private#913 step 4) ────────────────
+
+const RULES_37 = { read: true, contexts: ["pr-claim / pr-claim", "standard / test"], rulesets: [21805316, 22333366] };
+const AUTO_MERGE = `name: auto-merge
+on:
+  pull_request:
+    types: [opened, reopened, ready_for_review, synchronize]
+permissions:
+  contents: read
+jobs:
+  auto-merge:
+    permissions:
+      contents: read
+      id-token: write
+    uses: bounded-systems/.github/.github/workflows/_auto-merge.yml@2cd9ebc0a2543b3ba11dc7673b351a9d1f6c9445
+`;
+const RUST_ROOT = ["Cargo.toml", "lakefile.lean"];
+
+test("readRules: the required contexts and the rulesets that require them; anything but a 200 array is unreadable", () => {
+  const r = readRules({ status: 200, body: [
+    { type: "required_status_checks", ruleset_id: 22333366, parameters: { required_status_checks: [{ context: "standard / test" }] } },
+    { type: "required_status_checks", ruleset_id: 21805316, parameters: { required_status_checks: [{ context: "pr-claim / pr-claim" }] } },
+    { type: "required_signatures", ruleset_id: 1 },
+  ] });
+  assert.deepEqual(r, RULES_37);
+  assert.deepEqual(readRules({ status: 200, body: [] }), { read: true, contexts: [], rulesets: [] });
+  // A failed read is never an empty gate.
+  assert.deepEqual(readRules({ status: 403, body: { message: "no" } }), { read: false, reason: "403" });
+  assert.deepEqual(readRules({ status: 200, body: { not: "an array" } }), { read: false, reason: "200" });
+});
+
+test("classifyRepo: dark factory — the standard and the claim required, and the arming lane present, is gate_ready with no finding", () => {
+  const row = classifyRepo({ repo: "desk", files: [wf(".github/workflows/standard.yml", KEYCARD), wf(".github/workflows/auto-merge.yml", AUTO_MERGE)], root: RUST_ROOT, run: run("success"), rules: RULES_37 });
+  assert.deepEqual(row.dark_factory, { required_checks: ["pr-claim / pr-claim", "standard / test"], rulesets: [21805316, 22333366], arming_lane: "auto-merge.yml", legacy_arming: false, gate_ready: true });
+  assert.deepEqual(row.findings, []);
+  assert.deepEqual(row.gaps, []);
+  // The caller is org-managed, so it is not counted as extra CI.
+  assert.deepEqual(row.extra, []);
+  assert.ok(row.managed.includes("auto-merge.yml"));
+});
+
+test("classifyRepo: dark factory — gated but unarmed is a finding; a caller nothing requires is the fail-open finding; a legacy armer does not count", () => {
+  const unarmed = classifyRepo({ repo: "k", files: [wf(".github/workflows/standard.yml", KEYCARD)], root: RUST_ROOT, run: run("success"), rules: RULES_37 });
+  assert.deepEqual(unarmed.findings, ["arming-lane-absent"]);
+  assert.equal(unarmed.dark_factory.gate_ready, false);
+
+  const ungated = classifyRepo({ repo: "k", files: [wf(".github/workflows/standard.yml", KEYCARD)], root: RUST_ROOT, run: run("success"), rules: { read: true, contexts: [], rulesets: [] } });
+  assert.deepEqual(ungated.findings, ["gate-absent"], "green that gates nothing is the fail-open case");
+  assert.equal(ungated.dark_factory.gate_ready, false);
+
+  // No caller and no rules: caller-absent already says it; gate-absent is about a caller whose green decides nothing.
+  const bare = classifyRepo({ repo: "k", files: [], root: [], rules: { read: true, contexts: [], rulesets: [] } });
+  assert.deepEqual(bare.findings, ["caller-absent"]);
+
+  // Only the legacy lane: still unarmed — its precondition is false by construction (.github-private#929).
+  const legacy = classifyRepo({ repo: "k", files: [wf(".github/workflows/standard.yml", KEYCARD), wf(".github/workflows/dependabot-auto-merge.yml", "name: dependabot-auto-merge\non: pull_request\n")], root: RUST_ROOT, run: run("success"), rules: RULES_37 });
+  assert.deepEqual(legacy.findings, ["arming-lane-absent"]);
+  assert.equal(legacy.dark_factory.legacy_arming, true);
+  assert.equal(legacy.dark_factory.arming_lane, null);
+
+  // Gated by something other than the standard (this repo's own `schema`): gated, unarmed, not gate_ready — the standard is not what is required.
+  const schema = classifyRepo({ repo: "dot", files: [wf(".github/workflows/standard.yml", KEYCARD), wf(".github/workflows/auto-merge.yml", AUTO_MERGE)], root: RUST_ROOT, run: run("success"), rules: { read: true, contexts: ["pr-claim / pr-claim", "schema"], rulesets: [1] } });
+  assert.deepEqual(schema.findings, []);
+  assert.equal(schema.dark_factory.gate_ready, false);
+});
+
+test("classifyRepo: dark factory — unreadable rules are a gap with the status, never a finding; not measured at all is null", () => {
+  const unreadable = classifyRepo({ repo: "k", files: [wf(".github/workflows/standard.yml", KEYCARD)], root: RUST_ROOT, run: run("success"), rules: { read: false, reason: "403" } });
+  assert.deepEqual(unreadable.findings, []);
+  assert.deepEqual(unreadable.gaps, ["rules-unreadable:403"]);
+  assert.equal(unreadable.dark_factory.gate_ready, null);
+  assert.equal(unreadable.dark_factory.required_checks, null);
+  // Workflows unreadable AND rules readable: gated, but whether it is armed is unknown — no arming finding on top of the workflows gap.
+  const dark = classifyRepo({ repo: "k", files: null, filesError: "403", root: null, rootError: "403", rules: RULES_37 });
+  assert.deepEqual(dark.findings, []);
+  assert.equal(dark.dark_factory.arming_lane, null);
+  assert.equal(dark.dark_factory.gate_ready, false);
+  // The unit surface: rules not passed is "not under measurement", stated as null rather than defaulted to ungated.
+  assert.equal(classifyRepo({ repo: "k", files: [], root: [] }).dark_factory, null);
+});
+
+test("summarize + renderSummary: the dark-factory totals count what was measured, and the row prints even at zero", () => {
+  const rows = [
+    classifyRepo({ repo: "ready", files: [wf(".github/workflows/standard.yml", KEYCARD), wf(".github/workflows/auto-merge.yml", AUTO_MERGE)], root: RUST_ROOT, run: run("success"), rules: RULES_37 }),
+    classifyRepo({ repo: "gated", files: [wf(".github/workflows/standard.yml", KEYCARD)], root: RUST_ROOT, run: run("success"), rules: RULES_37 }),
+    classifyRepo({ repo: "unmeasured", files: [wf(".github/workflows/standard.yml", KEYCARD)], root: RUST_ROOT, run: run("success") }),
+  ];
+  const t = summarize(rows);
+  assert.equal(t.gated, 2);
+  assert.equal(t.arming_lane, 1);
+  assert.equal(t.gate_ready, 1);
+  const snap = buildSnapshot({ now: "2026-09-08T12:00:00Z", rows, denominator: { public_repos: 3, enumerated: 3, verified: true, archived: 0, rows: 3 }, fleet: { unavailable: "x" }, standard: { head_sha: null, selftest: { state: "none" } }, strict: false });
+  assert.match(renderSummary(snap), /\| gated \/ arming lane \/ dark-factory ready \| 2 \/ 1 \/ 1 \|/);
+});
+
 test("assertDenominator: exact equality, and a non-integer is a refusal too", () => {
   assert.deepEqual(assertDenominator({ enumerated: 94, publicRepos: 94 }), { ok: true });
   assert.equal(assertDenominator({ enumerated: 93, publicRepos: 94 }).ok, false);
@@ -397,7 +493,7 @@ test("fleetSlice: the repo's red rows and whether the feed lists it unobserved",
 
 // ── the sweep, against a fake GitHub ─────────────────────────────────────────
 
-function fakeGitHub({ publicRepos, repos, workflowsByRepo, rootByRepo, runsByRepo, fleet = null, selftest = "success" }) {
+function fakeGitHub({ publicRepos, repos, workflowsByRepo, rootByRepo, runsByRepo, rulesByRepo = {}, fleet = null, selftest = "success" }) {
   const json = (status, body) => ({ status, headers: new Headers(), json: async () => body, text: async () => JSON.stringify(body) });
   const text = (status, body) => ({ status, headers: new Headers(), json: async () => { throw new Error("not json"); }, text: async () => body });
   return async (url) => {
@@ -424,6 +520,11 @@ function fakeGitHub({ publicRepos, repos, workflowsByRepo, rootByRepo, runsByRep
     }
     if (rest.startsWith("contents/")) return rootByRepo[repo] ? json(200, rootByRepo[repo].map((name) => ({ name, type: "file" }))) : json(403, {});
     if (rest.startsWith("properties/values")) return json(403, {});
+    if (rest.startsWith("rules/branches/")) {
+      const rr = rulesByRepo[repo];
+      if (rr === "forbidden") return json(403, {});
+      return json(200, (rr ?? []).map((context, i) => ({ type: "required_status_checks", ruleset_id: 100 + i, parameters: { required_status_checks: [{ context }] } })));
+    }
     if (rest.startsWith("actions/workflows/")) {
       const r = runsByRepo[repo];
       if (r === "forbidden") return json(403, {});
@@ -452,12 +553,14 @@ test("sweep: the happy path — rows, denominator, standard block, fleet join, a
     publicRepos: 3,
     repos: ["keycard", "repo-health", "night-audit"],
     workflowsByRepo: {
-      keycard: { ".github/workflows/standard.yml": KEYCARD, ".github/workflows/deps.yml": DEPS },
+      keycard: { ".github/workflows/standard.yml": KEYCARD, ".github/workflows/deps.yml": DEPS, ".github/workflows/auto-merge.yml": AUTO_MERGE },
       "repo-health": { ".github/workflows/ci.yml": REPO_HEALTH_CI },
       // night-audit: an empty repo — no workflows dir at all
     },
     rootByRepo: { keycard: ["Cargo.toml", "lakefile.lean"], "repo-health": ["deno.json"], "night-audit": [] },
     runsByRepo: { keycard: "forbidden" },
+    // keycard is gated on the two contexts the dark factory needs; the other two have no rules at all.
+    rulesByRepo: { keycard: ["standard / test", "pr-claim / pr-claim"] },
     fleet: { generated_at: "2026-09-04T14:13:32Z", repos_known: 97, repos_observed: 92, coverage_complete: false, unobserved: ["bounded-systems/night-audit"], red: [{ repo: "bounded-systems/repo-health", workflow: "ci", conclusion: "failure", since: "s", run_url: "r" }] },
   });
   const snap = await sweep({ fetchImpl, token: "t", now: "2026-09-04T15:00:00Z", headSha: "d126d721fa50275e12af0bdeaf1a2ff3016eedfd", log: () => {} });
@@ -476,6 +579,12 @@ test("sweep: the happy path — rows, denominator, standard block, fleet join, a
   assert.equal(by["night-audit"].test_lane, "n/a");
   assert.equal(snap.repos[0].findings.length >= snap.repos[snap.repos.length - 1].findings.length, true);
   assert.equal(snap.totals.rows, 3);
+  // The dark-factory read rode along: keycard is gated, armed and ready; the two without a caller are neither gated nor findings for it.
+  assert.equal(by.keycard.dark_factory.gate_ready, true);
+  assert.deepEqual(by.keycard.dark_factory.required_checks, ["pr-claim / pr-claim", "standard / test"]);
+  assert.deepEqual(by["repo-health"].dark_factory, { required_checks: [], rulesets: [], arming_lane: null, legacy_arming: false, gate_ready: false });
+  assert.deepEqual(snap.totals.gated, 1);
+  assert.deepEqual(snap.totals.gate_ready, 1);
 });
 
 test("sweep: an unavailable fleet feed is recorded, not fatal, and rows carry no join", async () => {