diff --git a/packages/gittensory-engine/src/index.ts b/packages/gittensory-engine/src/index.ts
index fd53f064b2..8de49cc58b 100644
--- a/packages/gittensory-engine/src/index.ts
+++ b/packages/gittensory-engine/src/index.ts
@@ -236,6 +236,14 @@ export {
   type IterateLoopOutcome,
   type IterateLoopResult,
 } from "./miner/iterate-loop.js";
+export {
+  isSlopBandWithinThreshold,
+  shouldSubmit,
+  SUBMISSION_GATE_PASSING_CONCLUSION,
+  type SubmissionGateCandidate,
+  type SubmissionGateDecision,
+  type SubmissionGateMode,
+} from "./miner/submission-gate.js";
 export {
   codingAgentModeExecutes,
   isGlobalMinerCodingAgentPause,
diff --git a/packages/gittensory-engine/src/miner/submission-gate.ts b/packages/gittensory-engine/src/miner/submission-gate.ts
new file mode 100644
index 0000000000..ac1849a20a
--- /dev/null
+++ b/packages/gittensory-engine/src/miner/submission-gate.ts
@@ -0,0 +1,108 @@
+// Gated-submission trigger (#2336): THE safety-critical chokepoint of Phase 4 -- the actual decision point
+// that decides "call gittensory_open_pr NOW" for an autonomous run. Conservatively requires BOTH a predicted-
+// gate PASS AND a slop score under a configurable threshold before a local-write open_pr action spec is ever
+// built. Any ambiguity (a missing/errored signal) resolves to NOT submitting -- this function never defaults
+// to allow.
+//
+// SEQUENCING: runs BEFORE `buildOpenPrSpec` (src/mcp/local-write-tools.ts) is ever called -- i.e. before the
+// Governor chokepoint (#2340) ever sees an open_pr action spec to evaluate. The two are complementary, not
+// redundant: this gates on CONTENT-QUALITY signals (predicted-gate conclusion, slop risk) specific to the
+// candidate diff; the chokepoint gates on RESOURCE/GOVERNANCE signals (rate-limit, budget, reputation, self-
+// plagiarism, dry-run mode) that apply to every write action class, not just open_pr. "The actual call site
+// invoking buildOpenPrSpec / gittensory_open_pr is gated exclusively through this function" (this issue's own
+// deliverable) is a POLICY this and every future call site must honor -- wiring a real call site is a later,
+// separate issue (mirrors #2333/#2335's own split between loop mechanics and policy).
+//
+// INPUT SHAPE: `predictedGateVerdict`/`slopAssessment` are typed exactly as the fields `SelfReviewVerdict`
+// (self-review-adapter.ts, #2334) already carries, so a caller can pass the SAME verdict the iterate-loop's
+// own self-review (#2333) already computed at handoff time -- this is a defense-in-depth RE-CHECK of that
+// verdict immediately before submission, not a redundant re-computation from scratch.
+//
+// DRY-RUN: mirrors `src/settings/autonomy.ts`'s deny-by-default dial (`AUTONOMY_LEVELS`, `"observe"` as the
+// floor) for safe rollout of THIS function's own thresholds -- distinct from, and evaluated separately from,
+// the Governor chokepoint's own dry-run/live action-mode dial (#2342), which gates autonomous WRITING at all
+// for a repo. `"observe"` here is specifically for safely calibrating the predicted-gate/slop thresholds
+// against live traffic before ever trusting them to gate a real submission.
+
+import type { PredictedGateVerdict } from "../predicted-gate.js";
+import type { SelfReviewSlopAssessment, SelfReviewSlopBand } from "./self-review-adapter.js";
+
+/** The one literal conclusion value that counts as a clear predicted-gate pass -- same literal self-review-
+ *  adapter.ts's `SELF_REVIEW_PASSING_CONCLUSION` uses, kept as an independent constant here so this module has
+ *  no runtime dependency beyond types on self-review-adapter.ts. */
+export const SUBMISSION_GATE_PASSING_CONCLUSION = "success" as const;
+
+const SLOP_BAND_SEVERITY: Readonly<Record<SelfReviewSlopBand, number>> = Object.freeze({
+  clean: 0,
+  low: 1,
+  elevated: 2,
+  high: 3,
+});
+
+/** True when `band` is at or under `threshold`'s severity (inclusive) -- e.g. a `"low"` band is within a
+ *  `"elevated"` threshold, and a band exactly equal to the threshold still passes. */
+export function isSlopBandWithinThreshold(band: SelfReviewSlopBand, threshold: SelfReviewSlopBand): boolean {
+  return SLOP_BAND_SEVERITY[band] <= SLOP_BAND_SEVERITY[threshold];
+}
+
+/** `"observe"` mirrors `AUTONOMY_LEVELS`' deny-by-default floor: {@link shouldSubmit} still computes and
+ *  returns the real signal-based decision (for logging), but structurally forces `allow: false` regardless --
+ *  not left to an external caller to remember to also check the mode before acting on `allow: true`. */
+export type SubmissionGateMode = "observe" | "enforce";
+
+export type SubmissionGateCandidate = {
+  /** `null` means the predictor was unreachable or errored -- fails closed, exactly like a genuine non-passing
+   *  verdict, never treated as "no opinion, so allow". */
+  predictedGateVerdict: PredictedGateVerdict | null;
+  /** `null` means the slop check errored -- fails closed, exactly like a genuine over-threshold assessment. */
+  slopAssessment: SelfReviewSlopAssessment | null;
+  /** The maximum slop band that still permits submission (inclusive of this exact band). */
+  slopThreshold: SelfReviewSlopBand;
+  mode: SubmissionGateMode;
+};
+
+export type SubmissionGateDecision = {
+  allow: boolean;
+  /** Always populated when `allow` is `false` (including in `"observe"` mode, prefixed to distinguish a
+   *  would-have-allowed dry-run from a real block) -- every decision is auditable, not just denials. */
+  reasons: string[];
+};
+
+/** The pure signal check, independent of `mode` -- {@link shouldSubmit} layers the observe/enforce dial on
+ *  top of this. Returns an empty array only when BOTH signals genuinely pass. */
+function evaluateSubmissionSignals(candidate: SubmissionGateCandidate): string[] {
+  const reasons: string[] = [];
+
+  if (candidate.predictedGateVerdict === null) {
+    reasons.push("predicted_gate_unavailable");
+  } else if (candidate.predictedGateVerdict.conclusion !== SUBMISSION_GATE_PASSING_CONCLUSION) {
+    const blockerCodes = candidate.predictedGateVerdict.blockers.map((blocker) => blocker.code).join(",");
+    reasons.push(`predicted_gate_not_passing:${candidate.predictedGateVerdict.conclusion}${blockerCodes ? `:${blockerCodes}` : ""}`);
+  }
+
+  if (candidate.slopAssessment === null) {
+    reasons.push("slop_assessment_unavailable");
+  } else if (!isSlopBandWithinThreshold(candidate.slopAssessment.band, candidate.slopThreshold)) {
+    reasons.push(`slop_band_exceeds_threshold:${candidate.slopAssessment.band}>${candidate.slopThreshold}`);
+  }
+
+  return reasons;
+}
+
+/**
+ * THE gate: build (or invoke) `gittensory_open_pr`'s action spec ONLY when this returns `allow: true`. Requires
+ * BOTH a clean predicted-gate pass AND a slop band at or under the configured threshold; any missing signal, or
+ * `mode: "observe"`, forces `allow: false`. Pure; identical inputs always yield the identical decision.
+ */
+export function shouldSubmit(candidate: SubmissionGateCandidate): SubmissionGateDecision {
+  const reasons = evaluateSubmissionSignals(candidate);
+  const signalsPass = reasons.length === 0;
+
+  if (candidate.mode === "observe") {
+    return {
+      allow: false,
+      reasons: signalsPass ? ["observe_mode_active:would_have_allowed"] : ["observe_mode_active:would_have_blocked", ...reasons],
+    };
+  }
+  return { allow: signalsPass, reasons };
+}
diff --git a/packages/gittensory-engine/test/submission-gate.test.ts b/packages/gittensory-engine/test/submission-gate.test.ts
new file mode 100644
index 0000000000..a070684bc3
--- /dev/null
+++ b/packages/gittensory-engine/test/submission-gate.test.ts
@@ -0,0 +1,150 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+
+import {
+  isSlopBandWithinThreshold,
+  shouldSubmit,
+  SUBMISSION_GATE_PASSING_CONCLUSION,
+  type PredictedGateVerdict,
+  type SelfReviewSlopAssessment,
+  type SelfReviewSlopBand,
+  type SubmissionGateCandidate,
+} from "../dist/index.js";
+
+function passingVerdict(): PredictedGateVerdict {
+  return {
+    predicted: true,
+    basis: "public_config",
+    pack: "oss-anti-slop",
+    conclusion: "success",
+    title: "Predicted gate: pass",
+    summary: "Every check is expected to pass.",
+    readinessScore: 92,
+    confirmedContributor: undefined,
+    blockers: [],
+    warnings: [],
+    funnel: null,
+    note: "",
+  };
+}
+
+function failingVerdict(blockers: PredictedGateVerdict["blockers"] = [{ code: "duplicate_pr_risk", title: "Likely duplicate", detail: "Matches an existing open PR." }]): PredictedGateVerdict {
+  return {
+    predicted: true,
+    basis: "public_config",
+    pack: "oss-anti-slop",
+    conclusion: "failure",
+    title: "Predicted gate: fail",
+    summary: "At least one check is expected to fail.",
+    readinessScore: 15,
+    confirmedContributor: undefined,
+    blockers,
+    warnings: [],
+    funnel: null,
+    note: "",
+  };
+}
+
+function slop(band: SelfReviewSlopBand, slopRisk = 0): SelfReviewSlopAssessment {
+  return { slopRisk, band, findings: [] };
+}
+
+function baseCandidate(overrides: Partial<SubmissionGateCandidate> = {}): SubmissionGateCandidate {
+  return {
+    predictedGateVerdict: passingVerdict(),
+    slopAssessment: slop("clean"),
+    slopThreshold: "low",
+    mode: "enforce",
+    ...overrides,
+  };
+}
+
+test("barrel: the public entrypoint re-exports the submission gate (#2336)", () => {
+  assert.equal(typeof shouldSubmit, "function");
+  assert.equal(typeof isSlopBandWithinThreshold, "function");
+  assert.equal(SUBMISSION_GATE_PASSING_CONCLUSION, "success");
+});
+
+test("pass/pass: a clean predicted-gate pass with slop under threshold allows, with no reasons", () => {
+  const decision = shouldSubmit(baseCandidate());
+  assert.deepEqual(decision, { allow: true, reasons: [] });
+});
+
+test("fail/pass: a non-passing predicted-gate verdict blocks even with slop cleanly under threshold", () => {
+  const decision = shouldSubmit(baseCandidate({ predictedGateVerdict: failingVerdict() }));
+  assert.equal(decision.allow, false);
+  assert.equal(decision.reasons.length, 1);
+  assert.match(decision.reasons[0] ?? "", /^predicted_gate_not_passing:failure:duplicate_pr_risk$/);
+});
+
+test("fail/pass: a non-passing verdict with NO blockers listed still formats a reason, without a dangling separator", () => {
+  const decision = shouldSubmit(baseCandidate({ predictedGateVerdict: failingVerdict([]) }));
+  assert.equal(decision.reasons[0], "predicted_gate_not_passing:failure");
+});
+
+test("pass/fail: a clean predicted-gate pass blocks when slop exceeds the configured threshold", () => {
+  const decision = shouldSubmit(baseCandidate({ slopAssessment: slop("high"), slopThreshold: "low" }));
+  assert.equal(decision.allow, false);
+  assert.deepEqual(decision.reasons, ["slop_band_exceeds_threshold:high>low"]);
+});
+
+test("both-fail: a non-passing verdict AND over-threshold slop blocks with both reasons listed", () => {
+  const decision = shouldSubmit(baseCandidate({ predictedGateVerdict: failingVerdict(), slopAssessment: slop("high"), slopThreshold: "low" }));
+  assert.equal(decision.allow, false);
+  assert.equal(decision.reasons.length, 2);
+  assert.ok(decision.reasons.some((r) => r.startsWith("predicted_gate_not_passing")));
+  assert.ok(decision.reasons.some((r) => r.startsWith("slop_band_exceeds_threshold")));
+});
+
+test("fail-closed: a null predictedGateVerdict (predictor unreachable) blocks, never treated as no-opinion-so-allow", () => {
+  const decision = shouldSubmit(baseCandidate({ predictedGateVerdict: null }));
+  assert.equal(decision.allow, false);
+  assert.deepEqual(decision.reasons, ["predicted_gate_unavailable"]);
+});
+
+test("fail-closed: a null slopAssessment (slop check errored) blocks, never treated as no-opinion-so-allow", () => {
+  const decision = shouldSubmit(baseCandidate({ slopAssessment: null }));
+  assert.equal(decision.allow, false);
+  assert.deepEqual(decision.reasons, ["slop_assessment_unavailable"]);
+});
+
+test("fail-closed: both signals missing blocks with both unavailable reasons listed", () => {
+  const decision = shouldSubmit(baseCandidate({ predictedGateVerdict: null, slopAssessment: null }));
+  assert.equal(decision.allow, false);
+  assert.deepEqual(decision.reasons, ["predicted_gate_unavailable", "slop_assessment_unavailable"]);
+});
+
+test("observe mode: forces allow: false even for signals that would otherwise cleanly pass", () => {
+  const decision = shouldSubmit(baseCandidate({ mode: "observe" }));
+  assert.equal(decision.allow, false);
+  assert.deepEqual(decision.reasons, ["observe_mode_active:would_have_allowed"]);
+});
+
+test("observe mode: a would-have-blocked decision is distinguishable from a would-have-allowed one, with the real reasons preserved", () => {
+  const decision = shouldSubmit(baseCandidate({ mode: "observe", predictedGateVerdict: null }));
+  assert.equal(decision.allow, false);
+  assert.deepEqual(decision.reasons, ["observe_mode_active:would_have_blocked", "predicted_gate_unavailable"]);
+});
+
+test("isSlopBandWithinThreshold: a band exactly equal to the threshold passes (inclusive boundary)", () => {
+  assert.equal(isSlopBandWithinThreshold("elevated", "elevated"), true);
+});
+
+test("isSlopBandWithinThreshold: a band one severity level under the threshold passes", () => {
+  assert.equal(isSlopBandWithinThreshold("low", "elevated"), true);
+});
+
+test("isSlopBandWithinThreshold: a band one severity level over the threshold fails", () => {
+  assert.equal(isSlopBandWithinThreshold("high", "elevated"), false);
+});
+
+test("isSlopBandWithinThreshold: the full clean..high ordering is respected end to end", () => {
+  const order: SelfReviewSlopBand[] = ["clean", "low", "elevated", "high"];
+  for (let i = 0; i < order.length; i += 1) {
+    for (let j = 0; j < order.length; j += 1) {
+      const band = order[i] as SelfReviewSlopBand;
+      const threshold = order[j] as SelfReviewSlopBand;
+      assert.equal(isSlopBandWithinThreshold(band, threshold), i <= j, `${band} within ${threshold}`);
+    }
+  }
+});