diff --git a/PROJECT_STATE.md b/PROJECT_STATE.md
index 71c54c04..ff04c353 100644
--- a/PROJECT_STATE.md
+++ b/PROJECT_STATE.md
@@ -1054,8 +1054,8 @@ whole-branch review + fix wave).
   ≤200 chars); new read-only `tht cte info <name> --session <id> --json` (index/total from
   `cte_plan.json`, same source as `next_cte`); `tht cte plan --doc -` writes
   `cte_plan_doc.json` (chain documentation; `cte_plan.json` stays a load-bearing `list[str]`).
-- **Gate (JS):** `gate/artifact-contracts.js` (soft validators → self-corrective `textResult`,
-  TypeBox untouched) + `gate/enrich.js` (pure, catalog lookups injected);
+- **Gate (JS):** `gate/core/artifact-contracts.js` (soft validators → self-corrective
+  `textResult`, TypeBox untouched) + `gate/core/enrich.js` (pure, catalog lookups injected);
   `prepareReviewerArguments` now coerces `artifact.data` too (GLM stringified-param
   mitigation); `SKILL.md` Phase 5/6 + disciplines rewritten (plan via `reviewer_confirm
   kind:"cte_plan"` with payload A; `cte_result` gates send THIN data only — never SQL/preview
diff --git a/docs/general/pi-configuration.md b/docs/general/pi-configuration.md
index 86a6d912..5cf8fe25 100644
--- a/docs/general/pi-configuration.md
+++ b/docs/general/pi-configuration.md
@@ -128,8 +128,10 @@ harness/.pi/
 ├── extensions/
 │   ├── aritmolab-provider.js    ← provider LLM solo-progetto
 │   ├── tht-gate.js               ← gate human-in-the-loop
-│   ├── reserved-labels.mjs       ← utility condivisa (NON auto-caricata; .mjs ignorato)
-│   └── gate/                     ← modulo usato da tht-gate.js
+│   └── gate/
+│       ├── core/                 ← enforcement e utility condivise del gate
+│       ├── disambiguation/       ← policy F1/F3
+│       └── memory/               ← policy F2/F8
 ├── settings.json                 ← (opzionale) override delle impostazioni utente
 └── themes/
     └── thothii-mono.json         ← tema del progetto
diff --git a/harness/.pi/extensions/gate/__tests__/artifact_contracts.test.js b/harness/.pi/extensions/gate/__tests__/artifact_contracts.test.js
index 6b604f5b..42431010 100644
--- a/harness/.pi/extensions/gate/__tests__/artifact_contracts.test.js
+++ b/harness/.pi/extensions/gate/__tests__/artifact_contracts.test.js
@@ -7,7 +7,7 @@ const {
   validateCtePlanV2,
   validateCteResultThin,
   validatePhaseSummaryV2,
-} = require("../artifact-contracts.js");
+} = require("../core/artifact-contracts.js");
 
 // --- validateCtePlanV2 (payload A) ------------------------------------------------
 
diff --git a/harness/.pi/extensions/gate/__tests__/builders.test.js b/harness/.pi/extensions/gate/__tests__/builders.test.js
index 25a6c0e9..64e7e32b 100644
--- a/harness/.pi/extensions/gate/__tests__/builders.test.js
+++ b/harness/.pi/extensions/gate/__tests__/builders.test.js
@@ -18,7 +18,7 @@ const {
   buildSchemaLinkingRequest,
   buildJoinReviewRequest,
   withChildLinkage,
-} = require("../builders.js");
+} = require("../core/builders.js");
 
 const GOLDEN = path.join(__dirname, "golden");
 const golden = (name) => JSON.parse(fs.readFileSync(path.join(GOLDEN, name)));
diff --git a/harness/.pi/extensions/gate/__tests__/enrich.test.js b/harness/.pi/extensions/gate/__tests__/enrich.test.js
index 5002b76a..8a743a6d 100644
--- a/harness/.pi/extensions/gate/__tests__/enrich.test.js
+++ b/harness/.pi/extensions/gate/__tests__/enrich.test.js
@@ -6,7 +6,7 @@ const {
   enrichCtePlanV2,
   buildCteResultV2,
   enrichPhaseSummaryV2,
-} = require("../enrich.js");
+} = require("../core/enrich.js");
 
 // --- enrichCtePlanV2 --------------------------------------------------------------
 
@@ -202,7 +202,7 @@ test("enrichPhaseSummaryV2 preserves open_questions/checks untouched", () => {
 
 // --- appendLedgerSection -----------------------------------------------------------
 
-const { appendLedgerSection } = require("../enrich.js");
+const { appendLedgerSection } = require("../core/enrich.js");
 
 test("appendLedgerSection appends only the phase's substantive decisions", () => {
   const data = { schema_version: 2, summary: "s", sections: [{ title: "Criteri", items: [] }] };
diff --git a/harness/.pi/extensions/gate/__tests__/gate_memory_promote.test.js b/harness/.pi/extensions/gate/__tests__/gate_memory_promote.test.js
index 100114d4..9b00f878 100644
--- a/harness/.pi/extensions/gate/__tests__/gate_memory_promote.test.js
+++ b/harness/.pi/extensions/gate/__tests__/gate_memory_promote.test.js
@@ -1,6 +1,8 @@
 const test = require("node:test");
 const assert = require("node:assert");
 const { createMemoryGate } = require("../memory/index.js");
+const { buildMultiselectRequest } = require("../core/builders.js");
+const { isReserved } = require("../core/reserved-labels.mjs");
 const { createFakePi } = require("./fake_pi_runtime.js");
 
 
@@ -74,6 +76,10 @@ test("the public Memory facade owns F8 policy and mutation ordering", async () =
         return null;
       },
     },
+    reviewer: {
+      buildMultiselect: buildMultiselectRequest,
+      isReserved,
+    },
     waitForReviewer: async (runtimeContext, widget) => {
       const response = await runtimeContext.ui.input(JSON.stringify(widget), "");
       return JSON.parse(response);
diff --git a/harness/.pi/extensions/gate/__tests__/gate_memory_selection.test.js b/harness/.pi/extensions/gate/__tests__/gate_memory_selection.test.js
index fe654550..cbbea336 100644
--- a/harness/.pi/extensions/gate/__tests__/gate_memory_selection.test.js
+++ b/harness/.pi/extensions/gate/__tests__/gate_memory_selection.test.js
@@ -1,6 +1,8 @@
 const test = require("node:test");
 const assert = require("node:assert");
 const { createMemoryGate } = require("../memory/index.js");
+const { buildMultiselectRequest } = require("../core/builders.js");
+const { isReserved } = require("../core/reserved-labels.mjs");
 const { createFakePi } = require("./fake_pi_runtime.js");
 
 
@@ -71,6 +73,10 @@ function setupRecall(choices) {
         return null;
       },
     },
+    reviewer: {
+      buildMultiselect: buildMultiselectRequest,
+      isReserved,
+    },
     waitForReviewer: async (runtimeContext, widget) => {
       const response = await runtimeContext.ui.input(JSON.stringify(widget), "");
       return JSON.parse(response);
diff --git a/harness/.pi/extensions/gate/__tests__/gate_stringified_params.test.js b/harness/.pi/extensions/gate/__tests__/gate_stringified_params.test.js
index 1c24c6c3..e7169eb9 100644
--- a/harness/.pi/extensions/gate/__tests__/gate_stringified_params.test.js
+++ b/harness/.pi/extensions/gate/__tests__/gate_stringified_params.test.js
@@ -75,7 +75,7 @@ test("prepareReviewerArguments leaves a legacy markdown string artifact.data UNC
 
 test("GATE_CODE_FILES blocks writes to gate extensions, not session artifacts", () => {
   assert.ok(GATE_CODE_FILES.test("harness/.pi/extensions/tht-gate.js"));
-  assert.ok(GATE_CODE_FILES.test(".pi/extensions/reserved-labels.mjs"));
+  assert.ok(GATE_CODE_FILES.test(".pi/extensions/gate/core/reserved-labels.mjs"));
   assert.equal(GATE_CODE_FILES.test("sessions/s1/schema_linking.json"), false);
   assert.equal(GATE_CODE_FILES.test("sessions/s1/sql_final.sql"), false);
 });
diff --git a/harness/.pi/extensions/gate/__tests__/module_boundaries.test.js b/harness/.pi/extensions/gate/__tests__/module_boundaries.test.js
new file mode 100644
index 00000000..32ff4b10
--- /dev/null
+++ b/harness/.pi/extensions/gate/__tests__/module_boundaries.test.js
@@ -0,0 +1,43 @@
+const test = require("node:test");
+const assert = require("node:assert");
+const { readdirSync, readFileSync } = require("node:fs");
+const { dirname, extname, join, relative, resolve, sep } = require("node:path");
+
+const gateRoot = resolve(__dirname, "..");
+const domainRoots = ["disambiguation", "memory"];
+
+
+function productionFiles(root) {
+  return readdirSync(root, { withFileTypes: true }).flatMap((entry) => {
+    const path = join(root, entry.name);
+    if (entry.isDirectory()) {
+      return entry.name === "__tests__" ? [] : productionFiles(path);
+    }
+    return [".js", ".mjs"].includes(extname(entry.name)) ? [path] : [];
+  });
+}
+
+
+function relativeImports(path) {
+  const source = readFileSync(path, "utf8");
+  return [...source.matchAll(/(?:from\s+|import\s*(?:\(\s*)?|require\s*\(\s*)["'](\.[^"']+)["']/g)]
+    .map((match) => match[1]);
+}
+
+
+test("gate domain modules receive shared behavior as capabilities", () => {
+  for (const domain of domainRoots) {
+    const root = join(gateRoot, domain);
+    for (const path of productionFiles(root)) {
+      const imports = relativeImports(path).map((specifier) =>
+        relative(gateRoot, resolve(dirname(path), specifier)).split(sep).join("/"));
+      const violations = imports.filter((target) =>
+        target !== domain && !target.startsWith(`${domain}/`));
+      assert.deepEqual(
+        violations,
+        [],
+        `${relative(gateRoot, path)} imports gate implementation directly: ${violations.join(", ")}`,
+      );
+    }
+  }
+});
diff --git a/harness/.pi/extensions/gate/__tests__/reserved_labels.test.js b/harness/.pi/extensions/gate/__tests__/reserved_labels.test.js
index f71d1da1..9dd83870 100644
--- a/harness/.pi/extensions/gate/__tests__/reserved_labels.test.js
+++ b/harness/.pi/extensions/gate/__tests__/reserved_labels.test.js
@@ -1,6 +1,6 @@
 const test = require("node:test");
 const assert = require("node:assert");
-const { isReserved, stripReserved } = require("../../reserved-labels.mjs");
+const { isReserved, stripReserved } = require("../core/reserved-labels.mjs");
 
 test("Altro variants (any punctuation/case) are reserved", () => {
   assert.equal(isReserved("Altro — specifica…"), true);
diff --git a/harness/.pi/extensions/gate/artifact-contracts.js b/harness/.pi/extensions/gate/core/artifact-contracts.js
similarity index 100%
rename from harness/.pi/extensions/gate/artifact-contracts.js
rename to harness/.pi/extensions/gate/core/artifact-contracts.js
diff --git a/harness/.pi/extensions/gate/builders.js b/harness/.pi/extensions/gate/core/builders.js
similarity index 100%
rename from harness/.pi/extensions/gate/builders.js
rename to harness/.pi/extensions/gate/core/builders.js
diff --git a/harness/.pi/extensions/gate/enrich.js b/harness/.pi/extensions/gate/core/enrich.js
similarity index 100%
rename from harness/.pi/extensions/gate/enrich.js
rename to harness/.pi/extensions/gate/core/enrich.js
diff --git a/harness/.pi/extensions/reserved-labels.mjs b/harness/.pi/extensions/gate/core/reserved-labels.mjs
similarity index 100%
rename from harness/.pi/extensions/reserved-labels.mjs
rename to harness/.pi/extensions/gate/core/reserved-labels.mjs
diff --git a/harness/.pi/extensions/gate/disambiguation/index.js b/harness/.pi/extensions/gate/disambiguation/index.js
index bed430b5..4c1ca098 100644
--- a/harness/.pi/extensions/gate/disambiguation/index.js
+++ b/harness/.pi/extensions/gate/disambiguation/index.js
@@ -1,6 +1,17 @@
 import { Type } from "typebox";
 
 
+export const NEW_SESSION_CLARIFICATION_KICKOFF =
+	"2. Nel primo turno identifica la SOLA ambiguità con maggiore impatto sulla query e " +
+	"chiama subito `reviewer_select` con opzioni concrete. Niente lunga narrazione, elenco " +
+	"di tutte le ambiguità o ricapitolazione preliminare.\n";
+
+
+export const EMPTY_SESSION_CLARIFICATION_KICKOFF =
+	"Se la sessione e' in fase 1 e non ha decisioni, dopo `session show` chiama " +
+	"`reviewer_select` subito: non produrre testo libero.\n";
+
+
 function normalizedAssumptions(assumptions) {
 	let normalized = assumptions;
 	if (typeof normalized === "string") {
diff --git a/harness/.pi/extensions/gate/memory/index.js b/harness/.pi/extensions/gate/memory/index.js
index e7da0fc9..f9fb6851 100644
--- a/harness/.pi/extensions/gate/memory/index.js
+++ b/harness/.pi/extensions/gate/memory/index.js
@@ -1,8 +1,5 @@
 import { Type } from "typebox";
 
-import { buildMultiselectRequest } from "../builders.js";
-import { isReserved } from "../../reserved-labels.mjs";
-
 // Compatibility note: reviewer labels move verbatim from the composition root.
 // Tickets #22 and #23 require observable parity; translating existing chrome is a
 // separate product behavior change rather than part of these extractions.
@@ -80,14 +77,14 @@ function shouldSkipEmptyRecall({ meritCount, allowEmpty, advance }) {
 
 
 async function reviewRecall(ctx, params, phase, dependencies) {
-	const { workflow, ledger, waitForReviewer, toTextResult } = dependencies;
+	const { workflow, ledger, reviewer, waitForReviewer, toTextResult } = dependencies;
 	try {
 		const { session, advance } = params;
 		const options = normalizeMemoryOptions(params.options);
 		const typeError = ledger.validate(ctx, options, session);
 		if (typeError) return toTextResult(typeError);
 		const meritOptions = options
-			.filter((option) => !isReserved(option.label))
+			.filter((option) => !reviewer.isReserved(option.label))
 			.map((option) => ({
 				id: option.id,
 				label: option.label,
@@ -110,7 +107,7 @@ async function reviewRecall(ctx, params, phase, dependencies) {
 					"avanzamento automatico alla fase successiva.",
 			);
 		}
-		const widget = buildMultiselectRequest({
+		const widget = reviewer.buildMultiselect({
 			id: `u${Date.now()}`,
 			phase,
 			allowEmpty: params.allow_empty ?? false,
@@ -225,7 +222,7 @@ function splitPromotionChoices(candidates, choices) {
  */
 function installMemoryGate(
 	pi,
-	{ workflow, memory, ledger, waitForReviewer, toTextResult },
+	{ workflow, memory, ledger, reviewer, waitForReviewer, toTextResult },
 ) {
 	pi.registerTool({
 		name: "reviewer_memory_promote",
@@ -285,7 +282,7 @@ function installMemoryGate(
 					);
 				}
 				const options = promotionOptions(candidates);
-				const widget = buildMultiselectRequest({
+				const widget = reviewer.buildMultiselect({
 					id: `u${Date.now()}`,
 					phase: phase.id,
 					title: "Quali concetti chiariti salvare nella memoria riutilizzabile?",
diff --git a/harness/.pi/extensions/tht-gate.js b/harness/.pi/extensions/tht-gate.js
index b3ec142e..6cf8179d 100644
--- a/harness/.pi/extensions/tht-gate.js
+++ b/harness/.pi/extensions/tht-gate.js
@@ -6,7 +6,7 @@
 //      the reference implementation PHASE_NAMES array (truncated to 7) is gone; F8/datamart can no
 //      longer drift out of sync.
 //  (2) D2/D4 widget-descriptor: the reviewer interaction is emitted as a
-//      widget-descriptor JSON (built by ./gate/builders.js) and awaited by id, instead
+//      widget-descriptor JSON (built by ./gate/core/builders.js) and awaited by id, instead
 //      of rendered by blocking native TUI primitives (ctx.ui.select/custom).
 //
 // PRESERVED VERBATIM from the source (load-bearing runtime glue, spec D4):
@@ -30,12 +30,12 @@ import {
 	buildArtifactGate,
 	buildSchemaLinkingRequest,
 	buildJoinReviewRequest,
-} from "./gate/builders.js";
+} from "./gate/core/builders.js";
 import {
 	validateCtePlanV2,
 	validateCteResultThin,
 	validatePhaseSummaryV2,
-} from "./gate/artifact-contracts.js";
+} from "./gate/core/artifact-contracts.js";
 import {
 	memoizeGetColumns,
 	enrichCtePlanV2,
@@ -43,10 +43,14 @@ import {
 	enrichCteResultColumns,
 	enrichPhaseSummaryV2,
 	appendLedgerSection,
-} from "./gate/enrich.js";
+} from "./gate/core/enrich.js";
 import { createMemoryGate } from "./gate/memory/index.js";
-import { createDisambiguationGate } from "./gate/disambiguation/index.js";
-import { isReserved } from "./reserved-labels.mjs";
+import {
+	createDisambiguationGate,
+	EMPTY_SESSION_CLARIFICATION_KICKOFF,
+	NEW_SESSION_CLARIFICATION_KICKOFF,
+} from "./gate/disambiguation/index.js";
+import { isReserved } from "./gate/core/reserved-labels.mjs";
 
 // Load the workflow contract once when Pi loads the extension. Asking the model to
 // discover/read the skill as its first action proved unreliable with remote models:
@@ -204,9 +208,7 @@ const NUOVA_DOMANDA_KICKOFF_PROVIDED = (sessionId, hasRetrievalPack = false) =>
 		: "1. Il retrieval pack non era ancora disponibile: come PRIMA chiamata tool esegui " +
 			"subito `tht search pack \"<domanda originale nel messaggio utente>\" --session " +
 			sessionId + "` e usa il risultato.\n") +
-	"2. Nel primo turno identifica la SOLA ambiguità con maggiore impatto sulla query e " +
-	"chiama subito `reviewer_select` con opzioni concrete. Niente lunga narrazione, elenco " +
-	"di tutte le ambiguità o ricapitolazione preliminare.\n" +
+	NEW_SESSION_CLARIFICATION_KICKOFF +
 	"Regole non negoziabili: una domanda al reviewer per volta; mai promuovere/escludere/" +
 	"correggere senza conferma; le interazioni passano dai tool reviewer_*; testo libero col prefisso '!'. " +
 	"MAI `tht phase advance|reopen` né `tht decision add` da shell.";
@@ -225,7 +227,8 @@ const RIPRENDI_KICKOFF = (hasRetrievalPack = false) =>
 	"cio' che non e' registrato non e' avvenuto) e riprendi da li'.\n" +
 	"Esegui il passo 1 ORA, in QUESTO stesso turno, chiamando subito il tool `bash` per " +
 	"`tht session show`: NON limitarti a dichiarare l'intenzione e NON " +
-	"terminare il turno prima di aver chiamato i tool. Se la sessione e' in fase 1 e non ha decisioni, dopo `session show` chiama `reviewer_select` subito: non produrre testo libero.\n" +
+	"terminare il turno prima di aver chiamato i tool. " +
+	EMPTY_SESSION_CLARIFICATION_KICKOFF +
 	"Valgono le stesse regole non negoziabili: una domanda per volta, conferma esplicita, tool " +
 	"reviewer_*, niente phase advance/reopen o decision add da shell, una fase alla volta.";
 
@@ -617,6 +620,10 @@ export default function (pi) {
 				ctx, decisionAddArgs(session, decision), recovery,
 			),
 		},
+		reviewer: {
+			buildMultiselect: buildMultiselectRequest,
+			isReserved,
+		},
 		waitForReviewer: emitAndWait,
 		toTextResult: textResult,
 	});
diff --git a/harness/tests/test_module_boundaries.py b/harness/tests/test_module_boundaries.py
new file mode 100644
index 00000000..3c14ed4b
--- /dev/null
+++ b/harness/tests/test_module_boundaries.py
@@ -0,0 +1,72 @@
+"""Architecture contracts for the internal workflow modules."""
+
+from __future__ import annotations
+
+import ast
+from pathlib import Path
+
+import pytest
+
+
+THT_ROOT = Path(__file__).resolve().parents[1] / "tht"
+DOMAIN_PACKAGES = ("evidence", "memory")
+
+
+def _package(path: Path) -> tuple[str, ...]:
+    relative = path.relative_to(THT_ROOT).with_suffix("").parts
+    return ("tht", *relative[:-1])
+
+
+def _resolve_import_from(package: tuple[str, ...], node: ast.ImportFrom) -> set[str]:
+    if node.level:
+        keep = len(package) - (node.level - 1)
+        base = package[: max(keep, 0)]
+    else:
+        base = ()
+    module = (*base, *node.module.split(".")) if node.module else base
+    resolved = {".".join(module)} if module else set()
+    if not node.module or node.module == "tht":
+        resolved.update(
+            ".".join((*module, alias.name))
+            for alias in node.names
+            if alias.name != "*"
+        )
+    return resolved
+
+
+def _imports(path: Path) -> set[str]:
+    tree = ast.parse(path.read_text(), filename=str(path))
+    package = _package(path)
+    imported: set[str] = set()
+    for node in ast.walk(tree):
+        if isinstance(node, ast.Import):
+            imported.update(alias.name for alias in node.names)
+        elif isinstance(node, ast.ImportFrom):
+            imported.update(_resolve_import_from(package, node))
+    return imported
+
+
+def test_relative_import_resolution_reaches_a_sibling_domain() -> None:
+    imports = (
+        "from ..memory import core",
+        "from .. import memory",
+        "from tht import memory",
+    )
+
+    for statement in imports:
+        node = ast.parse(statement).body[0]
+        assert isinstance(node, ast.ImportFrom)
+        assert "tht.memory" in _resolve_import_from(("tht", "evidence"), node)
+
+
+@pytest.mark.parametrize("domain", DOMAIN_PACKAGES)
+def test_python_domain_does_not_import_another_domain(domain: str) -> None:
+    forbidden = {f"tht.{other}" for other in DOMAIN_PACKAGES if other != domain}
+    violations: list[str] = []
+
+    for path in sorted((THT_ROOT / domain).rglob("*.py")):
+        for imported in sorted(_imports(path)):
+            if any(imported == root or imported.startswith(f"{root}.") for root in forbidden):
+                violations.append(f"{path.relative_to(THT_ROOT)} -> {imported}")
+
+    assert violations == []
diff --git a/tools/replay/extract.mjs b/tools/replay/extract.mjs
index 657c96c8..64fc42f4 100644
--- a/tools/replay/extract.mjs
+++ b/tools/replay/extract.mjs
@@ -138,7 +138,7 @@ if (sessionCounts.size > 1) {
 }
 const answered = calls.filter((c) => resultsByCallId.has(c.callId));
 
-// --- build descriptors (mirrors harness/.pi/extensions/gate/builders.js) ----
+// --- build descriptors (mirrors harness/.pi/extensions/gate/core/builders.js) ----
 
 // Infer the workflow phase (F1..F8) of a gate from its title, so the frontend's
 // WorkflowBar lights up the correct dot during replay. Patterns (from real