diff --git a/middleware.ts b/middleware.ts
index 1933a57..1af30ef 100644
--- a/middleware.ts
+++ b/middleware.ts
@@ -4,7 +4,7 @@
  * Customer calls use verified Zitadel bearer identity and receive immutable
  * x-0pt-verified-* headers. Explicit machine routes may instead use the
  * shared X-Internal-Token convention; mutation handlers verify it again for
- * defence in depth.
+ * defence in depth. The canonical-fact write is one such explicit machine route.
  */
 import { NextResponse, type NextRequest } from 'next/server';
 import { assertAuthConfigSafe, resolveAuthContext } from '@/src/auth/context';
@@ -26,6 +26,9 @@ const EXEMPT_PATTERNS: RegExp[] = [
 /** Routes that may be reached with a service token instead of end-user bearer auth. */
 const INTERNAL_SERVICE_ROUTES: RegExp[] = [
   /^\/api\/0pt\/quality\/bridge-run$/,
+  // Acquisition engine -> 0pt canonical observation write (machine-to-machine,
+  // same X-Internal-Token class as the quality bridge; not a blanket bypass).
+  /^\/api\/0pt\/canonical\/facts$/,
   /^\/api\/0pt\/internal\/evidence-outbox\/dispatch$/,
   /^\/api\/0pt\/internal\/er\/candidates$/,
   /^\/api\/0pt\/search\/definitions$/,
diff --git a/sql/020_canonical_facts.sql b/sql/022_canonical_facts.sql
similarity index 100%
rename from sql/020_canonical_facts.sql
rename to sql/022_canonical_facts.sql
diff --git a/src/repositories/canonical-fact-repository.ts b/src/repositories/canonical-fact-repository.ts
index 6b4f7b6..4e22ed7 100644
--- a/src/repositories/canonical-fact-repository.ts
+++ b/src/repositories/canonical-fact-repository.ts
@@ -1,7 +1,7 @@
 /**
  * src/repositories/canonical-fact-repository.ts
  * =============================================
- * Storage seam for 0pt canonical entities/facts/relations (sql/020).
+ * Storage seam for 0pt canonical entities/facts/relations (sql/022).
  * Same split as source-repository.ts: one interface, an in-memory
  * implementation (dev/test) and a Postgres implementation (production),
  * chosen once via resolveStoreMode.
diff --git a/src/services/canonical-fact-service.ts b/src/services/canonical-fact-service.ts
index 96bd620..e636227 100644
--- a/src/services/canonical-fact-service.ts
+++ b/src/services/canonical-fact-service.ts
@@ -1,7 +1,7 @@
 /**
  * src/services/canonical-fact-service.ts
  * ======================================
- * 0pt's canonical structured-observation write/read surface (sql/020).
+ * 0pt's canonical structured-observation write/read surface (sql/022).
  *
  * Ownership boundary: 0pt stores normalized OBSERVED facts (what a source
  * said, when, from which artifact). L0RE owns epistemic propositions and
diff --git a/src/validation/0pt-schemas.ts b/src/validation/0pt-schemas.ts
index acfc881..148a359 100644
--- a/src/validation/0pt-schemas.ts
+++ b/src/validation/0pt-schemas.ts
@@ -264,7 +264,7 @@ export const activateSourceSchema = z.object({
   actor_id: z.string().min(1).optional(),
 });
 
-/** POST /api/0pt/canonical/facts — canonical structured observation write (sql/020). */
+/** POST /api/0pt/canonical/facts — canonical structured observation write (sql/022). */
 const canonicalEntityInputSchema = z.object({
   entity_type: z.string().min(1),
   identity_namespace: z.string().min(1),
diff --git a/tests/auth/middleware-internal-token.test.ts b/tests/auth/middleware-internal-token.test.ts
index ec57c4f..a7bad48 100644
--- a/tests/auth/middleware-internal-token.test.ts
+++ b/tests/auth/middleware-internal-token.test.ts
@@ -45,6 +45,13 @@ describe('middleware.ts: internal-token path for /api/0pt/quality/bridge-run', (
     expect(res.status).toBe(200);
   });
 
+  it('a valid X-Internal-Token lets the acquisition engine write canonical facts', async () => {
+    const res = await middleware(
+      req('/api/0pt/canonical/facts', { 'x-internal-token': 'engine-shared-secret' }),
+    );
+    expect(res.status).toBe(200);
+  });
+
   it('an invalid X-Internal-Token still falls through to the ordinary Bearer requirement (401, not a bypass)', async () => {
     const res = await middleware(req('/api/0pt/quality/bridge-run', { 'x-internal-token': 'wrong-secret' }));
     expect(res.status).toBe(401);
diff --git a/tests/p0/canonical-facts.test.ts b/tests/p0/canonical-facts.test.ts
index 0e3e7f4..9c9b854 100644
--- a/tests/p0/canonical-facts.test.ts
+++ b/tests/p0/canonical-facts.test.ts
@@ -1,5 +1,5 @@
 /**
- * Canonical structured observations (sql/020): idempotent write, conflict
+ * Canonical structured observations (sql/022): idempotent write, conflict
  * preservation, tenant isolation and relation identity resolution.
  */
 import { describe, it, expect } from "vitest";