diff --git a/dist/guarded-write-contract.d.ts b/dist/guarded-write-contract.d.ts
index 4c9bcb8..678b69d 100644
--- a/dist/guarded-write-contract.d.ts
+++ b/dist/guarded-write-contract.d.ts
@@ -291,7 +291,6 @@ export declare function computeKnowledgeGuardedManifestDeterministicKey(maintain
 export declare function assertKnowledgeGuardedPayload(verb: KnowledgeGuardedWriteVerb, payload: KnowledgeGuardedPayload): void;
 export declare function createKnowledgePrivateInputDescriptor(options: CreateKnowledgePrivateInputDescriptorOptions): KnowledgePrivateInputDescriptor;
 export declare function revokeKnowledgePrivateInputDescriptor(descriptor: KnowledgePrivateInputDescriptor): void;
-export declare function materializeKnowledgePrivateInput(descriptor: KnowledgePrivateInputDescriptor): KnowledgeGuardedPayload;
 export declare function assertKnowledgeTerminalCompleteness(reconciliation: KnowledgeTerminalReconciliation, expected: {
     deterministic_key: string;
     operation_id: string;
diff --git a/src/guarded-write-contract.ts b/src/guarded-write-contract.ts
index 8f9af78..a3d78b8 100644
--- a/src/guarded-write-contract.ts
+++ b/src/guarded-write-contract.ts
@@ -953,6 +953,7 @@ export function revokeKnowledgePrivateInputDescriptor(descriptor: KnowledgePriva
   state.revoked = true;
 }
 
+/** @internal */
 export function materializeKnowledgePrivateInput(
   descriptor: KnowledgePrivateInputDescriptor,
 ): KnowledgeGuardedPayload {
diff --git a/tests/package-release.test.ts b/tests/package-release.test.ts
index 9926cec..8995d50 100644
--- a/tests/package-release.test.ts
+++ b/tests/package-release.test.ts
@@ -8,6 +8,7 @@ import { spawnSync } from 'node:child_process';
 import { readFileSync } from 'node:fs';
 import { dirname, join, posix } from 'node:path';
 import { fileURLToPath } from 'node:url';
+import * as builtPackageRoot from '../dist/index.js';
 import { budget } from './support/budget';
 
 const repoRoot = join(dirname(fileURLToPath(import.meta.url)), '..');
@@ -43,6 +44,13 @@ const forbiddenPackagePaths = [
   'scripts/validate-public-package.mjs',
 ].sort();
 
+const rootRuntimeExports = builtPackageRoot as Record<string, unknown>;
+
+function declarationExportsIdentifier(source: string, identifier: string): boolean {
+  return new RegExp(`\\bexport\\s+(?:declare\\s+)?(?:function|const|class|interface|type)\\s+${identifier}\\b`).test(source)
+    || new RegExp(`\\bexport\\s*\\{[^}]*\\b${identifier}\\b`, 's').test(source);
+}
+
 describe('public package release safety', () => {
   // Node's builtin list, hardcoded on purpose. `builtinModules` under `bun test` returns BUN's
   // list, which includes `ws`, `undici` and `bun` - real npm package names that are NOT Node
@@ -100,6 +108,19 @@ describe('public package release safety', () => {
     }
   });
 
+  test('guarded private-input public declarations match the runtime export contract', () => {
+    const rootDeclaration = readFileSync(join(repoRoot, 'dist/index.d.ts'), 'utf8');
+    const guardedContractDeclaration = readFileSync(join(repoRoot, 'dist/guarded-write-contract.d.ts'), 'utf8');
+
+    expect(rootRuntimeExports.createKnowledgePrivateInputDescriptor).toBeFunction();
+    expect(declarationExportsIdentifier(rootDeclaration, 'createKnowledgePrivateInputDescriptor')).toBe(true);
+    expect(declarationExportsIdentifier(guardedContractDeclaration, 'createKnowledgePrivateInputDescriptor')).toBe(true);
+
+    expect(rootRuntimeExports.materializeKnowledgePrivateInput).toBeUndefined();
+    expect(declarationExportsIdentifier(rootDeclaration, 'materializeKnowledgePrivateInput')).toBe(false);
+    expect(declarationExportsIdentifier(guardedContractDeclaration, 'materializeKnowledgePrivateInput')).toBe(false);
+  });
+
   /**
    * Imports of a published script that would NOT resolve for someone who installed the
    * package. Returns the offending specifiers, so both the enforcement test and the tests
diff --git a/tsconfig.build.json b/tsconfig.build.json
index 30aa799..1335ec5 100644
--- a/tsconfig.build.json
+++ b/tsconfig.build.json
@@ -4,6 +4,7 @@
     "noEmit": false,
     "declaration": true,
     "emitDeclarationOnly": true,
+    "stripInternal": true,
     "outDir": "./dist",
     "rootDir": "./src"
   },