fix: credential get fallback, update type field, and code refinements (v2.47.1) (czlonkowski#703)

- GET /credentials/:id is not in the n8n public API; fall back to
  list + filter, catching both 403 and 405 responses
- Forward optional `type` field in credential update for n8n versions
  that require it in PATCH payload
- Strip `data` field from create/update credential responses
- Code simplification: typed error handling, consolidated booleans,
  null-coalescing in version fetch

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: czlonkowski

CHANGELOG.md

@@ -7,6 +7,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [2.47.1] - 2026-04-04
+
+### Fixed
+
+- **Credential get fallback** — `n8n_manage_credentials({action: "get"})` now falls back to list + filter when `GET /credentials/:id` returns 403 Forbidden or 405 Method Not Allowed, since this endpoint is not in the n8n public API
+- **Credential update accepts `type` field** — `n8n_manage_credentials({action: "update"})` now forwards the optional `type` field to the n8n API, which some n8n versions require in the PATCH payload
+- **Credential response stripping** — `create` and `update` handlers now strip the `data` field from responses (defense-in-depth, matching the `get` handler pattern)
+
+Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en
+
 ## [2.47.0] - 2026-04-04
 
 ### Added

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "n8n-mcp",
-  "version": "2.47.0",
+  "version": "2.47.1",
   "description": "Integration between n8n workflow automation and Model Context Protocol (MCP)",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

package.json

@@ -2994,6 +2994,7 @@ const createCredentialSchema = z.object({
 const updateCredentialSchema = z.object({
   id: z.string({ required_error: 'Credential ID is required' }),
   name: z.string().optional(),
+  type: z.string().optional(),
   data: z.record(z.any()).optional(),
 });
 
@@ -3027,7 +3028,23 @@ export async function handleGetCredential(args: unknown, context?: InstanceConte
   try {
     const client = ensureApiConfigured(context);
     const { id } = getCredentialSchema.parse(args);
-    const credential = await client.getCredential(id);
+    let credential;
+    try {
+      credential = await client.getCredential(id);
+    } catch (getError: unknown) {
+      // GET /credentials/:id is not in the n8n public API — fall back to list + filter
+      const status = (getError as { statusCode?: number }).statusCode;
+      const msg = (getError as Error).message ?? '';
+      const isUnsupported = status === 405 || status === 403 || msg.includes('not allowed');
+      if (!isUnsupported) {
+        throw getError;
+      }
+      const list = await client.listCredentials();
+      credential = list.data.find((c) => c.id === id);
+      if (!credential) {
+        return { success: false, error: `Credential ${id} not found` };
+      }
+    }
     // Strip sensitive data field — defense in depth against future n8n versions returning decrypted values
     const { data: _sensitiveData, ...safeCred } = credential;
     return {
@@ -3059,10 +3076,11 @@ export async function handleCreateCredential(args: unknown, context?: InstanceCo
 export async function handleUpdateCredential(args: unknown, context?: InstanceContext): Promise<McpToolResponse> {
   try {
     const client = ensureApiConfigured(context);
-    const { id, name, data } = updateCredentialSchema.parse(args);
+    const { id, name, type, data } = updateCredentialSchema.parse(args);
     logger.info(`Updating credential: id="${id}"${name ? `, name="${name}"` : ''}`);
     const updatePayload: Record<string, any> = {};
     if (name !== undefined) updatePayload.name = name;
+    if (type !== undefined) updatePayload.type = type;
     if (data !== undefined) updatePayload.data = data;
     const credential = await client.updateCredential(id, updatePayload);
     const { data: _sensitiveData, ...safeCred } = credential;

src/mcp/handlers-n8n-manager.ts

@@ -135,13 +135,7 @@ export class N8nApiClient {
    * Internal method to fetch version once
    */
   private async fetchVersionOnce(): Promise<N8nVersionInfo | null> {
-    // Check if already cached globally
-    let version = getCachedVersion(this.baseUrl);
-    if (!version) {
-      // Fetch from server
-      version = await fetchN8nVersion(this.baseUrl);
-    }
-    return version;
+    return getCachedVersion(this.baseUrl) ?? await fetchN8nVersion(this.baseUrl);
   }
 
   /**

src/services/n8n-api-client.ts

@@ -248,10 +248,11 @@ function checkDataRetentionSettings(workflow: WorkflowInput): AuditFinding[] {
     return [];
   }
 
-  const savesAllErrors = settings.saveDataErrorExecution === 'all';
-  const savesAllSuccess = settings.saveDataSuccessExecution === 'all';
+  const savesAllData =
+    settings.saveDataErrorExecution === 'all' &&
+    settings.saveDataSuccessExecution === 'all';
 
-  if (!savesAllErrors || !savesAllSuccess) {
+  if (!savesAllData) {
     return [];
   }