Bug Description

Hi team,

An n8n community team member asked me to raise this as a GitHub issue.

We are seeing an issue with the n8n MCP server where get_workflow_details returns an empty workflow.tags array for workflows that definitely have tags assigned in the n8n UI.

This does not appear to be a general authentication or access issue. Other MCP functionality is working correctly:

• search_workflows returns workflows successfully
• get_workflow_details returns the workflow successfully
• nodes, connections, settings, trigger count, scopes, active state, and other metadata are all returned correctly
• the issue seems isolated to workflow.tags

According to the MCP tools reference, get_workflow_details should return workflow.tags as an array of tag objects with id and name: https://docs.n8n.io/advanced-ai/mcp/mcp_tools_reference/#get_workflow_details

We also checked the API documentation and confirmed that workflow tags are a first-class concept, including GET /workflows/{id}/tags and the workflowTags:list scope: https://docs.n8n.io/api/api-reference/ https://docs.n8n.io/api/authentication/

At the moment, the MCP response includes the tags field, but it is always returned as [] even when the workflow is tagged in the UI.

To Reproduce

1. Identify a workflow that has one or more tags assigned in the n8n UI.
2. Call the n8n MCP HTTP endpoint using the get_workflow_details tool for that workflow.
3. Inspect the returned workflow.tags field.
4. Observe that workflow.tags is returned as an empty array.

Example tool call pattern:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_workflow_details",
    "arguments": {
      "workflowId": "1kRH6KjLDbZaSLtQ"
    }
  }
}

Expected behavior

get_workflow_details should return the assigned workflow tags in workflow.tags, matching the MCP documentation.

We expected workflow.tags to contain the workflow's tag objects with id and name, not an empty array.

Debug Info

Debug info

core

• n8nVersion: 2.20.7
• platform: npm
• nodeJsVersion: 24.14.1
• nodeEnv: production
• database: postgres
• executionMode: regular
• concurrency: -1
• license: enterprise (production)
• consumerId: aec14b95-6751-405a-b2e3-12da8b9d3f0d

storage

• success: none
• error: all
• progress: false
• manual: true
• binaryMode: s3

pruning

• enabled: true
• maxAge: 336 hours
• maxCount: 10000 executions

client

• userAgent: mozilla/5.0 (macintosh; intel mac os x 10_15_7) applewebkit/537.36 (khtml, like gecko) chrome/149.0.0.0 safari/537.36
• isTouchDevice: false

cluster

• instanceCount: 1
• versions: 2.20.7
• instances:
  • instanceKey: 5fa99a96-4cda-4edd-bcdc-0aa43848a5e2, hostId: main-TyRJCkxbtyDDL1Za, instanceType: main, instanceRole: leader, version: 2.20.7
• checks:
  • check: hostid-clash, status: succeeded, warnings: -
  • check: lifecycle, status: succeeded, warnings: -
  • check: split-brain, status: succeeded, warnings: -
  • check: version-mismatch, status: succeeded, warnings: -

Generated at: 2026-06-05T12:09:47.523Z

Additional context:

• The workflows tested do have tags visible in the n8n UI
• search_workflows not returning tags is understood, since it appears to return preview data only
• The issue is specifically with get_workflow_details
• The MCP call succeeds and returns the rest of the workflow details correctly
• This suggests the problem may be specific to how workflow tags are fetched or exposed in the MCP response

Operating System

macOS 10.15.7

n8n Version

2.20.7

Node.js Version

24.14.1

Database

PostgreSQL

Execution mode

main (default)

Hosting

self hosted