The MCP Server for my ABP Studio 3.0.4 installation is not starting up. I've already tried reinstalling and deleting the .abp/studio folder, as well as reverting to 3.0.3 but the issue persists. I tried it on a colleague's PC and the issue was the same.
Steps to reproduce the issue:
- Install ABP Studio
- Wait for all background tasks to finish
- ping localhost:38280 -> Connection refused
8 Answer(s)
-
0
What “connection refused” means here: the MCP endpoint is served by ABP Studio itself (“ABP Studio runs a local MCP server in the background”). If
localhost:38280refuses the connection, the MCP server process inside Studio didn’t start or is being blocked/crashing, so nothing is listening on that port. (Also note: MCP works only while ABP Studio is running.)Most common cause in locked-down/corporate environments (and consistent with “same on colleague’s PC”) is endpoint security / antivirus / firewall policy blocking the ABP Studio local service from binding to localhost ports or killing the background process.
- Action: Temporarily disable/allowlist in your security product (Defender / Kaspersky / CrowdStrike etc.) for ABP Studio and retry.
- Action: Ensure no policy blocks local loopback traffic to
127.0.0.1/localhost.
Verify the port isn’t occupied by something else (another process could prevent Studio from binding, leading to no listener):
- Windows (PowerShell):
netstat -aon | findstr :38280If it shows a PID, identify it:tasklist /fi "PID eq <PID>"Stop that process (or change the conflicting software), then restart ABP Studio.Collect ABP Studio logs to see why the backend/MCP fails to start (this is the definitive next step):
- Windows default log locations used by ABP Studio:
C:\Users\<yourusername>\.abp\studio\backend\logsC:\Users\<yourusername>\.abp\studio\ui\logs
- After reproducing, check the most recent log files for errors around “mcp”, “listen”, “Kestrel”, “address already in use”, or crashes.
- Windows default log locations used by ABP Studio:
Upgrade note: MCP support/fixes have shipped across Studio versions (release notes mention MCP-related fixes). If you can, update to the latest available ABP Studio version and retry; it may include MCP stability fixes.
If this turns out to be environment/security-policy related and you need official assistance for allowlisting/requirements in your organization, please contact via the validated link below.
Links:
- https://abp.io/docs/10.4/studio/model-context-protocol
- https://abp.io/docs/10.4/studio/release-notes
- https://abp.io/contact
This response was generated by AI. If it didn’t solve your problem, feel free to post a new answer — our support team will jump in to help you soon.
Markdown supported.Copy, paste, or drag & drop images and files (max 100 MB per file, 100 MB total per post) -
0
The logs unfortunately show neither that a connection has been succesfull or unsuccesful. Procmon and eventviewer also showed no error related to the mcp server. Whatever it is, it fails silently.
We are going to try installing ABP Studio on a fresh PC on a vanilla Windows installation and without any policies to make sure this is not an issue on our organization now.
Markdown supported.Copy, paste, or drag & drop images and files (max 100 MB per file, 100 MB total per post) -
0
[alper] said: can we test this MCP server on our side? can you provide information about this MCP
It is the MCP Server that is supposed to start with ABP Studio directly. The one defined here https://abp.io/docs/latest/studio/model-context-protocol
Markdown supported.Copy, paste, or drag & drop images and files (max 100 MB per file, 100 MB total per post) -
0
Hi @PDarioJer
We've removed the ABP Studio MCP server support after the launch of ABP Agent.
We also removed the document but somehow it is still present. We'll check it. https://github.com/abpframework/abp/pull/25518/
Markdown supported.Copy, paste, or drag & drop images and files (max 100 MB per file, 100 MB total per post) -
0
[yekalkan] said: Hi @PDarioJer
We've removed the ABP Studio MCP server support after the launch of ABP Agent.
We also removed the document but somehow it is still present. We'll check it.
https://github.com/abpframework/abp/pull/25518/
Thanks for the info, is there another way to use installed coding AI tools (codex, claude, etc.) to work with ABP instead of the AI Agent? A skill or a plug-in maybe?
Markdown supported.Copy, paste, or drag & drop images and files (max 100 MB per file, 100 MB total per post) -
0
Yes, there are rules & skills for ABP: https://github.com/abpframework/abp/tree/dev/.agents/skills https://github.com/abpframework/abp/tree/dev/ai-rules
Markdown supported.Copy, paste, or drag & drop images and files (max 100 MB per file, 100 MB total per post)
