# Bug OP-20415 - MCP response with 200 to notifcation requests

Project: OpenProject
Status: confirmed
URL: https://community.openproject.org/work_packages/OP-20415

## Open points

_No work packages_

## Details

| Attribute | Value |
| --- | --- |
| Date |  |
| Priority | Low |
| Module | Artificial Intelligence / MCP Server (MCP) |
| Target versions |  |
| Observed in versions | 17.9.1 |
| Sprint |  |
| Backlog bucket |  |
| Bug found in version (deprecated) |  |
| Found in mobile app version |  |
| Follow-up feedback e-mail |  |
| Requires doc change | No |
| Accessibility | No |
| Pull preview |  |
| List |  |
| Labels |  |

## People

| Attribute | Value |
| --- | --- |
| Assignee |  |
| Accountable |  |
| Product manager |  |
| Developers |  |
| Designer |  |
| Ordered by |  |
| Signed off by |  |
| Interest by |  |

## Planning

| Attribute | Value |
| --- | --- |
| Relevance |  |

## Costs

| Attribute | Value |
| --- | --- |
| Votes |  |
| Work |  |
| Labor costs |  |

## Description

### Steps to reproduce

1.  Send an RPC notifcation request
    

```bash
curl -i -u "apikey:$OP_API_KEY" -X POST https://openproject.local/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{
    "jsonrpc": "2.0",
    "method": "notifications/notexists",
    "params": {}
}'
```

### What is the buggy behavior?

*   The Server response with status 200 and body null
    
    <img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/925443/content">
    

### What is the expected behavior?

1.  According to the MCP standart the server **MUST** response with 202 and no body or with 400:  
    [https://modelcontextprotocol.io/specification/2026-07-28/basic/transports/streamable-http#sending-messages](https://modelcontextprotocol.io/specification/2026-07-28/basic/transports/streamable-http#sending-messages)
    
2.  Since there are notifcations defined yet we probably can just response with 400:  
    <img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/925446/content">
    

###