Burp HTTP/SSE MCP server appears in /mcp and works manually, but tools are not injected into assistant native tool list

What version of the Codex App are you using (From “About Codex” dialog)?

26.513.40821

What subscription do you have?

Enterprise

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

Environment:

• Codex desktop app on Windows
• Burp MCP server (https://github.com/portswigger/mcp-server) at http://127.0.0.1:9876/
• Config: C:\Users\ricardo\.codex\config.toml

Config:
[mcp_servers.Burp]
url = "http://127.0.0.1:9876/"

Observed:

• /mcp shows Burp
• Manual MCP HTTP/SSE handshake works
• tools/list returns Burp tools
• tools/call send_http1_request successfully requests https://example.com
• Assistant session does not expose any native mcp__Burp__... tools

Expected:
Discovered Burp MCP tools should be available as native callable tools in the assistant session.
/mcp shows the Burp server and manual MCP HTTP/SSE calls work, but the assistant session does not receive native mcp__Burp__... tools.

What steps can reproduce the bug?

Steps to reproduce:

1. Run Burp Suite with the Burp MCP server enabled and listening at:

http://127.0.0.1:9876/

1. Add the MCP server to Codex user config at:

C:\Users\username\.codex\config.toml

[mcp_servers.Burp]
url = "http://127.0.0.1:9876/"

1. Restart Codex Desktop.

1. In Codex, run /mcp and confirm the Burp MCP server appears in the MCP list.

1. Start a chat and ask Codex to use Burp MCP, for example:

"Make a GET request to https://example.com using Burp MCP."

1. Observe that the assistant does not have native Burp MCP tools exposed, e.g. no callable tool namespace like:

mcp__Burp__send_http1_request

1. Independently verify that Burp MCP works by manually connecting to the MCP HTTP/SSE endpoint:

• GET http://127.0.0.1:9876/
• read the returned sessionId
• POST initialize
• POST notifications/initialized
• POST tools/list
• POST tools/call with send_http1_request

1. The manual MCP call succeeds and returns HTTP/2 200 OK from https://example.com.

What is the expected behavior?

After Codex discovers the Burp MCP server, the Burp MCP tools should be injected into the assistant session as native callable tools.

Additional information

All the content of this issue was generated by the Codex itself.