inspector support streamable-http support via cli

[xxradar]

Describe the bug Does inspector support streamable-http support via cli ? (MCP Inspector v0.12.0) It does work via WebUI

To Reproduce Steps to reproduce the behavior:

npx @modelcontextprotocol/inspector --cli http://127.0.0.1:8001/mcp --method tools/list
npx @modelcontextprotocol/inspector --cli http://127.0.0.1:8001 --method tools/list

Expected behavior NA

Logs

% python server.py
INFO:     Started server process [71313]
INFO:     Waiting for application startup.
[05/16/25 09:40:26] INFO     StreamableHTTP session manager started                                                                                                 streamable_http_manager.py:109
INFO:     Application startup complete.
INFO:     Uvicorn running on http://127.0.0.1:8001 (Press CTRL+C to quit)

INFO:     127.0.0.1:62597 - "GET /sse HTTP/1.1" 404 Not Found
INFO:     127.0.0.1:62601 - "GET /sse HTTP/1.1" 404 Not Found

Additional context Server is using:

...
from mcp.server.fastmcp import FastMCP

# Create server
mcp = FastMCP("Echo Server", host="127.0.0.1", port=8001)
...
if __name__ == "__main__":
    mcp.run(transport="streamable-http")

[olaservo]

Hi @xxradar , CLI mode doesn't support as the same transports as UI mode yet, so I changed this issue to a feature request.

[xxradar]

Thx @olaservo for the update. Looking forward.

[ryanjclark]

@olaservo would you be able to review my PR for this issue?

[ofek]

We are also very interested in this feature internally as we only support this transport type for development tools.