cline
MCP : Request failed with status code 503
What happened?
when i open MCP Servers Marketplace，its error。 Request failed with status code 503. It's been two days, and the problem is still the same
Steps to reproduce
Relevant API REQUEST output
Operating System
win 10
Cline Version
3.7.1
Additional context
No response
Can you try accessing the marketplace server in your browser, and see if anything is blocking access to it?
https://api.cline.bot/v1/mcp/marketplace
@zouzhe1 Are you using any kind of proxy with Cline or VSCode? 503 is normally an indication that the page is not available to the client, but if you browser is able to access the page fine, I have to wonder if a proxy or something in the middle between Cline and the MCP server list is causing this.
Also please update to the latest version (3.8.2) and see if the problem persists.
@zouzhe1 Are you using any kind of proxy with Cline or VSCode? 503 is normally an indication that the page is not available to the client, but if you browser is able to access the page fine, I have to wonder if a proxy or something in the middle between Cline and the MCP server list is causing this.
Also please update to the latest version (3.8.2) and see if the problem persists.
I don't use proxies to access it, but when I open the MCP Servers Marketplace, 503 appears, and when I state in vscode's configuration that https://cline.bo does not use proxies, 503 still appears.
I have the same problem. I have a proxy, but both the browser and VS Code use it. The browser works fine but Cline gets a 503. I'll see if I can capture anything about the request to work out the differences.
I can also view https://api.cline.bot/v1/mcp/marketplace successfully from the simple browser within VS Code itself, but it appears that Cline's requests to the marketplace do not flow through the webview console, so I can't see the headers of the request or the body of the response in the network pane. Perhaps I'm doing it wrong, so if anyone can suggest how to debug the outgoing network requests from Cline that would be appreciated.
Here are the debug messages in the console, but they don't seem to say much other than that there was a 503 error.
OK, I've worked out what's happening in my case: Cline is using my proxy to make its request to the marketplace, but it is doing it incorrectly. When making an HTTPS connection over an HTTP proxy, the client is supposed to use the CONNECT method, but instead Cline is just running a GET of the https:// URI. I'll see if I can vibe code my way to a solution on this, but if anyone has any useful information about what libraries Cline uses for HTTPS or how they work, please add it so that I can direct the AI a bit better.
The behaviour I'm seeing is exactly what is described at https://github.com/axios/axios/issues/925#issuecomment-574617787 - it seems that axios still has this bug present. I'm not sure if this is because Cline uses an old version of axios, or if the bug has resurfaced due to other code changes. I don't really have the skills to investigate this further without assistance.
same issue on macos. In my case I can access https://api.cline.bot/v1/mcp/marketplace on my browser but cannot access it from cline(error with 503). No matter using proxy or not.
Thanks for reporting this MCP request failure! This has been consolidated into the comprehensive MCP system issues tracking issue #4391. The 503 status code problems you identified are now part of the broader MCP remote server improvements being tracked there.
