Bug with MCP context provider resource reading

[leaft]

Before submitting your bug report

• I believe this is a bug. I'll try to join the Continue Discord for questions
• I'm not able to find an open issue that reports the same bug
• I've seen the troubleshooting guide on the Continue Docs

Relevant environment info

- OS: macOS
- Continue version: 0.9.250
- IDE version: 1.96.2
- Model: any
- config.json: the mcp config
  
  "modelContextProtocolServers": [
      {
        "transport": {
          "type": "stdio",
          "command": "npx",
          "args": [
            "-y",
            "@modelcontextprotocol/server-postgres",
            "postgresql://postgres@localhost/postgres"
          ]
        }
      }
    ]
  },

Description

I found a bug related to mcp context provider, the source code pieces are below

continue/core/context/providers/MCPContextProvider.ts

Lines 73 to 78 in 5a1437a

	async loadSubmenuItems(
	args: LoadSubmenuItemsArgs,
	): Promise<ContextSubmenuItem[]> {
	return (this.options as MCPContextProviderOptions).submenuItems;
	}
	}

continue/core/context/providers/MCPContextProvider.ts

Line 42 in 5a1437a

const { mcpId, uri } = MCPContextProvider.decodeMCPResourceId(query);

continue/core/context/providers/MCPContextProvider.ts

Lines 27 to 32 in 5a1437a

	static decodeMCPResourceId(mcpResourceId: string): {
	mcpId: string;
	uri: string;
	} {
	return JSON.parse(mcpResourceId);
	}

To make it concise, the main problem is the mcp server uri, which exposed by the mcp server, will be directly used as the mcp context provider's options.submenuItems.id, and when you input @mcp and select the resource, the query is actually a uri string, but not a json string, which will then fail in JSON.parse and the error appears (in the right bottom of vscode, as the image below shows).
Since the mcpId is allocated innerly, so change the mcp server's code is useless. Currently, a simple way to fix the problem is to make the loadSubmenuItems return right id string. I have tested the change and confirmed the code could work in this case, but I haven't tested it thoroughly.

async loadSubmenuItems(
    args: LoadSubmenuItemsArgs,
  ): Promise<ContextSubmenuItem[]> {
    return (this.options as MCPContextProviderOptions).submenuItems.map((item, index) => ({
      ...item,
      id: JSON.stringify({
        mcpId: String(index),
        uri: item.id,
      })
    }));
  }

Glad if this can help.

To reproduce

Make your mcp config is right, and the select a mcp context, chat

Log output

No response

[Patrick-Erichsen]

The fix you proposed makes sense to me. If you don't mind opening a PR with the fix we'd love to get this merged!

[leaft]

Fine, I will make a PR soon.

[leaft]

The fix you proposed makes sense to me. If you don't mind opening a PR with the fix we'd love to get this merged!

Done with #3662
I can provide proper help if need