Add fixed OAuth callback port option for MCP servers in Copilot

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#319,440 1 comment 8 reactions 1 assignee View on GitHub

@TylerLeonhardt is already working on this.

Since Jun 1, 2026.

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Description

authentication feature-request mcp
Feature Request: Add fixed OAuth callback port option for MCP servers in Copilot
Problem

When connecting to a remote MCP server that requires OAuth authentication, VS Code Copilot binds to a random ephemeral port for the localhost callback (e.g. http://localhost:54321/callback). The MCP spec states that authorization servers SHOULD accept any loopback port, but many identity providers require the exact redirect_uri (including port) to be pre-registered.

There are a couple reasons this is not always practical:

  • Enterprise identity providers (Cognito, Entra ID, Okta in strict mode) enforce exact redirect URI matching as a security policy
  • Organizations with compliance requirements may not be able to relax redirect URI validation
Proposed Solution

Allow users to specify a fixed callback port in the MCP server's oauth configuration:

// .vscode/mcp.json
{
  "servers": {
    "my-server": {
      "type": "http",
      "url": "https://mcp.example.com",
      "oauth": {
        "clientId": "my-client-id",
        "callbackPort": 8080
      }
    }
  }
}

When callbackPort is set, the OAuth callback listener binds to that specific port instead of an ephemeral one, producing a predictable redirect URI (e.g. http://localhost:8080/callback) that can be pre-registered with the identity provider.

Other Client Examples

This pattern has been adopted by a handful of clients already:

Dominant language
TypeScript
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