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Missing MCP-Protocol-Version: <protocol-version> during Server Metadata Discovery #758

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Description

@symdeb

Describe the bug
Missing MCP-Protocol-Version: during Server Metadata Discovery

To Reproduce
View the requests

Expected behavior
MCP clients SHOULD include the header MCP-Protocol-Version: during Server Metadata Discovery to allow the MCP server to respond based on the MCP protocol version.

Logs


method:OPTIONS
headers:
Cf-Ray:975b781a9c32332d-TPE
Cf-Ipcountry:TW
Origin:http://localhost:6274
Accept-Encoding:gzip, br
Accept-Language:en-US,en;q=0.9,zh;q=0.8
X-Forwarded-Proto:https
Referer:http://localhost:6274/
Sec-Fetch-Dest:empty
Cf-Visitor:{"scheme":"https"}
Sec-Fetch-Site:cross-site
Sec-Fetch-Mode:cors
Cf-Connecting-Ip:112.104.98.45
Cf-Device-Type:desktop
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36
Priority:u=1, i
Cdn-Loop:cloudflare; loops=1
Accept:*/*
Access-Control-Request-Method:GET
Access-Control-Request-Headers:mcp-protocol-version
Host:www.-----.com
X-HTTPS:1
URL: /.well-known/oauth-protected-resource/api/oauth

method:GET
headers:
Cf-Device-Type:desktop
Cf-Ipcountry:TW
Accept-Encoding:gzip, br
Cf-Ray:975b781ee956332d-HKG
X-Forwarded-Proto:https
Cf-Visitor:{"scheme":"https"}
Sec-Ch-Ua-Platform:"Linux"
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36
Sec-Ch-Ua:"Not)A;Brand";v="8", "Chromium";v="138", "Google Chrome";v="138"
Sec-Ch-Ua-Mobile:?0
Accept:*/*
Origin:http://localhost:6274
Sec-Fetch-Site:cross-site
Sec-Fetch-Mode:cors
Sec-Fetch-Dest:empty
Referer:http://localhost:6274/
Accept-Language:en-US,en;q=0.9,zh;q=0.8
Priority:u=1, i
Cf-Connecting-Ip:112.104.98.45
Cdn-Loop:cloudflare; loops=1
Host:www.------.com
X-HTTPS:1
Content-Length:0
URL: /.well-known/oauth-protected-resource/api/oauth


Activity

  1. added
    spec complianceLabel for issues and PRs that are related to adding or fixing support for a specific spec feature.
    on Aug 28, 2025
  2. cliffhall commented on Sep 6, 2025

    @cliffhall
    Member

    This will be fixed by #787

    Image
  3. self-assigned this
    on Sep 6, 2025
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