HTTP MCP Server does not work with VSCode as an MCP Client in Stateless mode #5133

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1. aparikh36

   added

   status: waiting-for-triage

   on Dec 21, 2025
2. aparikh36

   changed the title [-]HTTP MCP Server does not work with VSCode/Claude Code as an MCP Client in Stateless mode[/-] [+]HTTP MCP Server does not work with VSCode as an MCP Client in Stateless mode[/+] on Dec 21, 2025
3. hocinehacherouf commented on Dec 22, 2025

   

   hocinehacherouf

   on Dec 22, 2025

   More actions

   Hello, I am confirming this issue. Since the VS Code update (1.107), I am unable to connect to my MCP stateless server. I've tested this on Spring AI 1.1.0 and 1.1.2 with the same result.

   Environment:

   • Spring Boot: 3.5.8
   • Java: 21
   • VS Code: 1.107.1

   Error Log from VS Code:

   2025-12-22 18:12:36.502 [info] Connection state: Starting
   2025-12-22 18:12:36.502 [info] Starting server from LocalProcess extension host
   2025-12-22 18:12:36.503 [info] Connection state: Running
   2025-12-22 18:12:36.874 [error] Error: MPC -32603: Unrecognized field "form" (class io.modelcontextprotocol.spec.McpSchema$ClientCapabilities$Elicitation), not marked as ignorable (0 known properties: ])
    at [Source: UNKNOWN; byte offset: #UNKNOWN] (through reference chain: io.modelcontextprotocol.spec.McpSchema$InitializeRequest["capabilities"]->io.modelcontextprotocol.spec.McpSchema$ClientCapabilities["elicitation"]->io.modelcontextprotocol.spec.McpSchema$ClientCapabilities$Elicitation["form"])
       at R8i.O (vscode-file://vscode-app/c:/Users/*******/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/workbench/workbench.desktop.main.js:2265:35574)
       at R8i.L (vscode-file://vscode-app/c:/Users/*******/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/workbench/workbench.desktop.main.js:2265:35369)
       at Sce.value (vscode-file://vscode-app/c:/Users/*******/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/workbench/workbench.desktop.main.js:2265:34358)
       at E.C (vscode-file://vscode-app/c:/Users/*******/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/workbench/workbench.desktop.main.js:29:2349)
       at E.fire (vscode-file://vscode-app/c:/Users/*******/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/workbench/workbench.desktop.main.js:29:2568)
       at cMs.pushMessage (vscode-file://vscode-app/c:/Users/*******/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/workbench/workbench.desktop.main.js:604:55563)
       at lli.$onDidReceiveMessage (vscode-file://vscode-app/c:/Users/*******/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/workbench/workbench.desktop.main.js:604:52099)
       at zRt.S (vscode-file://vscode-app/c:/Users/*******/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/workbench/workbench.desktop.main.js:3894:40815)
       at zRt.Q (vscode-file://vscode-app/c:/Users/*******/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/workbench/workbench.desktop.main.js:3894:40593)
       at zRt.M (vscode-file://vscode-app/c:/Users/*******/AppData/Local/Programs/Microsoft%20VS%20Code/resources/app/out/vs/workbench/workbench.desktop.main.js:3894:39681)
   

   VS Code Details:

   Version: 1.107.1 (user setup)
   Commit: 994fd12f8d3a5aa16f17d42c041e5809167e845a
   Date: 2025-12-17T14:15:14.850Z
   Electron: 39.2.3
   ElectronBuildId: 12895514
   Chromium: 142.0.7444.175
   Node.js: 22.21.1
   V8: 14.2.231.21-electron.0
   OS: Windows_NT x64 10.0.26100
   

   👍React with 👍2Reacted by Anton Tarasov and flopevel
4. flopevel commented on Dec 30, 2025

   

   flopevel

   on Dec 30, 2025

   More actions

   Hi, We are experiencing the same problem:
   2025-12-30 15:52:00.279 [error] Error: MPC -32603: Unrecognized field "form" (class io.modelcontextprotocol.spec.McpSchema$ClientCapabilities$Elicitation), not marked as ignorable (0 known properties: ])
   We have a reactive MCP server with type: ASYNC y protocol: STATELESS
5. devxb commented on Jan 8, 2026

   

   devxb

   on Jan 8, 2026

   Last edited by devxb

   More actions

   I resolved this issue by using a filter.

   I registered a filter at the servlet level, and when an MCP request comes in, the filter removes elicitation.form from the request payload before it is processed.

   There is already a related PR that addresses this issue, and I think it should be merged:
   modelcontextprotocol/java-sdk#725

   spring-ai-starter-mcp-server-webmvc:1.1.2

   ❤️React with ❤️2Reacted by flopevel and guwei0kanyun
6. adityamparikh

   added a commit that references this issue on Jan 11, 2026

   feat: change MCP server protocol from streamable to stateless

   ...

   7528f2f
7. jsurls

   added a commit that references this issue on Jan 20, 2026

   Upgrade MCP SDK to 0.17.1

   ...

   This issue will close once commit eb03b47 is merged into the 'main' branch.

   eb03b47
8. ilayaperumalg

   closed this as completedin d81e47don Jan 22, 2026
9. pull

   added a commit that references this issue on Jan 22, 2026

   Upgrade MCP SDK to 0.17.2

   ...

   This issue will close once commit d81e47d is merged into the 'main' branch.

   d81e47d
10. chabinhwang

    added 2 commits that reference this issue on Jan 24, 2026

    Upgrade MCP SDK to 0.17.2

    ...

    This issue will close once commit ac47a76 is merged into the 'main' branch.

    ac47a76

    Upgrade MCP SDK to 0.17.2

    ...

    This issue will close once commit a306567 is merged into the 'main' branch.

    a306567