Skip to content

Node REPL broken: sandboxPolicy missing in MCP request meta (version mismatch) #29211

Closed as duplicate

Description

@memeshe069-beep

Bug Description

Node REPL MCP server rejects all js calls with error:
Mcp error: -32602: js: codex/sandbox-state-meta: missing field sandboxPolicy

Environment

  • Codex App: 26.616.5445.0 (Windows Store)
  • Codex CLI: 26.616.41845
  • Node REPL runtime: a89897d3d9baa117
  • OS: Windows 10 x64
  • Node: v24.14.0

Root Cause

The node_repl.exe binary requires sandboxPolicy field in MCP request _meta.codex/sandbox-state-meta, but Codex CLI (26.616.41845) does not inject this field. This is a version mismatch between the App and CLI/runtime.

Attempted Fixes (all failed)

  1. Deleted and re-downloaded cua_node runtime (downloaded same broken version)
  2. Replaced entire runtime with App's bundled version (26.616.5445)
  3. Fixed @oai/sky package.json exports ("./dist/": "./dist/")
  4. Verified module imports work standalone, but MCP transport rejects before JS runs

Impact

  • Computer Use completely unusable
  • In-app Browser unusable
  • Chrome extension unusable
  • All Node REPL-dependent features broken

Workaround

WScript.Shell SendKeys works for basic Windows automation but lacks Computer Use capabilities.

Activity

  1. added
    bugSomething isn't working
    appIssues related to the Codex desktop app
    windows-osIssues related to Codex on Windows systems
    mcpIssues related to the use of model context protocol (MCP) servers
    on Jun 20, 2026
  2. Necmttn commented on Jun 21, 2026

    @Necmttn

    The MCP request meta should be versioned or capability-negotiated. If the Node REPL runtime requires codex/sandbox-state-meta.sandboxPolicy, the client should either always include that field or fail startup with "runtime requires meta schema X, client provides Y."

    A regression should pair old CLI/new runtime and new CLI/old runtime, then assert missing meta fields produce a compatibility diagnostic before user JS calls run. That beats surfacing a generic -32602 from inside the tool.


    Generated with ax.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    appIssues related to the Codex desktop appbrowserbugSomething isn't workingcomputer-usemcpIssues related to the use of model context protocol (MCP) serverswindows-osIssues related to Codex on Windows systems

    Type

    No type

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions