[Windows][MCP OAuth] Fresh startup requires reauthentication despite valid file-stored credentials

What version of Codex CLI is running?

0.153.4

What subscription do you have?

ChatGPT Plus

Which model were you using?

gpt-5.6-sol high

What platform is your computer?

Windows x64

What terminal emulator and version are you using (if applicable)?

Windows Terminal

Codex doctor report

What issue are you seeing?

codex mcp login mfc_ca succeeds and OAuth credentials are correctly stored in %USERPROFILE%\.codex\.credentials.json.

I verified without exposing token values that the stored credential has:

• the correct MCP server URL
• issuer
• access token
• refresh token
• an expiration time in the future
• read-only Money Forward scopes

However, every fresh Codex CLI startup reports:

The mfc_ca MCP server requires OAuth reauthentication.
MCP startup incomplete (failed: mfc_ca)

The issue also reproduces with Codex 0.154.0-alpha.3 and with features.mcp_2026_07_28=true.

What steps can reproduce the bug?

1. Configure a remote Streamable HTTP MCP server using OAuth.
2. Set mcp_oauth_credentials_store = "file".
3. Run codex mcp logout mfc_ca.
4. Run codex mcp login mfc_ca.
5. Complete OAuth successfully in the browser.
6. Confirm that the OAuth credential is stored and still unexpired.
7. Start a fresh Codex CLI session.
8. Codex immediately asks for OAuth reauthentication again.

What is the expected behavior?

No response

Additional information

No response

Reproduce the flow with codex mcp logout mfc_ca, codex mcp login mfc_ca, and a fresh startup, then inspect the credentials in %USERPROFILE%\.codex\.credentials.json. Verify how the fresh session handles the unexpired file-stored OAuth credential on Windows; done means it starts the MCP server without requesting reauthentication.