Published reported case

Reported case: MCP works in Codex CLI but is unavailable in Codex Desktop

A human-reviewed reported case. The claim is limited to the listed surface, version, operating system, account/workspace context, and observation date.

EXPOSED published Source C · current

Check your own evidence Evidence archive

Observed boundary

The same MCP configuration can execute a tool in standalone Codex CLI but the Codex Desktop thread reports it unavailable.

A contributor reports the same MCP configuration working through standalone Codex CLI while the Codex Desktop session reports the tool unavailable.

The checkpoint labels the first bounded layer supported by this source. It does not prove the same root cause in another environment or assign fault.

Evidence status

First checkpoint: EXPOSED
Review state: published
Confirmed by human: yes
Indexable: yes
Observed: 2026-06-26
Evidence valid until: 2026-10-01T23:59:59.000Z

Scoped environment

Host: codex
Primary surface: desktop
Comparison surface: standalone CLI / codex exec
Operating system: Windows 10.0.26200 x64
Version scope: Desktop 26.623.5175.0; standalone CLI 0.142.0; bundled CLI 0.142.3
Account scope: custom provider, details omitted
Workspace/session scope: same user config.toml

Reported workaround and verification

Scoped observation, not a universal fix

Bounded workaround

Use the standalone Codex CLI/codex exec surface for the same bounded task while retaining the original configuration unchanged.

Verification recorded

The named MCP tool completes the representative call in standalone CLI while the contemporaneous Desktop thread still reports it unavailable.

Rollback or stop condition

If the standalone CLI also cannot call the tool, stop using this record and re-diagnose registration, authentication, or execution.

Primary upstream source

MCP tools reported available in CLI but unavailable in Codex Desktopopenai/codex contributor report

Capability Lab reviewed the bounded observation; it is not OpenAI and this page does not imply OpenAI endorsement or affiliation.

What this record does not prove

The report supports comparing surfaces; it does not establish a universal Desktop defect.
The two surfaces can still differ in bundled version, process environment, session, account, or workspace.
It does not establish a product-wide incident, universal affected-version range, or publisher fault.
Issue closure does not establish a fixed version unless the upstream source explicitly documents one.
It does not raise Capability Doctor confidence; user-supplied checkpoint evidence still controls a new diagnosis.