Codex Desktop 26.616.x: new conversation fails with "Invalid request: missing field inputSchema" while old threads and CLI work

What version of the Codex App are you using (From “About Codex” dialog)?

26.616.5445.0 Both stable and beta Appx packages reproduced the issue on this machine: - OpenAI.Codex 26.616.5445.0 - OpenAI.CodexBeta 26.616.5445.0 The regression was first noticed after updating the Microsoft Store stable app from the previous working version; an earlier failing stable build observed during troubleshooting was 26.616.3767.0.

What subscription do you have?

ChatGPT Pro

What platform is your computer?

Microsoft Windows NT 10.0.26100.0 x64 Additional environment: - Windows Store Codex Desktop App - Agent environment: WSL / Ubuntu - Codex CLI: codex-cli 0.139.0

What issue are you seeing?

After updating Codex Desktop 26.616.x, creating a new conversation or new project fails before normal chat starts.

Full user-visible errors:

创建任务时出错
Invalid request: missing field `inputSchema`

启动对话时出错
Invalid request: missing field `inputSchema`

English summary:

New conversation / new task fails with:
Invalid request: missing field `inputSchema`

Important behavior:

Existing old conversations continue to work in the Desktop UI.
New conversations fail immediately after sending any prompt.
The same shared Codex configuration works through CLI in normal local use.
Installing Codex Beta did not fix it. Stable and Beta both reproduced the same failure.
Disabling node_repl in shared config.toml was tested as a quarantine attempt, did not fix the issue, and was rolled back successfully.
No local evidence points to Firecrawl as the malformed tool descriptor source.

Environment details, PII redacted:

Codex App:
- Stable: OpenAI.Codex 26.616.5445.0
- Beta: OpenAI.CodexBeta 26.616.5445.0

Codex CLI:
- codex-cli 0.139.0

Agent:
- WSL / Ubuntu

CODEX_HOME:
- /mnt/c/Users/<USER>/.codex

CODEX_CLI_PATH:
- C:\Users\<USER>\.codex-tools\codex-wsl-launcher.exe

Configured MCP servers:
- node_repl
- firecrawl

Firecrawl:
- remote HTTP MCP
- bearer_token_env_var = FIRECRAWL_API_KEY
- token is not included in config or this report

One-pass local diagnostic conclusion:

ROOT_CAUSE_LIKELY_APP_INJECTED_OR_BUNDLED_TOOL

Most likely breakpoint:

Desktop app-injected / bundled Browser Use + node_repl / cua_node dynamic tool surface,
or a related remote app-server / feature-flag rollout.

The local diagnostic did not find a persisted readable log containing the exact server-rejected descriptor name. The error shown by Desktop also does not name the offending tool.

### What steps can reproduce the bug?

Feedback ID: 019ece18-4940-7df3-b6bd-a551dbfc953c

### What is the expected behavior?

Creating a new Codex Desktop conversation should start a normal chat session.

If one of the Desktop-injected, bundled, or MCP tool descriptors is malformed, the app should either:

1. include the required `inputSchema`, or
2. reject / disable only the offending tool, or
3. show a diagnostic error naming the exact offending tool descriptor.

The user should not be blocked from starting all new conversations when existing old conversations and CLI sessions can still work.

### Additional information

I have a redacted diagnostic zip that can be attached:

```text
codex_ui_inputschema_onepass_redacted_20260620T174931Z.zip

The diagnostic zip contains:

DIAGNOSTIC_SUMMARY.md
OFFICIAL_BUG_REPORT.md
RETURN_MANIFEST.md
redacted/config_toml_redacted.toml
analysis/root_cause_hypothesis_matrix.csv
analysis/static_descriptor_findings.md
analysis/validated_descriptor_findings.md
analysis/tool_descriptor_candidates.csv
analysis/missing_inputschema_candidates.csv
analysis/node_repl_runtime_summary.txt
raw/codex_mcp_list.txt
raw/appx_codex_packages.txt
raw/eventlogs_codex_recent7d_redacted.txt
results/run_summary.json
artifacts/zip_safety_scan.txt

Zip safety scan result:

UNSAFE ENTRIES DETECTED: none

The diagnostic intentionally excluded:

- .codex/auth.json
- raw .codex session JSONL
- tokens
- cookies
- secrets
- raw dumps
- local_only_do_not_upload/

Diagnostic hypothesis matrix summary:

unlikely: user Firecrawl MCP malformed descriptor
unlikely: config-only node_repl entry is sufficient to trigger the issue
unlikely: CODEX_CLI_PATH / launcher bridge failure
unlikely: WSL / CLI binary failure

likely: Desktop app-injected or bundled Browser Use + node_repl / cua_node dynamic tool surface
likely: related remote app-server or feature-flag rollout affecting new-thread tool descriptor assembly

Related public issue if useful for deduplication:

openai/codex#28978

The practical impact is severe: old Desktop conversations are still usable, but all new Desktop conversations / projects are blocked.