Desktop codex_app MCP tools break strict Responses providers (Meta): Recursive JSON schemas not supported #44144

What

On ChatGPT/Codex Desktop (Windows, app 26.903.8094.0, bundled codex 0.153.4), any request with model routed to Meta's Responses API via OpenCode Go (muse-spark-1.3-contributor, https://opencode.ai/zen/[go/v1/responses](https://www.golinks.io/v1/responses?trackSource=github)) fails immediately, before any tool executes:

Error from provider (Console Go): Upstream request failed: [invalid_request_error] Recursive JSON schemas are not currently supported

Meta documents that recursive schemas return HTTP 400 (https://ai.developer.meta.com/docs/features/structured-output). GPT models accept the same request fine.

Desktop-only

Same machine, same codex version (bundled 0.153.4 binary), same config/model/provider: codex exec succeeds (PROVIDER_OK). Only Desktop fails. The delta between CLI and Desktop is the Desktop-injected mcp_servers.codex_app (automation_update, create_thread, send_message_to_thread, fork_thread, handoff_thread) plus Desktop-managed node_repl. All user MCP servers disabled, all [plugins] identical in the passing CLI run. By elimination the recursive $ref comes from the Desktop-only app tools (nested message/thread content shapes are the classic pattern).

Ask

Either sanitize recursive $refs in tool schemas before sending (inline local refs / replace cycles with permissive object, cf. anomalyco/opencode#29295 / #16910), or support user-side disabling of codex_app tools. Currently a user-side [mcp_servers.codex_app] table without full transport is rejected (invalid transport), and the table is injected via -c so it can't be overridden from config.toml.

Repro

1. Provider with wire_api=responses pointing at a strict Meta endpoint, model muse-spark-1.3-contributor + model_catalog_json entry.
2. Desktop: send anything (even 'yo') -> instant invalid_request_error.
3. Same binary CLI exec -> works.