Codex `rust-v0.139.0` adds web search in code mode and richer MCP schema support
OpenAI's Codex `rust-v0.139.0` ships standalone web search in code mode, improved MCP tool schema compatibility, and a range of TUI and sandbox bug fixes.
Score breakdown
The `oneOf`/`allOf` schema preservation and web search additions extend Codex's compatibility with richer MCP tools and broaden what code mode agents can do without leaving the coding workflow.
- 01Code mode can now call standalone web search directly, including from nested JavaScript tool calls, returning plaintext results (#26719).
- 02Tool and connector input schemas now preserve `oneOf` and `allOf`; large schemas retain more shallow structure during compaction (#24118, #27084).
- 03`codex resume --last` and `codex fork --last` now correctly treat the trailing argument as an initial prompt, not a session ID (#26818).
Codex `rust-v0.139.0` adds the ability for code mode to call standalone web search directly, including from nested JavaScript tool calls, with results returned as plaintext. On the tooling side, input schemas for tools and connectors now correctly preserve `oneOf` and `allOf` constructs, and the compaction logic for large schemas retains more shallow structure — both changes aimed at improving compatibility with richer MCP tools.
The `codex doctor` command now includes editor and pager environment details in its local report while redacting raw values in JSON output.
The `codex doctor` command now includes editor and pager environment details in its local report while redacting raw values in JSON output. Plugin marketplace automation also gains improvements: `codex plugin marketplace list --json` now exposes each marketplace source, and plugin lists can return from the cached remote catalog before refreshing in the background.
Several notable bugs were resolved: `codex resume --last "..."` and `codex fork --last "..."` now correctly treat the trailing argument as an initial prompt rather than a session ID; MCP startup warnings from subagents are now scoped to their owning thread, eliminating duplicate parent-thread alerts and stuck startup spinners; image edits now route through the exact referenced file paths instead of guessing from conversation history; and thread resets via `/new`, `/clear`, and `/fork` no longer drop cloud-managed requirements or feature flags. On the infrastructure side, release builds once again publish separate symbol archives with line tables for improved crash symbolication, and the embedded V8 toolchain was updated to `rusty_v8` `149.2.0`.
Key facts
- 01Code mode can now call standalone web search directly, including from nested JavaScript tool calls, returning plaintext results (#26719).
- 02Tool and connector input schemas now preserve `oneOf` and `allOf`; large schemas retain more shallow structure during compaction (#24118, #27084).
- 03`codex resume --last` and `codex fork --last` now correctly treat the trailing argument as an initial prompt, not a session ID (#26818).
- 04MCP startup warnings from subagents are now scoped to their owning thread, preventing duplicate alerts and stuck spinners in the TUI (#26639).
- 05Thread resets (`/new`, `/clear`, `/fork`) no longer drop cloud-managed requirements or feature flags during TUI config reloads (#25177).
- 06Sandbox execution now preserves approved escalation decisions and enforces configured proxy-only networking more consistently (#24981, #27035).
- 07The embedded V8 toolchain was updated to `rusty_v8` `149.2.0` (#26464).
Topics
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