OpenAI / github.com/openai/codex Codex CLI v0.134.0: Search Your Conversation History, MCP Tools Run in Parallel
OpenAI released Codex CLI v0.134.0 on May 26, adding search across local conversation history with case-insensitive matching and result previews. The release also makes read-only MCP tools run concurrently and cleans up profile management.
OpenAI shipped Codex CLI v0.134.0 on May 26. The most immediately useful change is conversation history search. The MCP layer also gets concurrent execution for read-only tools, and --profile takes over as the single consistent way to select profiles across all Codex flows.
Search Conversation History
You can now search across all your local Codex conversations. The search is case-insensitive and shows result previews alongside each match, so you can find the session where you worked through a particular problem without scrolling through dozens of entries.
This fills an obvious gap. As Codex conversation logs accumulate, navigating back to specific sessions had relied entirely on timestamps or memory. Search makes older context actually reachable.
Concurrent Read-Only MCP Tools
MCP tools that advertise readOnlyHint: true now run in parallel instead of sequentially. If a workflow calls several read-only tools in sequence (checking file contents, querying an API, reading config), they all fire at once. The output is still assembled in order before being handed to the model.
This is a throughput win for agent workflows that stack multiple read queries before deciding what to do next.
Profile Management Cleanup
--profile is now the primary profile selector across the CLI, TUI, and sandbox flows. Legacy profile configs that don’t match the current format are rejected with migration guidance rather than silently accepted. If you have older profile configs, you’ll see a message pointing you to the format change.
MCP Schema and Environment Improvements
The MCP setup now supports per-server environment targeting, so you can point individual servers at different environment variable sets. Streamable HTTP servers also get OAuth options.
Connector tool schemas are more reliable in two ways: local $ref/$defs structures are preserved when schemas are passed to the model, and oversized schemas are automatically compacted before exposure. Both fix edge cases where complex tool definitions would get mangled or truncated.
Extension tools also now receive conversation history as context, which gives plugin authors more to work with when deciding how a tool should respond.
Bug Fixes
The release fixes Windows TUI rendering corruption by restoring virtual terminal mode correctly on startup. Workspace-specific usage-limit messages now display properly, and Node-based tools correctly pick up Codex’s managed network proxy environment.
Sources: Release v0.134.0 — OpenAI on GitHub, May 26, 2026; Codex CLI changelog — OpenAI Developers