OpenAI shipped Codex CLI version 0.134.0 on May 26. Per the GitHub release notes, the headline items are conversation-history search and concurrent execution of read-only MCP tools, plus a profile-config migration step and additional hook context.

Conversation history is searchable

The release notes’ exact wording: “Added search across local conversation history, including case-insensitive content matches with result previews.” Codex previously stored conversation history but did not offer a search surface inside the CLI. The 0.134.0 release lets you find prior conversations by content match rather than by timestamp.

Read-only MCP tools run in parallel

The bullet that does the most: “Let read-only MCP tools run concurrently when they advertise readOnlyHint.” readOnlyHint is an MCP spec field server authors set on individual tools. Tools marked readOnlyHint: true now fire concurrently within the same Codex session.

Profile config migration is enforced

--profile becomes the primary profile selector. Per the release notes: “Made --profile the primary profile selector across CLI, TUI permissions, and sandbox flows, with legacy profile configs rejected through migration guidance.” Legacy configurations are not silently accepted; they are rejected and the CLI prints migration guidance.

Hook context is richer

The release notes also describe richer hook input: “Added richer extension and hook context, including conversation history for extension tools and subagent identity in hook inputs.” Per-server environment targeting and OAuth options for streamable HTTP MCP servers ship in the same release.

The reframe — that read-only MCP concurrency is the third default-on flip this week — is taken up in your MCP tools are running in parallel now.