Jev Tool Runner

It selects a native Codex tool call with Jev before the coding model is invoked. Codex then executes that call through its own tool runtime, approvals and sandbox, the result stays in the conversation, and the coding model handles reasoning, edits and the final answer — the router itself never opens files or runs commands.

It intercepts the model-provider request, so an optional MCP call or PreToolUse hook cannot remove reasoning that has already occurred the way this can. The desktop app's already-running tasks are not patched either: you use the wrapper to launch or resume a Codex CLI session.

The Codex adapter offers bounded, numbered reads of relative source paths explicitly named in the current user message. Jev chooses among at most eight offers or hands control to the coding model, and Codex executes at most four selected calls before handoff; completed calls are excluded from later choices.

The current user goal, a small set of tool choices and completion metadata — not source-file output. The README is explicit that the router does not open repository files, execute commands or conduct a separate investigation; it only decides among host-supplied native calls.

With Node 22+ and an authenticated Codex CLI: npm ci, npm run build, then node dist/router-cli.js --key-file /path/to/private.env -- -C /path/to/your/project. For an existing session, pass resume SESSION_ID after the --. The README notes it was verified with Codex CLI 0.153.4.

Unsupported requests, missing tool support, provider failures and timeouts all fall back to the ordinary coding-model request. The exported ToolSelector interface can choose among other host-supplied native calls without gaining execution privileges, and the wrapper does not change the selected model, reasoning effort, permissions or hook trust.

Not for this architecture. The README says the older autonomous runner, MCP server and investigation hooks are not the native tool selector and their historical benchmarks do not establish savings for it. Verification is through npm run test:all and npm run check plus a live smoke harness with --baseline and --offline modes; those runs consume usage and are not run by CI.