jev-gateway
Local proxy for Codex, Claude Code, OpenCode, Kilo, Gemini, and Devin: Jev picks the tool each turn, fails open, listens on 127.0.0.1 only.
Overview
jev-gateway (github.com/vinilana/jev-gateway, MIT, npm jev-gateway 0.5.1) is vinilana's localhost proxy for coding agents. Launchers jev-codex, jev-claude, jev-opencode, jev-kilo, jev-gemini, and jev-devin start a background gateway on 127.0.0.1, then run the real CLI unchanged. Each turn the gateway asks Jev which tool fits. When Jev is confident, Codex requests can be rewritten toward that tool. When Jev is unsure or offline, traffic passes through unchanged. First-run setup stores keys in ~/.jev-gateway/.env after one live Jev check. Jev can be reached via TypeSafe, OpenRouter, Vercel AI Gateway, or OpenCode Zen per the README provider table.
Problem: Coding agents send large tool menus to expensive reasoning models every turn, even when a fast decision could pick the right tool.
Built for: Developers running Codex, Claude Code, OpenCode, Kilo, Gemini CLI, or Devin locally who want Jev to steer tool_choice without replacing their login.
First indexed on Jev Directory: 2026-09-18
Creator and team
- Name
- vinilana
- Handle
- @vinilana
How Jev is used
- Role in the product flow
- Per agent turn Choice over declared tools before the upstream LLM request is sent
- Primitives
- Choice
- State in
- Tool names, descriptions, and conversation context the gateway extracts from OpenAI, Anthropic, or Gemini compatible requests.
- Decision out
- Steered tool_choice for Codex when allowed, or a short hint appended for Claude Code hint mode.
- npm install -g jev-gateway and run jev-codex or another launcher
- Pick Jev provider in setup and paste API key
- Use jev-codex --dashboard to watch routing, latency, and token counts
- Toggle jev-codex --routing off for baseline comparison on similar tasks
jev-gateway picks the tool name for agent HTTP traffic. gargpratyush-jev-router and 0xnatoshi-jev-codex-router style projects pick model tier or reasoning depth per turn instead. vinilana-jev-eval-agent and vinilana-jev-browser are sibling repos from the same author for eval and browser automation. The gateway fails open: Jev errors never block the upstream CLI. It listens on localhost only. Measure on your own tasks before you trust bench medians.
Sourced performance claims
- README Claude Code caveat: extended thinking and prompt cache block forced tool_choice, so the gateway adds a non-binding hint. Expect better tool picks on large tool lists, not lower cost or latency.Source: github.com/vinilana/jev-gateway README Using it with Claude Code
- README Benchmark section cites jev-gateway-bench: 120 agent sessions on chess tasks; medians vary by model and task; five runs per cell is a small sample; Opus 5 feature task got worse with routing on some metrics.Source: github.com/vinilana/jev-gateway README Benchmark
- GitHub repo vinilana/jev-gateway had 301 stars and 41 forks on 2026-10-07. npm jev-gateway latest is 0.5.1 published 2026-10-06 per CHANGELOG.Source: GitHub and npm, 2026-10-07
Features and stack
Features
- Six jev- launchers with shared ~/.jev-gateway/.env
- Dashboard on port 8790 with peer discovery and routing reasons
- --routing off baseline mode for A/B token comparison
- Codex Responses API support including apply_patch style tools
- OpenCode agent bypass warnings from opencode debug config
Stack
- Node.js 22.15+
- TypeSafe, OpenRouter, Vercel AI Gateway, or OpenCode Zen for Jev
- Codex, Claude Code, OpenCode, Kilo, Gemini CLI, or Devin installed
Pricing: MIT open source; Jev calls bill through whichever provider key you configure; agent subscriptions stay separate.
Links
FAQ
- Can Claude Code force a tool like Codex?
- No. The README says Claude Code runs with extended thinking and cached conversations, so the gateway uses hint mode only. Codex can force the tool when the API allows it.
- What happens if Jev is down?
- README: every request goes straight to the LLM. The gateway never makes a request fail because Jev errored.
- Which npm version should I install?
- CHANGELOG shows 0.5.1 on 2026-10-06 with a Codex reviewer tool_choice fix. npm install -g jev-gateway pulls latest unless you pin.
Related learn guides
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