Show HN: Smart model routing directly in Claude, Codex and Cursor

One endpoint. Every model. Always the right one. A drop-in proxy for Anthropic, OpenAI, and Gemini that picks the best model for every request: using a tiny on-box embedder, not a vibes-based prompt. 🥇 #1 on the RouterArena leaderboard 1 — Acc-Cost Arena 76.09. Built by Weave: The #1 engineering intelligence platform, loved by Robinhood, PostHog, Reducto, and hundreds of others. Point Claude Code, Codex, Cursor, or your own app at localhost:8080. The router: The fastest way: point Claude Code, Codex, or opencode at the hosted Weave Router with one command. No clone, no Docker, no Postgres. npx @workweave/router That's it. The installer asks which tool (Claude Code, Codex, or opencode), walks you through scope (user vs. project), grabs a router key, and wires the right config file. Other flavors: npx @workweave/router --claude # skip the picker, Claude Code npx @workweave/router --codex # skip the picker, OpenAI Codex CLI npx @workweave/router --opencode # skip the picker, opencode npx @workweave/router --scope project # per-repo, commits settings.json (or .codex/ / opencode.json) npx @workweave/router --local # self-hosted localhost:8080 npx @workweave/router --base-url https://router.acme.internal npx @workweave/router@0.1.0 # pin a version Requires Node ≥ 18 (Claude Code and opencode paths also need jq). Full flag reference: install/npm/README.md. If you want the router (and dashboard) running on your own box: # 1. Drop a provider key in. OpenRouter is the recommended baseline. echo "OPENROUTER_API_KEY=sk-or-v1-..." >> .env.local # 2. Boot Postgres + router on :8080 and seed an rk_ key. make full-setup The router is up at http://localhost:8080, the dashboard at http://localhost:8080/ui/ (password: admin), and your rk_... key prints in the logs. # Call it like Anthropic curl -sS http://localhost:8080/v1/messages \ -H "Authorization: Bearer rk_..." \ -d '{"model":"claude-sonnet-4-5","max_tokens":256, "messages":[{"role":"user","content":"hi"}]}' # ...or like OpenAI curl -sS http://localhost:8080/v1/chat/completions \ -H "Authorization: Bearer rk_..." \ -d '{"model":"gpt-4o-mini", "messages":[{"role":"user","content":"hi"}]}' # Peek at the routing decision without proxying curl -sS http://localhost:8080/v1/route -H "Authorization: Bearer rk_..." -d '...' Wire it into your tools Claude Code. Run make install-cc to wire Claude Code at the local self-hosted router (it's also invoked automatically at the end of make full-setup). For the hosted router, use npx @workweave/router above. Codex (OpenAI CLI). npx @workweave/router --codex patches ~/.codex/config.toml (or /.codex/config.toml with --scope project) with a managed [model_providers.weave] block and sets model_provider = "weave". Codex's existing OPENAI_API_KEY flows through to api.openai.com for the plan-based passthrough; the router key rides in an X-Weave-Router-Key HTTP header. Re-install and --uninstall --codex rewrite/remove only the managed block, leaving the rest of your Codex config untouched. opencode. npx @workweave/router --opencode merges a provider.weave entry into ~/.config/opencode/opencode.json (or /opencode.json with --scope project). It uses opencode's bundled @ai-sdk/anthropic provider pointed at the router's /v1 endpoint — the router speaks the Anthropic Messages API natively, so opencode works unmodified. The router key and identity headers ride alongside the provider config; re-install rewrites only the managed block and --uninstall --opencode strips it. Cursor (early beta, performance may not be the best). Settings → Models → Override OpenAI Base URL → http://localhost:8080/v1, paste rk_... as the API key. Switching on/off. After installing, npx @workweave/router off --claude (or --codex / --opencode) routes that client straight to its provider again without discarding the router config; on flips it back, and status reports which way it's pointing. Claude Code also gets /router-off, /router-on, and /router-status slash commands. Cursor toggles via the same Settings → Models override above. See install/README.md. Endpoint Format POST /v1/messages Anthropic Messages, routed POST /v1/chat/completions OpenAI Chat Completions, routed POST /v1beta/models/:action Gemini generateContent, routed POST /v1/route Returns the decision, no upstream call GET /v1/models · POST /v1/messages/count_tokens Anthropic passthrough GET /health · GET /validate liveness + key check Deeper docs 📐 Configuration reference: every env var, BYOK encryption, OTel knobs, cluster routing. 🛠️ Contributing: layering rules, hot-reload dev, migrations, tests, the whole engineering loop. 🏗️ Architecture: package layout, import contracts, recipes for adding endpoints / providers / strategies. Roadmap Token-aware rate limiting (Redis sliding window per installation) Sub-installations for tenant hierarchies Speculative dispatch + hedging for tail latency Footnotes Lu, Y., Liu, R., Yuan, J., Cui, X., Zhang, S., Liu, H., & Xing, J. RouterArena: An

Show HN: Smart model routing directly in Claude, Codex and Cursor

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