workweave/router
Model router for agentic systems. Routes every prompt to the right model in <50ms. Cut costs 40-70% with just an endpoint change. - workweave/router
500 stars · 23 forks · 0 watchers · Go Topics: codex, anthropic, ai-gateway, openai-compatible, claude-code, agentic-coding, model-router
README
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.
Built by Weave: The #1 engineering intelligence platform, loved by Robinhood, PostHog, Reducto, and hundreds of others.
What it does Point Claude Code, Codex, Cursor, or your own app at localhost:8080. The router:
🎯 Routes per request. A cluster scorer derived from Avengers-Pro 1 picks the right model from your enabled providers, every turn. 🔌 Speaks everyone's API. Anthropic Messages, OpenAI Chat Completions, Gemini native. Streaming, tools, vision, the works. 🧠 Knows OSS too. DeepSeek, Kimi, GLM, Qwen, Llama, Mistral via OpenRouter (or any OpenAI-compatible endpoint). 🔒 BYOK by default. Provider keys stay on your box, encrypted at rest. 📊 Observable. OTLP traces out of the box. See them in the Weave dashboard (http://localhost:8080/ui/dashboard) or drop in Honeycomb, Datadog, Grafana, whatever.
30-second quickstart 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. Or: self-host the whole stack 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.local2. 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 <repo>/.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 <repo>/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.Two keys, don't mix them up:
sk-or-... / sk-ant-... / sk-... = your upstream provider key. Lives in .env.local. rk_... = your router key. Clients send this as a Bearer token.
Endpoints
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.
Star history
Footnotes
Zhang, Y. et al. Beyond GPT-5: Making LLMs Cheaper and Better via Performance–Efficiency Optimized Routing (Avengers-Pro). arXiv:2508.12631, 2025. https://arxiv.org/abs/2508.12631 ↩