weave-os/router
Model router for agentic systems. Routes every prompt to the right model in <50ms. Cut costs 40-70% with just an endpoint change.
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.*
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What it does
Point Claude Code, Codex, Cursor, or your own app at localhost:8080. The router:
- 🎯 Routes per action. A cluster scorer derived from
- 🔌 Speaks everyone's API. Anthropic Messages, OpenAI Chat Completions,
- 🧠 Knows OSS too. DeepSeek, Kimi, GLM, Qwen, Llama, Mistral via
- 🔒 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,
30-second quickstart
The fastest way: point Claude Code, Codex, opencode, or pi at the hosted Weave Router with one command. No clone, no Docker, no Postgres.
npx @weave-os/router
That's it. The installer asks which tool (Claude Code, Codex, opencode, or pi), walks you through scope (user vs. project), grabs a router key, and wires the right config file. Other flavors:
npx @weave-os/router --claude # skip the picker, Claude Code
npx @weave-os/router --codex # skip the picker, OpenAI Codex CLI
npx @weave-os/router --opencode # skip the picker, opencode
npx @weave-os/router --pi # skip the picker, pi + Loom UI
npx @weave-os/router --scope project # per-repo, commits settings.json (or .codex/ / opencode.json)
npx @weave-os/router --local # self-hosted localhost:8080
npx @weave-os/router --base-url https://router.acme.internal
npx @weave-os/[email protected] # pin a version
Requires Node ≥ 18 (Claude Code, opencode, and pi paths also need jq). Full
flag reference: install/npm/README.md.
The npm package is published as @weave-os/router. The former
@workweave/router package remains available as a compatibility alias and
continues to receive the same releases.
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.local
2. Set a dashboard password. Without one, inference still runs but
dashboard administration is disabled.
echo "ROUTER_ADMIN_PASSWORD=replace-with-a-strong-password" >> .env.local
3. Boot Postgres + router on :8080 and seed an rk_ key.
make full-setup
The router is up at , the dashboard at
, 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 '...'
What that stack looks like
Only the grey boxes are off your machine. The router, the scorer, Postgres, and your provider keys all stay local; prompts go from the router straight to the provider you configured, never to Weave.
flowchart LR
client["Claude Code, Codex, opencode,
pi, Cursor, your own app"]
router["Router :8080
/v1/messages · /v1/chat/completions
/v1beta/models · /v1/route"]
scorer["Cluster scorer
in-process ONNX embedder"]
hmm["HMM policy sidecar :8093
optional, make up-hmm"]
pg[("Postgres
installations, rk_ keys,
encrypted BYOK keys, usage")]
ui["Dashboard /ui
selfhosted mode only"]
providers["Anthropic · OpenAI · Gemini
OpenRouter and any
OpenAI-compatible endpoint"]
otel["Your OTLP collector
Honeycomb, Datadog, Grafana"]
client -->|"rk_… bearer token,
streamed response back"| router
router -->|"embed and score the action"| scorer
router -.->|"ROUTER_DEFAULT_STRATEGY=hmm"| hmm
router -->|"auth, config, usage"| pg
pg --> ui
router -->|"provider key from env or BYOK"| providers
router -.->|"spans and usage logs"| otel
classDef external fill:#f4f4f5,stroke:#a1a1aa,color:#3f3f46
class providers,otel external
Multi-replica deployments also need Pub/Sub (PUBSUB_*) for cache
invalidation; docker compose runs the emulator for you.
Optional: self-host the frozen HMM policy
The default stack uses the in-process cluster scorer. To run the frozen HMM policy as a companion container, add a Google API key and use the opt-in target:
echo 'GOOGLE_API_KEY=...' >> .env.local
make up-hmm
This does not change the default strategy. See
sidecars/hmm/README.md for artifact verification,
embedding compatibility, and explicit HMM selection.
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 @weave-os/router
above.
Codex (OpenAI CLI). npx @weave-os/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".
The provider preserves Codex's existing ChatGPT OAuth login while the router
key rides in an X-Weave-Router-Key HTTP header and the installer selects the
HMM strategy for the public hosted endpoint. --codex --local and custom
self-hosted URLs keep their router's configured default because the HMM
sidecar is optional. HMM and forced selections in the native Codex family
(gpt-5.6-sol, gpt-5.6-terra, gpt-5.6-luna) use that OAuth credential;
every other selected model uses its WorkWeave deployment or BYOK credential,
matching the Claude Code plugin's model-to-credential dispatch.
Codex does not load third-party slash-command files, so the installer ships the
router directives as native Codex skills: $force-model (alias
$fm ), $unforce-model (alias $ufm), and
`$router-feedback