BitRouter

The minimal interpretable model router that learns & adapts to your agent workflows.

Point any OpenAI-compatible agent at your local BitRouter instance, choose bitrouter/auto, and keep working.

- OPENAI_BASE_URL=https://api.openai.com/v1
+ OPENAI_BASE_URL=http://localhost:4356/v1

Then set the request model to:

bitrouter/auto

BitRouter runs locally and exposes an OpenAI-compatible API, so existing agents and tools can switch over with minimal changes.

You can also give your coding agent the /bitrouter skill to install, configure, migrate to, and troubleshoot BitRouter for you:

npx skills add bitrouter/bitrouter

Try BitRouter Cloud →: Don’t want to run the router locally? Use https://api.bitrouter.ai/v1 as your base URL instead.

Core features

Minimal core. Lightweight & extensible.

One Rust router sits between your agents and every model provider. Extend it with providers, routing policies, tools, skills, and sub-agents without rebuilding your workflow around a new agent runtime.

Interpretable decisions. Under your control.

Routing policy lives in files you own. Routes are inspectable, changes are diffable, and a live policy changes only when you explicitly publish it.

A customizable router. Adapt it to your workflow.

Start with bitrouter/auto, then shape the models, rules, guardrails, and evaluation objective around your own loop. BitRouter learns from the outcomes you admit and proposes a new policy you can review, publish, or revert.

Integrates with your agent stack

Keep the clients and workflows you already use:

• Model APIs — OpenAI Chat Completions and Responses, Anthropic Messages, and Google Gemini generateContent, with cross-protocol routing.
• Coding agents — built-in Codex and Claude support through bro code, native launchers, and ACP adapters.
• Tools & skills — aggregate configured MCP servers behind one endpoint, with tools and SEP-2640 skills available through the same gateway.

Benchmarks

On Terminal-Bench 2.1, BitRouter cut API cost by 40.9% while achieving nearly the same reward as using gpt-5.6-sol alone.

| Configuration | Reward | Cost / trial | Cost savings | | --- | ---: | ---: | ---: | | gpt-5.6-sol only | 81.56% | $0.830 | — | | BitRouter | 81.25% | $0.490 | 40.9% | | Random model mix | 76.50% | $0.553 | 33.4% |

BitRouter dynamically routed between GPT-5.6, Kimi K3, and DeepSeek V4 Flash, retaining nearly all of GPT-5.6’s task performance while substantially reducing model cost.

The random baseline used the same model mix, showing that the savings come from routing decisions—not simply using cheaper models.

Results use the strict 80-task common-valid set and frozen API prices. This is a research benchmark, not an official Terminal-Bench submission.

See the full study and limitations and the BitRouterAI/benchmarks dataset for reproducible results.

Install

# macOS / Linux
curl --proto '=https' --tlsv1.2 -LsSf https://github.com/bitrouter/bitrouter/releases/latest/download/bitrouter-installer.sh | sh

# Homebrew
brew install bitrouter/tap/bitrouter

# Windows
powershell -ExecutionPolicy Bypass -Command "irm https://github.com/bitrouter/bitrouter/releases/download/v1.0.0-alpha.31/bitrouter-installer.ps1 | iex"

# npm
npm install -g bitrouter

# From source (Cargo)
cargo install bitrouter

Quick start

bro code (aka. BitRouter Orchestrator) is BitRouter's CLI workspace for coding-agent conversations. On the first run, bro guides you through setup and opens the default agent. Use bro code directly when you want to choose an agent or resume a session.

bro                                  # first-run setup, then the default agent
bro code                             # open a conversation and choose an agent
bro code codex                       # start an interactive Codex ACP session
bro code claude                      # start an interactive Claude ACP session
bro run claude "summarize this repo" # run one headless agent turn

BitRouter discovers a compatible local coding-agent CLI automatically. Its built-in Codex and Claude adapters require Node.js 22+ and npx; when the local CLI is unavailable, the adapter uses its bundled worker.

Use the surrounding bro commands to inspect and control the router while you work:

bro requests                      # settled requests and spend
bro route <model>                 # explain how a model name resolves
bro start                         # start the local router
bro stop                          # stop the local router
bro restart                       # restart the local router
bro init                          # scaffold advanced routing configuration

bro claude and bro codex launch each harness's native interface with per-process BitRouter overrides. bro code <agent> keeps the conversation inside BitRouter's interface; bro run <agent> is the headless equivalent.

See docs/CLI.md for the complete command reference, session controls, flags, and config resolution.

Workflow recipes

Ready-made policy specs for common agentic workflows start in templates/auto-router/: a predictive bitrouter/auto / bitrouter/auto:cost ladder using GPT-5.6 as the strong tier, Kimi K3 as balanced, and DeepSeek V4 Pro as economy. Treat it as a starting point and evaluate it against your own loop before publishing a live policy.

Models & providers

BitRouter routes to a model, not a provider. Each model below is served by many providers — its own lab, hyperscalers (AWS Bedrock, Alibaba Cloud), gateways (OpenRouter, OpenCode), and serverless clouds — and BitRouter picks the cheapest route per call. The bars are those routes: the more providers serve a model, the more room the router has to move.

Bring your own key to any of them, or use one BitRouter Cloud account with no keys at all. Frontier models from OpenAI, Anthropic, Google, and xAI also route over a subscription sign-in (Claude Pro/Max, GitHub Copilot, ChatGPT Codex) instead of a key.

The chart is generated from dist/registry/ on every catalog change — it is never hand-maintained, so it cannot drift from what the router actually resolves. Full catalog in registry/.

Talk to founders

Try BitRouter Cloud → or reach out directly:

Want a first-party provider integration, or building an open-source agent/harness? Email [email protected] or book a meeting — open-source builders get up to 50% off for you and your community.

Development

• docs/DEVELOPMENT.md — workspace architecture and SDK internals
• CONTRIBUTING.md — contribution workflow, issue reporting, and provider updates
• CLAUDE.md — guidance for AI coding agents working in this repository
• skills/ — the /bitrouter Agent Skill (source of truth)

Star History

License

Licensed under the Apache License 2.0.