@relayplane/proxy

Stop pinning your agents to one model. RelayPlane routes each request to the one that fits the task.

A free, local proxy that sends every request to the right model by complexity, so your traffic costs a fraction of running it all on the frontier. It also meters each agent and kills runaway loops before they burn your budget. It caught a 72,900-token agent stuck in a 21-minute loop that produced nothing.

RelayPlane is a proxy that runs on your machine. It is a drop-in replacement for the OpenAI and Anthropic base URLs: no Docker, no Python, no account, and nothing leaves your machine. MIT licensed, no paid tiers, everything included.

Quick start (30 seconds)

npm install -g @relayplane/proxy
relayplane start

Point Claude Code (or any tool that speaks the Anthropic or OpenAI API) at it:

export ANTHROPIC_BASE_URL=http://localhost:4100
claude

That is the whole setup. Open http://localhost:4100 for the live dashboard, or run relayplane watch for a live cost ticker in your terminal. Using API keys instead of Claude Code? relayplane init walks you through it. 11 providers are supported, including OpenAI, Anthropic, Google, xAI, Groq, and OpenRouter.

What you get

• Live cost intelligence. Every request priced as it happens, with per-model and per-agent breakdowns, in a local dashboard and CLI.
• Model routing. Send simple work to cheap models and hard work to frontier models, by complexity tier or per agent. Changing models is a config edit, never a code change.
• Spend guardrails. Hard budget caps (block, downgrade, or warn), plus anomaly detection that catches velocity spikes, token-explosion loops, and repetition before they become a bill.
• Failover. Circuit breaker and cross-provider cascade: a 429 on one provider fails over instead of failing your run.
• Local and private by default. Passthrough is the default mode: your credentials and traffic stay yours. No telemetry required.

Why we built it (and how we know it works)

We run an autonomous engineering pipeline that ships real code every day, and all of its traffic goes through RelayPlane. Over the last four months that is 6,000+ pipeline runs at roughly 1,900 requests a day, routed, priced, and guarded by this proxy.

The payoff is the swap seam. When we wanted to test a cheaper coding model, we changed two fields in one config file, watched the live cost pane, and reverted nine hours later when the numbers said no:

// one role, one edit, no code changes
"coder": { "provider": "anthropic", "model": "claude-sonnet-5" }
// vs
"coder": { "provider": "opencode", "model": "openrouter/moonshotai/kimi-k3" }

If you run agents seriously, this is the control you are missing: one pane for spend, one seam for swapping models, one place to say "never spend more than this."

How it compares

	RelayPlane	claude-code-router	LiteLLM	OpenRouter
Runs locally	yes	yes	yes	no (cloud)
Anthropic API compatible	yes	yes	partial	no
Live per-agent cost pane	yes	per-request estimates	budgets (platform teams)	dashboard (cloud)
Spend guardrails (caps, anomaly, kill)	yes	no	budgets	no
Free / open source	MIT, everything	MIT	OSS + paid enterprise	5.5% fee

Different tools for different jobs: LiteLLM is built for platform teams, OpenRouter is a hosted marketplace, claude-code-router focuses on multi-agent orchestration. RelayPlane is the local cost-and-control pane for people who run agents on their own machine.

Auto-start with Claude Code

Add to ~/.claude/settings.json so the proxy is always up when you open Claude Code:

{
  "env": {
    "ANTHROPIC_BASE_URL": "http://localhost:4100"
  }
}

In passthrough mode RelayPlane forwards your own credentials untouched, so Claude Code keeps its own login. RelayPlane observes, routes, and meters; it does not change your identity to the provider.

Docs

• Quickstart
• Configuration (routing, cascade, budgets, anomaly detection, cache, credential pool)
• Claude Code integration
• CLI reference
• Changelog

Privacy

Passthrough by default: RelayPlane forwards your own credentials and does not modify your traffic unless you turn routing on. The optional mesh (shared, anonymized routing signals) can be disabled with relayplane mesh off. Your prompts stay on your machine.

License

MIT. No paid tiers. Everything in this repo is the whole product.