RelayPlane vs Martian Router
Martian Router routes your traffic through their cloud to reduce LLM costs. RelayPlane keeps your data local and your costs in check, with 73.4% measured cost reduction and no data leaving your machine.
TL;DR
Choose RelayPlane when you want:
- npm install and running in 30 seconds, no account required
- 73.4% cost reduction with prompts that never leave your machine
- Per-session budget caps and kill switch for runaway agents
- MIT open source with local SQLite cost tracking you own forever
- Claude Code and Cursor integration with one baseURL swap
Martian Router may work for you if you need:
- Enterprise-scale cloud routing with dedicated account management
- Gateway-level response caching for high-volume enterprise workloads
- Cloud dashboard with team-level cost analytics across a large org
- Sales-led enterprise onboarding and SLA guarantees
Feature Comparison
| Feature | RelayPlane | Martian Router |
|---|---|---|
| Product type RelayPlane is an MIT-licensed npm package that runs on localhost, nothing leaves your machine by default. Martian Router is a cloud-hosted service; all traffic is routed through Martian's infrastructure. | npm-native LLM proxy (local-first) | Cloud-based AI gateway and intelligent model router (SaaS) |
| Install method RelayPlane installs with one npm command and starts proxying immediately. Martian requires creating an account, generating an API key from their dashboard, and pointing your SDK at their cloud gateway before any routing begins. | npm install -g @relayplane/proxy | Account signup + API key + base URL swap to Martian's cloud endpoint |
| No account required RelayPlane starts with no signup, no credit card, and no cloud dependency. Martian Router requires account creation and API key generation before any requests can be routed. | ||
| Data stays on your machine RelayPlane runs entirely on localhost by default. Martian Router is a cloud-based gateway: every LLM request is routed through Martian's servers for model selection and caching, meaning your prompts and outputs pass through their infrastructure. | ||
| Measured cost reduction Martian Router published an enterprise case study in April 2026 claiming 40% LLM cost reduction for a Fortune 500 customer via intelligent routing and caching. RelayPlane's 73.4% reduction was measured on its own development usage and published in a benchmark Gist. Workloads and savings will vary. | 73.4% (measured on own usage, published Gist) | 40% (Fortune 500 enterprise case study, 2026-04-20) |
| Cost reduction mechanism Martian's 40% reduction leverages gateway-level response caching and cloud-side model routing. RelayPlane routes requests to cheaper models based on task complexity and enforces per-session budget caps with a kill switch, stopping runaway agents before they burn your budget. | Complexity-based model routing + local cost tracking with kill switch | Intelligent cloud routing + response caching |
| Per-session budget caps and kill switch RelayPlane can enforce a hard spend limit per session and kill the proxy when that limit is reached, preventing stuck or looping agents from quietly running up costs. Martian Router provides cost visibility and monitoring but does not offer runtime spend intervention. | ||
| Stuck-agent detection RelayPlane detects when an agent is looping or burning cost without making progress and can terminate the session. Martian Router focuses on routing optimization and does not include runtime anomaly detection for agent behavior. | ||
| Free tier RelayPlane has no request cap or free tier limit. Martian Router offers a free tier with limits; enterprise features and higher throughput require a paid plan or enterprise contract. | MIT open source, fully free to self-host | Free tier available; paid plans for higher volume and enterprise features |
| Local cost tracking RelayPlane logs every request's exact dollar cost in local SQLite with no data leaving your machine. Martian provides cost analytics in a cloud dashboard, but all telemetry is stored on their servers. | ||
| Data retention RelayPlane stores all logs in a local SQLite file you own and retain indefinitely. Martian Router stores request data on their cloud infrastructure under their data retention and privacy policy. | Unlimited (local SQLite, you own the file) | Cloud-hosted, retention governed by Martian's data policy |
| Works with Claude Code and Cursor RelayPlane is designed for Claude Code, Cursor, Windsurf, and Aider with direct integration docs. Martian exposes an OpenAI-compatible API that can be configured manually, but coding assistant integration is not a documented primary use case. | Via OpenAI-compatible API (not documented for coding assistants) | |
| Open source RelayPlane is MIT licensed and fully open source. Martian Router is a proprietary cloud service. | MIT | |
| Enterprise focus Martian Router's published case study and positioning target enterprise customers with high LLM spend. RelayPlane targets individual developers, AI agent builders, and small teams who want local-first cost control without cloud infrastructure. | Developer and agent builder focus | Enterprise focus (Fortune 500 case study, sales-led) |
Why Developers Choose RelayPlane Over Martian Router
73.4% vs 40%, and your data never leaves your machine
Martian Router published a Fortune 500 case study in April 2026 claiming 40% LLM cost reduction through intelligent cloud routing and response caching. RelayPlane measured 73.4% cost reduction on its own development usage. The key difference: Martian achieves its savings by routing your traffic through their cloud. RelayPlane achieves greater savings while keeping your prompts, outputs, and cost data entirely on localhost, no cloud account, no data egress, no third party seeing your requests.
npm install vs account, API key, and cloud routing
RelayPlane installs in one npm command and proxies LLM requests in under 30 seconds with no account required. Martian Router requires creating an account, generating an API key from their dashboard, and pointing your SDK at their cloud gateway before a single request is routed. For developers who want to move fast without vendor onboarding, the friction difference is significant.
A kill switch, not just a dashboard
Martian routes your traffic through their cloud. RelayPlane keeps your data local and your costs in check. The distinction matters most when an agent goes rogue: RelayPlane can enforce a hard per-session budget cap and kill the proxy when it is hit, stopping a looping agent before it runs up your bill. Martian Router provides cost monitoring and visibility, but does not offer runtime spend intervention. Observing a problem is not the same as stopping it.
Local-first by default, not a privacy setting you have to enable
Martian Router is a cloud-based gateway. Every request your agent makes passes through Martian's infrastructure for model selection and caching, which means your prompts, completions, and usage patterns are visible to a third party by design. RelayPlane runs on localhost and stores all telemetry in a local SQLite file you own. Nothing leaves your machine by default, no opt-in required, no enterprise privacy tier needed.
Martian Router Solves Enterprise Scale Problems. RelayPlane Solves Developer Cost Problems.
Martian Router is a capable cloud AI gateway with intelligent model routing and response caching. Their April 2026 enterprise case study, showing 40% LLM cost reduction for a Fortune 500 customer, is credible evidence that cloud-based routing and caching can meaningfully reduce costs at enterprise scale. If you are a large organization with a dedicated AI platform team, a cloud vendor relationship, and workloads where caching provides high hit rates, Martian Router is worth evaluating.
But if you are a developer or AI agent builder who wants to start cutting LLM costs today, without creating a cloud account, without routing your prompts through a third-party gateway, and without a sales cycle, Martian Router is not the right fit. RelayPlane installs in one npm command, runs on localhost, achieves 73.4% measured cost reduction, and stores every request log in a local SQLite file you own. Your data stays on your machine. Your budget cap has a kill switch. No signup. No cloud.
Get Running in 30 Seconds
No account. No cloud. No monthly fee: