RelayPlane vs Vercel AI Gateway
Vercel AI Gateway is an AI request gateway built into Vercel's edge infrastructure, available only to Vercel-deployed applications. RelayPlane is an MIT-licensed npm proxy that runs on any Node.js host with no cloud dependency. Here is how they compare for teams who need portability and cost control.
TL;DR
Choose RelayPlane when you want:
- npm install and running in 30 seconds on any machine, no Vercel account needed
- LLM proxying that works on localhost, VPS, Docker, CI, or any cloud
- Per-request cost tracking stored locally with no data leaving your machine
- Model routing and auto-downgrade to control spend in real time
- OpenAI-compatible drop-in with one baseURL swap, works with Claude Code and Cursor
Vercel AI Gateway may work for you if:
- Your application is deployed on Vercel and you want zero additional setup
- You are already using Vercel's AI SDK and want a single-platform experience
- Vercel billing for AI usage fits your existing budget process
- You do not need local development proxying or infrastructure portability
Feature Comparison
| Feature | RelayPlane | Vercel AI Gateway |
|---|---|---|
| Product type RelayPlane is a standalone npm binary that intercepts LLM requests on any Node.js host. Vercel AI Gateway is a feature of Vercel's platform: it runs on Vercel's edge network and is only available to applications deployed on Vercel. | npm-native LLM proxy, runs anywhere | AI gateway built into Vercel's edge infrastructure |
| Requires Vercel deployment RelayPlane runs on localhost, a VPS, a Docker container, a CI runner, or any machine with Node.js. Vercel AI Gateway is only accessible when your application is deployed on Vercel's infrastructure. | ||
| Install method RelayPlane is one install command away from proxying requests on any machine. Vercel AI Gateway is toggled in the Vercel dashboard and available only to deployed projects. | npm install -g @relayplane/proxy | Enabled via Vercel project settings (no npm install) |
| Works on localhost RelayPlane is designed for local development: start it, point your LLM client at localhost:4100, and every request is proxied and logged. Vercel AI Gateway does not run locally. | ||
| Works on VPS, Docker, bare metal RelayPlane runs wherever Node.js runs. Teams on AWS, GCP, Fly.io, Railway, or self-hosted infrastructure can use it without any cloud dependency. Vercel AI Gateway is exclusive to Vercel-deployed apps. | ||
| No vendor lock-in RelayPlane is infrastructure-agnostic. You can move your application to any host without changing your LLM proxy setup. Vercel AI Gateway ties your gateway layer to Vercel: migrating away from Vercel means losing the gateway. | ||
| Per-request cost tracking RelayPlane logs the exact dollar cost of every request in a local SQLite database with no data leaving your machine. Vercel AI Gateway shows usage and cost in the Vercel dashboard, tied to Vercel's billing. | Usage visible in Vercel dashboard | |
| Local SQLite cost storage RelayPlane stores all request data, model usage, and costs in a local SQLite file. No data is sent to any cloud service. Vercel AI Gateway stores usage data on Vercel's infrastructure. | ||
| Model routing and auto-downgrade RelayPlane can route requests to different models based on complexity, cost thresholds, or provider availability, with automatic fallback. Vercel AI Gateway routes requests to AI providers but does not perform model-level routing or auto-downgrade. | ||
| Spend governance and budget limits RelayPlane can enforce spend limits and reroute or block requests when budgets are exceeded. Vercel AI Gateway does not provide request-level spend enforcement. | ||
| OpenAI-compatible drop-in RelayPlane exposes a local OpenAI-compatible endpoint: set OPENAI_BASE_URL=http://localhost:4100 and your existing OpenAI client code works with zero changes. Vercel AI Gateway is accessed through Vercel's AI SDK provider, which requires using the AI SDK in your application code. | Via AI SDK provider abstraction | |
| Works with Claude Code and Cursor RelayPlane works as a transparent proxy for any tool that makes HTTP requests to an LLM, including Claude Code, Cursor, Windsurf, and Aider. Vercel AI Gateway is not accessible as a local proxy for IDE tools. | ||
| Open source RelayPlane is MIT licensed with full source available. Vercel AI Gateway is a proprietary feature of Vercel's commercial platform with no open-source option. | MIT | |
| No account required to start RelayPlane starts with zero signup and zero cloud dependency. Vercel AI Gateway requires a Vercel account and a deployed project. | ||
| Pricing model RelayPlane has no gateway fee when self-hosted. Vercel AI Gateway usage is billed through Vercel's platform pricing, which varies by plan. | MIT open source, free self-hosted | Included in Vercel plans, usage billed by Vercel |
| Works outside Vercel infrastructure RelayPlane is a general-purpose LLM proxy with no cloud dependency. Vercel AI Gateway is only available to applications running on Vercel's edge network. |
Why Teams Choose RelayPlane When They Need Portability and Cost Control
npm install and running in 30 seconds, on any machine
npm install -g @relayplane/proxy and every LLM request your application makes is proxied, logged, and cost-tracked. No Vercel account, no deployment, no cloud dependency. RelayPlane runs on the same machine where you write code: your laptop, your CI runner, your Docker container, your VPS. Vercel AI Gateway requires a Vercel account, a deployed project on Vercel's infrastructure, and an application built with Vercel's AI SDK. If you are not deploying to Vercel, the gateway is not available to you at all.
Infrastructure portability vs platform lock-in
RelayPlane is infrastructure-agnostic by design. You can run it on Fly.io today, move to AWS next quarter, and run it locally in between. Your gateway configuration, cost data, and routing rules follow your application. Vercel AI Gateway is coupled to Vercel's deployment platform. If your team is evaluating whether to stay on Vercel, migrate to another host, or run a hybrid setup, tying your LLM gateway to Vercel is an architectural constraint that will surface at the worst possible time.
Real-time cost control, not just cost visibility
RelayPlane tracks costs and can enforce them: route away from expensive models when budgets are hit, block requests that would exceed a per-session limit, auto-downgrade from GPT-4o to GPT-4o-mini when spending thresholds are crossed. Vercel AI Gateway provides usage data through the Vercel dashboard. That is useful for understanding what you spent. It does not let you set a limit that stops spending before it happens.
Local-first means your data stays on your machine
RelayPlane stores all request data in a local SQLite file. No prompt content, no response data, and no cost metadata is sent to any cloud service. Teams with data residency requirements, sensitive prompts, or IP concerns can use RelayPlane without routing usage telemetry through a third-party platform. Vercel AI Gateway stores usage data on Vercel's infrastructure as part of their platform.
Vercel AI Gateway is a Good Fit If You Are All-In on Vercel. RelayPlane Works Everywhere Else.
Vercel AI Gateway is a reasonable choice for teams that are already fully committed to Vercel's deployment platform and want to consolidate their AI infrastructure billing into their existing Vercel account. If your frontend, backend, and AI usage all live on Vercel, the gateway provides a convenient unified view with no additional tooling to manage.
But if you are running any part of your stack outside Vercel, developing locally, deploying to a different cloud, or building tools like Claude Code integrations that run on your development machine, Vercel AI Gateway is simply not available. RelayPlane installs in one command, runs wherever Node.js runs, and gives you cost tracking and model routing with no platform dependency. For teams who want infrastructure flexibility, or who are not on Vercel at all, RelayPlane is the practical choice.
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