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 on localhost, VPS, Docker, CI, or any cloud
- API keys that never leave your machine or VPC
- 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
Who Should Pick Which?
| Your situation | RelayPlane | Vercel AI Gateway |
|---|---|---|
| Your app is deployed on Vercel and uses the Vercel AI SDK | — | |
| You need LLM proxying on localhost or in CI pipelines | — | |
| You deploy on AWS, GCP, Fly.io, Railway, or Docker | — | |
| Your API keys must stay on-prem or inside your VPC | — | |
| You use Claude Code, Cursor, or other IDE coding agents | — | |
| You want per-request cost limits and model auto-downgrade | — | |
| You need zero additional tooling within Vercel's platform | — | |
| You require an auditable open-source proxy codebase | — | |
| You are 100% committed to the Vercel platform long-term | — |
Feature Comparison
| Feature | RelayPlane | Vercel AI Gateway |
|---|---|---|
| Deployment model 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. | Local-first — runs on your machine or VPC | Hosted — Vercel edge network only |
| 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 |
| 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. | ||
| BYOK (bring your own provider key) Both support BYOK with no token markup. RelayPlane reads provider keys from local environment variables — keys stay on your machine or VPC and are never transmitted elsewhere. Vercel AI Gateway also supports BYOK with 0% markup; keys are stored and managed inside Vercel project settings (see: vercel.com/docs/ai-gateway/authentication-and-byok). | ||
| Key storage location RelayPlane reads OPENAI_API_KEY and other provider keys from local environment variables. No key material is transmitted to any cloud service. Vercel AI Gateway stores provider keys in Vercel's cloud infrastructure under your project settings. | Local env vars / .env — keys never leave your machine | Vercel project settings dashboard (cloud-stored) |
| 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 spend and token usage 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. | ||
| Built-in AI observability RelayPlane stores all telemetry (token counts, per-request cost, latency) in local SQLite — no cloud egress. Vercel AI Gateway provides built-in observability (TTFT, token counts, spend, request logs) in the Vercel dashboard (see: vercel.com/docs/ai-gateway/capabilities/observability); data is stored on Vercel's infrastructure. | Local: tokens, cost, latency per request | Dashboard: TTFT, token counts, spend, traces |
| Gateway-level rate limiting RelayPlane lets you set per-session or per-day spend limits that block or reroute requests before they reach the provider. Vercel AI Gateway states it does not impose its own rate limits (source: vercel.com/docs/limits); upstream provider rate limits still apply, and Vercel platform execution timeouts (max 300 s on Pro) constrain long-running requests. | Configurable spend governance rules | No gateway-level rate limits added |
| Model routing and auto-downgrade RelayPlane can route requests to different models based on task complexity, cost thresholds, or provider availability, with automatic fallback. Vercel AI Gateway supports failover between providers (e.g. OpenAI → Anthropic) but does not perform model-complexity routing or automatic cost-based downgrade. | Provider-level failover only | |
| Spend governance and budget limits RelayPlane can enforce spend limits and reroute or block requests when budgets are exceeded at the request level. Vercel AI Gateway provides a platform-level on-demand budget cap (default $200) that pauses all projects, not individual request-level spend enforcement. | Platform-level budget cap only | |
| 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 rebuilding your gateway integration. | ||
| 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 — you can audit the key path and request handling yourself. 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 (see: vercel.com/docs/ai-gateway/pricing). Vercel Pro is $20/month/seat; BYOK avoids token markup but platform execution costs still apply. | MIT open source, free self-hosted | Included in Vercel plans; usage billed by Vercel |
| Typical migration effort Switching to RelayPlane from a direct OpenAI/Anthropic client requires one baseURL environment variable change. Adopting Vercel AI Gateway from a non-Vercel app requires migrating your LLM calls to use the Vercel AI SDK provider abstraction and deploying to Vercel. | One env var change — ~10 minutes | Requires AI SDK rewrite — hours to days |
Local-first: your keys stay on your machine
RelayPlane is a trust-first proxy. Three principles guide how it handles your data.
Keys stay on your machine
Provider API keys are read from local environment variables and never transmitted to any cloud service — not even RelayPlane's servers.
Data stays in your SQLite
All request logs, token counts, costs, and latency data are stored in a local SQLite file. No telemetry leaves your machine or VPC.
Open key-path — audit it yourself
RelayPlane is MIT-licensed open source. The complete path from your key to the provider can be audited in the source code. No closed-source proxy layer between you and your AI provider.
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 at the individual request level 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. It does provide real built-in observability (TTFT, token counts, spend, request traces), BYOK with no token markup, and provider-level failover. 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.
Get Running in 30 Seconds
No Vercel account. No deployment. No code changes:
Sources
- Vercel AI Gateway — Overview (vercel.com/docs/ai-gateway)
- Vercel AI Gateway — Authentication & BYOK (vercel.com/docs/ai-gateway/authentication-and-byok)
- Vercel AI Gateway — Observability (vercel.com/docs/ai-gateway/capabilities/observability)
- Vercel AI Gateway — Pricing (vercel.com/docs/ai-gateway/pricing)
- Vercel Platform Limits (vercel.com/docs/limits)
- Vercel AI Gateway — Getting Started (vercel.com/docs/ai-gateway/getting-started)
- Vercel Pricing Plans (vercel.com/pricing)