RelayPlane vs Helicone
Helicone is a cloud-hosted LLM observability platform and AI gateway with request logging, caching, and prompt management. RelayPlane is an MIT-licensed npm package that runs on localhost with no account required. Here is how they compare for Node.js developers and AI agent builders.
TL;DR
Choose RelayPlane when you want:
- npm install and running in 30 seconds, no account
- Local SQLite cost tracking with no data leaving your machine
- MIT open source with no monthly fee, request caps, or retention limits
- Claude Code and Cursor integration with one baseURL swap
- An independent product with a focused cost-intelligence roadmap
Helicone may work for you if you need:
- Cloud-hosted observability dashboard with team seats and org management
- Gateway-level response caching (Pro plan)
- Prompt versioning and management tools (Pro plan)
- SOC-2 and HIPAA compliance with dedicated support (Team plan)
Feature Comparison
| Feature | RelayPlane | Helicone |
|---|---|---|
| Product type RelayPlane is a local proxy you install via npm and run on localhost. Helicone is a cloud-hosted observability and gateway service; all requests route through their infrastructure at ai-gateway.helicone.ai. | npm-native LLM proxy (local-first) | Hosted LLM observability platform and AI gateway (SaaS-first) |
| Install method RelayPlane ships as an npm package: one command and you are proxying requests locally. Helicone has no npm package of its own. Integration is a base URL swap to their cloud gateway plus a HELICONE_API_KEY header added to every request. | npm install -g @relayplane/proxy | No npm package -- point openai SDK at ai-gateway.helicone.ai and add a header |
| No account required RelayPlane starts with no signup, no credit card, and no cloud dependency. Helicone requires account creation at us.helicone.ai/signup and API key generation from the dashboard before any requests can be logged. | ||
| Free tier RelayPlane has no request cap or free tier limit. Helicone's Hobby plan allows 10,000 requests per month with only 7 days of data retention and a single seat before you must upgrade. | MIT open source, fully free to self-host | 10,000 requests/month, 7-day retention, 1 seat (Hobby plan) |
| Pricing model Helicone publicly repositioned to 0% markup pricing, so the gateway itself no longer adds a per-request fee. Paid tiers still apply for hosting, longer retention tiers, additional seats, and the cloud account requirement itself (Pro is $79/month for extended retention and seats; Team is $799/month for SOC-2/HIPAA). RelayPlane has no paid gateway tier because it runs on your machine -- no cloud account required. | MIT open source, free self-hosted, no cloud account | Advertises 0% markup; paid tiers for hosting, retention, seats |
| Data retention RelayPlane stores request logs in a local SQLite file that you own and retain indefinitely. Helicone's free tier deletes logs after 7 days. Permanent retention requires an Enterprise contract. | Unlimited (local SQLite, you own the file) | 7 days (Hobby), 1 month (Pro), 3 months (Team), forever (Enterprise) |
| Local cost tracking RelayPlane logs every request's exact dollar cost in local SQLite with no data leaving your machine. Helicone provides cost analytics in a cloud dashboard, but all data is sent to and stored on their servers. | ||
| No data leaves your machine RelayPlane runs entirely on localhost by default. Helicone is a cloud-hosted gateway: every request passes through ai-gateway.helicone.ai and all telemetry is stored in their cloud. | ||
| Open source Both projects publish source code. RelayPlane is MIT licensed. Helicone is open source on GitHub and can be self-hosted with Docker or Kubernetes Helm charts, though their managed cloud is the primary product. | MIT | Open source on GitHub (self-hostable via Docker or Kubernetes) |
| Works with Claude Code and Cursor RelayPlane is designed for Claude Code, Cursor, Windsurf, and Aider with direct integration docs. Helicone exposes an OpenAI-compatible gateway that can be configured manually, but coding assistant integration is not a documented use case. | Via OpenAI-compatible gateway (manual header config, not documented for coding assistants) | |
| LLM caching Helicone offers response caching at the gateway level on Pro and above. RelayPlane focuses on cost tracking and routing without a caching layer. | Yes (Pro plan and above) | |
| Prompt management Helicone Pro includes prompt versioning and optimization tooling. RelayPlane does not include prompt management features. | Yes (Pro plan and above -- versioning and optimization) | |
| Complexity-based model routing RelayPlane routes simple tasks to cheaper models based on request complexity. Helicone supports load balancing across providers and automatic failover, but does not route based on request complexity or semantic content. | Load balancing and failover (not complexity-based routing) | |
| Provider integrations Helicone supports a broader range of providers natively in its cloud gateway. RelayPlane focuses on OpenAI-compatible endpoints and direct Anthropic support. | OpenAI, Anthropic, and OpenAI-compatible endpoints | OpenAI, Anthropic, Azure OpenAI, Gemini, Groq, Mistral, DeepSeek, Together AI, and 100+ models |
| Recently acquired Helicone was acquired by Mintlify in March 2026. RelayPlane is an independent project. Acquisitions can affect roadmap priorities, pricing, and long-term support for standalone products. | Acquired by Mintlify (March 2026) | |
| Per-tenant isolation RelayPlane treats each tenant as a physically isolated lane — budget caps, rate limits, and audit records are namespaced per tenant so a runaway agent on one tenant cannot affect others. Helicone has no per-tenant isolation concept. | First-class: separate request queues, budgets, and audit namespace per tenant | |
| Instant kill-switch API RelayPlane provides a single HTTP call that immediately stops all traffic for a tenant using an in-memory flag (no disk round-trip). Helicone has no kill-switch mechanism. | POST /v1/tenants/:id/kill — halts all traffic within one request cycle | |
| Spec-match verification RelayPlane's spec-match plugin (POST /v1/spec-match) uses a cheap judge model to verify whether an agent's output meets its acceptance criteria. Returns per-criterion pass/fail with evidence. Helicone has no equivalent. | Built-in: LLM evaluates agent output against acceptance criteria before task completion | |
| Compliance audit bundle export RelayPlane uses a checksum-linked audit chain where each entry references the previous one — modification is detectable. Helicone provides request logs in its dashboard with CSV export on paid plans, but no tamper-proof chain. | Tamper-proof HMAC-chained audit log, exportable as JSON/CSV/JSONL | Request logs viewable in dashboard; CSV export on paid plans |
Why Node.js Developers Choose RelayPlane Over Helicone
One npm command vs signup, dashboard, and a cloud API key
npm install -g @relayplane/proxy and you are proxying LLM requests in under 30 seconds. Helicone requires creating an account at us.helicone.ai, generating an API key from their dashboard, and adding that key as a request header to every API call before a single request is logged. For Node.js developers who want to move fast, the friction difference is measured in minutes not seconds. And Helicone has no npm package at all: integration is a base URL swap to their cloud service.
Local-first with zero data egress vs a cloud gateway that sees every request
RelayPlane runs on your machine: no data leaves your machine, no cloud account, no vendor who can see your prompts or outputs. Helicone recently announced a 0% markup position, which is a great move, but it does not change the underlying shape of the product: every request still routes through ai-gateway.helicone.ai, and every log is stored in their cloud. Free tier retention is 7 days, Pro is $79/month for longer retention and seats, Team is $799/month, and an account and API key are required before a single request is logged. RelayPlane keeps logs in a local SQLite file you own indefinitely, and adds a budget cap with a kill switch so a runaway agent cannot quietly burn the month's spend -- features a pure observability layer cannot offer.
Your logs stay on your machine forever. Not in someone else's cloud.
RelayPlane stores all request logs in a local SQLite file on your machine. You own the file, you retain it indefinitely, and no data leaves your environment by default. Helicone is a cloud-hosted gateway: every request passes through ai-gateway.helicone.ai, and retention caps at 7 days on the free tier. Even on the Pro plan, logs are deleted after one month unless you pay for Enterprise.
An independent product vs a recently acquired service
Helicone was acquired by Mintlify in March 2026. Acquisitions frequently shift roadmap priorities toward the acquirer's core product. RelayPlane is an independent cost intelligence proxy with a focused roadmap around local-first cost tracking and intelligent model routing. If long-term continuity and roadmap independence matter for your stack, that distinction is worth weighing.
Helicone Solves Observability Problems. RelayPlane Solves Developer Cost Problems.
Helicone is a genuinely useful product for teams that want a managed cloud dashboard for LLM request logging, cost analytics, and prompt management. Its open-source codebase and support for 100+ models across providers like OpenAI, Anthropic, Azure, Gemini, Groq, and DeepSeek make it a credible choice for production observability at scale.
But if you are a Node.js developer or AI agent builder who wants to start proxying LLM requests today, without creating an account, without a 7-day log retention window, and without routing every request through a third-party cloud gateway, Helicone is not the right fit. RelayPlane installs in one npm command, runs on localhost, and stores every request log in a local SQLite file you own indefinitely. No signup. No billing. No cloud.
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