Get Started with API Gateway: A First-Steps Guide

Getting started with an API gateway means answering one question before writing any config: what problem are you actually solving? An API gateway sits between clients and your backend services, handling routing, authentication, rate limiting, and logging in one place instead of scattering that logic across every service. If you're reading this, you probably already have an API (or several) and you're tired of duplicating auth checks, rate limits, or logging code everywhere.

This guide walks through the practical steps of getting started: choosing the right type of gateway for your situation, setting up your first route, and avoiding the mistakes that slow teams down in week one.

Step 1: Figure Out What You're Gatewaying

Before picking a tool, clarify your actual use case. There are three common starting points:

• You have multiple internal microservices and want a single entry point for external clients. You need routing, service discovery, and probably request aggregation.
• You have one API and want to control access — issuing keys, rate limiting, tracking usage per customer. You need an API management layer more than a routing layer.
• You're building on top of a third-party service (like an LLM provider) and want to turn it into your own controlled API with keys, logs, and billing hooks. You need a proxy layer with authentication and metering.

These three cases lead to different tools. Confusing them is the most common reason "getting started" turns into weeks of misconfigured infrastructure.

Step 2: Pick the Right Kind of Gateway

Cloud-native gateways (AWS API Gateway, Azure API Management, Google Cloud API Gateway) are the default choice if you're already deep in one cloud and need tight integration with serverless functions, IAM, and VPCs. They're powerful but come with a learning curve around stages, resource policies, and mapping templates.

Self-hosted gateways (Kong, Tyk, KrakenD) give you full control and portability across clouds. Good if you run multiple environments or want to avoid vendor lock-in, but you own the ops burden — scaling, patching, and monitoring the gateway itself.

Managed SaaS layers built for a specific job are worth considering when your need is narrower than "route everything." If you're exposing a third-party API (for example, turning existing AI provider access into a proper product API), a purpose-built layer can save you from reinventing key management, streaming support, and usage tracking. This is the exact gap SubToAPI fills: it turns your existing Claude access into an HTTPS API with application-scoped keys, streaming, tool use, and usage metadata, without you building a gateway from scratch.

Step 3: Set Up Your First Route

Regardless of which gateway you choose, the first working setup usually involves the same three pieces: an upstream target, a route, and a policy (auth, rate limit, or transformation).

Here's what that looks like conceptually with a generic gateway config:

routes:
  - path: /v1/orders
    upstream: http://orders-service:8080
    plugins:
      - key-auth
      - rate-limiting:
          limit: 100
          period: minute

The pattern is always the same: define where traffic goes, define who's allowed to send it, and define how much of it they can send. Once that first route works end to end, adding more services is mostly repetition.

If your starting point is "expose an existing service as a clean API with keys and usage tracking" rather than "route between many internal services," you can skip building this yourself. With SubToAPI, the equivalent first step is generating a key and making a call:

curl https://api.subtoapi.app/v1/messages \
  -H "Authorization: Bearer $SUBTOAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4-5",
    "max_tokens": 512,
    "messages": [{"role": "user", "content": "Hello"}]
  }'

No routing config, no plugin chain to assemble — the quickstart covers the full setup in a few minutes.

Step 4: Add Authentication and Rate Limits Early

Don't leave auth and rate limiting as "phase two." Most teams that skip this early end up retrofitting it under pressure once traffic grows or a client abuses the API. At minimum, decide:

• How keys are issued and rotated
• Whether limits are per key, per IP, or per endpoint
• What happens when a limit is hit (429 with a clear message, not a silent drop)

If you're building this on a managed layer, check what's included before you build it yourself. SubToAPI issues per-application keys (sub_live_...) with usage metadata built in, which covers most of what teams build manually in their first gateway sprint — see pricing for how plans scale with seats.

Step 5: Instrument Logging and Usage Metadata Before You Need It

The second most common regret after "we didn't add rate limiting early enough" is "we can't tell which client is generating this traffic." Whatever gateway you choose, make sure every request logs enough to answer: which key, which route, how long, what status code. If you're working with streaming responses or tool calls, confirm your gateway supports capturing metadata for those too — see streaming and tools for how that works when the underlying API involves both.

A Reasonable First-Week Plan

1. Identify whether you're routing microservices, managing one API, or wrapping a third-party service.
2. Pick a gateway type that matches — cloud-native, self-hosted, or a managed layer built for your specific case.
3. Stand up one working route with auth and a rate limit.
4. Add logging with per-key usage data from day one.
5. Only then start adding more routes, teams, or seats.

Trying to solve all five in parallel is what makes getting started with an API gateway feel harder than it needs to be.

Questions

Do I need an API gateway if I only have one API? Not necessarily a full gateway, but you still need auth, rate limiting, and usage tracking. A lightweight managed layer often covers this without the overhead of a general-purpose gateway.

What's the fastest way to get started without managing infrastructure? Use a managed gateway or API layer that already handles keys, rate limits, and logging. For example, signing up for SubToAPI gives you a working API key and endpoint in minutes rather than days of gateway configuration.

Should I build my own gateway or use a managed one? Build your own if you need custom routing logic across many internal services. Use a managed one if your goal is exposing a single service (internal or third-party) as a controlled, billable API — it's almost always faster and cheaper than the engineering time to build and maintain it yourself.