Go guide — every framework

Golang rate limiting,per customer and per plan.

One module with a net/http middleware and native Gin, Echo, and Fiber adapters. Each checks the caller’s key, charges their credits, and applies their plan’s rate limit.

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  • Keys issued per customer
  • Credits that refill
  • Limits per plan, not per process

Official SDKs with drop-in middleware for the stack you already run

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API requests validated
100M+
Average key validation
<5ms
Average analytics ingest
<5ms
Check and log, end to end
<10ms

The usual Go rate limiter counts requests. It doesn’t know your customers.

Go’s token bucket (golang.org/x/time/rate) is excellent for protecting one process. Per-customer limits mean a map of limiters, a mutex, eviction, and a shared store for replicas.

With x/time/ratetoday
// main.go — with x/time/ratevar limiter = rate.NewLimiter(rate.Limit(10), 20) // 10 req/s, bursts of 20

if !limiter.Allow() {
	http.Error(w, "too many requests", http.StatusTooManyRequests)
	return
}
  • One global bucket unless you build a per-key map
  • Per-process state; replicas multiply the limit
  • No API keys: issuing, hashing, scoping, and revoking them is still yours to build
  • No credit balance: a request can’t cost 5 on one route and 1 on another, or refill each month
  • One limit for everyone — no per-plan limits for Free, Pro, and Enterprise customers
  • No per-customer usage log to answer “why was I blocked?” or bill against
With ReqKey in Goone middleware
  • API keys issued per customer, prefixed, hashed, and revocable from the dashboard
  • A credit balance per customer — price each route, refill every hour, day, week, or month
  • Rate limits set per plan, shared by all of a customer’s keys, from 1 second to 24 hours
  • The same count on every worker, instance, and region — no Redis to run
  • Over the limit? A 429 with Retry-After, and no credits charged
  • Every request logged per customer — status, latency, endpoint — in under 5ms
The verdict goes into the request or framework context — credits remaining, consumer, request ID. See the code

Go in three steps, one of them code.

ReqKey runs inside your API, not in front of it. Your server asks one question per request and gets an answer in under 5ms.

  1. 1

    Install the SDK

    go get github.com/Req-Key/reqkey-go@latest

  2. 2

    Set your project key

    Copy it from the dashboard into REQKEY_PROJECT_KEY. It stays on your server.

  3. 3

    Add the middleware

    Every request is checked, charged, and logged before your handler runs.

main.gogo get github.com/Req-Key/reqkey-go@latest
package main
 
import (
	"encoding/json"
	"net/http"
	"os"
 
	"github.com/Req-Key/reqkey-go"
)
 
func main() {
	mux := http.NewServeMux()
	mux.HandleFunc("GET /protected", func(w http.ResponseWriter, r *http.Request) {
		decision, _ := reqkey.DecisionFromContext(r.Context())
		_ = json.NewEncoder(w).Encode(map[string]any{"ok": true, "request_id": decision.RequestID})
	})
 
	protect := reqkey.MustHTTPMiddleware(reqkey.MiddlewareOptions{
		ProjectKey:   os.Getenv("REQKEY_PROJECT_KEY"),
		APIID:        "api_payments",
		Mode:         reqkey.ModeBoth,   // validate keys AND record analytics
		KeyName:      "X-Startup-Key",   // where consumers send their key
		ExcludePaths: []string{"/health", "/docs/*"},
	})
 
	_ = http.ListenAndServe(":8080", protect(mux))
}
Also in Go: net/http, Gin, Echo, Fiber, ChiFull Go reference

Every request gets one of these answers

  • 200Valid key, credits charged — your handler runs
  • 402Out of credits
  • 403Key disabled, or not allowed on this API
  • 429Over the rate limit — no credits charged

Where ReqKey sits

Your customer
Your APIReqKey, under 5ms
Your handler

Responses go straight back to your customer. ReqKey sees the key check and the log line, nothing else.

Credits

Charge each route what it costs you.

A lookup can cost 1 credit and a render 5, from the same balance. Excluded paths are never validated, charged, or recorded. In Go:

Per-route credits · Go
// Exact paths or trailing-* prefixes: never validated, charged, or recorded
ExcludePaths: []string{"/health", "/openapi.json", "/docs/*", "/cron/*"},
 
// Or decide per request with a resolver
ShouldProtect: func(ctx context.Context, request *reqkey.MiddlewareRequest) (bool, error) {
	return strings.HasPrefix(request.Path, "/api/"), nil
},
 
// Charge different endpoints differently (non-negative integers)
CreditsResolver: func(ctx context.Context, request *reqkey.MiddlewareRequest) (int, error) {
	if request.Method == http.MethodPost {
		return 5, nil
	}
	return 1, nil
},

Rate limits

Set limits on plans, not in code.

Your Go code never hard-codes a number. Each plan carries its credits, refill, and rate limit; moving a customer to Pro changes all three with no deploy.

PlanCreditsRate limit
Free1,000 / month5 req / s
Pro50,000 / month50 req / s
Scale1,000,000 / month500 req / s
429Over the limit, a call is answered with Retry-After and costs nothing — no credits and no quota.

Example plans. You name them and pick the numbers.

Notes for Go teams hit in production.

No framework dependency

The core module is the client plus net/http middleware; framework adapters are separate import paths.

Concurrency-safe

Create the middleware once and share it across goroutines.

Shared options

MiddlewareOptions is the same for every adapter, so switching routers is one line.

Go rate limiting: the questions teams ask.

Something else? Ask the team or read the docs.

  • Gin, Echo, and Fiber. Chi and anything else speaking net/http use the standard middleware.

  • Yes — client.Verify(ctx, key, reqkey.VerifyOptions{APIID: ...}) from any code.

  • On their plan or on the customer (consumer) in ReqKey — a number of requests per window from 1 second to 24 hours, shared by all of that customer’s keys. Your Go code never hard-codes a limit, so upgrading a customer is a dashboard change, not a deploy.

  • A check averages under 5ms. ReqKey runs inside your app as middleware, not as a gateway in front of it, so responses go straight back to your customer.

  • You choose: fail closed and answer 503, or fail open and let requests through. Invalid keys are denied either way, and a validation is never retried, so no one is charged twice.

Guides for each Go framework.

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