Function writeRateLimitResponse

internal/server/middleware_ratelimit.go:621–638

writeRateLimitResponse sends a 429 response with Retry-After and X-RateLimit-* headers.

(w http.ResponseWriter, cfg rateLimitConfig)

// writeRateLimitResponse sends a 429 response with Retry-After and X-RateLimit-* headers.
func writeRateLimitResponse(w http.ResponseWriter, cfg rateLimitConfig) {
	// Calculate retry-after from the rate (seconds until one token is available)
	retryAfter := int(math.Ceil(1.0 / float64(cfg.Rate)))
	if retryAfter < 1 {
		retryAfter = 1
	}
	if retryAfter > 3600 {
		retryAfter = 3600
	}

	// Calculate requests per minute for the limit header
	limitPerMinute := int(math.Ceil(float64(cfg.Rate) * 60))

	w.Header().Set("Retry-After", strconv.Itoa(retryAfter))
	w.Header().Set("X-RateLimit-Limit", strconv.Itoa(limitPerMinute))
	w.Header().Set("X-RateLimit-Remaining", "0")
	writeError(w, http.StatusTooManyRequests, "rate_limited", "Too many requests. Please try again later.")
}