SigNoz/signoz · error · basemodel.ApiError

couldn't prepare request: %w

Error message

couldn't prepare request: %w

What it means

http.NewRequestWithContext rejected the request line — almost always a malformed URL (unsupported scheme, control characters, or an unparseable URL string) since the method is a constant. Wrapped as an internal error by the gateway request helper.

Source

Thrown at ee/query-service/app/api/cloudIntegrations.go:324

) (*ResponseType, *basemodel.ApiError) {

	reqMethod := http.MethodGet
	var reqBody io.Reader
	if payload != nil {
		reqMethod = http.MethodPost

		bodyJson, err := json.Marshal(payload)
		if err != nil {
			return nil, basemodel.InternalError(fmt.Errorf(
				"couldn't serialize request payload to JSON: %w", err,
			))
		}
		reqBody = bytes.NewBuffer([]byte(bodyJson))
	}

	req, err := http.NewRequestWithContext(ctx, reqMethod, url, reqBody)
	if err != nil {
		return nil, basemodel.InternalError(fmt.Errorf(
			"couldn't prepare request: %w", err,
		))
	}

	for k, v := range headers {
		req.Header.Set(k, v)
	}

	client := &http.Client{
		Timeout: 10 * time.Second,
	}

	response, err := client.Do(req)
	if err != nil {
		return nil, basemodel.InternalError(fmt.Errorf("couldn't make request: %w", err))
	}

	defer response.Body.Close()

View on GitHub (pinned to 5069bf80b0)

Solutions

1. Log the exact URL being requested
2. Fix the gateway/cloud URL configuration so it is a valid absolute http(s) URL
3. Add a startup or pre-call url.Parse sanity check

u, err := url.Parse(rawURL)
if err != nil || (u.Scheme != "http" && u.Scheme != "https") || u.Host == "" {
    return fmt.Errorf("invalid gateway URL: %q", rawURL)
}

Validate the URL before building the request; fail with configuration context rather than the generic prepare error.

When it happens

Trigger: requestAndParseResponse builds a request from a URL that net/http cannot parse: empty or non-http(s) scheme, whitespace/control chars, or a URL assembled from empty config values.

Common situations: Unset or misconfigured gateway base URL, a template producing 'https://.<empty-domain>', or copied URLs with stray characters.

Related errors

• gateway_unsupported
• couldn't serialize request payload to JSON: %w
• couldn't make request: %w
• couldn't read response: %w
• ErrCodeInvalidGatewayConfig

AI-assisted analysis of SigNoz/signoz@5069bf80b0 (2026-08-28). Data as JSON: /api/errors/77abca24f4b7e279. Report an issue: GitHub.