googleapis/mcp-toolbox · error

unable to parse Timeout string as time.Duration: %s

Error message

unable to parse Timeout string as time.Duration: %s

What it means

This error comes from the HTTP source's Initialize when time.ParseDuration cannot parse the configured Timeout string into a valid time.Duration. The Timeout field must be a Go duration string such as "30s", "5m", or "1h30m". A missing unit (e.g. "30") or garbage text makes parsing fail and the source aborts initialization.

Source

Thrown at internal/sources/http/http.go:91

	Timeout                string            `yaml:"timeout"`
	DefaultHeaders         map[string]string `yaml:"headers"`
	QueryParams            map[string]string `yaml:"queryParams"`
	ReturnFullError        bool              `yaml:"returnFullError"`
	DisableSslVerification bool              `yaml:"disableSslVerification"`
	AllowedIPRanges        []string          `yaml:"allowedIpRanges"`
	CustomBlockedIPRanges  []string          `yaml:"customBlockedIpRanges"`
	AllowPrivateNetworks   bool              `yaml:"allowPrivateNetworks"`
}

func (r Config) SourceConfigType() string {
	return SourceType
}

// Initialize initializes an HTTP Source instance.
func (r Config) Initialize(ctx context.Context, tracer trace.Tracer) (sources.Source, error) {
	duration, err := time.ParseDuration(r.Timeout)
	if err != nil {
		return nil, fmt.Errorf("unable to parse Timeout string as time.Duration: %s", err)
	}

	var tr *http.Transport
	if defaultTr, ok := http.DefaultTransport.(*http.Transport); ok {
		tr = defaultTr.Clone()
	} else {
		tr = &http.Transport{}
	}

	logger, err := util.LoggerFromContext(ctx)
	if err != nil {
		return nil, fmt.Errorf("unable to get logger from ctx: %s", err)
	}

	if r.DisableSslVerification {
		tr.TLSClientConfig = &tls.Config{
			InsecureSkipVerify: true,
		}

View on GitHub (pinned to 8cc6e09de2)

Solutions

1. Set Timeout to a valid Go duration string, e.g. "30s" or "2m"
2. Remember the unit is mandatory: use "500ms" not "500"
3. Check the YAML config for the http source's `timeout:` key — remove quotes-irrelevant typos and stray characters

Example fix

// before
timeout: 30
// after
timeout: 30s

func validTimeout(s string) bool {
    _, err := time.ParseDuration(s)
    return err == nil
}
// usage: if !validTimeout(cfg.Timeout) { fix config before Initialize }

src, err := cfg.Initialize(ctx, tracer)
if err != nil && strings.Contains(err.Error(), "unable to parse Timeout") {
    log.Fatalf("bad timeout format in http source config: %v", err)
}

When it happens

Trigger: Config.Initialize calls time.ParseDuration(r.Timeout) and gets an error: Timeout set to "30" (no unit), "seconds", "", "thirty seconds", or any string outside Go's duration syntax.

Common situations: Copy-pasting a plain integer timeout from another tool's config; forgetting units like "ms" vs "s"; empty Timeout field in YAML; assuming the value is seconds by default.

Understand the failure class

• Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.
• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• failed to parse BaseUrl %v
• invalid allowedIpRanges: %w
• invalid queryTimeout %q: %w
• %s is not a valid http method
• `introspectionEndpoint` is not allowed when `mcpEnabled` is

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/c3172a5383320239. Report an issue: GitHub.