jaegertracing/jaeger · error

invalid start_time: %w

Error message

invalid start_time: %w

What it means

Same parsing path as end_time but for the start_time field of GetDependenciesInput. After end_time is resolved (default time.Now()), start_time defaults to endTime-24h; if an explicit start_time cannot be parsed, the handler wraps the parse error with "invalid start_time". It indicates malformed client input, not a backend problem.

Source

Thrown at cmd/jaeger/internal/extension/jaegerquery/internal/mcptools/internal/handlers/get_dependencies.go:53

		queryService: queryService,
	}
	return h.handle
}

func (h *getDependenciesHandler) handle(
	ctx context.Context,
	_ *mcp.CallToolRequest,
	input types.GetDependenciesInput,
) (*mcp.CallToolResult, types.GetDependenciesOutput, error) {
	endTime, err := parseDependencyTime(input.EndTime, time.Now())
	if err != nil {
		return nil, types.GetDependenciesOutput{}, fmt.Errorf("invalid end_time: %w", err)
	}

	defaultStart := endTime.Add(-24 * time.Hour)
	startTime, err := parseDependencyTime(input.StartTime, defaultStart)
	if err != nil {
		return nil, types.GetDependenciesOutput{}, fmt.Errorf("invalid start_time: %w", err)
	}

	if !startTime.Before(endTime) {
		return nil, types.GetDependenciesOutput{}, errors.New("start_time must be before end_time")
	}

	lookback := endTime.Sub(startTime)
	deps, err := h.queryService.GetDependencies(ctx, endTime, lookback)
	if err != nil {
		return nil, types.GetDependenciesOutput{}, fmt.Errorf("failed to get dependencies: %w", err)
	}

	links := make([]types.DependencyLink, 0, len(deps))
	for _, d := range deps {
		links = append(links, types.DependencyLink{
			Caller:    d.Parent,
			Callee:    d.Child,
			CallCount: d.CallCount,

View on GitHub (pinned to 806f444784)

Solutions

1. Pass start_time as an RFC3339 timestamp, e.g. "2026-08-31T08:00:00Z".
2. Omit start_time to use the default 24h lookback before end_time.
3. Generate the value with time.Time.Format(time.RFC3339) instead of string concatenation.
4. Inspect the wrapped error for the specific parse failure.

Example fix

// before
input.StartTime = "24 hours ago"
// after
input.StartTime = time.Now().Add(-24 * time.Hour).Format(time.RFC3339)

func validStartTime(s string) bool {
	if s == "" { return true } // defaults to endTime-24h
	_, err := time.Parse(time.RFC3339, s)
	return err == nil
}

func isRFC3339(s string) bool {
	_, err := time.Parse(time.RFC3339, s)
	return err == nil
}

out, _, err := handler.Handle(ctx, req, input)
if err != nil && strings.HasPrefix(err.Error(), "invalid start_time") {
	input.StartTime = time.Now().Add(-24 * time.Hour).UTC().Format(time.RFC3339)
	out, _, err = handler.Handle(ctx, req, input)
}

When it happens

Trigger: Calling get_dependencies with input.StartTime set to an unparseable value such as "24 hours ago", "2026-08-31" (date only, if unsupported format), or a malformed RFC3339 string; also triggered when start_time's format is rejected even though end_time parsed fine.

Common situations: Clients computing lookback windows with relative expressions; constructing timestamps with time formatting differences (millisecond precision with wrong separator); hard-coded dates in tests or dashboards that predate a format change.

Related errors

• invalid end_time: %w
• trace_id is required
• start_time must be before end_time
• trace_id is required
• span_ids is required and must not be empty

AI-assisted analysis of jaegertracing/jaeger@806f444784 (2026-09-01). Data as JSON: /api/errors/e7c802900620fbe1. Report an issue: GitHub.