Context and Cost data from stdin

[saar120]

Use context_window and cost data from Claude Code's stdin JSON instead of parsing the transcript JSONL file
Fall back to transcript parsing for older Claude Code versions that don't provide context_window
Add fmtCost and fmtDuration template functions for displaying session cost and duration

[kostyay]

Overall: good feature with clean fallback logic. Struct definitions match the official Claude Code statusline API correctly. Using used_percentage over raw tokens is the right call given bug #13783 (cumulative tokens in total_input_tokens/total_output_tokens). A few suggestions below.

[kostyay]

This constant duplicates the 0.8 threshold already defined in tokens.GetContextConfig (UsableTokens = MaxTokens * 0.8). If that threshold ever changes, this will silently diverge.

Also, the 4-line const + if/cap block can collapse to one line with Go's builtin min():

// Scale to usable context (80% auto-compact threshold → multiply by 1.25)
data.ContextPctUse = min(*cw.UsedPercentage * 1.25, 100)

Requires Go 1.21+ (which this repo targets). Eliminates the constant, the comment block, and the if/cap.

[saar120]

Got it, but maybe it's better to avoid just stating it on the comments and use a threshold const instead.
I've moved the 0.8 threshold to a common const, that way if it change - only one const to update.

[kostyay]

The official docs also provide cost.total_lines_added and cost.total_lines_removed. Not blocking, but consider adding them for completeness:

type CostInfo struct {
	TotalCostUSD       float64 `json:"total_cost_usd"`
	TotalDurationMS    int64   `json:"total_duration_ms"`
	TotalAPIDurationMS int64   `json:"total_api_duration_ms"`
	TotalLinesAdded    int     `json:"total_lines_added"`
	TotalLinesRemoved  int     `json:"total_lines_removed"`
}

[saar120]

I saw them and thought they are redundant because the code already supports git added/removed , but I guess some users might want Claude data instead.
Added.

[kostyay]

This won't handle sessions over 60 minutes well — 125m 30s instead of 2h 5m. Long sessions are common. Suggest adding an hours branch:

"fmtDuration": func(ms int64) string {
	totalSec := ms / 1000
	hours := totalSec / 3600
	mins := (totalSec % 3600) / 60
	secs := totalSec % 60
	if hours > 0 {
		return fmt.Sprintf("%dh %dm", hours, mins)
	}
	if mins > 0 {
		return fmt.Sprintf("%dm %ds", mins, secs)
	}
	return fmt.Sprintf("%ds", secs)
},

[saar120]

good point - added + tests

[kostyay]

LGTM, thanks for contribution!