Implement the configuration layer that supports the entire cost
estimation pipeline:
- config/config.go: TOML-based config at ~/.config/cburn/config.toml
(XDG-compliant) with sections for general preferences, Admin API
credentials, budget tracking, appearance, and per-model pricing
overrides. Supports Load/Save with sensible defaults (30-day
window, subagents included, Flexoki Dark theme). Admin API key
resolution checks ANTHROPIC_ADMIN_KEY env var first, falling back
to the config file.
- config/pricing.go: Hardcoded pricing table for 8 Claude model
variants (Opus 4/4.1/4.5/4.6, Sonnet 4/4.5/4.6, Haiku 3.5/4.5)
with per-million-token rates across 5 billing dimensions: input,
output, cache_write_5m, cache_write_1h, cache_read, plus long-
context overrides (>200K tokens). NormalizeModelName strips date
suffixes (e.g., "claude-opus-4-5-20251101" -> "claude-opus-4-5").
CalculateCost and CalculateCacheSavings compute per-call USD costs
by multiplying token counts against the pricing table.
- config/plan.go: DetectPlan reads ~/.claude/.claude.json to
determine the billing plan type. Maps "stripe_subscription" to
the Max plan ($200/mo ceiling), everything else to Pro ($100/mo).
Used by the budget tab for plan-relative spend visualization.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Define the core data structures that flow through the entire pipeline:
- model/session.go: SessionStats (per-session aggregates including
token counts across 5 categories — input, output, cache_write_5m,
cache_write_1h, cache_read), APICall (deduplicated by message.id,
keyed to the final billed usage), and ModelUsage (per-model
breakdown within a session). Tracks subagent relationships via
IsSubagent/ParentSession fields.
- model/metrics.go: Higher-order aggregate types — SummaryStats
(top-level totals with per-active-day rates for cost, tokens,
sessions, and minutes), DailyStats/HourlyStats/WeeklyStats
(time-bucketed views), ModelStats (cross-session model comparison
with share percentages), ProjectStats (per-project ranking), and
PeriodComparison (current vs previous period for delta display).
- model/budget.go: BudgetStats with plan ceiling, custom budget,
burn rate, and projected monthly spend for the budget tab.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>