pricing

Documentation

Overview

Package pricing embeds pricing.json and computes the USD cost of a message.

Index

• type History
  • func HistoryForTest(entries []Table) (History, error)
  • func Load() (History, error)
  • func (h History) CostFor(m parse.Message) (cost float64, version string, unknown bool)
  • func (h History) Latest() Table
  • func (h History) TableAt(ts time.Time) Table
  • func (h History) VersionFor(ts time.Time, model string) string
  • func (h History) Versions() []string
• type ModelRate
• type Table
  • func (t Table) CostFor(m parse.Message) (float64, bool)

Types

type History

type History struct {
	// contains filtered or unexported fields
}

History is the time-indexed set of pricing tables, sorted ascending by Version.

func HistoryForTest

func HistoryForTest(entries []Table) (History, error)

HistoryForTest builds a History from a caller-provided slice.

Test-only helper. Exported because Go does not let _test.go in one package be imported by tests in another. Do not call from production code — use Load() instead, which reads the embedded history/*.json.

func Load

func Load() (History, error)

Load reads every embedded history/*.json file, validates each, and returns a History sorted by Version ascending. Duplicate versions are a build error.

func (History) CostFor

func (h History) CostFor(m parse.Message) (cost float64, version string, unknown bool)

CostFor resolves the applicable Table for m via fall-forward (see resolveTable) and returns cost, the stamped version string, and whether the model was missing from every snapshot at-or-after the date-resolved one. The stamped version is the snapshot whose rates produced the cost — the fall-forward source when the date-resolved snapshot predates the model.

func (History) Latest

func (h History) Latest() Table

Latest returns the highest-version entry.

func (History) TableAt

func (h History) TableAt(ts time.Time) Table

TableAt resolves the historical Table that applies to ts. Picks the largest entry with Version <= ts.UTC() date string. Falls back to earliest entry if ts predates all entries.

func (History) VersionFor

func (h History) VersionFor(ts time.Time, model string) string

VersionFor returns the pricing_version CostFor would stamp for a message with this timestamp and model, applying the same fall-forward resolution, without needing token counts. Used by staleness checks (PricingVersionStats).

func (History) Versions

func (h History) Versions() []string

Versions returns sorted version strings of every embedded entry.

type ModelRate

type ModelRate struct {
	InputPerMtok        float64 `json:"input_per_mtok"`
	OutputPerMtok       float64 `json:"output_per_mtok"`
	CacheReadPerMtok    float64 `json:"cache_read_per_mtok"`
	CacheWrite5mPerMtok float64 `json:"cache_write_5m_per_mtok"`
	CacheWrite1hPerMtok float64 `json:"cache_write_1h_per_mtok"`
}

ModelRate holds the per-million-token billing rates for one model.

type Table

type Table struct {
	Version  string               `json:"version"`
	Currency string               `json:"currency"`
	Models   map[string]ModelRate `json:"models"`
}

Table is a versioned snapshot of per-model billing rates decoded from a pricing JSON file.

func (Table) CostFor

func (t Table) CostFor(m parse.Message) (float64, bool)

CostFor returns USD estimate for the message and whether the model rate was missing from this Table.