Module usage_cost 

Provider-normalized token usage and shared raw/cache-aware USD estimates.

Structs

SessionCostAccumulator

Accumulates independently priced turns without repricing earlier model routes. Once a turn cannot be priced, a complete session total remains unknown.

SessionCostEstimate

Cache-aware and conservative session cost estimates in USD.

Constants

DEFAULT_CACHE_WRITE_MULTIPLIER

Default cache-write multiplier versus uncached input (5m TTL).

EXTENDED_TTL_CACHE_WRITE_MULTIPLIER

Anthropic 1h extended-TTL cache writes cost 2x base input.

Functions

cache_write_rate

Effective cache-write rate. extended_ttl selects the 2x 1h multiplier when the catalog does not declare an explicit write rate.

estimate_session_costs

Resolve pricing for provider/model and estimate session costs from accumulated harness usage. Returns None when the model cannot be resolved or pricing metadata is unavailable.

estimate_session_costs_with_pricing

Estimate session costs from an already-resolved ModelPricing.

normalized_turn_usage

Build a per-turn harness Usage sample from raw provider usage, applying the provider-specific normalization documented on provider_reports_exclusive_input so input_tokens always represents the total prompt token count across every provider.

prompt_tokens_for_rate_limit

Prompt volume that counts toward provider TPM-style rate limits. Cached and cache-write tokens are cheaper but still consume provider capacity.

provider_reports_exclusive_input

Returns true when provider reports prompt_tokens exclusive of cache-read and cache-creation tokens.

require_budget_pricing

Reject a priced session budget when its selected route cannot be priced. Call before any inference, including automatic compaction.