| name | pricing |
| description | Guide for updating model pricing in Splitrail. Use when adding new AI model costs or updating existing pricing data. |
Pricing Model Updates
Token pricing is defined in src/models.rs. Built-in models are populated by populate_defaults() into the runtime model registry, and user/config models can be merged with init_external_models().
Adding a New Model
- Add a
ModelInfo entry in populate_defaults() with:
pricing: Use PricingStructure::Flat { input_per_1m, output_per_1m } for flat-rate models, or PricingStructure::Tiered for threshold-based pricing.caching: Use the appropriate CachingSupport variant (None, OpenAI, Anthropic, OpenAIWithWrites, or Tiered).service_tiers: Leave empty unless the provider has distinct priority/flex/batch rates.dated_pricing: Leave empty unless pricing changes by usage date.is_estimated: Set to true only when pricing is not confirmed by a provider/tool source.input_token_semantics: Auto-derived for built-in models (defaults to ExcludesCache); only GPT/o-series models typically need IncludesCacheRead. External model configs should set this explicitly if it affects cache-read counting.
- If the model has aliases (date suffixes, provider-prefixed names, regional names, etc.), add entries to the alias section mapping each observed name to the canonical model name.
- Add or update tests in
src/models.rs for canonical pricing, aliases, caching, and estimated/non-estimated status.
Dated Pricing Overrides
Use dated_pricing when a model has temporary promotional pricing, launch pricing, or another time-bounded rate that should apply based on the original usage timestamp.
The default pricing and caching fields should represent the durable/current sticker price. Each DatedPricing override has a valid_until: NaiveDate exclusive end date and applies when usage_date < valid_until. For example, an introductory rate that applies through 2026-08-31 should use valid_until = NaiveDate::from_ymd_opt(2026, 9, 1).expect("valid date").
When adding a dated override:
- Keep the model's default
pricing/caching at the post-promo or durable rate.
- Add the temporary rate with
add_dated_pricing!() after add_model!().
- Add boundary tests for the final day of the temporary rate and the first day after it ends.
- Prefer dated calculator functions in analyzers that know the usage timestamp.
Price Calculation
Use models::calculate_total_cost_for_service_tier_at() when an analyzer has a message or event timestamp. This preserves historical costs across dated pricing windows.
Use the undated compatibility helpers, such as models::calculate_total_cost(), only for tests, config-like calculations, or call sites that truly do not know the usage date. Undated helpers use the model's default pricing/caching, not temporary dated overrides.
Common Pricing Sources
