Token counting
When the server proxy is configured, the counter calls Anthropic count_tokens with model: "claude-fable-5". If the API is unavailable, the UI keeps working in estimate mode and labels the result.
About Claude Cost Tools
This MVP exists to make Claude Fable 5 token and cost checks faster for developers without hiding the assumptions.
Methodology
How we calculate
Cost formula
Regular input, cache writes, cache reads, and output are priced separately. Batch and US-geo modifiers are applied after the base cost, matching the current MVP contract.
Data handling
The MVP proxy does not store pasted text. It only needs request status, rough character bucket, and timing for abuse and reliability checks.
Corrections
Pricing changes should be fixed in PRICING_CONFIG, rebuilt, and noted with a new last-verified date.
Last updated
June 12, 2026
Pricing constants are isolated in one config file and should be rechecked before launch.
Sources
Boundary
Estimates are for planning. Check your Anthropic invoice and current pricing before committing spend.
What this site is not
It is not affiliated with Anthropic, not a Claude login page, not a benchmark site, and not a general Fable game or literature resource.