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.
Model reference
Claude Fable 5: Pricing, Specs & Access
A compact reference for the Fable 5 cost and access details that affect token counting and launch planning.
Input$10.00 / MTok
Output$50.00 / MTok
Context1M tokens
Max output128K tokens
Quick specs
| Claude API model ID | claude-fable-5 |
|---|---|
| Amazon Bedrock ID | anthropic.claude-fable-5 |
| Vertex AI ID | claude-fable-5 |
| Knowledge cutoff | January 2026 |
| Prompt caching | 5m write, 1h write, and cache-read pricing supported |
Where you can use it
Claude APIClaude Platform on AWSAmazon BedrockGoogle Vertex AIMicrosoft FoundryClaude paid plans during access window
What happens after June 22
Subscription access is expected to shift toward usage credits. Treat that as a product-access question, not an API invoice calculation.
Fallback to Opus 4.8
Anthropic says safeguard-flagged requests can be routed away from Fable 5 and are not charged at Fable prices. The calculator keeps fallback out of the cost form so this page can be updated if Anthropic wording changes.
API migration gotchas
- Use
model: "claude-fable-5"for model-specific token counting. - Recheck sampling and thinking parameters when moving from older Claude code paths.
- Handle refusal stop reasons explicitly when safeguard routing matters to your app.
- Keep pricing constants in one place and rebuild after each pricing-source change.
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.