Fable 5's slow adoption suggests corporate willingness to pay for frontier AI has hit a ceiling

Anthropic's Fable 5 is considered the most capable AI model on the market. But new sales data shows U.S. companies are barely adopting it.

Spending data from financial services provider Ramp shows that companies are barely buying Anthropic's most powerful model through its API. In its first month after launch, Fable 5 accounted for only about six percent of the tokens purchased from Anthropic. Measured against total spending on Anthropic models, that number sat at 11.4 percent.

OpenAI's flagship model, GPT-5.6 Sol, captures 25 percent of tokens and 23 percent of spending at OpenAI. Overall, according to Ramp, Fable 5 brought in only about 75 percent of the model-related revenue that GPT-5.6 Sol generated, despite costing significantly more per token.

Fable 5 accounts for only a fraction of corporate spending on Anthropic models. | Image: Ramp AI Index

Ramp notes that the sample for the Fable data comes from the company's proprietary token spend management product and skews slightly toward tech companies. Actual Fable adoption is likely even lower than these estimates, assuming Fable 5 is used mainly for coding.