Comment by annjose

Not sure of any out-of-the-box tool. But Anthropic has a token count API which gives a near estimate of the input tokens for messages [1].

So this API can be used in a UserPromptSubmit hook [2] in the harness, get the token count for any model, calculate the cost and compare.

[1] https://platform.claude.com/docs/en/build-with-claude/token-...

[2] https://code.claude.com/docs/en/hooks