costBasis
A Claude Code settings key, read out of the shipped bundle. No mined inventory carries it: everything below comes from what this site has written about it.
Usage records now say whether cost came from built-in prices, your org's rates, or a guess.
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.246.
In the changelogs
2Releases whose published page names costBasis.
-
v2.1.246
Per-model usage says which price table produced the cost
Usage records now say whether cost came from built-in prices, your org's rates, or a guess.
named in this entry, found in this entry's text
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v2.1.246
Usage accumulation records the pricing source alongside the model
Usage records now note where the price came from, and the SDK exposes that field.
found in this entry's text
First cited
1The earliest release whose published evidence quoted costBasis was v2.1.246, 25 Aug 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table below.
Presence across releases
0The miner has never read a build containing this name. It is here because a changelog entry of ours names it, which is evidence that it existed and not evidence of which releases carried it. The inventory starts at v2.1.138 and everything older than that was never mined.
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the settings key does. All settings keys.