Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
0Signal: worth watching, 1 to 5
SchemasArea: what it touches
Internal ChangesKind: in v2.1.285,
Internal ChangesSection of the release
What
Zod is the library Claude Code uses to check that data, such as tool inputs and settings, has the expected shape. The copy bundled with Claude Code was updated. Changes include:
support for objects whose keys are symbols
skipping keys named __proto__
different handling of optional fields that have default values
a new way to fall back to a value when a check fails
changes to JSON Schema output, including tuple limits, number steps, and the hostname and credit_card string formats
a message that BigInt defaults cannot be represented in JSON Schema
Why
This library checks data throughout Claude Code, so validation can behave slightly differently. Data that was only just accepted or rejected before might now be treated the other way.
