Anthropic SDKs changed Files and Skills beta client behavior
In Python 1.2.0, TypeScript 0.122.0, Go 1.68.0, Java 2.59.0, Ruby 1.67.0 and C# 12.44.0, beta Files/Skills clients stop sending legacy beta headers and return stable shapes. The change also makes client.beta.skills.delete() delete the Skill and all versions, and renames BetaSkill to BetaContainerSkill. Explicit requests retaining the beta headers keep beta shapes.
Required action
Audit exact SDK versions, beta Files/Skills callers, response parsing and BetaSkill type references. Review beta.skills.delete() callers for whole-Skill deletion before upgrading; test using disposable fixtures.
Scope and evidence limits
Anthropic SDKs; behavior depends on whether a beta header is explicitly sent
Affected SDK upgrades change beta Files/Skills response shapes. client.beta.skills.delete() deletes a Skill and all its versions; BetaSkill is renamed BetaContainerSkill. Explicit beta headers retain beta shapes.
not_tested
Official sources
Affected components
client.beta.files, client.beta.skills, client.beta.skills.delete(), BetaSkill / BetaContainerSkill
Affected users
Developers upgrading Anthropic SDKs with Files or Skills integrations.
Migration guidance
Audit the listed SDK versions, use stable response shapes, update BetaSkill type references, and review whole-Skill deletion callers.
Correction history
- 2026-09-21: Live summary omits the material deletion consequence and exact introduction versions. In Python 1.2.0, TypeScript 0.122.0, Go 1.68.0, Java 2.59.0, Ruby 1.67.0 and C# 12.44.0, beta Files/Skills clients stop sending legacy beta headers and return stable shapes. The change also makes client.beta.skills.delete() delete the Skill and all versions, and renames BetaSkill to BetaContainerSkill. Explicit requests retaining the beta headers keep beta shapes.