Anthropic SDK (TypeScript) vs Spinach

The Anthropic TypeScript SDK is a monorepo shipping a core package alongside cloud-provider wrappers for Bedrock, Vertex, AWS, and Foundry. The defining recent move is a request/response middleware layer that landed in the core package and then propagated to every wrapper in a single release wave. The same cycle marked Claude Opus 4.1 as deprecated across the provider SDKs and refined the core package's Managed Agents types.

The work is converging the whole package family on one shared extensibility model: middleware first shipped in core, fanned out to five wrappers within days, and immediate follow-up patches corrected its interaction with request signing. The cadence is high and tightly coupled, with a single core change rippling across the family in one cycle. Model-lifecycle signals like the Opus 4.1 deprecation and the Managed Agents typing show the SDK tracking Anthropic's platform surface closely.

Expect continued hardening of the middleware path as more signing and timeout edge cases surface, and broader Managed Agents type coverage in the core package as that product matures.