Anthropic SDK (TypeScript) vs OpenRouter

The core sdk package moves quickly against the API — the latest release adds files and memory store operations, skill and user profile updates, and helpers for reading the workspace ID out of response headers, while removing a mid-conversation system content block the API no longer supports. Session-runner reliability got attention too, with tool-result sends now retried for at least the lease TTL. The Bedrock, Vertex, and Foundry packages, meanwhile, keep publishing versions whose entire changelog is an empty commit to trigger builds.

Two release streams with very different content share one feed. The core SDK follows the platform's expansion into agent infrastructure — Managed Agents sessions and threads, deployments, and now memory stores and skills — which means the SDK's surface is a fair readout of where the API itself is going. The provider packages are release-train artifacts, republished whenever the monorepo builds, and they routinely outnumber the substantive releases in any given window. The mid-conversation system block removal is worth noting as a rare subtraction: a feature the SDK shipped earlier this year is now gone from the API.

Expect the provider packages to keep shipping empty-commit tags whenever the core sdk moves, and the next real release to continue narrowing behavioral gaps between the TypeScript SDK and its siblings rather than adding surface.