DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.
Plugin installations via the SDK now support progress callbacks, enabling SDK consumers to track installation stages (started, completed, per-marketplace installed/failed).
Evidence
Progress callback (search for "Headless plugin installation progress")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
