Source Intelligence

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.

All of v2.1.248 Home All releases olderv2.1.247 v2.1.250newer
Claude Code v2.1.248

SDK control errors carry their subtype too

Under the hood
Useful2 Signal1
SDK

SDK control errors now name the request that failed instead of just a message.

What

Error replies for stopping a task, listing background tasks, generating a session title, renaming a session, submitting feedback and asking a side question now pass the request name along with the error rather than just stringifying it, making failures attributable.

Evidence

"generate_session_title"

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

See this entry in the whole of v2.1.248 →