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

Prewarm burst guard tested the wrong value

You'll notice
Useful2 Signal3
Session Prewarm

Background session prewarm now checks the concurrency limit instead of the delay value.

Feature flag
tengu_bg_prewarm_burst_concurrency Not enough to say

Nothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.

This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.248: not a boolean we can read

Read once, for one account on one subscription tier, against v2.1.248. It isn't a statement about your account. What a flag value here can and cannot tell you

What

The check controlling background session prewarm bursts tested the delay where it meant to test the concurrency limit. The two settings are still fetched remotely, falling back to 15000 ms between bursts and 3 sessions at a time.

Evidence

tengu_bg_prewarm_burst_concurrency

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 →