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 v2.1.227 Home All releases olderv2.1.226 v2.1.228newer
Claude Code v2.1.227

Liveness probing for remote sessions

Not switched on
Useful2 Signal3
Sessions

Remote sessions can detect a dead connection through probes and force a reconnect, off by default.

End-to-end liveness probing for remote workers is built but its advertising flag falls back to off.

Feature flag
tengu_ccr_idle_heartbeat On for this account, and not off by default

The flag server returned on for the one account this site reads, and nothing in this release compiles it off by default. The compiled default is shown below, and says which it is when we cannot read one: a fifth of gates compile in a string or a number rather than on or off, and most published releases have no gate table behind them at all. No client can see what the server returns for your account.

This account: on · anonymous baseline: on · compiled default in v2.1.227: on

These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.

Read once, for one account on one subscription tier, against v2.1.227. It isn't a statement about your account. What a flag value here can and cannot tell you

What

Remote worker sessions gain an end-to-end liveness check: the heartbeat can advertise supports_liveness_probe with the current interval, the event stream recognises a liveness_probe event, and a timer forces a reconnect when probes stop arriving. Advertising defaults to off in the client, and the SDK path gates it on tengu_ccr_idle_heartbeat, which falls back to off, so no build here turns it on by default.

Details
  • Logs cli_sse_liveness_probe_received on each probe and cli_sse_liveness_probe_handler_threw if handling one fails.
  • Success and failure counters are recorded as ccr_liveness_probe.
  • None of this machinery existed in 2.1.226.
Evidence

supports_liveness_probe, liveness_probe, cli_sse_liveness_probe_received

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

See this entry in the whole of v2.1.227 →