Gzip request-body compression is built with per-request decline reasons and a fallback latch, gated by two remote flags that both default off.
Claude Code can now compress outgoing API request bodies with gzip, decided per request by a helper that records exactly why it declined. It only applies on the Bun runtime, only to string bodies of at least 4096 characters, and never over unix sockets, proxies, mTLS or custom CA setups. Both remote gates default to off, so nothing is compressed in this build without a server-side value, and a rejected compressed request falls back to sending uncompressed and stops compressing afterwards.
- Enabled by either of two remote flags,
tengu_atomic_oceanortengu_gzip_request_bodies, both falling back to false. CLAUDE_CODE_GZIP_REQUEST_BODIESoverrides the flags: set true it forces compression on unless the kill switch has already tripped, set false it forces it off.- Skip reasons recorded per request are
env_off,not_bun_runtime,non_string_body,below_min_size,latched_off,flag_off, and the transport reasonsunix_socket,proxy,mtlsandcustom_ca. - A compressed request answered with 400, 403 or 415 from what looks like an Anthropic or Cloudflare hop is resent uncompressed, and compression is switched off for the rest of the process.
- When the rejection looks like it came from a non-Anthropic intermediary and the uncompressed retry succeeded, the off state is written to settings as
gzipRequestBodiesLatchedOffso later sessions skip compression too. - The saved off state is honoured for about 7 days and then cleared, and per-session state tracks whether it is currently in effect.
- Telemetry events are
tengu_gzip_request_body_fallbackfor a rejected compressed request andtengu_gzip_request_body_latch_clearedwhen the saved switch expires, alongside per-request outcome reporting.
tengu_atomic_ocean, return ((e.latchedOff = !0), (e.persistedLatchInEffect = !0), !0);
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
tengu_gzip_request_bodies Not enough to sayNothing 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 v2.1.236: not a boolean we can read
Read once, for one account on one subscription tier, against v2.1.236. It isn't a statement about your account. What a flag value here can and cannot tell you
A reading is one sample. Claude Code evaluates its flags remotely, so no client sees the targeting rule behind a value and this says nothing about your account.
A reading is one sample. Claude Code evaluates its flags remotely, so no client sees the targeting rule behind a value and this says nothing about your account.
New in this build: tengu_atomic_ocean