Ttl 429

Answer the research question "does a keep-alive ping that itself gets 429'd still refresh the prompt-cache TTL on Anthropic's side?" from captured turn-logs. A 429'd ping has no usage body, so its effect is only visible through the NEXT successful request on the same SESSION KEY. Runs .skills/ttl-429/scripts/ttl_429.mjs over one or more instance.*.ndjson turn-logs and classifies every 429'd ping as REFRESH (warm probe across the TTL boundary, no masking 200), NO-REFRESH (cold probe), or INCONCLUSIVE (boundary not crossed, or a success refreshed it first). Also prints per-session ping warmth, which flags PHANTOM keep-alive loops (a session whose every ping reads cold — an uncacheable aux context that should never have been armed). Pass --ttl-sec 3600 for an arm running --inject-extended-cache-ttl; default 300s is Anthropic's stock cache TTL. Read-only post-hoc analysis; spends no tokens.

node .skills/ttl-429/scripts/ttl_429.mjs [--ttl-sec N] <instance.ARM.ndjson> [more.ndjson ...]

mkdir -p ~/.claude/skills/ttl-429
curl -L https://claudskills.com/skills/ttl-429/SKILL.md \
  -o ~/.claude/skills/ttl-429/SKILL.md

@misc{ttl-429-2026,
  author    = {zapgun-ai},
  title     = {Ttl 429 [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/ttl-429/}
}