1 00:00:00,260 --> 00:00:03,980 Ever head off for lunch with a huge refactor open in your terminal, 2 00:00:04,440 --> 00:00:08,340 come back an hour later, and your first message feels slow and costly? 3 00:00:09,020 --> 00:00:09,780 There's a fix for that. 4 00:00:10,580 --> 00:00:14,600 This is The Claude Code Changelog, brought to you by Jellypod AI. 5 00:00:15,220 --> 00:00:15,720 I'm Lachlan. 6 00:00:16,208 --> 00:00:16,808 And I'm James. 7 00:00:17,168 --> 00:00:23,268 Today is Claude Code 2.1.299, released October 14, and the headline is idle 8 00:00:23,308 --> 00:00:24,688 compaction in the terminal. 9 00:00:25,208 --> 00:00:26,188 Here's the exact change. 10 00:00:26,688 --> 00:00:31,328 If a conversation is over 200K tokens and sits idle for about 54 minutes, 11 00:00:31,728 --> 00:00:35,288 Claude Code compacts it before the one hour prompt cache expires. 12 00:00:35,768 --> 00:00:39,028 So when you come back, your next message doesn't reprocess the whole thing. 13 00:00:39,562 --> 00:00:40,542 Why 54 minutes? 14 00:00:41,082 --> 00:00:42,702 Because the cache lasts an hour. 15 00:00:43,162 --> 00:00:47,762 The compaction fires with a few minutes to spare, while the big context is still 16 00:00:47,922 --> 00:00:48,342 warm. 17 00:00:49,042 --> 00:00:52,802 Without it, you'd come back at minute 65, the cache would've expired, 18 00:00:53,242 --> 00:00:57,522 and that first message would have to chew through all 200K tokens again. 19 00:00:57,970 --> 00:00:59,830 Right, and that's the practical impact. 20 00:01:00,390 --> 00:01:02,730 Long sessions are exactly where this bites. 21 00:01:03,070 --> 00:01:06,310 Big refactors, heavy debugging, huge tool outputs. 22 00:01:06,790 --> 00:01:11,050 Those push you past 200K, and those are also the sessions you walk away from for a 23 00:01:11,110 --> 00:01:12,390 meeting or a code review. 24 00:01:12,990 --> 00:01:15,070 Now the cost of walking away is handled for you. 25 00:01:15,715 --> 00:01:20,255 It's the same family of idea as what we covered in the Taming Subagent Bloat 26 00:01:20,335 --> 00:01:24,895 episode, with autoCompactWindow in 2.1.296. 27 00:01:25,595 --> 00:01:28,255 That one let worker subagents compact early. 28 00:01:28,975 --> 00:01:32,815 This one brings compaction thinking to your main interactive session, 29 00:01:33,335 --> 00:01:34,375 aimed at the cache clock. 30 00:01:35,098 --> 00:01:36,458 Now, how do you actually use it? 31 00:01:37,098 --> 00:01:38,078 Mostly you don't. 32 00:01:38,358 --> 00:01:40,058 It's on by default in the terminal. 33 00:01:40,538 --> 00:01:41,718 But there are two knobs. 34 00:01:42,198 --> 00:01:43,178 First, the threshold. 35 00:01:43,658 --> 00:01:50,358 Set CLAUDE_CODE_IDLE_COMPACT_MIN_TOKENS to change that 200K 36 00:01:50,418 --> 00:01:50,738 minimum. 37 00:01:51,238 --> 00:01:54,678 So if your sessions tend to sit around 120K and you want them covered, 38 00:01:55,178 --> 00:01:57,978 export it with a lower number before you launch claude. 39 00:01:58,878 --> 00:02:00,218 Second, the off switch. 40 00:02:00,898 --> 00:02:04,738 In settings.json, set idleCompaction to false. 41 00:02:05,498 --> 00:02:12,418 Both of these need version 2.1.290 or later, so run claude dash dash version 42 00:02:12,498 --> 00:02:14,158 first if you're not sure what you've got. 43 00:02:14,950 --> 00:02:16,670 Worth saying why you might turn it off. 44 00:02:17,030 --> 00:02:20,530 Compaction replaces the verbatim conversation with a summary. 45 00:02:21,050 --> 00:02:25,430 If you're mid investigation and you need an exact stack trace or exact line numbers 46 00:02:25,530 --> 00:02:27,730 later, a summary might not preserve them. 47 00:02:28,350 --> 00:02:32,790 A habit I'd suggest: before you step away, ask Claude to write the details you need 48 00:02:32,850 --> 00:02:34,570 into a notes file in the repo. 49 00:02:34,990 --> 00:02:37,310 That's my suggestion, not something from the release notes. 50 00:02:38,158 --> 00:02:38,638 Good call. 51 00:02:39,338 --> 00:02:41,098 And here's one the changelog does cover. 52 00:02:41,778 --> 00:02:48,678 2.1.299 updated /reload-skills so it says it re-sends the full skill 53 00:02:48,738 --> 00:02:52,518 list to Claude, and that's the way to get your skills back after compaction. 54 00:02:53,218 --> 00:02:56,538 So if Claude seems to have forgotten a custom skill after you return, 55 00:02:56,878 --> 00:02:57,238 run that. 56 00:02:58,157 --> 00:02:59,017 One more caveat. 57 00:02:59,417 --> 00:03:02,997 The changelog doesn't say what happens if you close the terminal or your laptop 58 00:03:03,097 --> 00:03:04,197 sleeps during that window. 59 00:03:04,777 --> 00:03:07,477 The feature is described as happening while the session sits idle, 60 00:03:07,717 --> 00:03:10,917 so I'd assume the session needs to be running, but that's an inference. 61 00:03:11,417 --> 00:03:12,857 Don't count on it for a closed lid. 62 00:03:13,445 --> 00:03:13,705 Fair. 63 00:03:14,345 --> 00:03:16,365 Now the smaller bits worth a mention. 64 00:03:16,925 --> 00:03:23,705 First, a new env var, CLAUDE_CODE_DISABLE_FILE_MENTIONS. 65 00:03:24,365 --> 00:03:29,645 With it set, when you @ mention a file, Claude gets the path to read with its file 66 00:03:29,725 --> 00:03:33,045 tools, rather than the contents getting stuffed into the prompt. 67 00:03:33,785 --> 00:03:35,765 Handy if you mention big files a lot. 68 00:03:36,580 --> 00:03:41,780 Second, in agent view, /effort and /fast now set what new sessions start with, 69 00:03:42,260 --> 00:03:46,000 and a bare /model, /effort or /fast opens a picker. 70 00:03:46,840 --> 00:03:52,000 Third, UserPromptSubmit hooks now run before a skill or custom slash command 71 00:03:52,040 --> 00:03:52,640 expands. 72 00:03:53,120 --> 00:03:57,080 So a hook that blocks the prompt also stops that command's embedded shell commands. 73 00:03:57,620 --> 00:04:00,100 If you use hooks as guardrails, that's a real tightening. 74 00:04:00,892 --> 00:04:02,952 And two safety and housekeeping ones. 75 00:04:03,552 --> 00:04:08,532 The resume command printed at exit now uses the session ID instead of the session 76 00:04:08,652 --> 00:04:12,312 name, so nothing in a name can run when you paste that line. 77 00:04:13,212 --> 00:04:17,852 And when you @ mention PDFs, their bytes are no longer kept in the session 78 00:04:17,971 --> 00:04:20,632 transcript, which helps memory and disk. 79 00:04:21,400 --> 00:04:22,080 So the takeaway. 80 00:04:22,560 --> 00:04:27,560 Update to 2.1.299, check whether your typical session crosses 200K, 81 00:04:28,000 --> 00:04:34,940 and if it doesn't, consider lowering CLAUDE_CODE_IDLE_COMPACT_MIN_TOKENS. 82 00:04:35,580 --> 00:04:39,460 If you rely on exact verbatim history, set idleCompaction to false, 83 00:04:39,640 --> 00:04:41,200 or save your notes to a file first. 84 00:04:42,047 --> 00:04:42,727 That's the update. 85 00:04:43,187 --> 00:04:45,747 Go check your version, and we'll catch you on the next release.