[Bug] Claude Code CLI performance degradation after sustained usage

[dannydanzka]

Bug Description Subject: Severe performance degradation in Claude Code CLI after short usage

Hello Anthropic Team,

I’d like to report a recurring performance issue I’ve been experiencing with Claude Code (CLI) over the last weeks.

After a short period of usage, the CLI becomes extremely slow to respond. The degradation is progressive and eventually makes the tool barely usable. This happens consistently even in relatively small projects.

To rule out local issues, I’ve already tried the following without success:

• Clearing CLI cache
• Deleting local session/state files
• Restarting the CLI
• Fresh terminal sessions
• Verifying no abnormal system resource constraints

Despite this, the slowdown persists once Claude Code has been used for a while, which suggests a possible issue related to:

• Session accumulation
• Memory leaks
• Context handling or state growth over time
• Background processes not being released correctly

The initial experience is fast and solid, but performance degrades sharply after continued interaction, which significantly impacts productivity—especially when using the CLI as part of an iterative development workflow.

I’m sharing this as constructive feedback in case it aligns with any known issues or helps prioritize investigation on the CLI performance side. If there are recommended diagnostics, flags, or logs I can provide, I’d be happy to help.

Thanks for the work you’re doing, and I hope this feedback is useful.

Best regards, Roberto Ramírez

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.5
• Feedback ID: 547badd0-bf97-4b1d-a3ea-afb065194b65

Errors

[]

[github-actions[bot]]

Found 3 possible duplicate issues:

1. https://github.com/anthropics/claude-code/issues/10881
2. https://github.com/anthropics/claude-code/issues/14463
3. https://github.com/anthropics/claude-code/issues/5024

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🤖 Generated with Claude Code

[davidbenhaim]

happening to me too

[x011]

It's happening to everyone. Check Reddit, it's full of complaints. Fire the @sshole that decided this change.

[asermax]

I believe this was mostly introduced in 2.1.3, downgraded to 2.1.2, and it's working considerably better.

[andersbusk]

Experiencing the same issue. I didn't find this when searching, so I posted myself. No issues in 2.1.2.

What I can add is Reproducable in 2.1.3, 2.1.4 and 2.1.5 Manjaro KDE with kernel 6.12.63-1-MANJARO konsole 25.12.0

[PaulRBerg]

also noticing this. there's severe lag when typing and using @ to find file references. and also Claude consumes a ridiculous amount of memory

[samhagman]

Experiencing the same issue. I didn't find this when searching, so I posted myself. No issues in 2.1.2.

For any version >2.1.2 I am also seeing this same issue. If my session gets longer than like half the context window it gets slower and slower until I can no longer type. I'm an M3 Mac with 48G ram. I have to stay at 2.1.2 to actually get any work done.

[TKasperczyk]

In addition to performance issues, Ctrl+C breaks after a few exchanges. It's caused by the lack of:

process.stdin.setRawMode(false);
process.stdin.unref();

in all versions since 2.1.2. The terminal gets stuck in raw mode with no way to reset it.