When Claude Code Loses Its Mind

You’re deep into a coding session with Claude Code. Everything’s going great. You’ve built context, explained your architecture, and Claude finally understands your spaghetti codebase. Life is good.

Then you make a fatal mistake: you ask Claude to read a PDF. Or maybe you paste a screenshot. Or perhaps you uploaded an image that was slightly too large.

And suddenly:

API Error: 400 {"type":"error","error":{"type":"invalid_request_error",
"message":"messages.43.content.1: thinking or redacted_thinking blocks
in the latest assistant message cannot be modified."}}

Congratulations. Your conversation is now cursed.

Or maybe you’re seeing one of these:

PDF too large. Try reading the file a different way (e.g., extract text with a CLI tool).

API Error: 400 - image dimensions exceed max allowed size

All three errors have the same root cause. And the same fix.

The Problem

Or: Why Your Conversation File Is Now 47MB

Here’s what happens when you feed Claude Code a large file: it gets base64-encoded and stored in your conversation history. That’s fine for small files. But for that 8MB architecture diagram? That base64 blob is now sent with every single API request.

Forever.

The errors you’ll see:

The “official” solution? Clear your conversation and start over. Lose all that precious context. Explain your codebase from scratch. Again.

Fun fact: Your conversation lives in ~/.claude/projects/ as .jsonl files. Some of these can grow to hundreds of megabytes. Yes, really.

The Solution

Or: Surgery Without Amputation

Enter claude-code-toolkit by Asif Kibria. It’s a scalpel where Anthropic offers you a chainsaw.

Instead of nuking your entire conversation, it:

1. Scans your conversation files for oversized content
2. Identifies the exact problematic blobs
3. Replaces them with harmless placeholders
4. Creates backups before touching anything

No context lost. No starting over. Just surgical removal of the tumor.

Quick Fix

Don’t want to install anything? Just run:

1. See what's broken
npx @asifkibria/claude-code-toolkit scan

1. Fix it
npx @asifkibria/claude-code-toolkit fix

That’s it. Two commands. Your conversation is healed.

Full Installation

For repeat offenders (and let’s be honest, you’ll be back):

1. Global install
npm install -g @asifkibria/claude-code-toolkit

1. Now you can use the short alias
cct scan
cct fix

The Command Arsenal

Pro tip: Always run scan before fix. Trust, but verify.

What Gets Removed?

The toolkit has sensible defaults:

Your actual conversation? Preserved. The 15MB screenshot of your terminal? Gone. Good riddance.

Prevention: macOS Screenshot Settings

Or: Stop Creating 8MB PNGs

If you’re on a Mac, your screenshots are probably massive PNGs. Retina displays + PNG compression = files that make Claude choke.

Switch to JPEG (smaller files):

1. Change default format to JPEG
defaults write com.apple.screencapture type jpg

1. Apply the change
killall SystemUIServer

Other format options:

Disable the shadow (even smaller files):

1. Remove the drop shadow from window screenshots
defaults write com.apple.screencapture disable-shadow -bool true
killall SystemUIServer

Pro tip: For quick one-off conversions, use sips:

1. Convert PNG to JPEG at 80% quality
sips -s format jpeg -s formatOptions 80 screenshot.png --out screenshot.jpg

Quick Reference Card

┌─────────────────────────────────────────────────────────────────┐
│               CLAUDE CODE TOOLKIT CHEATSHEET                    │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  EMERGENCY FIX (no install):                                    │
│     $ npx @asifkibria/claude-code-toolkit scan                  │
│     $ npx @asifkibria/claude-code-toolkit fix                   │
│                                                                 │
│  INSTALL GLOBALLY:                                              │
│     $ npm install -g @asifkibria/claude-code-toolkit            │
│                                                                 │
│  COMMON WORKFLOW:                                               │
│     $ cct health     → Check status                             │
│     $ cct scan       → Find problems                            │
│     $ cct fix        → Remove oversized content                 │
│     $ cct backups    → Verify backup exists                     │
│                                                                 │
│  CONVERSATION FILES:                                            │
│     📁 ~/.claude/projects/**/*.jsonl                            │
│                                                                 │
│  SIZE LIMITS:                                                   │
│     • Images/PDFs/Docs: 100KB base64                            │
│     • Text content: 500KB                                       │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

Conclusion

Key takeaways:

• 🔴 Large files get embedded in your conversation history. They’re sent with every API call until the end of time.
• 🔴 The cryptic API errors mean your conversation is corrupted. Not your fault. Mostly.
• ✅ Don’t nuke your conversation. Use cct scan and cct fix instead.
• ✅ Backups are automatic. You can always restore if something goes wrong.
• 🟡 Prevention beats cure. Think twice before uploading that 4K screenshot.

Acknowledgments

A big thank you to Asif Kibria for building this tool and saving countless Claude Code users from conversation purgatory. Open source at its finest.

Stay debugging, stay caffeinated. ☕

Related Resources:

• claude-code-toolkit on GitHub