November 28, 2025

Claude Code Restart Trajectory Analysis

How restarting Claude Code reduces token usage by clearing accumulated context.

Key Findings

Restarting Claude Code clears accumulated context - embedded file contents, background process notifications, and system reminders - while preserving essential conversation state. Payload size reduction ranges from 36% to 73% depending on session activity.

Example 1: Dramatic Reduction (73%)

fcvm FUSE Implementation Session -73%
Before Restart 10:49:20 UTC
File Size 272 KB
System Blocks 2 (15.1 KB)
CLAUDE.md ~53 KB
After Restart 10:49:20 UTC
File Size 73 KB
System Blocks 2 (15.0 KB)
Messages Fresh start
272 KB
Before
→
73 KB
After
199 KB
Saved
Before.txt After.txt

What caused the bloat?

Extended coding session with massive CLAUDE.md files and accumulated tool results:

  • CLAUDE.md files: ~53KB of project instructions embedded in context
  • Multiple message conversation history with embedded Read tool results
  • System reminders about TodoWrite, malware analysis, and file opens
  • Continuation summary from previous out-of-context session

Example 2: Moderate Reduction (36%)

Web UI Development Session -36%
Before Restart 05:24:43 UTC
Input Tokens 151,897
Output Tokens 10
File Size 4.08 MB
After Restart 05:25:53 UTC
Input Tokens 96,859
Output Tokens 14
File Size 3.90 MB
151,897
Before
→
96,859
After
55,038
Tokens Saved
Before.txt After.txt

What caused the bloat?

Typical development session with file reads and background processes:

  • Full _index.tsx file embedded (~131KB)
  • 4 background Bash process notifications
  • TodoWrite tool reminders
  • Multiple system reminders accumulated over session

All Download Files

Example 1: Before (73% case)

272 KB payload

Text

Example 1: After (73% case)

73 KB payload

Text

Example 2: Before (36% case)

151,897 tokens

Markdown JSON Text

Example 2: After (36% case)

96,859 tokens

Markdown JSON Text

Analysis

Payload Size Variance

Same conversation state, dramatically different payload sizes. Claude Code context accumulates with tool usage and conversation history.

  • 73% case: Long session with massive CLAUDE.md (53KB) and continuation summary
  • 36% case: Moderate session with large file reads and background processes

System Reminder Accumulation

<system-reminder> tags accumulate during sessions:

  • Background Bash process notifications (output available)
  • TodoWrite tool reminders
  • Malware analysis guidance
  • File open notifications from IDE

Embedded File Content

Major contributor to bloat: Read tool results stay in context.

  • Large source files (args.rs, _index.tsx)
  • Log files from test runs
  • CLAUDE.md project instructions

Continuation Summaries

When context overflows, Claude Code creates continuation summaries:

  • Previous session context compressed into ~6KB summary
  • Summaries themselves contribute to next session's context
  • Multiple continuations compound the overhead

Conclusions

  1. Dynamic Context: Payloads vary significantly (36-73%) within similar sessions.
  2. System Overhead: Background processes and reminders compound over time.
  3. File Embedding: Large file reads can increase payload size by 50%+.
  4. CLAUDE.md Impact: Large project instruction files are re-sent every request.
  5. Continuation Tax: Session continuations add overhead from summaries.
Tip: For long sessions, periodic restarts reduce cost. Be mindful of reading large files and keep CLAUDE.md files concise.

Technical Details

Property Value
Model claude-opus-4-5-20251101
Capture Method Claude Code Proxy
Examples Captured 2 before/after pairs