cc-context

How does Claude's context window grow within a session?

Tracks token consumption from JSONL usage data — showing peak context size, session size distribution, and total token footprint across all your Claude Code sessions.

Usage

npx cc-context
npx cc-context --json

Or open index.html in a browser and drag in .jsonl files.

Metrics

• Peak context — highest (input + cache_read + cache_create) seen in a session
• Size tiers — tiny / small / medium / large / huge (150K+ tokens)
• Total tokens — fresh input, cache reads, cache writes, output across all sessions
• Largest sessions — sessions that pushed closest to the 200K context limit

Sample output

cc-context — How does Claude's context window grow?

Sessions analyzed: 471

Peak context per session
  median   90K tokens
  p90     167K tokens
  max     190K tokens

Session size tiers
  tiny     0%   (0)   <5K   — single-turn
  small    2%   (8)   5K–20K
  medium  37%  (173)  20K–60K  — typical session
  large   27%  (126)  60K–150K
  huge    35%  (164)  150K+    — near context limit (200K window)

Total token consumption
  input (fresh)    5.1M
  cache reads     22.1B  (97% of total input)
  cache written  668.6M
  output          19.4M
  grand total     22.8B tokens

Median session uses 90K tokens (45% of the 200K window).
35% of sessions push past 150K tokens — approaching compaction territory.

License

MIT