cc-reducer-proxy

A local proxy that intercepts Claude Code API traffic and compresses the message history on every request — compounding token savings across the full session.

Unlike hook-based approaches that only compress output once at ingestion, the proxy re-applies compression on every API call, so old bloated tool results stay small for the lifetime of the session.

How it works

Claude Code → http://localhost:9099 → api.anthropic.com

Claude Code respects the ANTHROPIC_BASE_URL environment variable. Point it at the proxy and all traffic routes through it. The proxy compresses the messages array before forwarding each request, then streams the response back unchanged.

Compression pipeline

Applied on every API request, in order:

1. Re-compress tool results

Cleans bloat from Read, Bash, Grep, and Glob tool output:

• ANSI escape codes — color/formatting sequences stripped
• Progress indicators — percentage bars, spinners (⠋⠙⠹...), dot sequences, [####>---] bars
• Blank line collapse — 3+ consecutive blank lines → 1
• License headers — copyright/license comment blocks at the top of files replaced with [license header - N lines]
• Trailing whitespace — stripped from every line
• Repetitive lines (Bash only) — 3+ identical consecutive lines → 1 line + [repeated N times]
• Line truncation (Bash only) — output capped at 200 lines
• JSON minification — JSON output is compacted (whitespace removed)
• Timestamp prefixes — ISO timestamps at the start of log lines are stripped when detected in bulk

2. Deduplicate tool results

When the same tool call is made multiple times with identical parameters, only the most recent result is kept. Earlier results are replaced with a stub like [deduplicated — superseded by later Read of src/foo.py].

Applies to: Read (same file path + offset/limit), Bash (same command), Grep (same pattern + path + glob), Glob (same pattern + path).

3. Truncate stale results

Tool results older than 10 assistant turns are trimmed to 500 chars, with a [truncated — result from N turns ago] notice.

4. Hard cap

Tool results older than 5 assistant turns are capped at 4000 chars.

Setup

pip3 install -r requirements.txt

Usage

./run.sh

This starts the proxy on port 9099. In any shell where you want to use it:

export ANTHROPIC_BASE_URL=http://localhost:9099

Then start Claude Code as normal. The proxy runs transparently — Claude Code behaviour is identical.

To use a different port:

PORT=8080 ./run.sh

Stats

Savings are logged to ~/.claude/proxy-stats.jsonl on every request where something was compressed.

python3 report.py today   # today's savings
python3 report.py week    # last 7 days
python3 report.py all     # all time

Example output:

=== Today ===
Requests:        86
Saved:           1,191,475 chars (~397,158 tokens, 29.8% reduction)

  recompress:    5
  dedup_tools:   5
  stale_trunc:   100
  capped:        174