openChpok

Local compaction proxy for AI coding agents. Sits between your agent and the API, compacts verbose tool outputs before they reach the LLM. Saves up to ~80% of tokens on grep/ls/git log output — no changes to your agent required.

Works with Claude Code (Anthropic Messages API) and Codex CLI (OpenAI Responses API). Any client that talks one of those two protocols should work.

⚡ Quickstart

First, install the binary — see Install (one tar -xzf + mv).

# Terminal 1 — start the proxy
openchpok --port 8080

# Terminal 2 — point your agent at it, then run claude / codex
eval "$(openchpok env)"
claude "list files in this repo"   # or: codex "..."

✅ Verify it works

1. Open http://localhost:8080/ui — you should see your request appear, with "chars saved".
2. Check the JSONL log: tail -f ~/.cache/openchpok/proxy.jsonl.
3. No requests showing up? → Troubleshooting.

What eval "$(openchpok env)" actually does

$ openchpok env
export ANTHROPIC_BASE_URL=http://127.0.0.1:8080
export OPENAI_BASE_URL=http://127.0.0.1:8080/v1

$ eval "$(openchpok env)"   # runs those two exports in your current shell

$ # now claude / codex go through the proxy — nothing in ~/.codex/config.toml
$ # or your shell rc is changed permanently

✅ Supported agents

• ✅ Claude Code — zero config, uses ANTHROPIC_BASE_URL
• ✅ Codex CLI — zero config, uses OPENAI_BASE_URL (subscription auth via ~/.codex/auth.json is picked up automatically)
• ✅ Any client speaking Anthropic Messages or OpenAI Responses/Chat Completions

🎯 Why openChpok?

Your agent pastes the full output of grep, ls -la, git status, find into the next LLM turn — every time. Most of that is noise the model doesn't need. openChpok trims it on the way out.

• 💰 Cut token spend — verbose tool results shrink 35–80% before hitting the LLM
• 🚀 Zero agent changes — just point ANTHROPIC_BASE_URL / OPENAI_BASE_URL at the proxy
• 🔍 Full visibility — per-request stats at /ui, JSONL log at ~/.cache/openchpok/proxy.jsonl
• 🔒 Local-only — stdlib-only Go binary, no external deps, no telemetry
• 🔑 Reuses your auth — Anthropic API key, OpenAI API key, or ChatGPT subscription via codex login

🏗️ How it works

Agent (Claude Code / Codex / ...)
  │
  │  ANTHROPIC_BASE_URL / OPENAI_BASE_URL=http://localhost:8080
  ▼
┌──────────────────────────────┐
│       openChpok              │
│                              │
│  Match tool_use → tool_result│
│  Strip Codex envelope        │
│  Compact verbose output      │
│  Re-attach envelope          │
│  Forward to real API         │
│  Stream SSE back as-is       │
│  Log metrics                 │
└────────────┬─────────────────┘
             ▼
   api.anthropic.com / api.openai.com

Requests are compacted; responses pass through unmodified. For Codex, the proxy also preserves the stdout envelope (Chunk ID, Wall time, Process exited) while compacting only the useful body.

📉 Compactors

Savings measured on internal/compact/testdata/*.txt (go test -run TestCompressionBaseline -v ./internal/compact/...). Real-world savings vary by command and repo size.

Compactor	Trigger	What it does	Saving on fixture
git_status	git status	keeps section headers + per-file prefixes; drops advisory hints and ahead/behind noise	35–61%
git_log	git log --oneline	caps at 20 most recent lines, adds overflow marker	~78%
ls	ls -la, ls -R	-la: drops perms/owner/group/hardlinks/total, keeps raw byte sizes; -R: indent+dash tree	~78% on -la
grep	grep, rg (Bash)	top-of-output TOC (files by match count), per-file grouping, long-line truncation, hidden (N): footer	~80%
find	find	indent+dash directory tree, collapses large siblings into ... +K more, hidden (N): footer	~15%

More compactors & safety rules

Never compacted: Read/cat file content, Edit/Write tool results, Glob, errors. If a compactor produces output larger than its input, the raw output passes through unchanged.

Additional compactors in internal/compact/: git_diff, git_show, git_branch, git_reflog, git_stash, tree.

🔍 Examples

Snippets come from real fixtures in internal/compact/testdata/.

git status — 838 → 511 bytes (39% saved)

# git status (verbose)                          # openchpok git status (compact)
Your branch is ahead by 3 commits              On branch feature/refactor
(use "git push" to publish)                    Changes to be committed:
Changes not staged for commit:                 modified: internal/compact/compact_find.go
...                                            ...

ls -la — 2237 → 487 bytes (78% saved)

# ls -la (full metadata)                        # openchpok ls -la (compact)
drwxr-xr-x  33 user staff 1056 ... .           .claude/
-rw-r--r--   1 user staff  503 ... .gitignore  .gitignore 503
-rw-r--r--   1 user staff 20488 ... README.md  README.md 20488
...                                            20 files, 10 dirs

grep -rn foo . — 40000 → 8017 bytes (80% saved)

# grep -rn foo . (flat stream)                 # openchpok grep -rn foo . (grouped)
src/a.rs:19: ...                               547 matches in 15 files:
src/a.rs:79: ...                                 src/a.rs: 25
src/b.rs:9: ...                                  src/b.rs: 6
...                                            ...

📦 Install

GitHub Releases (recommended)

Download openchpok_<version>_<OS>_<arch>.tar.gz (or .zip on Windows) from the releases page, extract, and place the openchpok binary on your $PATH.

# Linux/macOS
tar -xzf openchpok_*.tar.gz
chmod +x openchpok
sudo mv openchpok /usr/local/bin/

From source

git clone https://github.com/sady4850/openChpok.git
cd openChpok
go build -o ./bin/openchpok ./cmd/openchpok

🔧 Configuration

Settings come from (in order of precedence): CLI flags → JSON config file → built-in defaults. The default config path is $XDG_CONFIG_HOME/openchpok/config.json (falls back to ~/.config/openchpok/config.json). Missing file is fine — defaults apply.

{
  "upstream": "https://api.anthropic.com",
  "port": 8080,
  "verbose": false,
  "dump_dir": ""
}

• CLI flags: openchpok --help
• Env exports helper: openchpok env --help
• Debug dumps: --dump-compacted <dir> writes .orig.txt, .comp.txt, .meta.json per tool call

📊 Dashboard

Open http://localhost:8080/ui — server-side rendered, auto-refreshes every 10s. Shows total requests, tool calls, chars saved, per-compactor savings, per-tool breakdown, and recent sessions. Same numbers as JSON at /api/stats:

curl -s http://localhost:8080/api/stats | jq '.requests, .tool_results, .total_saving_pct'

🛠️ Troubleshooting

• openchpok: command not found — ensure the install location is on your $PATH.
• Port 8080 is busy — run with a different port, e.g. openchpok --port 18080, and use http://localhost:18080/ui.
• Dashboard shows zero requests (Codex) — you may have hit openai/codex#16719: some codex CLI releases silently ignore OPENAI_BASE_URL and openai_base_url in config.toml. Fix: upgrade codex.
• Dashboard shows zero requests (Claude) — confirm the agent terminal has ANTHROPIC_BASE_URL pointing at the proxy.
• Auth errors (401/403):
  • Codex subscription: run codex login to populate ~/.codex/auth.json
  • Codex API-key: ensure OPENAI_API_KEY is set in the agent's terminal
  • Claude: ensure your Anthropic credentials are set for claude
• Telemetry/log file — local-only JSONL at ~/.cache/openchpok/proxy.jsonl; reset with rm ~/.cache/openchpok/proxy.jsonl.

📋 Requirements

• Go 1.25+
• Zero external dependencies — stdlib only

📝 License

Apache License 2.0 — see LICENSE and NOTICE.