lcc — Local Context Compiler MCP server

lcc — Local Context Compiler

Compact coding-agent context without summarizing it away. lcc cuts what the model does not need, keeps everything else byte for byte, and writes a receipt.

<!-- mcp-name: io.github.lucasmartins-ai/lcc -->

/compact vs lcc

Claude Code's /compact replaces your session with a summary written by a model. Summaries drop the exact error, path or line the agent needs two turns later. lcc does the opposite: old tool outputs leave the context but stay one recall away, and every user and assistant message is kept as it was.

Measured with lcc measure-session (PyPI 1.2.0, offline, exact o200kbase token count; re-run 2026-10-23). On main, whose stash note now states lines and size, the same session gives 28,983 (−49.2%). That session is one of the best cases. Across all 299 of my long sessions (100+ messages each, 36.3 M tokens) the median cut was 21.8% (middle half 15% to 31%, best 65%), with 0 messages lost (python benchmarks/research/longsessions.py, 2026-10-23, main). These are all my sessions: run it on yours and post the result.

In a pre-registered test on 172 real requests (evidence), an agent answering from the stashed context plus recall did as well as with the full context on file recall (+0.006, 95% CI −0.023 to +0.034) with 36.6% fewer tokens. It called recall for 90% of the questions about removed content. A /compact-style summary of the same sessions got 73% of exact values right (our reimplementation of /compact, written by Opus); full and verbatim context got 98%.

Install

pip install "local-context-compiler[tiktoken]"   # the CLI is `lcc`
lcc measure-session "$(ls -t ~/.claude/projects/*/*.jsonl | head -1)"   # your latest session

The second line reads your most recent Claude Code session, runs every mode offline and prints counts only. Nothing is changed and nothing leaves the machine.

Claude Code plugin (replaces the /compact summary). Function hooks are early access, so this needs Claude Code 2.1.274+ and the flag below:

export CLAUDE_CODE_ENABLE_FUNCTION_HOOKS=1
claude plugin marketplace add lucasmartins-ai/lcc
claude plugin install lcc@lcc --config provider=rules --config rulesMode=stashed

Allow mcppluginlcclccrecall so the agent can get removed outputs back. When a pass fails or removes too little, the plugin hands over to the built-in summary and says so in a toast. Details: Claude Code guide.

MCP (Claude Code, Cursor, Claude Desktop, any stdio client):

{"mcpServers": {"lcc": {"command": "lcc", "args": ["mcp"]}}}

Shortened. The full README is on GitHub.