The 30-second pitch

Your AI coding agent is burning tokens grepping OSS libraries it will barely use. xmp4 is a hosted MCP server that pre-indexes 856 popular open-source libraries with SCIP — the semantic code format Sourcegraph uses — and serves them through 17 tools. No clone. No grep. No false positives.

ASK: "Who calls Flask.wsgi_app in the flask repo and what does it do?"

with grep + local clone:
  git clone flask/flask          ~40 MB,   ~2 min
  grep -rn "wsgi_app" .          200+ matches, mostly noise
  cat src/flask/app.py | sed ... read 1000+ lines to find the body
  filter false positives         model spends tokens deciding what's real
  ──────────────────────────────────────
  total:                         ~15,000 tokens + disk + wall time

with xmp4:
  xmp4_info(symbol_name="Flask",    file_path="src/flask/app.py")         → signature,  20 tok
  xmp4_source(symbol_name="wsgi_app", file_path="src/flask/app.py")       → body,      180 tok
  xmp4_callers(symbol_name="wsgi_app", file_path="src/flask/app.py")      → 1 caller,   50 tok
  ──────────────────────────────────────
  total:                                                                    ~250 tokens

xmp4 is 60× cheaper here — and every result is SCIP-resolved, not text-matched.

The measured numbers (4 big OSS libs · reproducible)

Same realistic question on spring-boot · tokio · django · efcore: "give me the signature, body, and real callers of X."

GitMCP and Context7 look cheaper per call because they return less. To reach the same answer, GitMCP balloons to 42× more tokens — and still can't produce the semantic caller list. Context7 can't at any cost. Full whitepaper with Python harness →

Connect in 30 seconds

// Claude Code / Cursor / Claude Desktop — project `.mcp.json` or client config
{
  "mcpServers": {
    "xmp4": {
      "type": "http",
      "url": "https://mcp.example4.ai/mcp"
    }
  }
}

(The ready-to-paste config also lives at .mcp.json in this repo.)

Teach Claude how to use xmp4 (optional but recommended)

Install the xmp4 skill once per version — Claude will pick the cheapest tool path automatically (tests_for + view over grep):

# Claude Code
mkdir -p ~/.claude/skills/xmp4 && \
  curl -sfL https://example4.ai/xmp4-skill.md -o ~/.claude/skills/xmp4/SKILL.md



... [View full README on GitHub](https://github.com/0ics-srls/lsai-xmp4.public#readme)