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lci

MCP Server

lci mcp runs a Model Context Protocol server over stdio. It exposes 14 tools to AI assistants for searching and understanding a codebase without loading whole files into context — the same engine as lci search and the HTTP & Socket API, reached over the MCP transport instead.

Starting the server

Section titled “Starting the server”
Terminal window
lci mcp

Point your MCP client’s config at the lci binary with the mcp subcommand, for example in a Claude Code / Claude Desktop-style config:

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

Tool index

Section titled “Tool index”

| Tool | Output | Purpose | |------|--------|---------| | info | JSON | Per-tool help + server version | | search | JSON | Semantic + literal + regex content search | | find_files | JSON | File-path search (fuzzy / glob) | | get_context | JSON | Detailed context for object IDs or names, with call hierarchy + purity | | context | JSON | Save / load code-context manifests for agent handoff | | list_symbols | JSON | Enumerate + filter symbols (the “ls” for code) | | inspect_symbol | JSON | Deep inspect one symbol | | browse_file | JSON | Symbol outline for a file | | index_stats | JSON | Index status + health | | debug_info | JSON | Deep diagnostics | | semantic_annotations | JSON | Query @lci: labels / categories | | side_effects | JSON | Function purity + side-effect analysis | | code_insight | LCF | Codebase intelligence (overview / stats / structure / git) | | git_analysis | JSON | Git change analysis (duplicates / naming / metrics) |

code_insight is the session-startup workhorse: repository map, health dashboard, entry points, complexity/coupling/cohesion statistics, module and feature breakdowns, naming vocabulary, and git change/hotspot analysis.

Conventions

Section titled “Conventions”
  • Invocation: standard MCP tools/call with a name and an arguments object. Every tool returns its payload as the text of a single content[] entry.
  • Output formats: most tools emit JSON. The analysis tools (code_insight) emit LCF (LCI Compact Format) — a token-dense, section-based text format (LCF/1.0\nmode=...\ntier=...\ntokens=...\n---\n followed by == SECTION == blocks).
  • Object IDs: search, list_symbols, inspect_symbol, code_insight, etc. emit short encoded object_id strings (e.g. VE, tG). Feed them to get_context {"id": "..."} (comma-separated for several) to drill in.
  • Errors: failures return a structured error result {"operation": "<tool>", "message": "...", "success": false} with the result flagged as an error. Tools fail fast — no fake/zeroed payloads.
  • Determinism: all list output is sorted with total-order tiebreakers (no hash-iteration order in user-visible output).

search example

Section titled “search example”
{
  "name": "search",
  "arguments": {
    "pattern": "myFunction",
    "output": "ctx",
    "max": 20
  }
}

search is sub-millisecond in-memory content search (not file paths): literal match → optional synonym expansion → regex fallback (flags=rx). Results carry the enclosing symbol’s metadata (object_id, symbol_name, symbol_type, is_exported).