Labsco
MCP SERVER

MCP Cpp Project Indexer

by walti1972 ↗

Point an AI at a large C++ codebase and have it read exact source ranges instead of whole files.

Code Intelligence & Repository Indexing
Summary
Metadata first, source second — and it says which is which.

The discipline that makes this useful on a big tree is that locating and reading are separate operations. Routing tools return ranges and never source text, so a search does not spend context; only `read_symbol` and `read_range` return code. The docs are equally clear about the boundary: hunk intersections are routing hints, not analysis, and you are expected to read the source before making a claim about behaviour. Source file operations are jailed to the project's source directory.

What it is

A deterministic source-range indexer for large, module-heavy C++ projects. It maps symbols, files and C++20 modules to exact line ranges so a client can ask where something is and then read only that range. It is not a compiler, LSP replacement or semantic analyzer.

What you get
  • `find_symbol`, `find_declaration` and `find_symbols_glob` locate by name, with `matchKind` on every result saying why it matched
  • `read_symbol` returns one symbol's body, sliceable by offset; `read_range` reads explicit lines or an around-line window with `beforeLines` and `afterLines`
  • `get_nearest_symbol_for_line` maps a line from a diagnostic, a build error or a hunk onto the containing indexed range
  • `list_file_symbols`, `find_files`, `list_file_includes` and `get_file_structure` work when the file is already known
  • Change tracking, when git is available: `list_changed_files`, `list_recent_revisions`, `get_revision_summary`, `get_file_change_hunks` and `resolve_hunk_to_indexed_range` — read-only, with no generic command runner
  • `get_project_summary` plus `get_index_fingerprint`, `get_file_fingerprint`, `get_symbol_fingerprint` and `get_data_fingerprint` let a caller tell which cached facts went stale after a rebuild; `validate_fingerprints` checks up to 500 items in one call and returns metadata only
  • Routing controls narrow results before any source is read: `compact`, `symbolTypes`, `container`, `filePattern`, `exactOnly`, `hideNamespaces` and `limit`
Requirements

Python, a clone of the repository, and two steps: build the index with `build_project_index.py --root <project> --output-root <project>\.mcp-cpp-project-indexer`, then start `code_index_mcp_server.py` with `--project-root` and `--index-root`. For several clients or a long-lived process, add `--transport http --http-host 127.0.0.1 --http-port 8765`. No account, no network service.