How do I install Codelens?

Codelens is a local plugin. Install it using the provided package and add the generated configuration snippet to your AI app's MCP config file. Then restart your AI app.

Is Codelens safe to use?

Codelens scored 5.2/10 (moderate risk) in MCP Marketplace's automated security scan. It has 5 high or critical findings to review. It's listed, but review the security report on this page before installing.

What AI apps work with Codelens?

Codelens uses the Model Context Protocol (MCP) and works with any MCP-compatible AI app, including Claude, ChatGPT / Codex, Gemini, Copilot, Cursor, and more.

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Codelens MCP Server

by Segentic Lab

Developer ToolsModerate5.2MCP RegistryLocal

Free

Server data from the Official MCP Registry

Deterministic code maps for AI agents: 7 tree-sitter tools for TS/JS/Py — map, find, function_body

About

Deterministic code maps for AI agents: 7 tree-sitter tools for TS/JS/Py — map, find, function_body

Security Report

5.2

Moderate5.2Moderate Risk

codelens-mcp is a well-structured code analysis server with strong security controls. It properly validates file paths to prevent traversal attacks, uses read-only operations, and includes comprehensive input validation and error handling. Minor code quality observations around error handling consistency do not materially impact security. Supply chain analysis found 5 known vulnerabilities in dependencies (2 critical, 3 high severity).

3 files analyzed · 9 issues found

Security scores are indicators to help you make informed decisions, not guarantees. Always review permissions before connecting any MCP server.

Permissions Required

This plugin requests these system permissions. Most are normal for its category.

File System Read

Reads files on your machine. Normal for tools that analyze or process local data.

env_vars

Check that this permission is expected for this type of plugin.

process_spawn

Check that this permission is expected for this type of plugin.

How to Install

Add this to your MCP configuration file:

{
  "mcpServers": {
    "io-github-segentic-lab-codelens-mcp": {
      "args": [
        "-y",
        "codelens-mcp"
      ],
      "command": "npx"
    }
  }
}

Documentation

View on GitHub

From the project's GitHub README.

codelens-mcp

⚠️ Superseded by lens-mcp

codelens has merged into lens-mcp — one MCP server that maps both code and markdown docs. It carries every codelens tool (map, overview, functions, function_body, comments, find, info) unchanged, plus doc tools (outline, heading, links, search) and a unified map that returns a whole project's code structure and doc outlines in one call.

Use lens-mcp instead — git clone https://github.com/segentic-lab/lens-mcp. This repo remains only so existing links resolve; it is no longer developed.

(The description below is retained for reference.)

Deterministic structural code maps for AI agents. An MCP server (stdio) that gives agents the shape of a codebase — imports, exports, classes, functions, signatures, comments, TODO-markers — without reading whole files into context. Powered by tree-sitter WASM grammars: no native build step, installs anywhere Node 18+ runs.

The contract: codelens is a navigation map. Use it to locate code, then Read the actual source before judging or modifying it. A signature is not the body; an outline is not the section.

Tools

7 read-only tools. Every list in every response is capped, and every cap is reported with an explicit truncated flag — no silent cutoffs.

Tool	What it does
`map`	Per-file structural overview of a whole directory tree in one call. Skips `node_modules`, `dist`, `venv`, hidden dirs, etc. The orientation tool.
`overview`	One file's top-level structure: imports, exports, classes (with method names), functions — all with 1-based `line`/`endLine`.
`functions`	Every addressable function in a file — nested functions, methods, getters/setters, class-field arrows, object-literal properties, default exports — with reconstructed signatures, param types, return type, `async`/`exported` flags, and `parent` scope. (Anonymous callbacks passed as arguments and Python lambdas are not listed — they have no name to navigate to.)
`comments`	All comments with line ranges, kind (`line`/`block`/`doc`), and TODO/FIXME/FIX/BUG/HACK/NOTE/XXX marker detection (uppercase-only, no prose false-positives). `markersOnly: true` returns just the debt list.
`function_body`	Verbatim source of one function (with decorators) by bare or dotted name (`Widget.render`) — the focused read that replaces whole-file Reads. Ambiguous names fail listing the candidates; it never guesses.
`find`	"Where is X defined?" — locate function/method/class definitions by name across a directory. Definitions only, not call sites.
`info`	Server self-description: version, working directory (the path sandbox root), languages, caps.

overview, functions, and comments accept a single path or an array of up to 20 paths per call.

Languages

Extension	Language	Grammar
`.ts`, `.mts`, `.cts`	TypeScript	tree-sitter-typescript
`.tsx`	TypeScript + JSX	tree-sitter-tsx (dedicated grammar — JSX parses correctly)
`.js`, `.jsx`, `.mjs`, `.cjs`	JavaScript	tree-sitter-javascript
`.py`	Python	tree-sitter-python

Path sandbox

The server only reads files under its own working directory (the directory it was launched from). Relative paths resolve against it; absolute paths are accepted only if they point inside it; symlinks that escape it are rejected. The info tool reports the root, and every rejection names it. Launch the server from the project you want mapped.

Honesty guarantees

A file with syntax errors is never reported as a clean success: hasErrors: true plus parseErrors line ranges, because tree-sitter error-recovery can drop code near the error.
Errors set isError on the MCP result and return {error, path, hint} — the hint says how to fix the call.
Batch calls return per-file results plus an honest {requested, succeeded, failed} summary; isError only when every file failed.
Every cap is visible: truncated flags carry the true totals.

Install & run

npm install
npm run build    # tsc → dist/
npm test         # build + 62 tests (51 unit, 11 stdio e2e)
node dist/index.js   # stdio MCP server (launch from the project to analyze)

MCP client config:

{
  "mcpServers": {
    "codelens": {
      "command": "node",
      "args": ["/path/to/codelens-mcp/dist/index.js"],
      "cwd": "/path/to/project-to-analyze"
    }
  }
}

For agent authors

AGENTS.md in this repo is a paste-ready guide for teaching an agent to use these tools well — core model, per-tool tips, and the pitfalls (path sandbox, language coverage, the map-vs-territory rule).

License

AGPL-3.0 — see LICENSE.

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Codelens MCP Server

About

Security Report

Findings (9)Action required

Permissions Required

How to Install

Documentation

codelens-mcp

⚠️ Superseded by lens-mcp

Tools

Languages

Path sandbox

Honesty guarantees

Install & run

For agent authors

License

Reviews

No reviews yet

More Developer Tools MCP Servers

Git

Fetch

Toleno

mcp-creator-python

MarkItDown

MCP Marketplace