devlens

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Table of Contents

• What is DevLens?
• Why it helps
• The four surfaces
• Quick start
• 1 · CLI (@devlensio/cli)
  • CLI command reference
• 2 · MCP server
• 3 · Agent Skill (/devlens)
• 4 · Web UI
• Configuration
• What DevLens understands
• Architecture & repo layout
• DevLens Cloud
• Releasing
• Contributing
• License

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What is DevLens?

AI coding tools let you ship faster than ever — but that speed creates a new problem: codebases grow faster than anyone (human or AI) can understand them. Developers merge code they didn't fully read; new hires drown in unfamiliar structure; agents burn tokens re-reading files they've seen before.

DevLens turns any React / Next.js / Node.js / TypeScript repo into a living, queryable map:

1. Walks the AST — extracts every component (with prop types), hook, function (typed params + return), store, utility, route, and file.
2. Builds a typed dependency graph — CALLS, IMPORTS, READS_FROM, WRITES_TO, PROP_PASS, EMITS, LISTENS, WRAPPED_BY, GUARDS, HANDLES, TESTS, USES.
3. Scores every node by architectural importance (multi-pass, no AI).
4. Summarizes each node with an LLM — a technical summary (what it does), a business summary (what it means for the product), and a security assessment (severity + notes).
5. Serves that graph to you through a CLI, an MCP server, an agent skill, and an interactive web UI.

The analysis engine is the separate devlensio package; DevLens OSS is everything you interact with on top of it. Everything runs locally — your code never leaves your machine.

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Why it helps

• Understand AI-generated code — a visual + queryable map of what was built and how it connects, in plain English.
• Onboard in hours, not weeks — explore the graph and read per-node summaries instead of spelunking files.
• Blast-radius & impact analysis — before you change something, see exactly what depends on it.
• Architecture audits — surface central nodes, circular dependencies, and bottlenecks.
• Security review — every node carries a severity + explanation; list and prioritize them.
• Living documentation — summaries regenerate as code changes; unchanged nodes are reused (90%+ free on re-runs).
• Token-efficient agents — a node summary is ~50 tokens vs ~2000 for the file. Agents query the graph instead of reading files, and target work with blast-radius/k-hop instead of scanning directories.

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The four surfaces

Surface	What it is	Install	Best for
CLI	devlens command — analyze + query from the terminal, JSON-friendly	npm i -g @devlensio/cli	scripts, terminals, CI
MCP server	devlens mcp — 14 tools over the Model Context Protocol	bundled in the CLI	Claude, Cursor, any MCP client
Agent Skill	/devlens — teaches an agent how to drive the CLI	npx @devlensio/skill install	Claude Code, Cursor, Kilo, opencode, pi
Web UI	interactive graph visualizer (Next.js)	bun run dev (from source)	visual exploration

All four read the same graph stored in ~/.devlens.

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Quick start

Install

Standalone binary — one command, no Node or Bun required (downloads a prebuilt native binary from GitHub Releases into ~/.devlens/bin):

macOS / Linux:

curl -fsSL https://raw.githubusercontent.com/devlensio/devlensOSS/main/scripts/install.sh | sh

Windows (PowerShell):

irm https://raw.githubusercontent.com/devlensio/devlensOSS/main/scripts/install.ps1 | iex