Java Lens MCP Server

An MCP server providing 75 semantic analysis tools for Java, built directly on Eclipse JDT for compiler-accurate code understanding. Its 40 documented tools cover type, analyze, hierarchy, position. It runs locally over stdio via the published package.

People connecting coding agent tools to Claude, Cursor, VS Code, or another MCP client. The project is written in Java.

VERIFIED ACTIVE

LAST COMMIT 2026-06-16 · ★ 37 · #65 OF 194 MAINTAINED CODING AGENT · VERIFIED 2026-08-25

MIT · Java · how we verify → /methodology

01 · Install Java Lens

before you install - you'll need

Set JAVA_PROJECT_PATH, JAVALENS_TESTS_REQUIRE_TOOLS before connecting.

Claude Code

claude mcp add pzalutski-pixel-javalens-mcp -- npx -y javalens-mcp

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "pzalutski-pixel-javalens-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "javalens-mcp"
      ]
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions

license MIT - declared in the repository

npm package javalens-mcp - unscoped; check the name against the project README before installing

registry namespace io.github.pzalutski-pixel is GitHub-verified and matches the repo owner

03 · What Java Lens can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

What you can build

With this server connected, an agent can search types, methods, fields by glob pattern, navigate to symbol definition, find all usages of a symbol, and find interface/class implementations.

Capability map

Tools grouped from the project's README - what Java Lens lets an agent do.

read & search

24 tools - e.g. Search types, methods, fields by glob pattern; Find all usages of a symbol; Find interface/class implementations

search_symbols · find_references · find_implementations · get_document_symbols · get_symbol_info · find_annotation_usages…

Type

4 tools - e.g. Get inheritance chain; Get type details at cursor; Find all new Type() calls

get_type_hierarchy · get_type_at_position · find_type_instantiations · find_type_arguments

Analyze

4 tools - e.g. Blast radius - direct call sites by depth, or the full transitive closure over the project graph (transitive=true); Variable read/write/declaration tracking within a method; opt-in followCalls tracks…

analyze_change_impact · analyze_data_flow · analyze_control_flow · analyze_file

Method

2 tools - e.g. Get method details at cursor; Find all Type::method expressions

get_method_at_position · find_method_references

Field

2 tools - e.g. Get field details at cursor; Find where fields are mutated

get_field_at_position · find_field_writes

Hierarchy

2 tools - e.g. Find all callers of a method; Find all methods called by a method

get_call_hierarchy_incoming · get_call_hierarchy_outgoing

Definition

1 tool - e.g. Navigate to symbol definition

go_to_definition

Validate

1 tool - e.g. Fast syntax-only validation

validate_syntax

Limitations (from the README)

Every answer is verified against the files on disk at query time. Before any tool logic runs, JavaLens content-hashes the known source files, detects edits, additions, and deletions (the agent reports nothing - the server discovers changes itself), repairs exactly what changed, waits for the search index to absorb the repair, and only then answers. There is no file watcher and no background thread - verification is s

Latest releases

v1.5.1 · 2026-06-16

v1.5.0 · 2026-06-12

v1.4.2 · 2026-06-11

04 · Who maintains Java Lens

JavaLens is maintained by pzalutski-pixel. We track 4 MCP servers from pzalutski-pixel - 4 actively maintained, 74 combined GitHub stars, oldest repo from Dec 2025. Full record: all servers from pzalutski-pixel.

05 · Facts

repository: github.com/pzalutski-pixel/javalens-mcp
category: coding agent - ranked #65 of 194 actively-maintained coding agent servers as of 2026-08-25.
release cadence: 6 releases in the last 90 days (latest 2026-06-16)
registry: io.github.pzalutski-pixel/javalens (active, first published 2026-04-08 · 14 versions)
packages: npm:javalens-mcp

06 · Java Lens FAQ

Is Java Lens still maintained?

Yes - as of 2026-08-25, its last commit was 2026-06-16 and it shipped 6 releases in the last 90 days. We re-verify nightly.

What can Java Lens do?

With this server connected, an agent can search types, methods, fields by glob pattern, navigate to symbol definition, find all usages of a symbol, and find interface/class implementations.

How do I install Java Lens?

Run `npx -y javalens-mcp`. The README documents 2 environment variables (JAVA_PROJECT_PATH, JAVALENS_TESTS_REQUIRE_TOOLS) to set first. Set JAVA_PROJECT_PATH, JAVALENS_TESTS_REQUIRE_TOOLS before connecting. You can also paste the ready-made client config above.

Does Java Lens run locally?

Yes - it's a stdio server: it runs on your machine (via npx) with your user's permissions. Your data stays local unless the server itself calls external APIs.

07 · Alternatives to Java Lens

Alternatives to Java Lens

Maintained coding agent servers if Java Lens isn't the fit.

Pairs well with

Servers that cover what Java Lens doesn't - only shown when the pairing reason fits the companion.

More coding agent MCP servers · Sharp Lens · Agentmap · Reachpad MCP · Raven