mcp-language-server MCP — 사용 사례, 설치 & 라이브 데모

왜 쓰나요

핵심 기능

LSP semantic operations: definition, references, rename, hover, diagnostics
Works with any stdio LSP (gopls, rust-analyzer, pyright, tsserver, clangd)
Single Go binary, easy install
edit_file uses LSP-backed rename for correctness
One MCP instance per LSP; compose multiple for polyglot repos

라이브 데모

실제 사용 모습

language-server.replay ▶ 준비됨

0/0

설치

클라이언트 선택

~/Library/Application Support/Claude/claude_desktop_config.json · Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "language-server": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/isaacphi/mcp-language-server"
      ],
      "_inferred": true
    }
  }
}

Claude Desktop → Settings → Developer → Edit Config 열기. 저장 후 앱 재시작.

~/.cursor/mcp.json · .cursor/mcp.json

{
  "mcpServers": {
    "language-server": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/isaacphi/mcp-language-server"
      ],
      "_inferred": true
    }
  }
}

Cursor는 Claude Desktop과 동일한 mcpServers 스키마 사용. 프로젝트 설정이 전역보다 우선.

VS Code → Cline → MCP Servers → Edit

{
  "mcpServers": {
    "language-server": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/isaacphi/mcp-language-server"
      ],
      "_inferred": true
    }
  }
}

Cline 사이드바의 MCP Servers 아이콘 클릭 후 "Edit Configuration" 선택.

~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "language-server": {
      "command": "TODO",
      "args": [
        "See README: https://github.com/isaacphi/mcp-language-server"
      ],
      "_inferred": true
    }
  }
}

Claude Desktop과 같은 형식. Windsurf 재시작 후 적용.

~/.continue/config.json

{
  "mcpServers": [
    {
      "name": "language-server",
      "command": "TODO",
      "args": [
        "See README: https://github.com/isaacphi/mcp-language-server"
      ]
    }
  ]
}

Continue는 맵이 아닌 서버 오브젝트 배열 사용.

~/.config/zed/settings.json

{
  "context_servers": {
    "language-server": {
      "command": {
        "path": "TODO",
        "args": [
          "See README: https://github.com/isaacphi/mcp-language-server"
        ]
      }
    }
  }
}

context_servers에 추가. 저장 시 Zed가 핫 리로드.

claude mcp add language-server -- TODO 'See README: https://github.com/isaacphi/mcp-language-server'

한 줄 명령. claude mcp list로 확인, claude mcp remove로 제거.

사용 사례

실전 활용법: mcp-language-server

How to rename a symbol safely across a repo

👤 Polyglot devs using agents ⏱ ~15 min intermediate

언제 쓸까: You want a rename that understands scope, not a find-replace.

사전 조건

Go installed — brew install go
The LSP for your language — gopls: go install golang.org/x/tools/gopls@latest; pyright: pip install pyright; etc.
Install the MCP — go install github.com/isaacphi/mcp-language-server@latest

흐름

Start the MCP pointed at your workspace + LSP

Add MCP config: command=mcp-language-server, args=['--workspace','.','--lsp','gopls'].✓ 복사됨

→ Tools appear
Find references first

references for symbol 'LegacyAuth' in file auth.go.✓ 복사됨

→ Precise cross-repo references
Rename

rename_symbol 'LegacyAuth' -> 'Auth' at the definition site.✓ 복사됨

→ All callsites updated correctly

결과: Semantically-correct rename across the repo.

함정

Agent falls back to text find-replace when the tool fails — Verify diagnostics after rename — compile errors mean the LSP refused and the agent cheated

함께 쓰기: github

How to let the agent navigate like you do in an IDE

👤 Agent users tired of re-grepping ⏱ ~10 min beginner

언제 쓸까: Agent keeps reading whole files to find one function.

흐름

Query definition

definition for 'computeTax' in src/billing.ts.✓ 복사됨

→ Exact file:line location
Pull diagnostics

diagnostics for the current file.✓ 복사됨

→ Red squigglies from the LSP

결과: Agent navigates like an IDE user.

함정

LSP not initialized — slow first call — Warm up with a list of files in the workspace; pyright especially is slow to index

함께 쓰기: contextplus

How to run multiple LSPs for a polyglot monorepo

👤 Devs on Go+TS+Python monorepos ⏱ ~25 min advanced

언제 쓸까: You want semantic ops in every language.

흐름

Register one MCP per LSP

Add 3 MCP entries: lsp-go (gopls), lsp-ts (tsserver), lsp-py (pyright), each scoped to its workspace subfolder.✓ 복사됨

→ 3 sets of language-specific tools
Use them in turn

For TypeScript questions use lsp-ts:definition; for Go use lsp-go:definition.✓ 복사됨

→ Correct semantics per language

결과: Semantically-aware navigation across all languages.

함정

Agent forgets which MCP handles which language — Rename tool prefixes descriptively and mention in your project memory

조합

다른 MCP와 조합해 10배 효율

language-server + contextplus

Combine LSP navigation with semantic/embedding search for broader queries

Use language-server's references for exact usages of computeTax, then contextplus semantic search to find conceptually-related functions.✓ 복사됨

language-server + github

Rename + commit + PR

Rename LegacyAuth to Auth via the LSP, commit to a new branch, open a PR.✓ 복사됨

도구

이 MCP가 노출하는 것

도구	입력	언제 호출	비용
definition	file: str, symbol_or_position	Jump to declaration	free (local LSP)
references	file: str, symbol_or_position	Find usages	free
diagnostics	file: str	Check errors/warnings	free
hover	file, position	Type info / docs for a symbol	free
rename_symbol	file, position, new_name	Safe rename	free
edit_file	file, edits	LSP-validated edit	free

비용 및 제한

운영 비용

API 쿼터: None — local LSP
호출당 토큰: Small — LSP responses are compact
금액: Free
팁: Use LSP-backed tools before embedding search — often cheaper and more precise.

보안

권한, 시크릿, 파급범위

최소 스코프: Filesystem read/write to the workspace

자격 증명 저장: None

데이터 외부 송신: Localhost only; LSP runs in-process

절대 부여 금지: Don't point it at workspaces with secrets — LSPs sometimes index them

edit_file respects LSP validation but doesn't guarantee atomicity across multi-file edits.

문제 해결

자주 발생하는 오류와 해결

tool returns 'LSP not ready'

First call triggers initialization — retry after 2-5 seconds, or warm up with a hover call.

gopls: 'no packages found'

Point workspace at the module root (where go.mod is), not a subfolder.

확인: go env GOMOD

pyright slow on big repos

Configure pyrightconfig.json to exclude vendored dirs.

rename_symbol reports success but compile still fails

Rename touched a string literal or reflection-based code the LSP can't see. Check grep for the old name.

대안

mcp-language-server 다른 것과 비교

대안	언제 쓰나	단점/장점
Context+	You want embedding + memory graph rather than LSP semantics	Not as precise on rename/references
Serena MCP	You want LSP with higher-level refactors	Different setup; Python-based

mcp-language-server