MCP wrapper for BSL Language Server

BSL MCP Server

A small MCP server that runs BSL Language Server as a JAR file and gives an agent BSL code analysis and formatting as JSON

MCP server

Medium risk

We rate an entry medium when the tool runs code, makes network calls or reads project files. Check what exactly it does before installing.

Why this level

  • bsl_format rewrites BSL files in the given directory
  • Runs an external Java JAR process with a configurable memory limit
All reasons and checks
Russian stack

phsin/mcp-bsl-ls

Install

Manual install

pip install -r requirements.txt
pip install -e .

Install from source after cloning the repository.

This is third-party code. Review the repository files before installing.

What it does

The server wraps the ready-made BSL Language Server JAR with two tools: bsl_analyze runs analysis on a .bsl/.os directory or file and returns a human-readable summary plus a structured JSON with diagnostics, paths, lines and severity levels, and bsl_format applies BSL Language Server's formatting rules to files. The server doesn't perform 1C platform syntax or function checks itself; that's BSL Language Server's own job. Timeouts are fixed at 5 minutes for analysis and 2 minutes for formatting, and JVM memory is tunable via an environment variable.

Who it is for. For 1C developers in Cursor who already have BSL Language Server set up and want a minimal MCP bridge to it without any custom analysis logic.

Good fit when

  • You want an agent to get BSL Language Server diagnostics right from the chat
  • You need to format a batch of BSL files by BSL Language Server's rules
  • You already have a configured .bsl-language-server.json and JAR file and just need an MCP interface to them

Not a fit when

  • You need 1C platform syntax checking: the README explicitly says the server doesn't do that
  • Java 8 or newer, or the BSL Language Server JAR, isn't set up
  • You need relative paths: the README requires absolute paths only

Example request

Check the C:\1C\lk\src\CommonModules directory for BSL Language Server diagnostics and show the top issues

Limitations

The server does not perform 1C platform syntax or function checks, only what BSL Language Server itself does. A separately downloaded BSL Language Server JAR and Java Runtime 8 or newer are required. Operation depends on absolute paths; relative ones may not work correctly. Analysis and formatting timeouts are not user-configurable.

How to disable. Remove the bsl-mcp block from ~/.cursor/mcp.json or uninstall the package with pip uninstall.

MCP

Transport
stdio
Authentication
not required
Environment variables
Environment variables
BSL_JAR
required
Path to the BSL Language Server JAR file.
BSL_CONFIG
Path to the .bsl-language-server.json settings file.
BSL_MEMORY_MB
JVM memory limit for analysis, in megabytes.

Security check

  • bsl_format rewrites BSL files in the given directory
  • Runs an external Java JAR process with a configurable memory limit

README in short

The README describes two tools, bsl_analyze and bsl_format, the Python, Java and BSL Language Server JAR requirements, an example Cursor MCP config with BSL_JAR, BSL_MEMORY_MB, BSL_CONFIG and BSL_LOG_LEVEL variables, an example .bsl-language-server.json, handling of common errors, the project structure, and a detailed troubleshooting section covering already-fixed issues like duplicate logs. MIT license.

FAQ

Does the server check 1C platform syntax itself?

No, the README explicitly says it does not perform platform syntax or function checks, only BSL Language Server's own diagnostics.

Why do absolute paths matter?

The README separately warns that relative paths may not work correctly with the server and recommends always using an absolute path.

Editors’ pick

A skills library that gives coding agents a development process: brainstorming, planning, TDD, subagents and code review

PluginMedium riskNo VPN needed292.5KRepository stars
Editors’ pick

Small composable skills for engineering with agents: plan grilling, TDD, bug diagnosis, code review and architecture

SkillLow risk271.4KRepository stars
Editors’ pick

GitHub toolkit for spec-driven development: the specify CLI adds agent commands and skills to a project, from principles to implementation

CLIMedium riskNo VPN needed139.3KRepository stars

Reference MCP servers

Model Context Protocol servers

Official

Official reference MCP servers: Filesystem, Fetch, Git, Memory, Sequential Thinking, Time and Everything

MCP serverMedium risk90.6KRepository stars
Foxx AIMCP wrapper for BSL Language Server

I am Foxx AI and I have already vetted this tool. Ask about install, setup or anything else, and I will keep it simple.