#MCP & LSP

OpenCode extends external capabilities via MCP (Model Context Protocol) and gets live language diagnostics via LSP (Language Server Protocol).

#MCP Overview

MCP lets the agent call databases, browsers, Slack, custom APIs, etc., without baking that logic into OpenCode itself.

Config locations:

• Global: mcp in ~/.config/opencode/opencode.json
• Project: project root opencode.json

#Configure MCP Servers

#stdio (local process)

{
  "mcp": {
    "filesystem": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/path/to/allowed"]
    }
  }
}

#SSE / HTTP (remote)

{
  "mcp": {
    "my-api": {
      "type": "sse",
      "url": "https://mcp.example.com/sse"
    }
  }
}

Use /connect in TUI for Providers interactively; MCP is usually maintained in config files.

#MCP and Permissions

MCP tool names often include a server prefix. Control via permission:

{
  "permission": {
    "mcp": {
      "*": "ask",
      "filesystem_*": "allow"
    }
  }
}

Security:

• Enable only MCP servers the project needs
• Default write/network MCP to ask
• Review MCP server source and scope

#Common MCP Use Cases

Explore subagent + read-only MCP avoids Build accidentally writing to production systems.

#LSP Integration

OpenCode can connect language servers and surface diagnostics (errors, warnings) after edits so the agent can self-correct.

#Enable

opencode.json:

{
  "lsp": {
    "typescript": {
      "command": "typescript-language-server",
      "args": ["--stdio"]
    },
    "python": {
      "command": "pyright-langserver",
      "args": ["--stdio"]
    }
  }
}

Install the corresponding LSP binaries on your machine.

#With the agent

1. Agent edits foo.ts
2. LSP returns type errors
3. Agent reads diagnostics and fixes

More reliable than the model guessing types alone.

#LSP permission

permission.lsp controls LSP tool access; usually allow by default.

#MCP vs LSP

Both can run together—they complement each other.

#Troubleshooting

#Next Steps

• Config & CLI Reference
• Practical Examples
• Architecture & Runtime