MCP Sidecar

MCP Sidecar is a lightweight, cross-platform server built in Go that allows AI coding agents to manage long-lived background processes. It exposes tools for starting, stopping, listing, and interacting with processes via stdin/stdout, solving workflows like running API servers or build watchers while continuing to interact with the agent.

Package and access

Local package with source-attributed installation metadata. Koskamo does not execute packages during review.

Community listingLocal stdioSource reviewed; not executedPublished by lsequeiraa

Vendor documentation

What you can do with it

Start an API server and wait for it to be ready
Run a build in watch mode while editing code
Start a database, seed it, run tests, and tear it down

Source and maintenance

Community listingRegistry 0.3.2

mcp-registry: io.github.lsequeiraa/mcp-sidecar@0.3.2 Source repository

Maintenance checked: Oct 31, 2026, 10:27 PM UTC

Packages and installation

Source-provided package data. Koskamo has not executed or live-probed this package.

mcp-sidecar 0.3.2

npm

mcp-sidecar package definition

{
  "version": "0.3.2",
  "transport": "stdio",
  "identifier": "mcp-sidecar",
  "registryType": "npm",
  "environmentVariables": [
    {
      "name": "SIDECAR_MAX_PROCESSES",
      "format": "string",
      "description": "Maximum number of concurrent managed processes (default: 10)"
    },
    {
      "name": "SIDECAR_BUFFER_SIZE",
      "format": "string",
      "description": "Output buffer size per stream in bytes (default: 1048576)"
    },
    {
      "name": "SIDECAR_KILL_TIMEOUT",
      "format": "string",
      "description": "Milliseconds to wait between graceful and forced termination (default: 5000)"
    },
    {
      "name": "SIDECAR_CLEANUP_AFTER",
      "format": "string",
      "description": "Seconds before exited processes are auto-removed. 0 disables cleanup (default: 1800)"
    },
    {
      "name": "SIDECAR_MAX_OUTPUT_SIZE",
      "format": "string",
      "description": "Global cap on bytes returned by the output tool. 0 means unlimited (default: 0)"
    },
    {
      "name": "SIDECAR_ALLOWED_EXECUTABLES",
      "format": "string",
      "description": "Comma-separated allowlist of executable names. When set, enables security mode with direct exec (no shell). Unset means security disabled."
    },
    {
      "name": "SIDECAR_BLOCKED_PATTERNS",
      "format": "string",
      "description": "Comma-separated regex patterns to reject in commands. Only applies when security is enabled."
    },
    {
      "name": "SIDECAR_AUDIT_LOG",
      "format": "string",
      "description": "Audit log destination. 'true' writes to cwd, 'temp' writes to OS temp dir, or a directory path. Unset disables audit logging."
    }
  ]
}

Tools

Reported by the attributed source; not independently observed by Koskamo.

No tool definitions available.

Connect from your client

Each snippet configures the same source-provided package; replace placeholders before use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Cursor

Merge this local stdio configuration, replace every placeholder environment value, and restart Cursor. Koskamo has not executed this package.

Cursor configuration

{
  "mcpServers": {
    "mcp-sidecar": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-sidecar@0.3.2"
      ],
      "env": {
        "SIDECAR_MAX_PROCESSES": "<YOUR_SIDECAR_MAX_PROCESSES>",
        "SIDECAR_BUFFER_SIZE": "<YOUR_SIDECAR_BUFFER_SIZE>",
        "SIDECAR_KILL_TIMEOUT": "<YOUR_SIDECAR_KILL_TIMEOUT>",
        "SIDECAR_CLEANUP_AFTER": "<YOUR_SIDECAR_CLEANUP_AFTER>",
        "SIDECAR_MAX_OUTPUT_SIZE": "<YOUR_SIDECAR_MAX_OUTPUT_SIZE>",
        "SIDECAR_ALLOWED_EXECUTABLES": "<YOUR_SIDECAR_ALLOWED_EXECUTABLES>",
        "SIDECAR_BLOCKED_PATTERNS": "<YOUR_SIDECAR_BLOCKED_PATTERNS>",
        "SIDECAR_AUDIT_LOG": "<YOUR_SIDECAR_AUDIT_LOG>"
      }
    }
  }
}

Cline

Merge this local stdio configuration, replace every placeholder environment value, and restart Cline. Koskamo has not executed this package.

Cline configuration

{
  "mcpServers": {
    "mcp-sidecar": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-sidecar@0.3.2"
      ],
      "env": {
        "SIDECAR_MAX_PROCESSES": "<YOUR_SIDECAR_MAX_PROCESSES>",
        "SIDECAR_BUFFER_SIZE": "<YOUR_SIDECAR_BUFFER_SIZE>",
        "SIDECAR_KILL_TIMEOUT": "<YOUR_SIDECAR_KILL_TIMEOUT>",
        "SIDECAR_CLEANUP_AFTER": "<YOUR_SIDECAR_CLEANUP_AFTER>",
        "SIDECAR_MAX_OUTPUT_SIZE": "<YOUR_SIDECAR_MAX_OUTPUT_SIZE>",
        "SIDECAR_ALLOWED_EXECUTABLES": "<YOUR_SIDECAR_ALLOWED_EXECUTABLES>",
        "SIDECAR_BLOCKED_PATTERNS": "<YOUR_SIDECAR_BLOCKED_PATTERNS>",
        "SIDECAR_AUDIT_LOG": "<YOUR_SIDECAR_AUDIT_LOG>"
      }
    }
  }
}

VS Code

Merge this local stdio configuration, replace every placeholder environment value, and restart VS Code. Koskamo has not executed this package.

VS Code configuration

{
  "servers": {
    "mcp-sidecar": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "mcp-sidecar@0.3.2"
      ],
      "env": {
        "SIDECAR_MAX_PROCESSES": "<YOUR_SIDECAR_MAX_PROCESSES>",
        "SIDECAR_BUFFER_SIZE": "<YOUR_SIDECAR_BUFFER_SIZE>",
        "SIDECAR_KILL_TIMEOUT": "<YOUR_SIDECAR_KILL_TIMEOUT>",
        "SIDECAR_CLEANUP_AFTER": "<YOUR_SIDECAR_CLEANUP_AFTER>",
        "SIDECAR_MAX_OUTPUT_SIZE": "<YOUR_SIDECAR_MAX_OUTPUT_SIZE>",
        "SIDECAR_ALLOWED_EXECUTABLES": "<YOUR_SIDECAR_ALLOWED_EXECUTABLES>",
        "SIDECAR_BLOCKED_PATTERNS": "<YOUR_SIDECAR_BLOCKED_PATTERNS>",
        "SIDECAR_AUDIT_LOG": "<YOUR_SIDECAR_AUDIT_LOG>"
      }
    }
  }
}

Claude Desktop

Merge this local stdio configuration, replace every placeholder environment value, and restart Claude Desktop. Koskamo has not executed this package.

Claude Desktop configuration

{
  "mcpServers": {
    "mcp-sidecar": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-sidecar@0.3.2"
      ],
      "env": {
        "SIDECAR_MAX_PROCESSES": "<YOUR_SIDECAR_MAX_PROCESSES>",
        "SIDECAR_BUFFER_SIZE": "<YOUR_SIDECAR_BUFFER_SIZE>",
        "SIDECAR_KILL_TIMEOUT": "<YOUR_SIDECAR_KILL_TIMEOUT>",
        "SIDECAR_CLEANUP_AFTER": "<YOUR_SIDECAR_CLEANUP_AFTER>",
        "SIDECAR_MAX_OUTPUT_SIZE": "<YOUR_SIDECAR_MAX_OUTPUT_SIZE>",
        "SIDECAR_ALLOWED_EXECUTABLES": "<YOUR_SIDECAR_ALLOWED_EXECUTABLES>",
        "SIDECAR_BLOCKED_PATTERNS": "<YOUR_SIDECAR_BLOCKED_PATTERNS>",
        "SIDECAR_AUDIT_LOG": "<YOUR_SIDECAR_AUDIT_LOG>"
      }
    }
  }
}

Let your agent find its tools

Find servers like MCP Sidecar from your agent. Add Koskamo once to search the index for endpoints, access requirements, and client setup. Public discovery needs no key.

Connect Koskamo Explore workflows

See all 6,671