CLI Reference

ZeroMCP ships two commands: serve and audit.

zeromcp serve

Start the MCP server. Scans tool directories, connects remote servers, and serves over configured transports.

zeromcp serve [options] [config-path]

Arguments

Flags

Example: stdio transport (default)

$ zeromcp serve
[zeromcp] v0.1.0
[zeromcp] Config: ./zeromcp.config.json
[zeromcp] Tools:  ./tools
[zeromcp] Loaded: hello
[zeromcp] Loaded: stripe_list_customers
[zeromcp] Loaded: github_list_issues
[zeromcp] 3 local + 0 remote = 3 tool(s)
[zeromcp] stdio transport ready

Example: HTTP transport

$ zeromcp serve --transport http --port 8080
[zeromcp] v0.1.0
[zeromcp] Config: ./zeromcp.config.json
[zeromcp] Tools:  ./tools
[zeromcp] Loaded: hello
[zeromcp] 1 local + 0 remote = 1 tool(s)
[zeromcp] HTTP transport listening on http://localhost:8080/mcp

All log output goes to stderr. For stdio transport, stdout is reserved for MCP JSON-RPC communication. For HTTP transport, the server listens on the specified port.

zeromcp audit

Run static analysis on tool files. Checks for security violations before publishing or deploying.

zeromcp audit [options] [tools-path]

Arguments

Flags

What it checks

• Permission declarations: Every tool must declare a permissions block (network, fs, exec)
• No direct env access: No process.env, os.environ, System.getenv, or ENV[] — use ctx.credentials
• No global fetch: No global fetch, http.get, urllib, etc. — use ctx.fetch
• No undeclared filesystem access: No fs.readFile, open(), etc. without declared fs permissions
• No hardcoded credentials: Scans for API key patterns, bearer tokens, and base64-encoded secrets
• No exec without permission: No child_process, subprocess, or exec() without declared exec permissions

Example: text output

$ zeromcp audit ./tools
✓ stripe/list_customers.js — permissions declared, no raw env access
✓ stripe/create_charge.js — permissions declared, no raw env access
✗ github/issues.js — uses global fetch (should use ctx.fetch)
✗ utils/helper.js — accesses process.env directly

2 passed, 2 failed

Example: JSON output

$ zeromcp audit --format json ./tools
{
  "passed": 2,
  "failed": 2,
  "results": [
    { "file": "stripe/list_customers.js", "status": "pass" },
    { "file": "stripe/create_charge.js", "status": "pass" },
    { "file": "github/issues.js", "status": "fail", "reason": "uses global fetch" },
    { "file": "utils/helper.js", "status": "fail", "reason": "accesses process.env" }
  ]
}

The audit CLI gates the community tool registry. Tools with violations cannot be published.

Environment Variables

CLI flags take precedence over environment variables. Environment variables take precedence over config file values.

Exit Codes

Precedence Order

When the same setting is specified in multiple places, the following order applies (highest to lowest):

1. CLI flags (--port 8080)
2. Environment variables (ZEROMCP_PORT=8080)
3. Config file (zeromcp.config.json)
4. Built-in defaults