Script

Overview

Script rules allow advanced routing decisions based on custom logic. They are useful when standard rule types cannot express a policy clearly.

When to use scripts

Use scripts for exceptional routing logic, not for ordinary domain or IP matching. A normal rule list is easier to read, faster to review and safer to maintain.

Configuration notes

• Keep each script focused on one decision.
• Document why the script is needed.
• Test against known domains before enabling it broadly.
• Use no-resolve only when you understand DNS implications.

Support Checks

If the result is surprising, simplify the script until it matches one known request, then add conditions back gradually.

Related pages

• Script Shortcuts
• Userspace WireGuard
• The Profiling Engine

Reference examples

These examples mirror the corresponding Chinese documentation page so the English page carries the same configuration material.

mode: Script

# https://lancellc.gitbook.io/clash/clash-config-file/script
script:
  code: |
    def main(ctx, metadata):
      ip = metadata["dst_ip"] = ctx.resolve_ip(metadata["host"])
      if ip == "":
        return "DIRECT"

      code = ctx.geoip(ip)
      if code == "LAN" or code == "CN":
        return "DIRECT"

      return "Proxy" # default policy for requests which are not matched by any other script

def main(ctx, metadata):
    # ctx.rule_providers["geoip"].match(metadata) return false

    ip = ctx.resolve_ip(metadata["host"])
    if ip == "":
        return "DIRECT"
    metadata["dst_ip"] = ip

    # ctx.rule_providers["iprule"].match(metadata) return true

    return "Proxy"

interface Metadata {
  type: string // socks5、http
  network: string // tcp
  host: string
  src_ip: string
  src_port: string
  dst_ip: string
  dst_port: string
  inbound_port: number
}

interface Context {
  resolve_ip: (host: string) => string // ip string
  resolve_process_name: (metadata: Metadata) => string
  resolve_process_path: (metadata: Metadata) => string
  geoip: (ip: string) => string // country code
  log: (log: string) => void
  proxy_providers: Record<string, Array<{ name: string, alive: boolean, delay: number }>>
  rule_providers: Record<string, { match: (metadata: Metadata) => boolean }>
}