GLOSSARY · Quick Reference
Clash Glossary: Core, Protocols & Routing Terms Explained
Subscription, node, proxy group, TUN — words that show up over and over in configs and tutorials, each explained briefly under one of six categories. Every term card has an anchor link reachable from the top category nav or the alphabetical index; if a definition still leaves you stuck, there's a link to troubleshooting and tutorials at the bottom.
- 26 terms
- 6 categories
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KERNEL / CLIENTS
Core & Clients
The core is the engine doing the work; the client is the cockpit wrapped around it. Get these two layers straight first, and most of what follows falls into place.
mihomo Core
The dominant core in today's Clash ecosystem, formerly known as Clash Meta. It parses configs, matches rules, and establishes proxy connections. Most GUI clients wrap a UI around it, while the core itself runs as a command-line binary and is open-sourced under GPL-3.0. When people say "Clash core" today, this is usually what they mean.
Clash Meta Former Name
The name mihomo used before its rename, gradually phased out after 2023. References to Clash Meta or Clash.Meta in older tutorials and configs all point to what is now mihomo. The "Meta" option in subscription converters also refers to this core.
Clash Verge Rev Desktop Client
A popular GUI client for Windows, macOS, and Linux desktops, built on the mihomo core. Its interface covers subscription management, rule switching, and log viewing. It continues development as a community fork after the original Clash Verge was discontinued, and has one of the largest install bases on desktop.
Clash Plus Cross-Platform Client
A GUI client for Windows, macOS, Android, and iOS, also built on the mihomo core, with a consistent interface and config across all platforms. The iOS version is distributed via the App Store; official site: clashplus.io. Our download page lists it as the top pick for each platform.
PROTOCOLS
Proxy Protocols
The encryption and transport method agreed upon between a node and the client. Every node in a subscription is labeled with a protocol name — knowing them all means you're no longer guessing when reading a config.
Shadowsocks SS · Protocol
An early, widely used encrypted proxy protocol with a simple packet structure and low overhead, configured with four elements: server address, port, password, and cipher method. It spawned variants like SSR, and most subscriptions today still offer SS or an improved version of it. Its config field is written as ss.
VMess / VLESS V2Ray-Family Protocols
Two protocols from the V2Ray project: VMess includes built-in encryption and user ID verification, while VLESS drops built-in encryption in favor of an outer TLS layer for lower overhead. Both are commonly paired with transports like WebSocket or gRPC, with config fields written as vmess and vless respectively.
Trojan Protocol
A proxy protocol disguised as normal HTTPS traffic, running entirely over TLS, with the server authenticating connections by password. Because it looks so close to regular web browsing, it's often used where disguise matters most. Its config field is written as trojan, and it requires a certificate and SNI.
Hysteria2 Protocol
A QUIC-based proxy protocol that runs over UDP with built-in congestion control, delivering notably better speeds on high-loss, high-latency connections. The second-generation protocol simplifies handshakes and disguise; its config field is written as hysteria2, and it needs support on both the core and the node.
RULES / ROUTING
Rules & Routing
Clash's core trick: which connections go through the proxy and which go direct is decided entirely by this group of concepts.
Rule-Based Routing Mechanism
A mechanism that decides whether each connection goes through the proxy, connects directly, or gets blocked, based on preset rules — Clash's core use case. Rules are matched top to bottom, stopping at the first match, so order directly affects the outcome. Common matching criteria include domain names, IP ranges, process names, and geolocation.
Proxy Groups proxy-groups
A way to bundle multiple nodes or lower-level proxy groups into a single exit point, written as proxy-groups in the config. Common types include manual selection select, automatic latency testing url-test, failover fallback, and load balancing load-balance. The destination names referenced in rules are actually proxy group names.
GeoIP Database
A database that determines a country or region from an IP address; rule entries like GEOIP,CN rely on it. The core loads an mmdb or dat format file at startup — an outdated file can misjudge newly allocated IP ranges, so it needs updating along with the client.
Rule Sets rule-provider
A mechanism for splitting large groups of related rules into separate files referenced on demand, declared via rule-providers in the config. Compared to writing thousands of rules directly into the main config, rule sets can be updated individually and loaded as needed, making them a common way to organize subscriptions and routing templates.
RUN MODES
Run Modes
The same config behaves completely differently depending on the mode. Before troubleshooting, check which mode the client is currently running in.
Rule Mode Rule
One of three basic modes: it evaluates each connection against the rule table in order, and is the recommended default for everyday use. Effects like routing local sites directly while sending everything else through the proxy come from Rule Mode, and the quality of the rule table directly determines how accurate the routing is.
Global Mode Global
One of three basic modes: it skips the rule table entirely and sends every connection to the exit selected in the GLOBAL proxy group. It's handy for quickly testing whether a node works, or for services that need to stay on the same exit throughout. Leaving Global Mode on long-term routes local traffic through the proxy too, which is usually slower.
Direct Mode Direct
One of three basic modes: no connection goes through the proxy at all, similar to temporarily turning the proxy off while the client keeps running. Switching to Direct Mode is the fastest way to test whether an issue is actually caused by the proxy.
TUN Mode Virtual Network Adapter
A mode where the core creates a virtual network adapter to take over all system traffic, independent of any app's proxy settings. Programs that ignore system proxy settings, like some games and command-line tools, get captured too. It requires administrator privileges to install the adapter driver and can run alongside system proxy settings.
System Proxy System Proxy
Writes the client's local port into the operating system's proxy settings, so browsers and apps that respect system proxy settings route through Clash automatically. It only affects programs that follow the system proxy setting, not UDP traffic or apps that ignore it — that's where TUN Mode fills the gap.
CONFIG SYNTAX
Config Syntax
A config file is just text written in YAML. Understand the three-section layout and a handful of key fields, and editing configs stops being a black box.
YAML Syntax
The text format used for Clash config files, which relies on indentation to express hierarchy and requires a space after every colon. The most common config error is mixing tabs and spaces or misaligning indentation — YAML has zero tolerance for either. Use an editor with syntax validation when editing.
Config File Profile · Subscription
A complete Clash configuration, usually called a Profile in clients, made up of three main parts: nodes, proxy groups, and rules. It can come from a subscription link that updates periodically, or be a file you maintain manually. Multiple profiles can coexist and be switched between — make sure you know which one you're editing before making changes.
Three-Section Layout proxies / groups / rules
The three key sections of a config: proxies lists all nodes, proxy-groups defines the proxy groups, and rules provides the routing rules. Look for these three sections first when reading a config, and troubleshoot in the order of nodes, proxy groups, then rules.
Mixed Port mixed-port
A local listening port that accepts both HTTP and SOCKS5 proxy traffic, written as mixed-port in the config, commonly set to 7890. Both system proxy settings and apps with manual proxy fields point to this same port; if it's already in use, the client will fail to start — change the port or close the conflicting program.
NETWORK BASICS
Networking Basics
Concepts that aren't unique to Clash but come up constantly during troubleshooting — five of the most frequently seen, picked out here.
Node Node · Server
A proxy server available for connection, represented in the config as an entry under the proxies section, including protocol, address, port, and authentication info. A subscription link is essentially a bundle of nodes plus matching rules. Node quality depends on the line, load, and ISP.
Latency Latency · Speed Test
The time it takes for the client to send a test request to a node and receive a response, measured in milliseconds. This number reflects just one handshake at that moment and doesn't equate to actual download speed — a low-latency node with limited bandwidth can still buffer on video. Weigh latency alongside the node's multiplier and region.
DNS Leak Privacy Issue
A situation where the system or browser bypasses the proxy and queries the ISP's DNS directly, exposing browsing activity to the local network. Clash's nameserver config and Fake-IP mode take over domain resolution to close this loophole.
Fake-IP DNS Mode
A DNS mode in the core where domain queries initially get a fake address in the 198.18.x.x range, with rule matching against the real domain happening when the connection is actually made. This skips the wait for resolution before routing, making pages load noticeably faster, and is the default enhanced mode in most clients.
UDP Relay UDP Relay
The ability to route UDP traffic through the proxy as well, which voice calls, some games, and the QUIC protocol all depend on. Both the node and the core need to support it, with the udp option enabled — if either side lacks support, UDP fails silently, showing up as web pages loading fine but voice calls not connecting.
Beyond the Definitions
Terms are just a starting point. Still stuck? Match your symptom against Troubleshooting; just installed a client? Walk through the Getting Started tutorial; for common questions and subscription issues, see the Help Center; no client yet? Grab one for your platform on the download page.