Fix Cursor Not Working With Clash: Timeout Troubleshooting

What a Cursor Timeout Looks Like

Cursor can appear to be installed correctly while every network operation fails as soon as Clash is enabled. The editor may open normally, local files may remain accessible, and ordinary websites may load, yet signing in stays on a spinner, the account window reports a timeout, or AI code completion returns a network error after several seconds. This pattern usually means that Clash is intercepting Cursor traffic but is sending one part of the connection through an unsuitable rule, node, DNS path, or TUN route.

Cursor traffic is not limited to one simple webpage request. The desktop application may contact authentication services, update services, API endpoints, telemetry endpoints, and streaming connections for assistant responses. These requests can use HTTPS over TCP 443, long-lived connections, HTTP/2, WebSocket-style streams, or several hostnames during one action. A browser test that succeeds therefore does not prove that Cursor has the same route or that every required connection is reachable through the selected policy group.

Start by separating a Clash problem from an application problem. Close Cursor completely, including its background process if your operating system keeps one running, then test the same network with Clash disabled. If Cursor works without Clash and fails immediately after Clash is enabled, the proxy path is the primary suspect. If it fails in both states, check the subscription, system clock, local firewall, account status, and the application installation before changing routing rules.

Use Clash Logs to Find the Failing Layer

The most useful evidence is the Clash connection log captured at the moment Cursor times out. In Clash Verge Rev or another mihomo-based client, open the connections or logs view, set the log level to info or temporarily to debug, then start Cursor and repeat one action only: sign in, refresh the account panel, or send one short completion request. Avoid testing all three actions together because the resulting entries can hide the first failure.

1. Turn on the Clash system proxy and select a known working proxy group rather than an automatic group with an unknown current node.
2. Open the live connection list and clear old entries if the client provides a clear button.
3. Launch Cursor, reproduce the timeout, and note the hostname, destination port, policy name, and final connection state.
4. Repeat the test with Clash disabled. Compare whether the same hostnames are reached directly and whether the failure disappears.
5. Switch to a second node in the same proxy group. If only one node fails, test the node before rewriting the rules.

A timeout is different from an explicit rule rejection. A request marked REJECT or blocked by an ad-filtering provider points to a rule problem. A request that remains in a connecting state and then expires usually points to an unreachable node, a blocked destination, a DNS failure, or a TUN route that never completes the connection. A request that connects successfully but repeatedly closes may indicate an incompatible proxy path, an idle timeout, or a problem with a long-lived stream.

Fix Rules That Send Cursor to the Wrong Policy

Rule matching is evaluated from top to bottom. The first matching rule wins, so a broad direct rule placed above a specific proxy rule can silently defeat the rule you intended to use. The opposite mistake is also common: a broad privacy or ad-blocking rule sends an authentication or API hostname to REJECT, making Cursor appear to be offline even though other applications work normally.

Look at the exact hostnames in the Clash log rather than guessing from the application name. Cursor may use different hosts for sign-in, license validation, extension metadata, update checks, and AI requests. Do not route every request containing the word “cursor” by keyword unless you have confirmed the side effects. Keyword rules can match unrelated domains and make future troubleshooting harder.

For a narrow test, place only the observed host suffixes above broad catch-all rules and send them to a dedicated group such as CURSOR. The group can contain two or three verified nodes. Keep the final MATCH rule at the bottom. A typical structure looks like this:

proxy-groups:
  - name: CURSOR
    type: select
    proxies:
      - Preferred Proxy
      - Backup Proxy
      - DIRECT

rules:
  - DOMAIN-SUFFIX,example.invalid,CURSOR
  - DOMAIN-SUFFIX,api.example.invalid,CURSOR
  - DOMAIN-SUFFIX,auth.example.invalid,CURSOR
  - MATCH,PROXY

The domains above are deliberately placeholders. Replace them only with hostnames shown in your own Clash logs or with documented provider information. Do not copy an unverified list from a random configuration because endpoint names can change, and routing a sensitive account service through an unsuitable location can create a new login or authorization problem.

Check rule order and policy names

Confirm that the policy name in the rule exactly matches a proxy group defined under proxy-groups. A spelling mismatch may prevent the configuration from loading, while a fallback to an unexpected group can send traffic through a slow node. Also check whether a rule provider is overriding your local rules. In mihomo, provider rules and generated rule sections can be large; search the complete active configuration rather than only the small editor view.

For diagnosis, temporarily use a simple policy arrangement: one selected node, one direct option, and a final proxy catch-all. Once Cursor works, restore the more complex automatic group and add rules back gradually. If the failure returns after restoring a rule provider, the provider or its order is the likely source.

Step-by-Step Recovery Procedure

The following procedure starts with low-risk checks and moves toward DNS and TUN changes. It is designed for Clash Verge, Clash Verge Rev, and other desktop clients that expose mihomo settings. Menu names vary slightly, but the concepts are the same.

1. Restart the application path. Quit Cursor completely, disable Clash, wait a few seconds, and confirm that Cursor can reach its account or completion service directly. Then close Cursor again before re-enabling Clash.
2. Test one known-good node. In Clash, choose a node that has recently opened a normal HTTPS page. Do not begin with url-test, fallback, or a load-balanced group because automatic selection may change while you are testing.
3. Use rule mode first. Turn on the system proxy and keep TUN disabled for the first comparison. If Cursor now works, the problem is likely related to TUN capture, DNS hijacking, or route conflicts rather than the basic proxy server.
4. Inspect the connection log. Reproduce one timeout and verify that the relevant Cursor hostname appears. Confirm the selected policy, destination port, and whether the entry ends in success, rejection, DNS error, or timeout.
5. Try a temporary global-mode test. Switch to global mode for one request. If the request succeeds only in global mode, review rule order, rule providers, and any direct or reject rules that match the destination.
6. Clear stale application state. Sign out only if the account interface is reachable. Avoid deleting project folders or credentials as a first response. A repeated timeout is usually a route issue, not corrupted source code.
7. Restore TUN carefully. Enable TUN only after system-proxy mode works. Approve the administrator or VPN permission prompt, then test again. If the connection disappears from the log, inspect the TUN stack, route installation, and conflicting VPN software.

After each step, use the same small test: open the account panel or request one short completion. Large prompts can create many simultaneous connections and make a marginal node appear worse than it is. Once the basic request succeeds, test a longer response and leave the editor open for several minutes to check whether streaming remains stable.

Resolve DNS and TUN Conflicts

DNS problems can look exactly like a proxy timeout. If Clash receives a hostname but cannot obtain an address, the connection never reaches the node. If fake-ip returns an address that Cursor or another local component cannot handle correctly, the application may repeatedly retry without a useful error. Check the DNS section of the Clash log and compare it with a direct system lookup.

On Windows, run nslookup example.com and ipconfig /all. On macOS, use scutil --dns and dig example.com. On Linux, use resolvectl status and resolvectl query example.com. Replace the example name with a hostname that appears in the active Clash log. The result does not need to match a specific public resolver; the important questions are whether it resolves consistently, whether the query reaches Clash when interception is enabled, and whether the returned address is usable by the selected mode.

Compare fake-ip and redir-host

mihomo commonly supports fake-ip and redir-host enhanced modes. Fake-ip gives matching domains a synthetic address, allowing Clash to associate later connections with the original hostname. Redir-host returns ordinary resolved addresses and can be easier to diagnose in environments where local applications do not behave well with synthetic addresses. Changing this setting affects many applications, so treat it as a controlled test and record the original value.

Also check whether a security suite, another VPN, Docker networking, or a manually configured DNS service is competing for port 53. Two services cannot reliably own the same local DNS listen address. Disable one competing service temporarily rather than adding several random DNS servers to the configuration.

Check TUN route ownership

TUN mode captures traffic below the normal application proxy layer. It is useful for applications that ignore system proxy settings, but it can conflict with another VPN adapter, enterprise security software, a virtual machine network, or a stale route left by a previous client. If system-proxy mode works and TUN mode fails, inspect the route table and adapter order before editing proxy rules.

On Windows, check the active adapters with ipconfig and routes with route print. On macOS, inspect interfaces with ifconfig and routes with netstat -rn. On Linux, use ip addr and ip route. You are looking for duplicate default routes, an unexpectedly preferred VPN adapter, or a TUN interface that disappears after permission approval. Disable other VPN clients during the test and restart Clash after changing TUN settings.

Separate Node Quality from Cursor Routing

A working rule cannot compensate for a node that is overloaded, geographically unsuitable, or unable to maintain long-lived HTTPS streams. Test the selected node with more than a latency number. A health check may complete a small request while Cursor's authentication or completion stream is reset later. Compare connection establishment, repeated requests, and stability over several minutes.

• Test at different times. If Cursor works in the morning but times out during peak hours, congestion is more likely than a static rule error.
• Compare two nodes in the same region. If one works and one fails, keep the working node in the dedicated group and report or remove the bad node.
• Watch for transport differences. A node using a particular UDP-based transport may behave differently from a TCP or TLS-based node on a restricted network.
• Check clock accuracy. TLS and account tokens depend on the system clock. Enable automatic time synchronization and verify the time zone before investigating certificates.
• Keep connection reuse in mind. Restart Cursor after changing nodes so existing sockets and cached failures do not make the new test misleading.

If the same node works for ordinary browsing but not for Cursor, inspect the specific destination entries and the proxy transport. If every node fails only for Cursor, focus on routing, DNS, application proxy inheritance, and endpoint blocking. If every application fails through that node, replace the node or refresh the subscription instead of adjusting Cursor-specific rules.

FAQ: Cursor and Clash Timeout Fixes

Keep the Working Configuration Stable

Once Cursor signs in and code completion remains responsive, export or back up the effective Clash configuration before making further changes. Write down the working mode, DNS enhanced mode, selected node group, TUN state, and any Cursor-specific rules. Then remove temporary global-mode settings and broad experimental rules one at a time. A stable configuration should have a clear catch-all rule, a small number of trusted proxy groups, no duplicate VPN capture, and logs that show the expected policy for Cursor traffic.

For a clean final test, restart both Clash and Cursor, verify one account action, request a short completion, and leave the editor open long enough to observe a streamed response. If the issue returns later, compare the node, subscription update, rule-provider version, and operating-system network changes against the recorded working state. That comparison is faster and safer than repeatedly deleting configuration files or switching every setting at once.