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Cursor Agent stops at work: check the proxy connection
Run Cursor’s network diagnostics, try its HTTP/1.1 setting, and gather evidence for IT to check firewall access and streaming.
Prices last read 2026-09-25
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Cursor Agent can stop responding when a corporate proxy disrupts streaming, TLS inspection interferes, or a firewall blocks required connections.Run Network diagnostics, then try Cursor’s documented HTTP/1.1 compatibility setting and restart the editor.Source: Network, proxy, and remote connections · 2026-09-25; Network Configuration · 2026-09-25
- 1. Run the documented diagnosticOpen Cursor Settings > Network > Run Diagnostics. Cursor says this checks connections to its servers and identifies problems affecting AI features or updates.
- 2. Change compatibility mode and restartIn Cursor Settings > Network, set HTTP Compatibility Mode to HTTP/1.1, then restart Cursor. This is the help page’s procedure for AI features failing behind a proxy.
Source: Network, proxy, and remote connections · 2026-09-25
The enterprise documentation also describes automatic HTTP/1.1 fallback. The manual setting remains explicitly documented in Cursor’s troubleshooting guide.
Source: Network Configuration · 2026-09-25; Network, proxy, and remote connections · 2026-09-25
Our suggested before-and-after check
Save the diagnostic results before changing the setting. After restarting, repeat one small, non-sensitive request, such as “Explain what a for loop does.” Record whether a response starts, finishes, or stalls, along with the time and any error text. Keep the request identical so IT can compare the two attempts.
Documented checks for IT
- Firewall: Cursor recommends domain allowlists. api2.cursor.sh handles most API requests; api5.cursor.sh handles Agent requests.
- TLS inspection: Cursor recommends inspection exclusions for its documented domains. Where inspection is mandatory, the proxy must support streaming, unbuffered SSE and long-running connections.
- Buffered responses: Cursor’s HTTP/1.1 streaming test should produce lines over five seconds. Output arriving together after five seconds indicates buffering.
Source: Network Configuration · 2026-09-25
For granular allowlists, check the full documented list, including regional Tab hosts: api4.cursor.sh, us-asia.gcpp.cursor.sh, us-eu.gcpp.cursor.sh and us-only.gcpp.cursor.sh. These, api3.cursor.sh for Tab, and repo42.cursor.sh for codebase search require HTTP/2. Agent recovery therefore does not establish that Tab or codebase search works.
Source: Network Configuration · 2026-09-25
Our suggested stopping point: if the request still stalls after the compatibility change and restart, hand IT the before-and-after diagnostics, timestamps and exact error. Ask them to use Cursor’s published connectivity tests and review the relevant proxy logs. Leave company network changes to IT. If Agent resumes, separately check the Tab and codebase-search tasks you actually use before closing the ticket.
Source: Network Configuration · 2026-09-25
your use of the Service is governed by that MSA.
Cursor Terms of Service, read September 25, 2026Source: Cursor Terms of Service · 2026-09-25
This clause applies when you use Cursor for an organization that has a Master Services Agreement with Anysphere. It identifies the governing agreement; it does not prescribe a proxy fix. Our recommendation is to route unresolved company-network changes through your organization’s IT process.
Source: Cursor Terms of Service · 2026-09-25
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Sources read on September 25, 2026