Composer 1.5 slow / ~timesout

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

It seems to frequently show reconnecting or just stops…

I added Network Diagnostics here… could be high load on your servers?

Steps to Reproduce

Running chats with Composer-1.5

Expected Behavior

not stop

Operating System

Windows 10/11

Version Information

Version: 2.6.20 (user setup)
VSCode Version: 1.105.1
Commit: b29eb4ee5f9f6d1cb2afbc09070198d3ea6ad760
Date: 2026-03-17T01:50:02.404Z
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Windows_NT x64 10.0.26200

For AI issues: which model did you use?

composer-1.5

Additional Information

Cursor Network Diagnostic Results

DNS: Success
Logs:
[2026-03-19T08:12:43.259Z] Host: api2.cursor.sh
[2026-03-19T08:12:43.260Z] Servers: 127.0.0.1
[2026-03-19T08:12:43.260Z] Resolved to 44.214.52.148 in 1ms
[2026-03-19T08:12:43.340Z] Resolved to 44.214.52.148 in 0ms
[2026-03-19T08:12:43.375Z] Resolved to 44.214.52.148 in 0ms
[2026-03-19T08:12:43.397Z] Resolved to 44.214.52.148 in 1ms
[2026-03-19T08:12:43.457Z] Host: api2.cursor.sh
[2026-03-19T08:12:43.457Z] Servers: system
[2026-03-19T08:12:43.457Z] Resolved to 52.203.129.191, 18.214.129.71, 54.243.226.154, 107.23.239.248, 34.235.86.15, 18.209.130.136, 3.225.147.202, 35.153.22.159 in 2ms
[2026-03-19T08:12:43.473Z] Resolved to 52.203.129.191, 18.214.129.71, 54.243.226.154, 107.23.239.248, 34.235.86.15, 18.209.130.136, 3.225.147.202, 35.153.22.159 in 0ms
[2026-03-19T08:12:43.514Z] Resolved to 52.203.129.191, 18.214.129.71, 54.243.226.154, 107.23.239.248, 34.235.86.15, 18.209.130.136, 3.225.147.202, 35.153.22.159 in 0ms
[2026-03-19T08:12:43.546Z] Resolved to 52.203.129.191, 18.214.129.71, 54.243.226.154, 107.23.239.248, 34.235.86.15, 18.209.130.136, 3.225.147.202, 35.153.22.159 in 0ms
[2026-03-19T08:12:43.546Z] Result: true

HTTP/2: Success
Logs:
[2026-03-19T08:12:43.156Z] Start
[2026-03-19T08:12:43.599Z] Host: api2.cursor.sh
[2026-03-19T08:12:43.599Z] Protocol: h2
[2026-03-19T08:12:43.599Z] Result: true in 443ms

SSL: Success
Logs:
[2026-03-19T08:12:43.157Z] Start
[2026-03-19T08:12:43.809Z] URL: https://api2.cursor.sh/
[2026-03-19T08:12:43.810Z] Status: 200
[2026-03-19T08:12:43.810Z] IP: 44.214.52.148
[2026-03-19T08:12:43.810Z] Issuer: C=US; O=Amazon; CN=Amazon RSA 2048 M01
[2026-03-19T08:12:43.810Z] Name: api2.cursor.sh
[2026-03-19T08:12:43.810Z] AltName: DNS:api2.cursor.sh, DNS:prod.authentication.cursor.sh, DNS:*.api2.cursor.sh
[2026-03-19T08:12:43.810Z] DNS Time: 4ms
[2026-03-19T08:12:43.810Z] Connect Time: 206ms
[2026-03-19T08:12:43.810Z] TLS Time: 206ms
[2026-03-19T08:12:43.810Z] Result: true in 653ms

API: Success
Logs:
[2026-03-19T08:12:43.175Z] Start
[2026-03-19T08:12:43.959Z] Result: true

Ping: Success
Logs:
[2026-03-19T08:12:43.192Z] Sending ping 1
[2026-03-19T08:12:43.615Z] Response: ‘ping’ in 423ms
[2026-03-19T08:12:43.615Z] Sending ping 2
[2026-03-19T08:12:43.971Z] Response: ‘ping’ in 356ms
[2026-03-19T08:12:43.971Z] Sending ping 3
[2026-03-19T08:12:44.202Z] Response: ‘ping’ in 231ms
[2026-03-19T08:12:44.202Z] Sending ping 4
[2026-03-19T08:12:44.371Z] Response: ‘ping’ in 169ms
[2026-03-19T08:12:44.371Z] Sending ping 5
[2026-03-19T08:12:44.543Z] Response: ‘ping’ in 172ms
[2026-03-19T08:12:44.543Z] Result: true

Chat: Success
Logs:
[2026-03-19T08:12:43.209Z] Starting stream
[2026-03-19T08:12:43.959Z] Response: ‘foo’ in 728ms
[2026-03-19T08:12:44.932Z] Response: ‘foo’ in 973ms
[2026-03-19T08:12:45.934Z] Response: ‘foo’ in 1002ms
[2026-03-19T08:12:46.954Z] Response: ‘foo’ in 1020ms
[2026-03-19T08:12:47.932Z] Response: ‘foo’ in 978ms
[2026-03-19T08:12:48.936Z] Result: true

Agent: Success
Logs:
[2026-03-19T08:12:43.229Z] Starting stream
[2026-03-19T08:12:43.231Z] Pushing first message
[2026-03-19T08:12:43.598Z] Response: ‘foo’ in 367ms
[2026-03-19T08:12:44.107Z] Pushing next message
[2026-03-19T08:12:44.277Z] Response: ‘foo’ in 679ms
[2026-03-19T08:12:44.784Z] Pushing next message
[2026-03-19T08:12:44.943Z] Response: ‘foo’ in 666ms
[2026-03-19T08:12:45.454Z] Pushing next message
[2026-03-19T08:12:45.617Z] Response: ‘foo’ in 674ms
[2026-03-19T08:12:46.125Z] Pushing next message
[2026-03-19T08:12:46.284Z] Response: ‘foo’ in 667ms
[2026-03-19T08:12:46.284Z] Result: true

Marketplace: Success
Logs:
[2026-03-19T08:12:43.100Z] Host: marketplace.cursorapi.com
[2026-03-19T08:12:43.398Z] Response in 298ms
[2026-03-19T08:12:43.398Z] Response: 200
[2026-03-19T08:12:43.398Z] Response Type: cors
[2026-03-19T08:12:43.398Z] Server: null
[2026-03-19T08:12:43.398Z] Result: OK in 298ms

Authentication: Success
Logs:
[2026-03-19T08:12:43.109Z] Host: prod.authentication.cursor.sh
[2026-03-19T08:12:43.341Z] Response: 200 in 232ms

Authentication UI: Success
Logs:
[2026-03-19T08:12:43.158Z] DNS lookup: authenticator.cursor.sh
[2026-03-19T08:12:43.278Z] Resolved authenticator.cursor.sh to 104.18.35.233 in 1ms

Cursor Tab: Success
Logs:
[2026-03-19T08:12:43.159Z] DNS lookup: api3.cursor.sh
[2026-03-19T08:12:43.260Z] Resolved api3.cursor.sh to 104.18.19.125 in 1ms

Agent Endpoint: Success
Logs:
[2026-03-19T08:12:43.160Z] DNS lookup: agent.api5.cursor.sh
[2026-03-19T08:12:43.296Z] Resolved agent.api5.cursor.sh to 44.197.141.31 in 1ms

Codebase Indexing: Success
Logs:
[2026-03-19T08:12:43.161Z] DNS lookup: repo42.cursor.sh
[2026-03-19T08:12:43.313Z] Resolved repo42.cursor.sh to 18.204.81.105 in 1ms

Downloads: Success
Logs:
[2026-03-19T08:12:43.145Z] Host: downloads.cursor.com
[2026-03-19T08:12:43.517Z] Response: 403 in 372ms

CDN: Success
Logs:
[2026-03-19T08:12:43.155Z] Host: cursor-cdn.com
[2026-03-19T08:12:43.488Z] Response: 404 in 333ms

Does this stop you from using Cursor

Sometimes - I can sometimes use Cursor

Hey, thanks for report. Your network looks totally fine, so it’s not on your side.

Composer 1.5 sometimes has latency spikes, which can make the client show reconnecting or freeze. The team is aware of this issue.

A couple things:

  1. If you catch it when it freezes, please send the Request ID (chat menu top right > Copy Request ID). That helps us see what happened on the backend.

  2. As a workaround, you can switch to auto or another model, like Claude 4.6 Sonnet, when Composer 1.5 is slow.

Related threads for context: Is Composer 1.5 down? Is composer 1.5 down?, Composer 1.5 Performance Issue Composer 1.5 Performance Issue.

Let me know if it doesn’t get better.

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