Troubleshooting

Quick answers to the most common Cosmos issues on macOS. Each question below is phrased the way you'd search for it, with the exact fix underneath.

macOS says Cosmos can't be opened (Apple cannot check it for malicious software)

This is expected on ad-hoc-signed builds. Clear the quarantine flag and reopen:

xattr -cr /Applications/Cosmos.app
open /Applications/Cosmos.app

A notarised release lands once we have the Apple Developer certificate, after which this warning disappears. See Install Cosmos on macOS for the full install flow.

First launch hangs for ~10 seconds

That pause is normal on the first run. The bundled Python sidecar unpacks into /tmp and verifies its assets; later launches are instant. If it stays hung for longer than 30 seconds, check the sidecar log or the advanced settings:

tail -n 100 ~/Library/Logs/aibran-sidecar.log

You can also open Settings → Advanced for sidecar status.

Claude Code doesn't see the cosmos MCP

Restart the tool after the wizard installs the server — most AI tools only read their MCP config at startup. Then verify the connection:

/mcp

The server is named cosmos (or ai-bran on older configs). If it still doesn't appear, re-run the wizard from Integrations → AI Coding Tools.

Cloud backup says Not signed in

Pro features need a Cosmos account. Open Settings → About → Sign up / Log in. The 30-day trial includes Pro, with no card required. More detail in Pro features & cloud backup.

Where does my data live, and can I delete it?

• Local: data/brain_v2/brain.db, stored next to the app.
• Cloud (Pro): the Supabase Storage bucket cosmos-backups/<your_user_id>/, reachable only by you via row-level security (RLS).

To delete: remove cloud backups in Settings → Files & Backup, and delete your local brain by removing the data/ folder.

Still stuck? Reach the team via Support & contact.