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)

Alpha builds may not be Apple-notarized yet. First, download the newest .dmg, move Cosmos.app into /Applications, right-click the app, choose Open, and confirm. If that still fails, clear the quarantine flag and reopen:

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

Public notarized builds should open without this fallback. See Install Cosmos on macOS for the normal 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.

Plus says Not signed in

Paid workflow gates need a Cosmos account. Open Settings → About → Sign up / Log in. The launch offer starts with 30 days free, then $6 for the first paid month, then $12/month. More detail in Cosmos Plus features.

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

• Local: data/brain_v2/brain.db, stored next to the app.
• Hosted backup/sync: roadmap services, not required for current Free or Plus usage.

To delete local data, remove your local brain by deleting the data/ folder. For account, waitlist, or billing-related deletion, contact support.

Still stuck? Reach the team via Support & contact.