Install

Mosaic is an MCP server you connect to your AI client. You'll need an API key — issue one from /account/keys after subscribing. Keys are shown once; copy it then.

Server URL: https://mcp.getmosaic.dev/sse

Claude Desktop

Open claude_desktop_config.json. macOS: ~/Library/Application Support/Claude/. Windows: %APPDATA%\Claude\.
Add Mosaic to the mcpServers block:

{
  "mcpServers": {
    "mosaic": {
      "url": "https://mcp.getmosaic.dev/sse",
      "headers": { "Authorization": "Bearer mk_live_xxxx" }
    }
  }
}

Restart Claude Desktop. Try: "Use Mosaic to summarize the competitive landscape for EGFR."

Cursor

Cursor → Settings → MCP → Add server.
Name: mosaic; type: URL; URL: https://mcp.getmosaic.dev/sse.
Headers: Authorization: Bearer mk_live_xxxx.
Enable the server. Try: "What synthetic-lethal whitespace exists for KRAS in Mosaic?"

Claude Code

Add the server with the claude CLI:

claude mcp add mosaic \
  --transport sse https://mcp.getmosaic.dev/sse \
  --header "Authorization: Bearer mk_live_xxxx"

In any Claude Code session: /mcp to confirm Mosaic is connected. Try: "Run mosaic_target_mechanisms on BRAF."

Troubleshooting

401 — key missing/revoked; reissue at /account/keys.
429 — over your plan quota; see pricing for tier limits.
Empty results on a well-known target — Mosaic labels partial layers honestly; some sub-layers are still being expanded (DepMap, GLiREL).