MCP server authentication

Authentication header

The Ssemble MCP server authenticates requests with an API key. Send it in the X-Ssemble-API-Key header:

X-Ssemble-API-Key: YOUR_API_KEY

The MCP server does not accept an Authorization: Bearer header. A request sent with Authorization: Bearer YOUR_API_KEY fails authentication. Use X-Ssemble-API-Key instead.

Example request

curl https://mcp.ssemble.com \
  -H "X-Ssemble-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json"

Troubleshooting

If your MCP client rejects requests or you see an authentication error, check that:

• You are setting the X-Ssemble-API-Key header, not Authorization.

• The key is copied in full, with no extra spaces or line breaks.

• The key has not been revoked or replaced by a newer one.