Authentication
Efimis MCP uses OAuth sign-in. Claude, Codex and ChatGPT handle authentication using Client ID Metadata Documents (CIMD), including obtaining and renewing access tokens.
Follow the connection guide to add Efimis to your client. You do not need to configure OAuth endpoints, publish client metadata or manage tokens yourself.
Sign in
Section titled “Sign in”- Connect Efimis in Claude, Codex or ChatGPT using your regional MCP URL.
- Follow the client’s sign-in prompt and sign in with your Efimis account.
- Review the requested access and complete authorization.
- Return to your client to use the available Efimis tools.
Your account determines your user identity, firm and permissions. No tenant or user context headers are required, and the MCP URL does not contain a tenant alias.
Internal users with access to multiple tenants may be prompted to select a tenant after login. This step applies only to accounts with access to more than one tenant.
Access and permissions
Section titled “Access and permissions”Signing in gives the client access to the tools and data available to your Efimis account. A successful connection does not grant additional permissions.
If a tool is missing, check your Efimis permissions and whether the feature is enabled for your firm. See Tools for how tool availability works.
Reconnect
Section titled “Reconnect”Your client manages the authenticated connection. If it asks you to sign in again, reconnect Efimis and complete the sign-in prompts. To use another account, disconnect and sign in with the intended account.
Troubleshooting
Section titled “Troubleshooting”| Symptom | What to do |
|---|---|
| Sign-in does not start or the connection fails | Check the regional MCP URL and use a current version of Claude, Codex or ChatGPT. Check whether your workspace administrator needs to approve the connection. |
| Sign-in is rejected | Check that you can sign in to Efimis and have access to the intended firm. Contact Efimis if access is expected. |
Repeated 401 errors |
Reconnect Efimis and sign in again. Contact us if the error continues. |
403 or an unavailable tool |
Check your account’s permissions and enabled firm features. |
| Wrong account or firm’s data | Disconnect and sign in with the intended account. Contact Efimis if your account’s firm access is incorrect. |
| Client registration or callback error | Check that you are using a supported client with CIMD selected where applicable. Contact us with the error details if it continues. |
| A different MCP client will not connect | Contact Efimis before using another client; only Claude, Codex and ChatGPT are currently supported. |
Further reading
Section titled “Further reading”For background on the standards used by supported clients:
- What is MCP? — the official introduction to the Model Context Protocol.
- CIMD in MCP — client identification in the MCP authorization specification.
- OAuth Client ID Metadata Documents — an overview of CIMD and links to its specification.
- Proof Key for Code Exchange (PKCE) — an overview of PKCE and links to further explanations.
Support
Section titled “Support”Contact connections@efimis.com for connection help, or to discuss another client or an unattended integration.
Include your firm name, MCP URL, client name and version, approximate time with timezone, and the error message. Include the tool name if a specific call failed.
Do not include passwords, access tokens or other credentials in support messages, logs or screenshots.