Lucid MCP connector with Writer AI

​@Miles_Baker you may find this thread to be very useful in addressing your question: 

If that still doesn’t work, would you be open to changing the AI app? Lucid already has Lucid Connector for Claude.

Thank you for posting this information in the Community, ​@aparrish!

​@Miles_Baker, will you please try using the following URLs and let me know if this allows for a successful Writer AI - Lucid connection? Thank you!

Authorization URL: https://mcp.lucid.app/oauth/authorize
Token URL: https://mcp.lucid.app/oauth/token

Hi,

I updated with this information but I’m still receiving a connection failed message

Hi ​@Miles_Baker, thank you for following up here. 

Could you please provide a screenshot of the “connection failed” message you’re receiving? 

Also to clarify, are you filling out the “OAuth2 client ID” and “OAuth2 client secret” fields?

Thanks for your patience while we figure this out!

Hi ​@Katie S. it’s just an overlay error saying ‘connection failed’ there isn’t a specific message aongside it. I’ve not filled out the “OAuth2 client ID” and “OAuth2 client secret” fields as I cann’t see anywhere in Lucid to generate it. 

Therefore I’ve got DCR set to ‘yes’

Thanks!

Hi ​@Miles_Baker, I’m sorry you’re still running into a “Connection failed” error here. To clarify, when you set DCR to “Yes”, do those “OAuth2 client ID” and “OAuth2 client secret” fields populate?

​@Katie S. When I set DCR to yes, these fields are not required - if I select no then I would need to provide this information

Hi Katie, Speaking with Writer I think this should be resolved if we’re able to generate an Oauth2 client ID and client secret - is there a way to do this in Lucid settings?

​@Miles_Baker, Thank you for following up here - after connecting with our Development Team, they have recomended the following. Please let me know if you have any questions here!

Here's a walkthrough for manually creating an OAuth client for the Lucid MCP server (https://mcp.lucid.app). The /Oauth/register endpoint accepts a one-shot, unauthenticated call. You will call it once from Postman/Bruno, save the credentials, and then configure your MCP client to use those static credentials for the rest of the flow.

1. Confirm valid redirect URIs

- https://... — any HTTPS URL (must have a host, no fragment, ≤ 2048 chars)

- http://localhost, http://127.0.0.1, http://[::1] — loopback only; any port is fine (RFC 8252).

- A custom private-use scheme like myapp://callback.

Up to 10 URIs per client. No http:// to a non-loopback host. No URL fragment.

2. Register the client (Postman/Bruno)

Create a new request:

- Method: POST - URL: https://mcp.lucid.app/oauth/register

- Headers: Content-Type: application/json

- Body (raw JSON):

{ "client_name": "Acme Corp MCP Integration", "redirect_uris": [ "https://acme.example.com/oauth/callback" ], "token_endpoint_auth_method": "client_secret_post" }

Send. On success, you get HTTP 201 with:

{ "client_id": "<32-byte url-safe token>", "client_secret": "<32-byte url-safe token>", "redirect_uris": [...], "client_name": "Acme Corp MCP Integration", "token_endpoint_auth_method": "client_secret_post" }

Save the client_id and client_secret immediately. There is no read endpoint and no way to recover them later; if they're lost, you’ll need to re-register and get fresh values.

3. Configure your MCP client

In your MCP client's configuration, plug in:

- Authorization endpoint: https://mcp.lucid.app/oauth/authorize 
- Token endpoint: https://mcp.lucid.app/oauth/token 
- Client ID and Client Secret from step 2 
- The same registered redirect URI

The client now uses the pre-registered credentials directly and never calls /oauth/register.

Alternative: Client ID Metadata Document (CIMD)

If hosting a static JSON file is easier than running the registration call, the server also accepts CIMD: host a document at a stable HTTPS URL describing the client, and use that URL itself as the client_id. No client_secret is involved (public client only). Useful for orgs that prefer to manage client metadata in their own infra.