Fathom API Authentication

How to authenticate Fathom API requests: one Bearer API key plus a connectionId. MindCloud runs the OAuth flow and refreshes Fathom tokens for you.

Every Fathom API request through MindCloud needs two things: a MindCloud API Key and a connectionId for your Fathom account. This page covers both, plus exactly how to send them, so you do not need to visit any other page to get authenticated.

Steps to authenticate

Create a MindCloud account at app.mindcloud.co if you do not already have one.
Generate a MindCloud API Key in API Keys. This is the Bearer token you send on every request. Keep it on your server.
Create a Fathom connection in Connections. Fathom uses OAuth. When you create the connection, you are redirected to sign in to Fathom and approve access — MindCloud stores the resulting tokens and refreshes them automatically, so your integration never has to.
Copy the connection’s connectionId — you will send it on every request alongside your MindCloud API Key.

How requests are authenticated

Authentication has two layers. Your MindCloud API Key authenticates the request to MindCloud, sent as a Bearer token in the Authorization header. The connectionId selects the connected Fathom account that should run the action. MindCloud stores and refreshes the Fathom credentials behind that connection, so you never send provider tokens with your requests.

Pass connectionId in the query string for GET and DELETE actions, and in the JSON body for POST, PUT, and PATCH actions.

For example, calling List Meetings with an Fathom connection looks like this:

curl --request POST \
  --url "https://connect.mindcloud.co/v2/universal/apps/fathom/actions/list-meetings/run" \
  --header "Authorization: Bearer $MINDCLOUD_API_KEY" \
  --header "Content-Type: application/json" \
  --data '{
  "connectionId": "$CONNECTION_ID",
  "arguments": {}
}'

The Authorization: Bearer <your MindCloud API Key> header authenticates you to MindCloud; the connectionId tells MindCloud which Fathom account to run the action against. Missing or invalid Authorization returns 401, and a missing or mismatched connectionId returns 400.

Connect Fathom with OAuth2

You need permission to create an OAuth app in Fathom and access to the app's client credentials.

Open Fathom OAuth documentation
Review Fathom's OAuth instructions before creating or editing your app.
Create or open your Fathom OAuth app
Register a Fathom OAuth app so Fathom issues a Client ID and Client Secret for MindCloud.
Set the redirect URL
Configure your Fathom OAuth app to use the MindCloud callback URL for this integration.
Enter the client credentials in MindCloud
Copy the Client ID and Client Secret from Fathom into the MindCloud connection form fields.
Finish the connection
Return to MindCloud, start the OAuth flow, sign in to Fathom, and approve access.

Keep your key safe

Keep your MindCloud API Key on your server; do not ship it in browser code, mobile apps, public repositories, or logs. Anyone with the key can call the Universal API as your MindCloud account, across every connection you have created.