Registering a vendor CTI adapter means importing its Call Center definition file and granting agents access. This assumes the vendor managed package is already installed. Treat this as legacy plumbing: for a new build, evaluate Service Cloud Voice before standing up a third-party adapter, because Open CTI retires on February 28, 2028.
- Install the vendor package
Install the telephony vendor managed package from AppExchange into a sandbox first. The package delivers the adapter code and usually a Call Center definition file you can import or clone.
- Import the Call Center definition file
In Setup, search Call Centers, then choose Import and select the vendor XML file. Confirm reqAdapterUrl uses HTTPS and that reqSalesforceCompatibilityMode is set to Lightning or Classic_and_Lightning for a Lightning console.
- Assign call center users
Open the imported call center, click Manage Call Center Users, and add the agents who should see the softphone. A user only loads the adapter if they are a member of a call center.
- Add the softphone to the app
In the Lightning app you use for service, add the Open CTI Softphone utility item so the panel appears in the utility bar. Without it, agents have no place for the adapter to render.
- Pilot and watch the console
Test with a small agent group on real call patterns. Keep the browser console open to catch adapter JavaScript errors that admins never see otherwise, and verify screen pop and call logging both fire.
The hosted location of the adapter or softphone. Use HTTPS so traffic between the telephony server and the browser is encrypted.
Set to Classic, Lightning, or Classic_and_Lightning. It defaults to Classic, which silently disables a Lightning adapter if left unset.
The unique call center identifier, up to 40 alphanumeric characters, starting with a letter, with no spaces and unique in the org.
Optional items that size the softphone panel so the vendor UI fits without scrollbars inside the utility bar.
- If reqSalesforceCompatibilityMode is missing it defaults to Classic, and a Lightning adapter will appear installed but do nothing.
- Users who are not assigned to the call center never load the adapter, so a working install can still show no softphone for some agents.
- Open CTI retires on February 28, 2028 and is already blocked for newly created Agentforce Service orgs, so new deployments should plan for Service Cloud Voice.
- In Salesforce Classic you must allowlist the adapter domain and any non-standard port in console settings; Lightning console apps do not need this.