name: cti-adapter-development description: "Use when building or debugging a browser-based CTI softphone adapter using the Salesforce Open CTI JavaScript API — covers callcenter.xml definition, Lightning utility item registration, core API methods (enableClickToDial, onClickToDial, screenPop, setSoftphonePanelHeight, saveLog), call logging as Task, and the lightning-click-to-dial LWC component. NOT for Service Cloud Voice Amazon Connect setup, Omni-Channel routing configuration, or CTI adapter AppExchange package selection." category: apex salesforce-version: "Spring '25+" well-architected-pillars:

• Security
• Reliability
• Operational Excellence triggers:
• "How do I build a custom CTI softphone adapter in Salesforce Lightning?"
• "Open CTI click-to-dial is not firing / onClickToDial callback never runs"
• "How do I register a softphone in the Lightning utility bar using callcenter.xml?"
• "CTI adapter not logging calls to Salesforce activities"
• "How do I use setSoftphonePanelHeight or screenPop in Open CTI?" tags:
• open-cti
• cti-adapter
• softphone
• click-to-dial
• call-logging
• lightning-utility-bar
• callcenter-xml inputs:
• "Telephony vendor requirements (SIP endpoint, WebRTC or PSTN bridge details)"
• "Lightning App where the softphone utility item should appear"
• "Salesforce objects to screen-pop on incoming calls (Contact, Case, Lead)"
• "Existing callcenter.xml or adapter page URL if already partially built" outputs:
• "Compliant callcenter.xml Call Center definition file"
• "JavaScript Open CTI adapter hosted page with API method implementations"
• "Lightning utility bar softphone configuration steps"
• "Call logging Task creation pattern using saveLog"
• "lightning-click-to-dial LWC integration snippet" dependencies: [] version: 1.0.0 author: Pranav Nagrecha updated: 2026-04-06

CTI Adapter Development

Use this skill when building, diagnosing, or extending a browser-based CTI (Computer Telephony Integration) softphone adapter with the Salesforce Open CTI JavaScript API. It covers the full adapter lifecycle: defining the Call Center in callcenter.xml, registering it as a Lightning utility bar item, implementing core Open CTI API calls, enabling click-to-dial on phone fields, logging calls as closed Task records, and integrating with the lightning-click-to-dial LWC component.

Before Starting

Gather this context before working on anything in this domain:

• Confirm the org has a Call Center definition registered under Setup > Call Centers. Open CTI requires a valid Call Center record tied to the user before any API calls succeed.
• Identify which Lightning App hosts the softphone. The utility bar must be configured for that specific app — Open CTI softphones do NOT appear in the Salesforce mobile app or Classic UI.
• Understand the telephony vendor's hosting requirements: the CTI adapter page (HTML + JS) must be served from a domain added to Salesforce CSP Trusted Sites and CORS allowed-origins. Omitting this causes the sforce.opencti namespace to fail silently.

Core Concepts

Open CTI JavaScript API

Open CTI is a browser-side JavaScript API exposed by Salesforce. The API namespace is sforce.opencti and it is injected into the adapter page by the platform — you do not load it via a <script src> tag. The adapter page is a hosted HTML file that runs inside the softphone panel iframe rendered in the Lightning utility bar. All API calls are asynchronous; callbacks receive a response object with success, returnValue, and errors fields.

Key API methods:

callcenter.xml Definition File

Every CTI adapter is defined by a callcenter.xml (Call Center Definition File). This XML file describes the adapter to Salesforce and is imported via Setup > Call Centers > Import. The root element is CallCenter and the key child elements are:

• InternalName — unique identifier (no spaces, used in API references)
• DisplayName — label shown in Setup UI
• AdapterUrl — the fully-qualified HTTPS URL of the adapter HTML page
• CTIVersion — must be "4.0" for Lightning / Open CTI for Lightning (not "3.0" which is Classic-only)
• RequiresCallCenter — set to "true" for users to be assigned

After import, users must be assigned to the Call Center via Setup > Call Centers > Manage Call Center Users.

Lightning Utility Bar Registration

The softphone panel is added as a utility bar item in a Lightning App. Navigate to Setup > App Manager, edit the target Lightning App, go to Utility Items, and add Open CTI Softphone. The utility item pulls its adapter URL from the assigned Call Center definition — you do not specify a URL directly in the utility item. Width, height, and panel label are configurable here. The utility bar item is desktop-only; the Salesforce mobile app does not render utility bars.

Call Logging with saveLog

sforce.opencti.saveLog creates a Task record. The value parameter is an object where keys are Task API field names. At minimum pass Subject, CallDurationInSeconds, CallType, Status, and WhoId or WhatId. The Task ActivityDate defaults to today. Logging should occur on call end, not call start, to capture accurate duration. If the adapter calls saveLog before enableClickToDial resolves, the API may return an error; always gate saveLog on a confirmed active session.

lightning-click-to-dial LWC Component

Salesforce provides the lightning-click-to-dial base component for use in record pages and list views. It renders a phone number as a clickable link that fires the Open CTI onClickToDial listener registered in the adapter. The component accepts value (phone string) and record-id attributes. Using this component is preferred over raw <a href="tel:..."> links because it participates in the Open CTI event system and respects enableClickToDial/disableClickToDial state.

Common Patterns

Pattern: Enabling Click-to-Dial on Adapter Load

When to use: The adapter must activate click-to-dial once when the softphone iframe loads so phone fields become clickable across the entire org session.

How it works:

1. On DOMContentLoaded, call sforce.opencti.enableClickToDial with a callback.
2. Inside the callback, check response.success. If true, register the onClickToDial listener.
3. In the onClickToDial listener, extract number and recordId to initiate the telephony call.
4. Call sforce.opencti.disableClickToDial immediately after the call connects to prevent double-dials.

Why not the alternative: Registering onClickToDial before enableClickToDial succeeds causes the listener to register against a deactivated state, meaning clicks on phone fields silently do nothing.

Pattern: Logging a Call as a Closed Task

When to use: Every call end should produce a Task record so supervisors and agents have a call history on the related record.

How it works:

1. On telephony call-end event (vendor-specific), capture duration and call direction.
2. Call sforce.opencti.saveLog with a value object containing at minimum: Subject, Status: 'Completed', CallType ('Inbound' or 'Outbound'), CallDurationInSeconds, and either WhoId (Contact/Lead) or WhatId (Account/Case/Opportunity).
3. In the callback, check response.success. Surface an error toast to the agent if logging fails.

Why not the alternative: Creating a Task via Apex REST from the telephony vendor backend requires OAuth token management and server-side configuration. saveLog runs in the user's browser session with their permissions, is simpler to implement, and creates the Task associated with the correct Call Center activity.

Pattern: Screen Pop on Inbound Call

When to use: When an inbound call arrives with a known caller ID, the agent's browser should automatically navigate to the caller's Contact or Case record.

How it works:

1. On inbound call event, perform an ANI (caller ID) lookup — typically via a Salesforce REST API callout or vendor webhook.
2. Once the Salesforce record ID is known, call sforce.opencti.screenPop with type: 'SOBJECT' and params: {recordId: '<18-char-id>'}.
3. If no record is found, use type: 'SEARCH' with params: {searchParams: '<phone-number>'} to open a search results page.

Decision Guidance

Recommended Workflow

Step-by-step instructions for an AI agent or practitioner working on this task:

1. Verify prerequisites — Confirm the telephony vendor adapter page URL is available over HTTPS, the domain is added to CSP Trusted Sites and CORS allowed-origins in Setup, and the user has a valid Salesforce license that supports Call Centers.
2. Author and import callcenter.xml — Create the Call Center definition file with CTIVersion set to 4.0 and AdapterUrl pointing to the hosted adapter page. Import via Setup > Call Centers. Assign relevant users to the Call Center.
3. Register the utility item — In App Manager, add the Open CTI Softphone utility item to the target Lightning App. Set appropriate panel width and height. Verify the softphone panel renders in the app.
4. Implement the adapter page — In the hosted HTML file, call sforce.opencti.enableClickToDial on load, register the onClickToDial listener, implement screenPop for inbound call ANI lookup, and wire call-end events to saveLog.
5. Test click-to-dial and screen pop — In a sandbox, click a phone field and confirm the onClickToDial callback fires with correct number and recordId. Trigger a screen pop and confirm navigation to the correct record.
6. Test call logging — End a test call and verify a Task record with the correct Subject, CallDurationInSeconds, CallType, and related WhoId/WhatId is created.
7. Review CSP and CORS — Confirm no browser console errors related to blocked frames, CORS rejections, or sforce is not defined errors before deploying to production.

Review Checklist

Run through these before marking work in this area complete:

• callcenter.xml uses CTIVersion 4.0 (not 3.0) and a valid HTTPS AdapterUrl
• Adapter page does not self-load the Open CTI script — it relies on platform injection
• enableClickToDial is called once on adapter load before onClickToDial is registered
• saveLog passes at minimum Subject, Status: 'Completed', CallType, and WhoId or WhatId
• screenPop falls back to type: 'SEARCH' when no record ID is available
• Adapter domain is in CSP Trusted Sites and CORS allowed-origins
• Users are assigned to the Call Center in Setup before testing

Salesforce-Specific Gotchas

Non-obvious platform behaviors that cause real production problems:

1. CTIVersion mismatch silently breaks the adapter — Using CTIVersion 3.0 in callcenter.xml loads the Classic Open CTI API, not the Lightning API. The sforce.opencti namespace is undefined and all calls fail without a clear error message in the Lightning console.
2. enableClickToDial must resolve before onClickToDial is registered — Calling onClickToDial before the enableClickToDial callback succeeds means the listener registers against a deactivated state. Phone field clicks are silently swallowed. Always nest onClickToDial inside the enableClickToDial success callback.
3. saveLog requires an active Call Center assignment — If the logged-in user is not assigned to a Call Center, saveLog returns success: false with the error User is not assigned to a Call Center. The call still appears to complete with no visible UI error unless the adapter explicitly checks response.success.
4. Utility bar is desktop-only — The Open CTI softphone panel does not render in the Salesforce mobile app or in Salesforce Classic. Agents using mobile or Classic see no softphone. This is a platform constraint, not a configuration error.
5. CSP and CORS must both be configured — Adding the adapter domain to CSP Trusted Sites alone is not sufficient. The domain also requires an entry in Setup > CORS Allowed Origins List (or the adapter URL must be framed correctly). Missing CORS causes sforce is not defined errors in the browser console because the platform cannot inject the API into a non-allowed origin.

Output Artifacts

Related Skills

• admin/app-and-tab-configuration — configuring the Lightning App utility bar where the softphone item lives
• architect/service-cloud-architecture — when to use Service Cloud Voice vs Open CTI at the architecture level