@klink.cloud/call-sdk

Headless JavaScript phone-call SDK for the K-Link Customer Support Platform.

It lets your application place and receive calls through your K-Link telephony
extension without exposing PBX credentials to the browser user. The SDK
authenticates against the K-Link public API with an API token, resolves the
extension's webphone credentials server-side, and then drives the WebRTC call
engine locally. No UI is included — you bring your own.

Install

Zero runtime dependencies — the telephony engine is bundled inside the
package and loaded lazily on init().

Prerequisites

A K-Link API token — create one under Settings → API Tokens
(kpt_...). Treat it like a password; on the web it should be delivered
to the page by your backend, not hard-coded.

The member you connect as must have a telephony extension assigned in
K-Link (Settings → Phone Extension).

Microphone permission in the browser.

Quick start

API

`KlinkCallSdk.init(config)`

Option	Type	Default	Description
`userEmail`	`string`	— (required)	K-Link member email whose extension to use
`accessToken`	`string`	— (required)	K-Link API token (`kpt_...`)
`apiBaseUrl`	`string`	`https://apigw.klinkcx.com`	Public API origin
`requestTimeoutMs`	`number`	`15000`	Credential-fetch timeout

Returns Promise<KlinkCallSdk>. Throws KlinkCallSdkError with code:
invalid_config · auth_failed · extension_not_found ·
extension_not_provisioned · network_error · init_failed.

Events

Event	Payload	When
`ready`	—	Engine started, registration in progress
`incoming`	`{ call }`	Inbound call ringing
`sessionStarted`	`{ call }`	Call established / dialing
`sessionEnded`	`{ callId, cause }`	Call ended
`remoteStream`	`{ callId, stream }`	Remote call audio available
`connected` / `disconnected`	—	PBX socket transport state
`registeredChange`	`{ registered }`	SIP registration state
`registrationFailed`	`{ code, message }`	Registration rejected
`error`	`{ scope, detail }`	Runtime errors
`destroyed`	—	After `destroy()`

on(event, fn) returns an unsubscribe function. once and off are also
available.

Call controls

call(number) · answer(callId) · reject(callId) · hangup(callId) ·
hold/unhold(callId) · mute/unmute(callId) · dtmf(callId, tones) ·
attachAudio(element) · getCalls() · isRegistered · destroy()

Audio (required)

The SDK renders no UI, but it can manage call audio for you — pass it an
<audio> element once and remote streams are piped in and released
automatically:

sdk.attachAudio(document.querySelector('audio')!)

Prefer to control playback yourself? Listen for the remoteStream event:

sdk.on('remoteStream', ({ callId, stream }) => {
	myAudioElement.srcObject = stream
})

Without one of these, calls connect but stay silent. See
examples/basic for a complete working app.

Example app

A minimal framework-free test UI lives in examples/basic
(it installs the published @klink.cloud/call-sdk from npm):

Security notes

Rotate or revoke API tokens from Settings → API Tokens at any time;
in-flight SDK instances keep working until the PBX signature expires, but
new init calls with a revoked token fail with auth_failed.

Issue one API token per integration so a leak is independently revocable.

The SDK only ever reads extensions belonging to the token's own tenant.

Install#

Prerequisites#

Quick start#

API#

KlinkCallSdk.init(config)#

Events#

Call controls#

Audio (required)#

Example app#

Security notes#