# Callr Docs Documentation > The Callr API enables seamless integration of voice and SMS capabilities into your platform. Key features include making and controlling voice calls with low-code flow control, recording, and call routing, generating and managing audio files, extracting insights from conversations using AI, ordering phone numbers worldwide, sending and receiving SMS messages. With a robust REST API and low-code tools, Callr empowers developers to quickly build communication features. ## Guides: Getting Started - [Getting Started with Callr](https://docs.callr.com/docs/getting-started-with-callr.md) - [Your First Call with Data](https://docs.callr.com/docs/your-first-call-with-data.md): Learn how to build your first Callr Actions scenario and receive call metadata on your local machine using ngrok. - [IP Subnets](https://docs.callr.com/docs/ip-subnets.md) ## Guides: CORE CALL FEATURES - [Track Calls (Call Tracking)](https://docs.callr.com/docs/call-tracking.md): Call tracking lets you measure and monitor phone calls by assigning unique phone numbers to specific campaigns, sources, or users. With Callr, you can easily set up call tracking using Callr Actions… - [Connect Two Numbers (Click-to-Call)](https://docs.callr.com/docs/connect-two-numbers.md): Click-to-Call lets you programmatically connect two phone numbers — for example, linking a sales agent with a customer — by initiating Outbound Calls from your application. - [Broadcast Calls](https://docs.callr.com/docs/broadcast-calls.md): Create powerful outbound voice flows. - [Call Detail Records (CDR)](https://docs.callr.com/docs/call-detail-records-cdr.md) - [Caller IDs](https://docs.callr.com/docs/caller-ids.md) - [Conference Calls](https://docs.callr.com/docs/conference-calls.md): Connect several callers together in the same audio room with the conference@v1 action: PIN codes, prompts, hold music and automatic leave. - [Build an IVR Menu](https://docs.callr.com/docs/ivr-menu.md): Greet callers, let them press a key to choose a department, and route the call with gather@v4 and dial@v2 — the classic "press 1 for sales" menu, in a few lines of YAML. - [Record and Transcribe Calls](https://docs.callr.com/docs/call-recording-transcription.md): Record a call with startRecording@v2, get the transcript when it is ready, extract the intent with openai@v3 and push everything to your platform. - [Voicemail & Answering Machine Detection](https://docs.callr.com/docs/voicemail.md): Take a message when nobody answers (record@v1 + saveRecordingFile@v1), notify your team by email or SMS, and detect answering machines on outbound calls with amd@v3. - [Marketplace Call Masking](https://docs.callr.com/docs/marketplace-call-masking.md): Connect buyers and sellers through temporary Callr numbers that keep their real numbers private, with your platform deciding who talks to whom. ## Guides: DATA INTEGRATION - [OAuth Integrations](https://docs.callr.com/docs/oauth-integrations.md) - [Push Data to Your Platform](https://docs.callr.com/docs/push-data-to-your-platform.md): Many voice applications don’t just handle calls — they collect and generate valuable data. - [Fetch Data from Your Platform](https://docs.callr.com/docs/fetch-data-from-your-platform.md): Fetch external data in real time. ## Guides: MESSAGING - [Send SMS with the API](https://docs.callr.com/docs/send-sms-api.md) - [Send SMS within a Call Flow](https://docs.callr.com/docs/send-sms-in-a-call-flow.md) - [Receive SMS](https://docs.callr.com/docs/receive-sms.md) - [Send Emails within a Call Flow](https://docs.callr.com/docs/send-an-email-within-a-call-flow.md) ## Guides: AI FEATURES - [Extract Call Data with AI](https://docs.callr.com/docs/extract-data-with-ai.md) - [Multi-Channel AI Agents](https://docs.callr.com/docs/multi-channel-ai-agents.md): Callr Actions now lets you build intelligent agents that work across multiple channels — voice calls, SMS, and APIs — using real-time speech recognition, LLMs like OpenAI, and seamless integrations… ## Guides: Callr Actions - [Introduction](https://docs.callr.com/docs/callr-actions.md) - [Actions](https://docs.callr.com/docs/callr-actions-actions.md): All Callr Actions actions, their parameters, results and examples. - [dial@v2](https://docs.callr.com/docs/action-dial.md) - [bridge@v3](https://docs.callr.com/docs/action-bridge.md) - [conference@v1](https://docs.callr.com/docs/action-conference.md) - [answer@v1](https://docs.callr.com/docs/action-answer.md) - [ringing@v1](https://docs.callr.com/docs/action-ringing.md) - [hangup@v1](https://docs.callr.com/docs/action-hangup.md) - [wait@v1](https://docs.callr.com/docs/action-wait.md) - [waitForSilence@v1](https://docs.callr.com/docs/action-waitforsilence.md) - [dtmf@v1](https://docs.callr.com/docs/action-dtmf.md) - [amd@v3](https://docs.callr.com/docs/action-amd.md) - [play@v3](https://docs.callr.com/docs/action-play.md) - [playRecordingFile@v1](https://docs.callr.com/docs/action-playrecordingfile.md) - [gather@v4](https://docs.callr.com/docs/action-gather.md) - [recognize@v3](https://docs.callr.com/docs/action-recognize.md) - [startRecording@v2](https://docs.callr.com/docs/action-startrecording.md) - [stopRecording@v2](https://docs.callr.com/docs/action-stoprecording.md) - [record@v1](https://docs.callr.com/docs/action-record.md) - [saveRecordingFile@v1](https://docs.callr.com/docs/action-saverecordingfile.md) - [sms@v1](https://docs.callr.com/docs/action-sms.md) - [email@v1](https://docs.callr.com/docs/action-email.md) - [fetch@v3](https://docs.callr.com/docs/action-fetch.md) - [javascript@v1](https://docs.callr.com/docs/action-javascript.md) - [memcache@v1](https://docs.callr.com/docs/action-memcache.md) - [log@v1](https://docs.callr.com/docs/action-log.md) - [googleAnalytics@v1](https://docs.callr.com/docs/action-googleanalytics.md) - [mixpanel@v1](https://docs.callr.com/docs/action-mixpanel.md) - [openai@v3](https://docs.callr.com/docs/action-openai.md) - [voicebot@v1](https://docs.callr.com/docs/action-voicebot.md) - [Templates](https://docs.callr.com/docs/callr-actions-templates.md): Ready-to-use Callr Actions scenarios: phone menus, voicemail, AI agents, call tracking and more. - [Route calls](https://docs.callr.com/docs/callr-actions-templates-route-calls.md) - [Never miss a call](https://docs.callr.com/docs/callr-actions-templates-never-miss.md) - [AI agents](https://docs.callr.com/docs/callr-actions-templates-ai-agent.md) - [Call data](https://docs.callr.com/docs/callr-actions-templates-understand-calls.md) - [Connect people](https://docs.callr.com/docs/callr-actions-templates-connect-people.md) - [Reminders & alerts](https://docs.callr.com/docs/callr-actions-templates-notify-and-verify.md) - [SMS](https://docs.callr.com/docs/callr-actions-templates-sms.md) - [Call tracking](https://docs.callr.com/docs/callr-actions-templates-track-calls.md) - [Integrations](https://docs.callr.com/docs/callr-actions-templates-build-and-integrate.md) - [Language Reference](https://docs.callr.com/docs/callr-actions-reference.md) - [Pre-defined Variables](https://docs.callr.com/docs/callr-actions-pre-defined-variables.md) - [Voices & Audio](https://docs.callr.com/docs/voices-and-audio.md): Pick a voice for your Callr Actions prompts, use the DragonHD and MAI natural voices, or bring your own Azure or ElevenLabs key. - [Live Debugger](https://docs.callr.com/docs/callr-actions-live-debugger.md): Debug your YAML call flows in real time — no extra setup required. ## Guides: SIP - [SIP Trunking Overview](https://docs.callr.com/docs/sip-trunking-overview.md): SIP trunking lets you connect external voice systems to Callr using the SIP protocol (Session Initiation Protocol). With SIP trunking, you can send and receive calls between Callr and your own… - [SIP Connectivity](https://docs.callr.com/docs/sip-connectivity.md) - [Connect to OpenAI](https://docs.callr.com/docs/connect-to-openai.md): Connect a Callr Phone Number to an OpenAI Realtime AI Agent - [Connect to Vapi](https://docs.callr.com/docs/connect-to-vapi.md): Connect a Callr Phone Number to a Vapi AI Agent - [Connect to ElevenLabs](https://docs.callr.com/docs/connect-to-elevenlabs.md): Route calls from a Callr phone number to an ElevenLabs Agent over SIP. ## Guides: MCP Server - [MCP (Docs)](https://docs.callr.com/docs/mcp.md) ## API Reference: Callr v2.0 REST API - [Introduction](https://docs.callr.com/reference/introduction.md) - [Getting Started](https://docs.callr.com/reference/getting-started-with-callr.md) - [Authentication](https://docs.callr.com/reference/authentication.md) - [Errors](https://docs.callr.com/reference/errors.md) - [Rate Limits](https://docs.callr.com/reference/rate-limits.md) - [Best Practices](https://docs.callr.com/reference/best-practices.md) - [Help & Support](https://docs.callr.com/reference/help-support.md) - [Migrating from JSON-RPC API](https://docs.callr.com/reference/migrating-from-json-rpc-v1.md) ## API Reference: Reference - System - [Ping the API](https://docs.callr.com/reference/ping.md): You can use this endpoint to check if the API is up and running. - Actions - [Search scenarios](https://docs.callr.com/reference/actionssearch.md): Search for Callr Actions scenarios. - [Create scenario](https://docs.callr.com/reference/actionscreate.md): Create a new Callr Actions scenario. - [Get scenario](https://docs.callr.com/reference/actionsget.md): Get a Callr Actions scenario. - [Update scenario](https://docs.callr.com/reference/actionsupdate.md): Update a Callr Actions scenario. You may send a partial object. - [Delete scenario](https://docs.callr.com/reference/actionsdelete.md): Delete a Callr Actions scenario. - [Start scenario](https://docs.callr.com/reference/actionsstartofflinerun.md): Run a Callr Actions scenario offline. This will execute the `api-initiated` branch of the scenario. - [Get an offline run](https://docs.callr.com/reference/actionsgetofflinerun.md): Get the status of an offline run. This will return the variables and their values. - [Cancel an offline run](https://docs.callr.com/reference/actionscancelofflinerun.md): Cancel an offline run. This will stop the execution of the scenario. - [Attach number to scenario](https://docs.callr.com/reference/actionsattachnumber.md): Attach a phone number to a Callr Actions scenario. Calls to this number will execute the `inbound-call` branch of the scenario. SMS received on this number will execute the `inbound-sms` branch of… - [Detach number from scenario](https://docs.callr.com/reference/actionsdetachnumber.md): Detach a phone number from a Callr Actions scenario. - Audio Files - [Search audio files](https://docs.callr.com/reference/audiofilessearch.md): Search for audio files. - [Upload audio file](https://docs.callr.com/reference/audiofilesupload.md): Upload a new audio file. To upload an audio file, the body should be a `multipart/form-data`. If you're sending an `application/json` body, you can only specify the name of the new audio file. The… - [Get audio file](https://docs.callr.com/reference/audiofilesget.md): Get audio file by SID. - [Delete audio file](https://docs.callr.com/reference/audiofilesdelete.md): Delete an audio file. - [Update audio file properties](https://docs.callr.com/reference/audiofilesupdate.md): Update the properties of an audio file. You can only update the name. - [Update audio file with upload](https://docs.callr.com/reference/audiofilesuploadfile.md): Update the content of an existing audio file. The content will be processed asynchronously. The `status` property of the updated audio file will transition through the following stages: -… - [Update audio file on the phone](https://docs.callr.com/reference/audiofilesphoneid.md): Update the content of an existing audio file by recording yourself over the phone. For a given audio file `sid`, this method will return a phone number and a code to enter as DTMF to record yourself.… - Billing - [Get credit balance](https://docs.callr.com/reference/billinggetcredit.md): Get your credit balance (for prepaid accounts only). **The value is in cents**. - [Get billing destinations](https://docs.callr.com/reference/billinggetdestinations.md): Get the list of billing destinations. - Calls - [Hangup a live call](https://docs.callr.com/reference/callshangup.md): Hang up a live call. - [Export calls](https://docs.callr.com/reference/callsexport.md): Export calls to a CSV file. The CSV file will be available for download for 24 hours. The export will be performed asynchronously. The task status can be checked with the `Tasks` endpoints. You… - End Users - [Search end users](https://docs.callr.com/reference/endusersearch.md): Search for end users. - [Create end user](https://docs.callr.com/reference/endusercreate.md): Create an end user. - [Get end user](https://docs.callr.com/reference/enduserget.md): Get an end user. - [Update end user](https://docs.callr.com/reference/enduserupdate.md): Update an end user. You may send a partial object. - [Delete end user](https://docs.callr.com/reference/enduserdelete.md): Delete an end user. **You cannot delete an end user that is associated with a Caller ID, or a Phone Number.** - Phone Numbers - [Search phone numbers](https://docs.callr.com/reference/numbersearch.md): Search for your phone numbers. - [Get phone number](https://docs.callr.com/reference/numberget.md): Get a phone number. - [Remove phone number from your account](https://docs.callr.com/reference/numberremove.md): Terminate the number subscription and immediately free up the number. If the number is currently attached to an actions scenario, it will be detached. Should there be a contract associated with the… - [Update a phone number](https://docs.callr.com/reference/numberupdate.md): Update a phone number. Attach the number to a Callr Actions scenario, or change the end user. - [Detach phone number from scenario](https://docs.callr.com/reference/numberdetach.md): Detach a phone number from its scenario. While the number remains allocated to your account, it is not engaged in any scenario. Any calls made to this number will be declined with an "unallocated… - [Attach phone number to scenario](https://docs.callr.com/reference/numberattach.md): Attach a phone number to a Callr Actions scenario. - [Assign phone number to end user](https://docs.callr.com/reference/numberassignenduser.md): Assign a phone number to an end user. - Phone Numbers Store - [Reserve numbers](https://docs.callr.com/reference/numberstorereserve.md): Reserve numbers before ordering. This method gives you a token to use with the `POST /numbers/store/{token}` method. Your booking is held for a maximum of 5 minutes. You can have only one reservation… - [Buy phone numbers](https://docs.callr.com/reference/numberstorebuyorder.md): Buy phone numbers previously reserved, with the token returned by the `/numbers/store` endpoint. - [Get reservation status](https://docs.callr.com/reference/numberstorevieworder.md): Get the status of a phone number reservation. - [Cancel reservation](https://docs.callr.com/reference/numberstorecancelorder.md): Cancel a phone number reservation. - [List available countries](https://docs.callr.com/reference/numberstorecountries.md): Get the list of countries available in the number store. - [List available number types](https://docs.callr.com/reference/numberstoretypes.md): Get the list of number types available in the number store. - [List available prefixes](https://docs.callr.com/reference/numberstoreprefixes.md): Get the list of prefixes available in the number store. - Recordings - [Search recordings](https://docs.callr.com/reference/recordingssearch.md): Search for your recordings. - [Update recordings](https://docs.callr.com/reference/recordingsupdatebulk.md): Update recordings in bulk. You may update the `read` status of your recordings by specifying the `sid` of the recording(s) you want to update. To update all of your recordings, do not specify any… - [Delete recordings](https://docs.callr.com/reference/recordingsdeletebulk.md): Delete recordings in bulk. You may delete your recordings by specifying the `sid` of the recording(s) you want to delete. To delete all of your recordings, do not specify any `sid`. - [Get recording](https://docs.callr.com/reference/recordingsget.md): Retrieve a recording. - [Update recording](https://docs.callr.com/reference/recordingsupdateone.md): Update a recording. You may send a partial object. - [Delete recording](https://docs.callr.com/reference/recordingsdeleteone.md): Delete a recording. - SMS - [Search SMS](https://docs.callr.com/reference/smssearch.md): Search for your SMS messages. - [Send SMS](https://docs.callr.com/reference/smssend.md): Send an SMS. If accepted, the SMS will cycle through the following statuses: - `created` - `pending` - `sent` - `remote-queued` - `delivered` At any time, the SMS can be in the following statuses:… - [Get SMS](https://docs.callr.com/reference/smsget.md): Get an SMS. - Tasks - [Get task](https://docs.callr.com/reference/taskget.md): Return the status of a task. - [Cancel task](https://docs.callr.com/reference/taskcancel.md): Cancel a task. The task must be in a `PENDING` or `RUNNING` state. If the task is `RUNNING`, the result is undefined. - Webhooks - [Search webhooks](https://docs.callr.com/reference/webhooksearch.md): Search for your webhooks. - [Create webhook](https://docs.callr.com/reference/webhookcreate.md): Create a new webhook. - [Get webhook](https://docs.callr.com/reference/webhookget.md): Get a webhook. - [Update webhook](https://docs.callr.com/reference/webhookupdate.md): Update a webhook. You cannot change the endoint URL. To change the URL, create a new webhook. - [Delete webhook](https://docs.callr.com/reference/webhookdelete.md): Delete a webhook. - [Search webhook logs](https://docs.callr.com/reference/webhooklogssearch.md): Search for your webhook logs. ## API Reference: Webhooks - Audio File - v2.audio-file.status - [Audio File status updated ](https://docs.callr.com/reference/audiofilestatuswebhook.md) - [Example](https://docs.callr.com/reference/webhook-v2-audio-file-updated.md): Triggered when an Audio File has an updated status - Billing - v2.billing.credit.topup - [Prepaid account credited](https://docs.callr.com/reference/billingcredittopupwebhook.md): Your prepaid account has been credited - v2.billing.credit.warning - [Prepaid credit warning reached](https://docs.callr.com/reference/billingcreditwarningwebhook.md): Your prepaid account has reached the warning threshold. Please top up your account to avoid service interruption. - [Example](https://docs.callr.com/reference/webhook-v2-billing-credit-warning.md): Triggered when your prepaid credit balance reaches the configured warning threshold - v2.billing.credit.shutdown - [Prepaid credit shutdown reached](https://docs.callr.com/reference/billingcreditshutdownwebhook.md): Your prepaid account has reached the shutdown threshold. Your account is currently disabled. Please top up your account to re-enable it. - [Example](https://docs.callr.com/reference/webhook-v2-billing-credit-shutdown.md): Triggered when your prepaid credit balance reaches the configured shutdown threshold - Call - v2.call.inbound.started - [Inbound call started](https://docs.callr.com/reference/callinboundstartedwebhook.md): An inbound call has started. An inbound call is a call to a Callr hosted phone number. - [Example](https://docs.callr.com/reference/webhook-v2-call-inbound-started.md): Triggered when an Inbound Call begins on your account - v2.call.inbound.hangup - [Inbound call ended](https://docs.callr.com/reference/callinboundendedwebhook.md): An inbound call has hung up - [Example](https://docs.callr.com/reference/webhook-v2-call-inbound-ended.md): Triggered when an Inbound Call ends on your account - v2.call.outbound.started - [Outbound call started](https://docs.callr.com/reference/calloutboundstartedwebhook.md): An outbound call has started. An outbound call is a call initiated from the Callr platform to an external phone number. - [Example](https://docs.callr.com/reference/webhook-v2-call-outbound-started.md): Triggered when an Outbound Call begins on your account - v2.call.outbound.hangup - [Outbound call ended](https://docs.callr.com/reference/calloutboundendedwebhook.md): An outbound call has hung up - [Example](https://docs.callr.com/reference/webhook-v2-call-outbound-ended.md): Triggered when an Outbound Call ends on your account - Number - v2.number.assigned - [Phone number assigned ](https://docs.callr.com/reference/numberassignedwebhook.md): A phone number was assigned to your account - [Example](https://docs.callr.com/reference/webhook-v2-number-assigned.md): Triggered when a Phone Number is assigned to your account - v2.number.unassigned - [Phone number unassigned ](https://docs.callr.com/reference/numberunassignedwebhook.md): A phone number was unassigned from your account - [Example](https://docs.callr.com/reference/webhook-v2-number-unassigned.md): Triggered when a Phone Number is unassigned from your account - Recording & Transcription - v2.recording.status - [Recording status updated ](https://docs.callr.com/reference/recordingstatuswebhook.md) - [Example](https://docs.callr.com/reference/webhook-v2-recording-updated.md): Triggered when a Recording has an updated status - SMS - v2.sms.inbound.received - [Inbound SMS received ](https://docs.callr.com/reference/smsinboundreceivedwebhook.md) - [Example](https://docs.callr.com/reference/webhook-v2-sms-inbound-received.md): Triggered when an Inbound SMS is received - v2.sms.outbound.status - [Outbound SMS status updated ](https://docs.callr.com/reference/smsoutboundstatuswebhook.md) - [Example](https://docs.callr.com/reference/webhook-v2-sms-outbound-updated.md): Triggered when an Outbound SMS has an updated status - Task - v2.task.updated - [Task status updated ](https://docs.callr.com/reference/taskstatuswebhook.md) - [Example](https://docs.callr.com/reference/webhook-v2-task-updated.md): Triggered when a Task has an updated status ## Recipes - [Answer a call masking lookup from your platform](https://docs.callr.com/recipes/answer-a-call-masking-lookup-from-your-platform.md) - [Attach a phone number to a Callr Actions flow](https://docs.callr.com/recipes/attach-a-phone-number-to-a-callr-actions-flow.md) - [Create a webhook and verify its signature](https://docs.callr.com/recipes/create-a-webhook-and-verify-its-signature.md) - [Create a Callr Actions flow with the API](https://docs.callr.com/recipes/create-callr-actions-scenario-with-the-api.md) - [Get a recording and its transcript](https://docs.callr.com/recipes/get-a-recording-and-its-transcript.md) - [Send an SMS with the API](https://docs.callr.com/recipes/send-an-sms.md) - [Start an appointment reminder and read the answer](https://docs.callr.com/recipes/start-an-appointment-reminder-and-read-the-answer.md) - [Start a Callr Actions flow with the API](https://docs.callr.com/recipes/start-callr-actions-flow-with-the-api.md) - [Upload an audio file and play it in a flow](https://docs.callr.com/recipes/upload-an-audio-file-and-play-it-in-a-flow.md) ## Changelog - [Callr Actions: startRecording@v2 and stopRecording@v2 return the Recording SID in lowercase](https://docs.callr.com/changelog/callr-actions-startrecordingv2-and-stoprecordingv2-return-the-recording-sid-in-lowercase.md) - [Callr Actions: DragonHD and MAI natural voices, and text-to-speech on your own Azure or ElevenLabs account](https://docs.callr.com/changelog/callr-actions-dragonhd-and-mai-natural-voices-and-text-to-speech-on-your-own-azure-or-elevenlabs-account.md) - [Callr Actions editor: documentation in the editor, new templates](https://docs.callr.com/changelog/callr-actions-editor-latest-versions-first-documentation-in-the-editor.md) - [Callr Actions: one way to play and prompt audio (tts / audioFile), with new action versions](https://docs.callr.com/changelog/callr-actions-one-way-to-play-and-prompt-audio-tts-audiofile-with-new-action-versions.md) - [Callr Actions: conference@v1 puts callers in a conference room](https://docs.callr.com/changelog/callr-actions-conferencev1-puts-callers-in-a-conference-room.md) - [Callr Actions: gather@v3 accepts an audio file or a text-to-speech prompt](https://docs.callr.com/changelog/callr-actions-gatherv3-accepts-an-audio-file-or-a-text-to-speech-prompt.md) - [Callr Actions: play@v2 plays audio files by SID](https://docs.callr.com/changelog/callr-actions-playv2-plays-audio-files-by-sid.md) - [Real-Time Apps Deprecation Notice](https://docs.callr.com/changelog/real-time-apps-deprecation-notice.md) - [JSON-RPC v1 API Deprecation Notice](https://docs.callr.com/changelog/json-rpc-v1-api-deprecation-notice.md) - [REST API v2 is Here!](https://docs.callr.com/changelog/rest-api-v2-is-here.md)