Updated Latest Features and Big Announcements
We promise we won't send anything else.
Batch Calling is now live! This feature allows you to make multiple calls simultaneously by simply uploading an Excel sheet.
Here’s how it works:
Batch Calling queues your calls without hitting concurrency limits, ensuring a seamless experience.
Pricing: $0.005 per dial (20k calls for $100)
We’ve completely overhauled our documentation to make it more user-friendly and comprehensive. We’ll continue updating it regularly based on your needs.
Have suggestions? Join us on Retell Discord and share your thoughts.
Want to find the answer more easily, feel free to join Retell Discord and ask questions in #AI Evy Channel.
We’ve added TTS (Text-to-Speech) latency details in call history and the Get-call API.
If you notice higher-than-usual TTS latency, switch to another TTS provider directly. (Please note that older latency fields are now deprecated.)
We’ve added the Branded Call feature!
Now, you can enable branded call functionality on each of your phone numbers. It’s a great way to build trust with your outbound calls and significantly improve conversion rates.
Once activated, the recipient will see your business name when you call.
You can now monitor your call records more effectively with these powerful new filters!
For examples:
A detailed dashboard now shows your daily call costs and costs by provider.
Easily track your spending at a glance.
You can now purchase them directly on the dashboard.
Additionally, you can see your live concurrent call usage in the bottom-left corner of the dashboard.
You can now access the Knowledge Base via API.
If you are using OpenAI’s LLM, we’ve added a Structured Output setting.
When enabled, it ensures responses follow your provided JSON Schema.
Note: This feature may increase the time required to save or update functions.
We’ve integrated Claude 3.5 Haiku with a pricing of $0.02/min.
You can now equip your Voice AI agents with your company’s knowledge in three simple ways:
For the "Scrape from Webpages" method, you can select auto-sync every 24 hours or manually sync anytime. No more manual updates!
Pricing for Knowledge Base:
A must-have for outbound campaigns.
If your calls are being marked as spam or blocked by carriers, this verification process will prevent that from happening.
Simply submit your business profile, and after review, if your business is legitimate, you're good to go!
We’ve added the OpenAI Realtime API to our platform. The average latency is 600-1000ms, but pricing is currently $1.5/minute. We expect the pricing will go down soon.
If you're using the call transfer feature and want the next agent to receive the caller’s number (instead of the Retell number), adjust the settings.
We’ve added the Workspace feature.
• For companies, you can now invite your teammates.
• For agencies, you can now create different organizations for your clients.
We’ve completed a full dashboard overhaul.
We’ve added a warm transfer feature.
If you need to provide background information and hand off the call to the next agent, this feature allows you to set up a prompt or static message for smooth transitions.
We’ve added a toggle to disable transcript formatting. This can help resolve the ASR (Automatic Speech Recognition) errors we recently discovered:
If you encounter issues related to number transcription, try out this toggle.
If you’ve added custom fields in Cal.com, you can now use them in Retell.
When using Cal.com functions, you can instruct the agent to collect specific information, and it will automatically display the collected data in the booking event.
1. More Languages
We’ve now supported more languages:
Simply change the language in the settings panel on the agent creation page.
You can now set the maximum duration for calls in minutes to prevent spam.
You can set the duration for detecting voicemail. In some B2B use cases, there are welcome messages before going to voicemail. Setting a longer voicemail detection time can solve this issue.
You can adjust the LLM Temperature to get more varied results. The default setting is more deterministic and provides better function call results.
You can now control the volume of the agent’s voice.
Guide the voice agent through IVR systems with button presses (e.g., “Press 1 to reach support”).
You can now integrate Retell AI with your telephony providers, using your own phone numbers (e.g., Twilio, Vonage). This works with both Retell LLM and Custom LLM.
Integration options:
You could make a multilingual agent who could speak English and Spanish at the same time.
You can also control how certain words are pronounced. This is useful when you want to make sure certain uncommon words are pronounced correctly.
We’ve added new settings for voice model selection:
We have upgraded our audio infrastructure to WebRTC, moving away from the original websocket-based system. This change ensures better scalability and reliability:
We've introduced the updates in our Call API V2, which now separates phone call and web call objects and includes a few field and API changes:
In response to abuse and misuse of our platform, we added some usage limits accordingly:
We've obtained the Vanta SOC 2 Type 1 certification and are currently awaiting the SOC 2 Type 2 certification.
Click on "Test LLM" to enter debugging mode. It works with both single prompts and stateful multi-prompt agents. Now, you can test the LLM without speaking. You can create, store, and edit the conversation.
Pro tip:
For multi-states prompt agent, you can change the starting point to the middle state and test from there.
Your stability is our top priority. We've added the capability to specify a fallback for TTS. In case of an outage with one provider, your agent can use another voice from a different provider.
The OpenAI GPT-4o LLM is now available on Retell. The voice interface API has not been released yet, but we plan to integrate it as soon as it becomes available. Stay tuned!
The pricing for GPT-4o is $0.10 per minute (optional).
You can now guide the model to pronounce a word, name, or phrase in a specific way. For example: "word": "actually", "alphabet": "ipa", "phoneme": "ˈæktʃuəli".
This feature is currently available only via the API but will soon be added to the dashboard.
Normalize the some part of text (number, currency, date, etc) to spoken to its spoken form for more consistent speech synthesis.
Now you could set if users stay silent for a period after agent speech, then end the call.
The minimum value allowed is 10,000 ms (10 s). By default, this is set to 600000 (10 min).
Techcrunch
Call Analysis: We've introduced metrics like Call Completion Status, Task Completion Status, User Sentiment, Average End-to-End Latency, and Network Latency for comprehensive monitoring. You can access these directly on the dashboard or through API.
Disconnection Reason Tracking: Get insights into call issues with the addition of "Disconnection Reason" in the dashboard and "get-call" object. For more details, refer to our Error Code Table.
Function Call Tracking: Transcripts now include function call results, offering a seamless view of when and what outcomes were triggered. Available in the dashboard and get-call API. For custom LLM users, can use tool call invocation event and tool call result event to pass function calling results to us, so that you can utilize the weaved transcript and can utilize dashboard to view when your function is triggered.
Reminder Settings: You can now configure reminder settings to define the duration of silence before an agent follows up with a response. Learn more.
Backchanneling: Backchannel is the ability for the agent to make small noises like “uh-huh”, “I see”, etc. during user speech, to improve engagement of the call. You can set whether to enable it, how often it triggers, what words are used. Learn more.
“Read Numbers Slowly”: Optimize the reading of numbers (or anything else) by making sure it is read slowly and clearly. How to Read Slowly.
Metadata Event for Custom LLM: Pass data from your backend to the frontend during a call with the new metadata event. See API reference.
Improved async OpenAI performance for better latency and stability. Highly recommended for existing Python Custom LLM users to upgrade to the latest version.
Improved webhook security with the signature "verify" function in the new SDK. Find a code example in the custom LLM demo repositories and in the documentation.
Additionally, the webhook includes a temporary recording for users who opt out of storage; please note that this recording will expire in 10 minutes.
We’ve got a shout out in the latest episode of Y Combinator’s podcast Lightcone.
LLM Model Options: Choose between GPT-3.5-turbo and GPT-4-turbo, with additional models coming soon. Available through both our API and dashboard.
Interruption Sensitivity Slider: Adjust how easily users can interrupt the agent. This feature is now accessible in our API and dashboard.
We've updated our pricing structure to be clearer and more modular.
Conversation voice engine API
- With OpenAI / Deepgram voices ($0.08/min)
- With Elevenlabs voices ($0.10/min)
LLM Agent
- Retell LLM - GPT 3.5 ($0.02/min )
- Retell LLM - GPT 4.0 ($0.2/min )
- Custom LLM (No charge)
Telephony
- Retell Twilio ($0.01/min )
- Custom Twilio (No charge)
Dashboard Updates: The history tab now includes a public log, essential for debugging and understanding your agent's current state, tool interactions, and more.
Enhanced API Responses: Our get-call API now provides latency tracking for LLM and websocket roundtrip times.
Ensure the authenticity of requests with our new IP verification feature. Authorized Retell server IPs are: 13.248.202.14, 3.33.169.178.
Enhancements for Custom LLM Users
Web Call Frontend Upgrades
SDK improvement: Our updated SDK maintains backward compatibility, ensuring smooth transitions and consistent performance.
Low Latency, Conversational LLM with Reliable Function Calls
Experience lightning-fast voice AI with an average end-to-end latency of just 800ms with our LLM, mirroring the performance featured in the South Bay Dental Office demo on our website. Our LLM has been fine-tuned for conciseness and a conversational tone, making it perfect for voice-based interactions. It is also engineered to reliably initiate function calls.
Single-Prompt vs. Stateful Multi-Prompt Agents
We provide two options for creating an agent. The Single-Prompt Agent is ideal for straightforward tasks that require a brief input. For scenarios where the agent's prompt is lengthy and the tasks are too complex for a single input to be effective, the Stateful Multi-Prompt Agent is recommended. This approach divides the prompt into various states, each with its own prompt, linked by conditional edges.
User-Friendly UI for Agent Creation and API for Programmatic Agent Creation
Our dashboard allows you to quickly create an LLM agent using prompts and the drag-and-drop functionality for stateful multi-prompt agents. You can seamlessly build, test, and deploy agents into production using our dashboard or achieve the same programmatically via our API.
Pre-defined Tool Calling Abilities such as Call Transfer, Ending Calls, and Appointment Booking
Leverage our pre-defined tool calling capabilities, including ending calls, transferring calls, checking calendar availability (via Cal.com), and booking appointments (via Cal.com), to easily build real-world actions. We also offer support for custom tools for more tailored actions.
Maintaining Continuous Interaction During Actions That Take Longer
To address delays in actions that require more time to complete, you can activate this feature. It enables the agent to maintain a conversation with the user throughout the duration of the function call. This ensures the voice AI agent keeps the interaction smooth and avoids awkward silences, even when function calls take longer.
Please note, the previous SDK version will be phased out in 60 days. We encourage you to transition to the latest SDK version.
Stay informed with system status on our new status page.
To streamline your troubleshooting process, we've introduced a public log within our get-call API. This new feature aids in quicker issue resolution and smoother integration, detailed further at the link below.
Thanks to recent cost reductions in our premium voice service, we're excited to pass these savings on to our customers. We're pleased to announce a new, lower price for our premium voice service—now just $0.12 per minute, down from $0.17. Enterprise pricing will also see similar reductions (please contact us at founders@retellai.com for more information).
Please note: The adjusted pricing will take effect from March 1st, and billing will be charged at the end of this month.
Gain more control over your voice output with new dashboard settings.
Tailor your voice interactions to suit your precise needs and preferences for a truly personalized experience.
Boost your communication security with our new webhook signatures. This feature enables you to confirm that any received webhook genuinely comes from Retell, providing an additional layer of protection.
We're excited to announce the launch of our multilingual version, now supporting German, Spanish, Hindi, Portuguese, and Japanese. Access and set your preferred language through our dashboard.
While this feature is currently available via API, we're working on extending support to our SDKs shortly.
Based on user feedback, we've introduced an opt-out option for storing transcripts and recordings. This feature, available in our API and the Playground, gives you more control over your data and privacy.
Dear Retell Community,
We are excited to share several updates and new features with you. Our goal is to continually improve our offerings to better meet your needs. Here's what's new:
We're excited to announce the availability of our discounted enterprise tiered pricing. For more information on that, please contact our team at founders@retellai.com.
We've launched improvements to further reduce latency (by approximately 30%). Try our demo on the website again and experience the magical speed.
We've introduced additional control parameters for agents for greater customization and control. Including:
These parameters have been added to our API. Documentation is being updated, and we are also working on incorporating these features into the SDKs. For more details, visit Create Agent API Reference.
This parameter enables the automatic termination of calls following a specified duration of user inactivity. It's designed to streamline operations and improve efficiency.
To enhance the utility of our transcripts, we are now including word-level timestamps. This feature is pending documentation updates, so stay tuned for more information at Audio WebSocket API Reference.
For users utilizing web calls, our latest client JavaScript SDK (version 1.3.0) now supports auto-reconnection of the socket in case of network disconnections. This ensures a more reliable and uninterrupted service.
We are dedicated to providing you with the best possible service and experience.
We welcome your feedback and are here to support you in making the most out of these new features.
Best regards,
Retell AI team 💛
Please note that our domain has changed. Make sure to update your bookmarks and records to stay connected with us seamlessly.
We've introduced Deepgram as our new TTS provider. Explore it on the Dashboard and discover your favorite one! The price is still $0.10/minute($6/h)
Also, we've added more voice choices from 11labs, ensuring more stable and diverse voice options for your projects.
Gain control over the stability and variability of your voice output, allowing for more tailored and dynamic audio experiences.
Enhance interactions with the ability for the agent to backchannel, using phrases like "yeah" and "uh-huh" to express interest and engagement during conversations.
By popular demand, our Python backend demo has transitioned to FastAPI. It includes Twilio integration and a simple function calling example, providing a more robust and user-friendly experience.
Our updated web frontend SDK makes integration easier and improves performance, allowing you to access live transcripts directly on your web frontend.
Our product now offers improved performance even in noisy settings, ensuring your voice interactions remain clear and uninterrupted.
Dear Retell Community,
We are thrilled to announce a new and significantly more affordable pricing tier featuring OpenAI's TTS. Effective immediately, you can take advantage of our state-of-the-art voice conversation API with OpenAI TTS at the new rate of $0.10 per minute.
This adjustment reflects our commitment to providing you with exceptional value and enhancing your voice interaction experience.
We believe this new pricing will make our product more accessible and allow you to leverage our technology for a wider range of applications.
We updated our SDK, so update your retell SDK to stay in the loop.
- https://www.npmjs.com/package/retell-sdk
- https://pypi.org/project/retell-sdk/
We added a frontend js SDK to abstract away the details of capturing mic and setting up playback.
- https://www.npmjs.com/package/retell-client-js-sdk
We update our documentation at https://docs.re-tell.ai/guide/intro to help people integrate.
We open sourced the LLM and twilio codes that powers our dashboard as a demo:
Node.js demo:
https://github.com/adam-team/retell-backend-node-demo
Python demo:
GitHub - adam-team/python-backend-demo
We open sourced the web frontend demo:
React demo using SDK :
GitHub - adam-team/retell-frontend-reactjs-demo
React demo using native JS:
Dear Retell Community,
In our quest to deliver a human-level conversation experience, we've made a strategic decision to refocus our efforts on voice conversation quality, while scaling back on certain other nice-to-haves. The current API will be phased out after this Wednesday at 12:00 PM. We warmly invite you to adopt our new API, designed to continue providing you with a magical AI conversation experience long-term.
🌟 Key Changes:
🌟 New Features:
We understand that this transition may require adjustments in your current setup, and we are here to support you through this change. Please feel free to reach out to us for any assistance or further information regarding the new API.
Thank you for your understanding and continued support.
Best regards,
Retell AI Team 💛
Dear Retell Community,
We are thrilled to announce a new and significantly more affordable pricing tier featuring OpenAI's TTS. Effective immediately, you can take advantage of our state-of-the-art voice conversation API with OpenAI TTS at the new rate of $0.10 per minute.
This adjustment reflects our commitment to providing you with exceptional value and enhancing your voice interaction experience.
We believe this new pricing will make our product more accessible and allow you to leverage our technology for a wider range of applications.
We updated our SDK, so update your retell SDK to stay in the loop.
- https://www.npmjs.com/package/retell-sdk
- https://pypi.org/project/retell-sdk/
We added a frontend js SDK to abstract away the details of capturing mic and setting up playback.
- https://www.npmjs.com/package/retell-client-js-sdk
We update our documentation at https://docs.re-tell.ai/guide/intro to help people integrate.
We open sourced the LLM and twilio codes that powers our dashboard as a demo:
Node.js demo:
https://github.com/adam-team/retell-backend-node-demo
Python demo:
GitHub - adam-team/python-backend-demo
We open sourced the web frontend demo:
React demo using SDK :
GitHub - adam-team/retell-frontend-reactjs-demo
React demo using native JS:
GitHub - adam-team/retell-frontend-reactjs-native-demo
Thank you for your understanding and continued support.
Best regards,
Retell AI Team 💛
Dear Retell Community,
We are thrilled to announce a new and significantly more affordable pricing tier featuring OpenAI's TTS. Effective immediately, you can take advantage of our state-of-the-art voice conversation API with OpenAI TTS at the new rate of $0.10 per minute.
This adjustment reflects our commitment to providing you with exceptional value and enhancing your voice interaction experience.
We believe this new pricing will make our product more accessible and allow you to leverage our technology for a wider range of applications.
We updated our SDK, so update your retell SDK to stay in the loop.
- https://www.npmjs.com/package/retell-sdk
- https://pypi.org/project/retell-sdk/
We added a frontend js SDK to abstract away the details of capturing mic and setting up playback.
- https://www.npmjs.com/package/retell-client-js-sdk
We update our documentation at https://docs.re-tell.ai/guide/intro to help people integrate.
We open sourced the LLM and twilio codes that powers our dashboard as a demo:
Node.js demo:
https://github.com/adam-team/retell-backend-node-demo
Python demo:
GitHub - adam-team/python-backend-demo
We open sourced the web frontend demo:
React demo using SDK :
GitHub - adam-team/retell-frontend-reactjs-demo
React demo using native JS:
GitHub - adam-team/retell-frontend-reactjs-native-demo
Thank you for your understanding and continued support.
Best regards,
Retell AI Team 💛