# Guide to Building No-Code AI Agents for Handling Calls (2025 Update) Author: Manav Mahajan Author URL: https://www.heltar.com/blogs/author/manav-mahajan Published: 2025-08-21 Category: AI Calling Category URL: https://www.heltar.com/blogs/category/ai-calling Tags: Whatsapp Business API, WhatsApp Chatbot, Business Chatbot Tag URLs: Whatsapp Business API (https://www.heltar.com/blogs/tag/whatsapp-business-api), WhatsApp Chatbot (https://www.heltar.com/blogs/tag/whatsapp-chatbot), Business Chatbot (https://www.heltar.com/blogs/tag/business-chatbot) URL: https://www.heltar.com/blogs/can-you-deploy-no-code-ai-agents-for-handling-calls ## Building no-code AI Calling Agents in Heltar Heltar lets you stand up a voice agent in two clean ways. You can **import** a ready agent from a JSON file, or **create** one inside the Agent builder with a simple system prompt and point-and-click settings. The screenshots you shared map to every step below. ## Option A - Import an agent from JSON ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-020052-1755809169507-compressed.png) 1. Go to **Agents**. 2. Click **Import Agent**. 3. **Upload** your JSON file. - The file carries your agent’s choices, for example model, voice, transcriber, call settings, knowledge base links, webhooks, and post-call variables. 4. **Save**. Your agent appears in the Agents list with its outbound and inbound number mappings ready to set. 5. Use this when you keep a standard agent template across teams or environments. ## Option B - Create an agent in the builder ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-020659-1755808637001-compressed.png) Click **Create an Agent**. You will see three zones: - **Left**, the **System Prompt** editor with a **Generate Draft** button. - **Middle** panel with all settings sections. - **Right** side with **Test Audio**, **Variables**, and a **Start Talking** button. You can get a working bot with only a strong **system prompt** on the left. Everything else below helps you fine-tune quality and control. ### 1) System Prompt ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-020753-1755808683099-compressed.png) Write the agent’s role and script. Use variables like {customer\_name} or {order\_id} to personalize. Tip, keep the greeting, purpose, 1 or 2 key questions, and closing lines here. Click **Generate Draft** if you want a starter. ### 2) LLM Model Open **LLM Model**. ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-020921-1755808773448-compressed.png) - **Model** dropdown, for example **gpt-4.1-mini**. The UI shows an approx per-minute cost beside the model. - **Temperature** slider, 0 to 1. Lower values keep replies crisp and on-script, higher values allow more variety. For sales confirmations and reminders, 0.2 to 0.4 works well. ### 3) Voice Open **Voice**. ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-015022-1755808723249-compressed.png) - **Voice Provider**, for example **Eleven Labs**. - **Voice Model**, for example **eleven\_flash\_v2\_5**. - **Voice**, choose a persona such as **Anika - Animated and Friendly** or any other voice you prefer. You can preview it. - **Voice Speed**, set 0.7 to 1.2. Keep near 1.0 for natural pace. - **Voice Stability**, controls emotion variance. Lower is more expressive, higher is more flat. - **Voice Similarity Boost**, how closely to follow the base voice. - **Voice Style**, 0 to 1 to slightly amplify style. Higher can sound more expressive but may add latency. ### 4) Transcriber Open **Transcriber.** ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-021106-1755808993119-compressed.png) - **Provider**, for example **Deepgram**. - **Model**, for example **nova-2-general**. - **Transcription Language**, pick the main call language, for example **hi** for Hindi. - Optional **Keywords** button to add phrases you care about. ### 5) Agent Configurations ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-015040-1755809243367-compressed.png) Control how the bot behaves in the moment. - **Silence Message Count**, how many times to repeat a silence prompt before ending. - **Wait till User Reply** in seconds, for example 6. - **Silence Message Language**. - **Silence Duration** in ms, the pause length that signals the caller has stopped. - **Interrupt Speech Duration** in seconds, how long the user must speak to cut in. - **Interrupt Min Words**, for example 3, prevents false cuts on filler sounds. ### 6) Call Settings ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-015046-1755809268584-compressed.png) Operational controls for the call. - **Auto Rescheduling**, toggle to let the agent reschedule if the user says they are busy. - **Background Noise**, toggle and **Volume** slider to add a light office hum if you want a human-like ambience. - **Noise Cancellation**, toggle if you want a cleaner line. - **Leave Voicemail Message**, toggle. - **Voicemail Type**, choose **Dynamic Voicemail Message** to let the agent speak a custom note. - **Time Limit**, total seconds the agent can stay active, default 300. ### 7) Functions ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-021833-1755809324455-compressed.png) Click **\+ Add** to attach abilities such as booking flows or call termination helpers. You can plug small actions here as your use case grows. ### 8) Knowledge Bases ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-021929-1755809380325-compressed.png) Give the agent reference material. - Click **Knowledge Bases** then **\+ Add New** or select an existing one. Use this for FAQs, policy lines, or product info. ### 9) Post Call Variables ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-022011-1755809424202-compressed.png) Decide what to extract after the call. - **Post Call Model**, for example **o4-mini**. - **Conversion Reason**, free text you want to record when a call is marked converted. - **Post Call Data Retrieval**, click **\+ Add** to define fields like call\_intent, appointment\_slot, nps\_score. These land in your logs or webhooks. ### 10) Webhook Set your endpoint to receive events such as started, connected, ended, disposition, and conversion. This is how you push results into your CRM. ### 11) WhatsApp Configurations Map the agent to the right **WhatsApp phone** so caller identity stays consistent across campaigns. ### 12) Call Initiation and Termination Fine-tune open and close. ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-015131-1755809494555-compressed.png) - **Call Initiation for Outbound**, choose **AI Initiates, AI begins with a dynamic begin message**. - **Initial delay** before the AI speaks, for example 1 second. - **Call Initiation for Inbound**, same options. - **Call Termination messages**, click **\+ Add** and write the lines you want the bot to use while ending. ## Test before you ship Use the **Test Audio** tab on the right, then click **Start Talking**. Speak back and see how the agent handles silence, interruptions, and handovers. Open the **Variables** tab to confirm your prompt variables are in place. ## Save and wire it into calls Click **Create** to save. Next, map your agent to an **Outbound Phone Number** and, if needed, set it as the **Inbound Agent** for a number. You are ready to use it in **Batch Call**, **Scheduled Calls**, or via the **Outbound API**. ## Quick build recipe 01. Write a clear system prompt with variables. 02. Pick model at a temperature suitable the needs of the model. 03. Select a voice, test speed and style. 04. Set Deepgram with the right language. 05. Tune silence and interrupt rules. 06. Add voicemail and time limit in Call Settings. 07. Define post-call fields, set webhook. 08. Add knowledge base if the agent must answer FAQs. 09. Test, save, and launch a small batch first. 10. That is the full path from blank screen to a production-ready calling agent, using the exact controls shown in your screenshots. ## Contact us if this is what your business needs! ![](https://prod.superblogcdn.com/site_cuid_clnw4nrag2342701vpmufcj1n2w/images/screenshot-2025-08-22-014505-1755807316581-compressed.png) Creating AI-based calling agents with Heltar’s Voice Bot API is as simple as electing filters for your model and crafting a prompt. From reminders and lead qualification to surveys and event invites, businesses can now run high-volume calling campaigns without lifting the phone themselves. With just a few clicks, what used to take hours of manual work can now be fully automated. [Contact us today](https://www.heltar.com/demo.html) for a demo. --- This blog is powered by Superblog. Visit https://superblog.ai to know more. ---