Vapi Voice Assistant

The Vapi deploy provider lets you push versioned prompts and tools from Ellaworks directly into Vapi assistants. Ellaworks creates or updates the assistant, creates and attaches its tools, imports assistants you already have in Vapi, and checks deployed assistants for drift.

Vapi Account Setup

Ellaworks authenticates to Vapi with a single API key. No other cloud setup is required.

1. Log in to the Vapi Dashboard.
2. Copy the API key for the Vapi organization that should own your assistants.

Connection Setup in Ellaworks

1. Store the API Key as a Secret

In Ellaworks, navigate to Environments / Secrets and add your Vapi API key as a secret (for example VAPI_API_KEY).

2. Add Vapi to an Environment

1. Open the environment (e.g. dev) and, under Providers, choose Vapi from Select provider, then click Add.
2. In the Secret field, pick the secret you created. You can also click Add Secret to create one inline.

Ellaworks stores the key as a secret reference, not as plain text:

[!NOTE] Global environment: If Vapi is configured on the Global (*) environment, its credentials apply to every environment automatically. Add Vapi to a specific environment only when it needs its own key.

Agent Configuration

A Vapi agent’s provider configuration mirrors the Vapi assistant object. Before every deploy, Ellaworks validates it, checking model, voice and transcriber against schemas generated from Vapi’s OpenAPI spec.

• Name: The assistant name in Vapi. A top-level name is required.
• Model: model.provider, model.model and model.messages. Your system prompt is placed in model.messages as a system message.
• Voice: voice.provider and voice.voiceId.
• Transcriber: transcriber.provider and its options.
• First Message: What the assistant says when the call starts.

[!IMPORTANT] Defaults for missing fields: If the model, voice or transcriber is incomplete, Ellaworks fills it before deploying: openai / gpt-4o for the model, openai / alloy for the voice, and deepgram / nova-2 for the transcriber. Set these explicitly if you want something else.

Prompt Fields

You can link registry prompts to these Vapi fields: the main system prompt, First Message, and the analysis prompts Success Evaluation, Structured Data, Summary and Success. The analysis prompts are written into the assistant’s analysisPlan.

Working with Tools

Vapi tools are created as standalone tools in your Vapi organization and attached to the assistant by ID through model.toolIds. On deploy, Ellaworks resolves each tool reference (e.g. my-tool@^1.0.0) to a Vapi tool UUID, creating the tool if it doesn’t exist in that environment yet or updating it if it does.

Built-in Call Controls

End Call, DTMF, SMS and Transfer Call can be switched on as simple flags on the agent. Ellaworks adds them to the assistant’s inline model.tools list, so no separate tool is created.

Supported Tool Types

The Ellaworks tool editor supports the Vapi tool types: API Request, Function, End Call, DTMF, SMS, Transfer Call, Code, Handoff, Bash, Computer, Text Editor, Query, MCP, Google Calendar Create Event, Google Calendar Check Availability, Google Sheets Row Append, Slack Send Message, and the GoHighLevel calendar and contact tools.

[!IMPORTANT] UUIDs only: Vapi accepts only tool UUIDs in model.toolIds. If a reference there can’t be matched to a tool Ellaworks deploys, the deploy fails instead of quietly shipping fewer tools. Add the tool to Ellaworks, or replace the entry with the tool’s Vapi UUID.

Importing Existing Assistants

Vapi supports agent import. Ellaworks lists the assistants in your Vapi account (up to 300), and for each one you import:

• The assistant name becomes the agent name, and a stable key is derived from it.
• The system messages in model.messages become a registry prompt named <stable-key>-imported-system.
• Each tool in model.toolIds is imported as a tool at version 1.0.0. Secret-like server fields (tokens, auth headers) are stripped, and you’ll see a warning.

Deploy Options

Full Deploy

A full deploy sends the whole assistant configuration — model, voice, transcriber, prompts and tools — to Vapi.

Prompt-Only Deploy

Vapi supports the Prompt only toggle in the deploy drawer. It pushes compiled prompts and nothing else: no tools, voice, model or transcriber rewrite. Ellaworks reads the live assistant from Vapi, replaces only the system prompt and First Message, and writes them back, so changes made in the Vapi dashboard are kept.

[!WARNING] Prompt-only deploys do not write the analysis-plan prompts (success evaluation, structured data, summary). Knowledge-base tools stay as they were at the last full deploy.

Troubleshooting & Typical Errors

Deployment Verification

1. Click Deploy in Ellaworks.
2. In the Vapi Dashboard, find your assistant and confirm the prompt, voice and tools.
3. Enable Drift Detection on the environment to have Ellaworks verify deployed assistants against their expected configuration daily. Only one environment per organization can have it enabled.