Book field jobs by phone with Vapi

In the left sidebar of the Crisphive dashboard, click Rehearsal in the Rehearsal | Live switch, then click Switch. Rehearsal is Crisphive’s sandbox: isolated test data, and no real customer or technician is ever texted or emailed. A key created while you are in Rehearsal starts with chsk_test_ and only ever touches the test data.

Go to Settings → Developer → API Keys (crisphive.com/app/settings/developer/api-keys) and click Create new API key. Creating keys needs Developer access, which by default only the Owner has.

Key type: Secret. Never Publishable — a publishable chpk_ key is only for the booking widget on your website and is refused everywhere else. Name: Vapi voice assistant.

In Expires in (days) keep 30 days for a test key. Keys always expire: 30 days by default, anything from 1 to 365 days chosen when you create the key. The Owner and Administrators are emailed 7 days before a key expires.

Under Scopes choose Restricted and select customers_view, customers_manage, job_view, job_create and job_manage. Nothing else is needed for booking.

Click Create API key, then Copy, then Done. The full key is shown only once — paste it into your password manager. If you lose it, create a new key and revoke the old one.

After you sign in to the Vapi dashboard (dashboard.vapi.ai), it opens Create an Agent with Inbound, Outbound, Support and a box “Or describe what you want to build”. Do not click Inbound: it starts Vapi’s AI Agent Builder chat, which asks about your business and writes its own prompt — one that does not follow the booking rules. Close the screen with the X at the top right.

In the left navigation click Assistants, then the green Create Assistant button. Vapi creates New Assistant straight away from a blank template. (A new account also has a sample assistant called Riley; leave it.)

At the top: the assistant’s name and version, and the buttons Composer, Talk and Publish. Below: the tabs Assistant, Logs, Tools, Analysis and Advanced. The Assistant tab shows Model Presets (Balanced is selected), the Transcriber, Model and Voice cards, then System prompt and First message.

A new assistant uses GPT-4.1 (OpenAI) in the Model card and the voice Elliot (Vapi) in the Voice card. Keep them for your first practice call; if a voice is hard to follow on the phone, try others in the Voice card. Whatever you change, run the practice call below again before going live.

The System prompt box holds Vapi’s placeholder “This is a blank template with minimal defaults…”. Select everything in it and paste the prompt below. Replace every [Business name] (in the prompt and the first message), [city] (for example “Ottawa, Canada”) and [timezone] — your business’s IANA timezone, for example America/Toronto. [timezone] appears three times: in the first line and twice in step 5. The timezone matters most: Crisphive reads every time as your business’s local clock. Do not click Generate — it rewrites the prompt.

Under First message, replace “Hello.” with the greeting in the box below the prompt card, with your business name in place of [Business name]. The selector next to it already reads Assistant speaks first — keep it.

Your changes stay a draft until you click Publish in Step 5.

Open Settings › Integrations (or click Create Credential on a tool page before typing anything there). In the Server Configuration dialog, click Add Custom Credential. The form New Custom Credential opens.

Authentication Type offers OAuth 2.0 (the default), HMAC and Bearer Token. Choose Bearer Token. Not OAuth 2.0: Vapi’s OAuth form is a client-credentials flow that asks for a Token URL, Client ID and Client Secret, which is not how Crisphive keys work.

Credential Name: for example Crisphive Rehearsal. Token: paste only your key, chsk_test_… — without the word Bearer. Header Name: keep Authorization (it is prefilled). Include Bearer Prefix: keep it on (the default). Leave Enable Encryption as it is.

Save. Vapi shows “Custom credential created successfully.” and a card with your credential name and Bearer Token • Authorization.

In the left navigation click Tools, then Create Tool. In the menu, under INTEGRATIONS, click MCP. The tool is created at once with the name mcp_tool.

Under Tool Settings, set Tool Name to crisphive (the description is optional). Under Server Settings, set Server URL to https://api.crisphive.com/mcp/voice and leave Timeout at 20 seconds.

Under Authorization, open the Credential dropdown (it shows No authentication) and pick your credential, listed as Crisphive Rehearsal (Bearer Token). Vapi shows Authentication enabled. Leave HTTP Headers and Encrypted Paths empty.

Under MCP Settings, keep Protocol on Streamable HTTP (SHTTP) — the default — not Server-Sent Events (SSE).

Click Publish on the tool page. The Publish Tool dialog shows what changed (step 1 of 2); click Next, optionally type a version name, and click Publish. The button now reads Published.

Open your assistant, go to its Tools tab and click Add tool. Tick crisphive. Its row shows the type MCP and Assign Tool Version: Latest, so the assistant always uses the newest published version of the tool.

Click Publish at the top of the assistant page, then Next and Publish in the dialog. The button reads Published and the version number goes up. The assistant only uses the tool, the prompt and the greeting after you publish.

Switch the Crisphive dashboard to Live; check job type durations, technician hours, skills and service areas.

Create a Secret key in live mode (chsk_live_…) with the same five scopes. Choose an expiry up to 365 days and set a calendar reminder a week before it; Owners and Administrators are also emailed 7 days before.

Click Edit on your Crisphive credential’s card (or create a new Bearer Token credential and pick it on the crisphive tool) and paste the chsk_live_… key into Token — still without the word Bearer. Publish the tool and the assistant again.

See Connect a phone number below.

Book a visit for yourself, check it on the live board, then cancel it.

Vapi offers free US phone numbers, and can import a number you already have with Twilio, Telnyx or Vonage. Assign the number to the assistant as the assistant that answers incoming calls.

With your phone provider, forward calls from your existing business number to the assistant’s number: always, when nobody answers, when the line is busy, or after hours. A good start is after-hours and missed calls only, so your team still answers during the day.

If your business has its own phone system, connect it over SIP. Ask your phone provider for the SIP details to use.

In Vapi, add a tool of type Transfer Call to the assistant.

Set the destination to your office or coordinator phone number.

The prompt already tells the assistant when to transfer: a complaint, a caller who asks for a person, and questions about an existing booking. Save and publish the assistant again.

In the assistant’s Analysis settings, add four fields to fill in after each call: the caller’s name, their phone number, the reason for the call and the message.

In Zapier, Make or n8n, start a new workflow with a webhook trigger that catches incoming data, and copy its web address.

In Vapi, paste that address as the post-call webhook, so Vapi sends the call summary there when a call ends.

Add a step that sends the name, phone number, reason and message as an email or a Slack message to whoever calls customers back.

Make a practice call where you only leave a message, and check that it reaches your team.