Quickstart

Create a flow and give the agent its instructions

Open Flow Builder in the sidebar and choose Create Flow. You can start from a template or from an empty canvas; for this walkthrough start empty so you see every piece.

The canvas opens with a Main Agent already placed. It’s the entry point of every call and the only node that carries the call’s persona. Select it and fill in the two prompts:

• System Prompt — who the agent is, for the whole call. Keep it to identity, tone, and hard limits:

  System Prompt

  You are Mia, the phone assistant for Northwind Dental in Seattle.
  Be warm and brief — this is a phone call, so keep every reply to one or two sentences.
  Never give medical advice. If you don't know something, say so and offer to take a message.

• Agent Prompt — what this agent must accomplish while the conversation is on it:

  Agent Prompt

  Greet the caller and ask how you can help.
  Answer questions about opening hours (Mon–Fri 8am–5pm), location (1200 Pine St), and parking (free garage on Pine).
  If they want to book or change an appointment, collect their full name and a callback number, confirm both back to them, and say the office will call within one business day.
  When the caller has nothing else, say a natural goodbye and then end the call.

Attach the three providers

An agent can’t hear, think, or speak until a provider node is connected for each job. Add an STT, an LLM, and a TTS node to the canvas and connect each one to the Main Agent.

The live list of vendors and models is in Models and voices. Publishing is refused if any of the three is missing, so the builder flags it early.

Talk to it in your browser

Open the Flow Tester from the builder toolbar and click the phone button. Allow microphone access when the browser asks. You’re now on a WebRTC call with the draft you have open — unsaved edits included — so you can iterate on prompts without publishing.

Say “Hi, what time do you close on Friday?” and then “I’d like to book a cleaning.” Watch the transcript, the per-turn latency (LLM TTFB) and token counts on the right; those numbers tell you whether a model is fast enough for phone use before a real caller finds out.

Adjust the prompts until the conversation feels right, then hang up with the red button.

Publish the flow

Click Publish. Talkif validates the flow and refuses to publish until it passes. The checks that matter most:

• exactly one Main Agent, and it’s the entry node
• the Main Agent has a System Prompt; every agent has an Agent Prompt
• an LLM, an STT and a TTS provider are configured, with models the platform currently offers
• every transition points at an agent that exists; agent and function names are unique

Publishing creates an immutable version. The draft stays editable; phone numbers and API calls use the published version until you publish again. Versioning, rollback and pinning are explained in Flows and versions.

Get a phone number

Open Phone Numbers in the sidebar and choose Purchase Number. Pick a country, then search by area code or digit pattern. Each result shows its capabilities (voice, SMS) and its monthly price. Confirm to buy; the number is provisioned instantly.

Purchases and rental are paid from your purchased balance — add a payment method and top up under Billing if you haven’t. Numbers renew monthly against the same balance; see Buy a number for pricing and what happens if renewal fails.

Already have numbers with a SIP carrier or a WhatsApp Business account? Skip the purchase and connect them instead — Bring your own SIP trunk, WhatsApp Business Calling.

Connect the flow to the number

Open the number you just bought and connect your published flow to it. From this moment, anyone who dials the number is answered by the agent — this is what makes a number inbound-capable.

A number is connected to at most one flow. If someone dials a number with no flow connected, Talkif answers busy and records a failed call in your history with the reason “no connected flow” — so a misconfigured number is visible, not silent. The same busy response is returned when your balance is below the $1.00 minimum.

Make a real call

Two ways, and it’s worth doing both:

Inbound — dial the number from your own phone. This is the path your customers will take.

Outbound — have the agent call you. From the dashboard use Start a call on the home screen (or Call Center → Calls), pick the flow, the number to call from, and your mobile as the destination. From the API, the same thing is one request:

Read the result

Open Call Center → History and select the call. You get three things for every call, test or real:

• the transcript, turn by turn, with who spoke and when
• the recording, playable in place
• the cost breakdown — telephony seconds, STT seconds, LLM tokens, TTS characters — each priced, summed to the amount taken from your balance

Costs are where model choice becomes visible: swap the LLM or TTS in the draft, run the same conversation in the Flow Tester, and compare. Cost breakdown explains every line.