Automated outbound calls with a voice agent, triggered from your software

An outbound call is one your voice agent makes rather than receives. Automated means you do not start it by hand. Your software does, at the moment something happens.

Your software requests it through the API, the door that lets your programs talk to Lera without going through the panel. It is like your invoicing software emailing an invoice the moment it is issued, without anyone clicking anything.

Picture a garage management system that knows a customer’s car is due for its annual service. It requests a call with the reason and the date, your agent calls, offers a day and, when the call ends, tells your software how it went.

Each call carries its call variables, the details your software sends about that customer, such as the reason, the date or a reference. Your agent uses them in the greeting, its instructions and its functions, written in double braces like {{reason}}.

You declare them on the agent’s page, in the Call variables section. Each one can have a default value, used if your software does not send it and during tests.

To let your software know how it went, the agent uses a function, a message to your software sent mid-call. For example, one that records whether the customer accepts the appointment, turns it down or asks to be called another day. If you are starting from scratch, the Outbound category in the templates has an appointment reminder and a periodic service call.

First, create and publish your agent. The call uses the published version, so publish again after every change.

Second, tell it which number to call from. In Phone numbers, open your line and, in the Outbound calls card, choose the agent that calls. With your Lera line, nothing else is needed. If you would rather show your own number, connect it over SIP and click “Activate outbound” with your provider’s address and credentials, which Lera does not store.

Third, decide what happens if voicemail picks up. On the agent’s page, under Voicemail, turn on “Detect voicemail” and choose between just hanging up, leaving a fixed message, which can include variables, or leaving one the agent writes.

Fourth, try it with your own mobile. On the agent’s page, click Test and open “Outbound test”. Enter your number and the variables, and your agent really calls you, at the usual cost. Functions return a sample response and do not touch your software.

Fifth, create your software’s key in Settings, API Keys, and store it, because it is shown only once. Have an Administrator create it, as a key acts with the role of whoever created it.

Finally, your software requests the call at https://leracore.com/api/v1/tools/start_outbound_call, with the key in the Authorization header. It sends the number in international format (+34...), the agent that calls and the variables. Lera replies with the call’s reference.

The time. It only calls between 9 am and 8 pm, Spanish mainland time, and never outside your agent’s opening hours if you have set them. It does not block weekends or public holidays by itself, so if you do not want to call on a Saturday, put it in the agent’s hours.

The opt-out list. If someone has asked not to be called, no call goes out to that number.

The destination. For now it only calls numbers in Spain, mobiles, landlines and freephone numbers, and never premium-rate numbers like 806 or 902.

And repeats. If your software sends the same request twice by mistake, the person is not called twice.

If something does not add up, Lera does not dial and tells your software why, for example that it is outside calling hours. Trying again is up to your software, because Lera does not retry on its own.

If the call goes out on your Lera line, they see that line’s number, and if they call back your agent answers. If you connect your own number over SIP, they see yours and your carrier bills the call. If the same agent can call from both, Lera uses yours first.

A call that never connects, because the line is busy, nobody answers or the number does not exist, shows in the call history as failed, with the reason, and is not charged.

Cold calling to sell is not allowed. Spanish law requires the prior consent of whoever receives a sales call, and when an agent makes the call, the prudent course is to always have it.

On top of that, companies covered by Spain’s Law 10/2025 on customer service must make their sales calls from a 400 number supplied by their carrier, connected to Lera as their own number. The Lera line cannot be used for that.

Confirming an appointment or giving notice of a service or an order are not sales calls, as long as there is no offer inside them. We explain it in detail in our guide to cold sales calls with a voice agent, at leracore.com/en/resources/cold-sales-calls-with-a-voice-agent.

During the free trial you can use everything. If you then choose a plan, outbound calls come with the Professional plan and above, and the API, which is what your software uses to request them, with the Advanced plan. On a plan, outbound calls use your included minutes, just like the calls you receive.

What if someone asks not to be called? You add them to the opt-out list, from your software with add_optout_number or by asking Maite, the panel’s copilot. From then on, no call goes out to that number.

What if my software sends the request twice? If you send your own reference, such as the job number, in idempotency_key, Lera will not call again with the same reference. Without it, it still stops a repeat to the same number with the same agent within the next two minutes.

Can I place an outbound call without writing any code? For a one-off call, Maite can place it if you ask and checks with you first. For visitors to your website, there is the “Call me back” button. To do it at scale from your software, you need the API.

How much does it cost to try? €20 free credit, no card needed. You can build your agent and hear it call you in an outbound test before you decide anything.