Lydia is hailing this as the first payment bot for the popular group messaging platform, though at first it will only be available in France, starting April 11.

The functionality is quite simple. Users invite the Lydia bot into their Slack channel. When they want to exchange money—perhaps one person is paying back someone who picked up the tab at lunch, or maybe the finance department wants to reimburse someone’s expenses—they just say so over Slack while mentioning “@lydiabot.”

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Those who already have the Lydia app will then get a notification asking them to validate the payment (the app and Slack should recognize they’re dealing with the same phone number and link up), and those who do not will be able to do the same over a special web page.

Lydia, which got $4 million in funding back in November 2014, already has over 300,000 users in France. According to spokesman Antoine Msika, it will start rolling out to other large European countries, such as Germany and the U.K., later this year.

Its functionality will also continue to spread across platforms. With a smartphone app, an Apple Watch app, and now a Slack bot under its belt, Msika said Lydia will next target integration with Facebook (FB) Messenger (which already has its own in-app payments platform).

The company also intends to see what’s possible using Microsoft’s (MSFT) big bots program—the software giant recently announced it is trying to stimulate a wave of automated “chat bots” that, it thinks, are the future of computer interaction.

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Slack already plays host to bots that let people do things like order an Uber ride through natural-language commands.

Ultimately, Lydia is hoping to somehow integrate its payment service with voice platforms.

“The idea is to show that we want to enable people to exchange money very easily and, if possible, without seeing any technology,” said Msika. “[Voice] would be the ultimate way to pay.”