API authentication from a facebook messenger bot conversation

Question

What is the best way to authenticate with an external API from a conversation with a bot on the facebook messenger platform?

For a broad example, I would like a user of

Answer 1

It depends how they come in.

1. If they come from your website, you can use the Send to Messengee button from within their account. Use the pass through param to link your account to the user thread. Here's an excerpt from the documentation:

The plugin takes in a pass-through parameter defined by you. This parameter is sent back to you via a callback. You can use this to link the authentication event to a person and/or transaction. For example, a person may enter an online flow for a specific transaction and click the Send-to-Messenger button. You can pass in data to know which user and transaction was tied to the authentication event. You should encode and encrypt this parameter.

2. If they come directly to your bot, you would have to present them with a login of some sort (your login) from within the conversation. This would happen in a link to an mobile web URLs.