then_that

The core design of chainhooks revolves around the concept of predicates. Each individual chainhook has a customizable predicate that specifies what information you are scanning for.

Predicates are defined in the If-this, then-that format. You'll write your condition in the if-this condition template and use then-that to output the result.

if-this Predicate Design

The if-this predicate design can use the following attributes to define the predicates. The 'scope' parameter is mandatory to use with any other parameters.

• scope (mandatory)
• equals
• op_return
  • ends_with
• p2pkh
• p2sh
• p2wpkh
• operation

Example:

{
  "if_this": {
    "scope": "txid",
    "equals": "0xfaaac1833dc4883e7ec28f61e35b41f896c395f8d288b1a177155de2abd6052f"
  }
}

then-that Predicate Design

The then-that predicate design can use the following attributes to output the result based on the if-this condition defined.

• http_post
  • url
  • authorization_header
• file_append
  • path

Example:

{
  "then_that": {
    "file_append": {
      "path": "/tmp/events.json",
    },
  },
}