Correlation ID #

The Correlation ID is typically used to track the flow of messages and to ensure that messages are processed in the correct order. For more information, see the AsyncAPI specification.

go-asyncapi supports the Correlation ID and generates the corresponding Go code for setting and getting its value in the generated message structs.

Overview #

The Correlation ID contains the path where this id is stored in the message. For example:

correlationId:
  location: $message.payload#/field1/10/field2

It can point either to payload or header. After the # symbol, it contains a path to the field.

Special symbols encoding #

AsyncAPI specification states that Correlation id location contains the JSON Pointer after the # symbol. According to the specification, the JSON Pointer is a string that contains a sequence of encoded symbols separated by /.

Special symbols are all symbols except the alphanumeric characters, -, . and _. So, they must be encoded according to the rules described below.

• Tilda symbol ~ must be written as ~0
• Forward slash / must be written as ~1
• Other symbols must be percent-encoded as described in RFC 3986 using the % character followed by two hexadecimal digits (encoding table)
• Path items wrapped in quotes (single or double) are always treated as strings. Quotes are stripped before path evaluation.

For example, the path with three parts ~field _1, 10 (must be a string json key, not an integer array index) and "field2"/foo must be written as $message.payload#/~0field%20_1/'10'/%22field2%22~1foo.