diff --git a/spec/asyncapi.md b/spec/asyncapi.md
index 9ecc1008b..f88ffc469 100644
--- a/spec/asyncapi.md
+++ b/spec/asyncapi.md
@@ -1064,6 +1064,7 @@ Describes a message received on a given channel and operation.
Field Name | Type | Description
---|:---:|---
+messageId | `string` | Unique string used to identify the message. The id MUST be unique among all messages described in the API. The messageId value is **case-sensitive**. Tools and libraries MAY use the messageId to uniquely identify a message, therefore, it is RECOMMENDED to follow common programming naming conventions.
headers | [Schema Object](#schemaObject) | [Reference Object](#referenceObject) | Schema definition of the application headers. Schema MUST be of type "object". It **MUST NOT** define the protocol headers.
payload | `any` | Definition of the message payload. It can be of any type but defaults to [Schema object](#schemaObject). It must match the schema format, including encoding type - e.g Avro should be inlined as either a YAML or JSON object NOT a string to be parsed as YAML or JSON.
correlationId | [Correlation ID Object](#correlationIdObject) | [Reference Object](#referenceObject) | Definition of the correlation ID used for message tracing or matching.
@@ -1103,6 +1104,7 @@ Name | Allowed values | Notes
```json
{
+ "messageId": "userSignup",
"name": "UserSignup",
"title": "User signup",
"summary": "Action to sign a user up.",
@@ -1166,6 +1168,7 @@ Name | Allowed values | Notes
```
```yaml
+messageId: userSignup
name: UserSignup
title: User signup
summary: Action to sign a user up.
@@ -1213,6 +1216,7 @@ Example using Avro to define the payload:
```json
{
+ "messageId": "messageId",
"name": "UserSignup",
"title": "User signup",
"summary": "Action to sign a user up.",
@@ -1230,6 +1234,7 @@ Example using Avro to define the payload:
```
```yaml
+messageId: userSignup
name: UserSignup
title: User signup
summary: Action to sign a user up.
@@ -1259,6 +1264,7 @@ If you're looking to apply traits to an operation, see the [Operation Trait Obje
Field Name | Type | Description
---|:---:|---
+messageId | `string` | Unique string used to identify the message. The id MUST be unique among all messages described in the API. The messageId value is **case-sensitive**. Tools and libraries MAY use the messageId to uniquely identify a message, therefore, it is RECOMMENDED to follow common programming naming conventions.
headers | [Schema Object](#schemaObject) | [Reference Object](#referenceObject) | Schema definition of the application headers. Schema MUST be of type "object". It **MUST NOT** define the protocol headers.
correlationId | [Correlation ID Object](#correlationIdObject) | [Reference Object](#referenceObject) | Definition of the correlation ID used for message tracing or matching.
schemaFormat | `string` | A string containing the name of the schema format/language used to define the message payload. If omitted, implementations should parse the payload as a [Schema object](#schemaObject).