HTTP methods and processors

Problem

API v1 is based on POST queries. However, according to many resources, using POST for queries in RESTful API is not a good practice:

• Swagger.io: best practices in API design
• MS Azure Architectural Center: Define API operations in terms of HTTP methods
• StackOverflow: REST API using POST instead of GET

Functional design

Using different HTTP methods GET and POST allows to distinguish between Query and Command processors clearly:

HTTP Method	Processor
GET	Query Processor
POST, PATCH, DELETE	Command Processor

Note: according to RESTful API design, queries should not change the state of the system. Current QueryFunction design allows it to execute commands through HTTP bus.