Add Swagger/OpenAPI Documentation for Public External API

[virgile-dev]

Feature Request

Is your feature request related to a problem or unsupported use case? Please describe.
Currently, the external API lacks public documentation, which creates challenges for third-party developers and integrators who need to interact with it. Without clear and structured documentation, users may struggle to understand endpoints, request/response formats, authentication methods, and error handling. This increases the risk of improper usage, support overhead, and slower adoption.

Describe the solution you'd like
How about implementing Swagger/OpenAPI documentation for the external API?
This would:

1. Provide an interactive, machine-readable documentation interface.
2. Clearly define all available endpoints, parameters, request/response schemas, and authentication requirements.
3. Allow users to test API calls directly from the documentation.
4. Improve developer experience and reduce onboarding time.

Considered drawbacks:

• Initial effort required to set up and maintain the Swagger/OpenAPI specification.
• Need to ensure the documentation stays synchronized with API updates.