### Answer
I don't have information about a downloadable OpenAPI/Swagger spec file (YAML or JSON) in the available sources.
Check out these potentially useful sources:
- [Platform Changelogs | Retell AI](
)
- [API References](
)
You may also want to reach out directly:
- [Contact Sales](
)
- [GitHub](
)
Would you like me to try to provide a general answer based on my knowledge instead?