This guide provides an overview of using the Dialogflow API and its reference documentation.
REST, gRPC, and client libraries
You can access the API via REST, gRPC, or one of the provided client libraries (built on gRPC).
Client libraries
Google provides client libraries for many popular languages to access this API. If your desired programming language is supported by the client libraries, you should use this option.
| Pros | Cons |
|---|---|
|
Maintained by Google.
Built-in authentication. Built-in retries. Idiomatic for each language. Efficient protocol buffer HTTP request body. |
Not available for all programming languages. |
REST
This API supports REST. See the REST reference for this API. Also see How to call Google APIs: REST edition.
| Pros | Cons |
|---|---|
|
Simple JSON interface.
Well supported by many Google and third-party tools and libraries. |
You must build your own client.
You must implement authentication. You must implement retries. Less efficient JSON HTTP request body. REST streaming is not supported by this API. |
gRPC
This API supports gRPC. See the RPC reference for this API, which provides a generic description of the types, methods, and fields generated for a gRPC library. Also see How to call Google APIs: RPC edition.
| Pros | Cons |
|---|---|
|
Supports
many programming languages.
Efficient protocol buffer HTTP request body. |
You must generate your own client from Google-supplied protocol buffers.
You must implement authentication. You must implement retries. |
Type, method, and field names
Depending on whether you are using client libraries, REST, or gRPC, the type, method, and field names for the API vary somewhat:
- REST is arranged by resource hierarchies and their methods.
- Client libraries and gRPC are arranged by services and their methods.
- REST field names use camel case, though the API service will accept either camel case or snake case.
- gRPC field names use snake case.
- Client library field names use either title case, camel case or snake case, depending on which name is idiomatic for the language.
Protocol buffers
Whether you are using client libraries, REST, or gRPC, the underlying service is defined using protocol buffers. In particular, the service uses proto3.
When calling the API, some request or response fields can require a basic understanding of protocol buffer well-known types.
In addition, when calling the REST API, the default value behavior for protocol buffers may result in missing fields in a JSON response. These fields are simply set to the default value, so they are not included in the response.
API versions
The following API versions are available:
- V3: Stable, generally available.
- V3Beta1: Used to share the latest, upcoming beta features.