Introduction

Hobby-RPC is a request-response protocol over HTTP messages.

Clients send JSON in the POST request's body and receive JSON in the response. They can call nullary and unary functions.

Nullary functions

To call a nullary function, a client should pass a function name(as the fn property). For example, to call a function named SomeNullaryFunction with curl:

curl -H "Content-Type: application/json" -X POST -d '{"fn":"SomeNullaryFunction"}' https://some.domain

Unary functions

To call an unary function, a client should pass a function name(as the fn property) and its input(as the in property). For example, to call a function named SomeUnaryFunction with curl:

curl -H "Content-Type: application/json" -X POST -d '{"fn":"SomeUnaryFunction","in":42}' https://some.domain

Responses

Servers can respond with:

• 200 OK:

  Happy path. JSON output in the body.

• 400 Bad Request:

  Something is wrong with the request. It could be a malformed JSON, or the Content-Type which doesn't start with 'application/json', or something else.

• 403 Forbidden:

  The Authorization header doesn't contain a valid token.

Authorization

Servers may choose to require clients to be authorized. In such cases, they will forbid any requests except those with valid tokens.

Clients may pass tokens as follows:

curl -H "Content-Type: application/json" -H "Authorization: SomeToken" -X POST -d '{"fn":"SomeNullaryFunction"}' https://some.domain

Implementations

Servers

• Node.js
• Ruby

Clients

• A client for web browsers