The Battlesnake API
Battlesnake is played by responding to a simple Webhook API.
This means developers build a web server that receives and responds to HTTP requests from the game engine. How your server responds to these requests controls how your Battlesnake behaves.
There are four webhooks that every Battlesnake needs to respond to:
Requests
All requests to your server come from the Battlesnake game engine and have the following properties.
Content-Type
Requests sent to your Battlesnake will contain JSON-encoded request bodies. Your server is resonsible for receiving and parsing this data correctly (although most modern web frameworks come with easy ways to handle this type of request).
Responses
All Battlesnakes must abide by these rules when responding to game engine requests.
If the game engine receives an invalid response from your Battlesnake it will consider it an error and act accordingly.
Content-Type
Responses must be JSON-encoded strings with the Content-Type header set to `application/json`.
Status Codes
All Battlesnakes responses must return a valid HTTP `200 OK`. If any other status code is returned, the game engine will consider it an invalid response.
Timeouts & Latency
Your Battlesnake server must respond to requests made by the game engine within the given timeout value.
Most of the time this will be 500 ms, however, this value can technically vary from game to game. Use the game information provided in the request to determine how long your Battlesnake should spend computing its next move.
If your response does not reach the game engine within the specified timeout, the game engine will consider it an invalid response.
Note that these values include round-trip latency, so communication between the game engine and your Battlesnake server should be taken into consideration.
Error Handling
In all error cases, the game engine will determine your Battlesnake's next move for you - even if that means certain elimination.
On the first move of a game, response errors will cause the game engine to move your Battlesnake up by default. This value is hardcoded into the game engine with no particular meaning behind it.
On all other turns, response errors will be handled by the game engine repeating your previous move for you. For example, if your Battlesnake successfully moves right on turn N, a timeout on turn N+1 will result in your Battlesnake moving right again.