README.md

@@ -1,5 +1,33 @@
 # bot-api
 
+## Introduction
+The function of the API is basically to access the images' metadata stored in the database.
+
+## Usage
+The API exposes some endpoints to interact with the database.
+
+### GET `/images`
+Allows to get a list of image documents.
+
+#### Query params
+- `limit`: an optional parameter, which accepts a non-negative integer that dictates the number of documents that the list will have. If its value is equal to `0`, or if this parameter is missing, the endpoint will return all the image documents in the database.
+-  `status`: an optional parameter, which accepts the values `consumed`, `available` and `unavailable`. It filters the documents that have only the `status` attribute equal to that indicated in the parameter's value. If the parameter is missing, no filter will be applied to the document.
+
+#### Example
+- `GET /images?limit=5&status=available`: will return 5 documents that have the `available` value in their `status` attribute.
+
+### PUT `/images/<id>`
+Modifies an existing image document. The request must provide a JSON-formatted body, with one or more valid document attributes. The existing document attributes will be replaced with the provided new ones.
+
+#### Params
+- `id`: the id of the document to be modified.
+
+#### Example
+- `PUT /images/61f7e48f0c651345677b7775` with body `{ "status": "consumed" }`: will modify the document referenced by the `id` param, changing their `status` value to `consumed`.
+
+### POST `/images`
+### POST `/login`
+## Installation
 To install dependencies:
 
 ```bash