Elvis is a tool that enables investigative journalists to analyze and visualize public procurements data and look for patterns that suggest corrupt behavior in public spending.

This is a Rails API, using MongoDB for storing and ElasticSearch for indexing/querying the data. It also has the purpose of filtering, analyzing and converting the results into a JSON the Vis.js frontend can draw.

Usage

NOTE: The use of Endpoint in the following examples assumes the path is applied on the domain oz.tenders.exposed.

Authentication is still bound to frontend. Please use the interface to create an account and confirm it.

Authorization:

Endpoint: POST api/v1/users/sign_in

Payload:

{
  "user": {
      "email": "[email protected]",
      "password": "123123123"
  }
}

Get your authentication_token from the response. You will need it to create networks.

Search contracts

NOTE: Any request related to contracts is an extension of the route /api/v1/contracts/.

Contracts can be sorted by years, countries, cpvs, suppliers or procuring_entities.

Common use cases:

####1. Get raw contracts:

Endpoint: POST api/v1/contracts

Payload:

{
    "query": {
        "countries": ["NL", "UK"],
        "years": [2013, 2014],
        "cpvs": ["79000000"],
        "suppliers": ["476105"],
        "procuring_entities": ["901"]
    }
}

All the parameters are optional. They act as filters. If you don't provide any, you will get all the contracts in the database (though I don't recommend trying that). Ex:

{
    "query": {
    }
}

You can provide as many of them as you like. For suppliers and procuring_entities, you have to use their slug_id attribute. You can get it from the response by using other filters.

NOTE: You can use the above Payload format for all POST requests under api/v1/contracts.

####2. Count contracts:

Endpoint: POST api/v1/contracts/count Payload: Same as above.

####3. Get aggregations based on filters:

You can use the following endpoints to get aggregations on certain filters (optionally based on other filters). For example:

Endpoint: POST api/v1/contracts/cpvs

Payload:

{
    "query": {
        "year": ["2013"]
    }
}

will give you a response like this:

{
  "search": {
    "count": 2409,
    "results": [
      {
        "key": "45000000",
        "doc_count": 3566,
        "name": "Construction work"
      },
      {
        "key": "60120000",
        "doc_count": 2028,
        "name": "Taxi services"
      },
      {
        "key": "66510000",
        "doc_count": 1613,
        "name": "Insurance services"
      }
    ]
  }
}

Let's break it down. It tells us that in all the contracts from 2013 we have 2409 unique CPVs. Then it gives us a list of them ordered descending. For each CPV, we have its key, which is the actual CPV code, a doc_count i.e. how many contracts with that CPV there were in 2013, and name which is the name of the industry field corresponding to that CPV code.

Again, you can play around with parameters to find facts about industries or just leave it empty to get a list with all the CPVs of all the contracts in the database.

The exact same rules apply for years and countries, with their corresponding endpoints: POST api/v1/contracts/years, POST api/v1/contracts/countries.

####4. Get details on certain suppliers / procuring entities:

Endpoint: POST api/v1/contracts/suppliers_details

Payload:

The usual, except for procuring_entities because in this case they are mutually exclusive. You can get details for certain suppliers by their x_slug_id. The following payload:

{
    "query": {
        "suppliers": ["441869"]
    }
}

will return a response like this:

{
  "search": {
    "count": 1,
    "results": [
      {
        "x_slug_id": "441869",
        "name": "Agilent Technologies Ltd",
        "total_earnings": 875536.18,
        "missing_values": 6,
        "median": {
          "50.0": 3
        },
        "contracts": []
      }
    ]
  }
}

Let's break it down. name is the name of the company; total_earnings is the total amount of money in EUR this company made in all the contracts from the database; missing_values represents its number of contracts where the value is missing. median is the median of the number of tenderers in all the contracts this supplier was involved. If you want to restrict the extent of these aggregations to contracts from a certain year etc., you can use their corresponding filters.

The same rules apply for procuring entities details, using the endpoint POST api/v1/contracts/procuring_entities_details.

Autocomplete for suppliers or procuring entities names

To retrieve autocomplete suggestions for a given string you have to:

GET api/v1/actor_autocomplete

Parameters:

• text - the string to autocomplete. The string to be longer than 1 character (>=2)
• max_suggestions - optional integer maximum number of suggestions - default 10

Example:

localhost:3000/api/v1/actor_autocomplete?text=hav&max_suggestions=100

Returns:

{
  "search": {
    "count": 2,
    "results": [
      {
        "name": "HAVANA BLUE B.V.",
        "x_slug_id": "441869"
      },
      {
        "name": "HAVERKAMP&BERGERS PROJECT COMMUNICATIE, KANDIDAAT A. BERGERS",
        "x_slug_id": "441870"
      }
    ]
  }
}