Approval voting API

Tallies approval ballots (each voter approves any subset of candidates), returning per-candidate approvals, ranking, winner and approval rate. Answers 'Who wins under approval voting?', 'What fraction of voters approved the winner?'.

Price$0.04per request

MethodPOST

Route/v1/gametheory/approval-voting

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

social-choicevotingapprovalballotselectiontallywinnerdecision

API URLhttps://x402.hexl.dev/v1/gametheory/approval-voting

Integration docs

Example request

{
  "candidates": [
    "A",
    "B",
    "C"
  ],
  "ballots": [
    {
      "approved": [
        "A",
        "B"
      ],
      "count": 3
    },
    {
      "approved": [
        "B",
        "C"
      ],
      "count": 2
    },
    {
      "approved": [
        "A"
      ],
      "count": 1
    }
  ]
}

Example response

{
  "totalBallots": 6,
  "approvals": {
    "A": 4,
    "B": 5,
    "C": 2
  },
  "winner": "B",
  "ranking": [
    "B",
    "A",
    "C"
  ],
  "winnerApprovalRate": 0.833333,
  "interpretation": "Approval winner is B with 5 approvals (83.3% of ballots)."
}

Input schema

{
  "type": "object",
  "required": [
    "candidates",
    "ballots"
  ],
  "properties": {
    "candidates": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "examples": [
        [
          "A",
          "B",
          "C"
        ]
      ]
    },
    "ballots": {
      "type": "array",
      "items": {
        "type": "object"
      },
      "examples": [
        [
          {
            "approved": [
              "A",
              "B"
            ],
            "count": 3
          },
          {
            "approved": [
              "B",
              "C"
            ],
            "count": 2
          },
          {
            "approved": [
              "A"
            ],
            "count": 1
          }
        ]
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}