Fisher's exact test (2x2) API

Performs Fisher's exact test on a 2x2 contingency table (left/right/two-tailed) with exact hypergeometric tail probabilities and the odds ratio — correct for small counts where chi-square fails. Answers 'Is there an exact association in this 2x2 table?', 'What is Fisher's exact p-value?'.

Price$0.08per request

MethodPOST

Route/v1/stats/fisher-exact-test

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

statisticsfisher-exactcontingency2x2categoricalp-valuesmall-sampleodds-ratio

API URLhttps://x402.hexl.dev/v1/stats/fisher-exact-test

Integration docs

Example request

{
  "a": 8,
  "b": 2,
  "c": 1,
  "d": 5
}

Example response

{
  "table": {
    "a": 8,
    "b": 2,
    "c": 1,
    "d": 5
  },
  "tail": "two",
  "pValue": 0.03496503,
  "pLeft": 0.99912587,
  "pRight": 0.02447552,
  "pTwoTailed": 0.03496503,
  "oddsRatio": 20,
  "rating": "significant",
  "interpretation": "Fisher's exact (two-tailed) p=0.03497 for 2x2 [[8,2],[1,5]]; association."
}

Input schema

{
  "type": "object",
  "required": [
    "a",
    "b",
    "c",
    "d"
  ],
  "properties": {
    "a": {
      "type": "integer",
      "examples": [
        8
      ]
    },
    "b": {
      "type": "integer",
      "examples": [
        2
      ]
    },
    "c": {
      "type": "integer",
      "examples": [
        1
      ]
    },
    "d": {
      "type": "integer",
      "examples": [
        5
      ]
    },
    "tail": {
      "type": "string",
      "enum": [
        "two",
        "left",
        "right"
      ]
    }
  }
}

Output schema

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