Champions Usage API

Endpoints

Five files. Every one repeats the fields of index.json, so a single request tells you both the data and how old it is. The last of them ranks players rather than Pokémon — see Trainer ladder.

Fetching

BASE=https://metaroll.app

curl -s $BASE/api/v1/index.json

curl -s $BASE/api/v1/ranking.json \
  | jq -r '.entries[:5][] | "\(.rank)  \(.name)"'

curl -s $BASE/api/v1/pokemon/kingambit.json | jq '.entry.moves[:3]'

// Works from a browser on any origin — Access-Control-Allow-Origin: *
const res = await fetch('https://metaroll.app/api/v1/pokemon/kingambit.json')
const { entry, capturedAt } = await res.json()

entry.rank          // 1
entry.previousRank  // 1
entry.moves[0]      // { name: "Sucker Punch", percent: 99.3 }

Naming a Pokémon

An id is the name lowercased, with every run of non-alphanumeric characters collapsed to a single hyphen. Build the path from a name you already have — there is no lookup step.

Kingambit            → kingambit
Tauros-Paldea-Aqua   → tauros-paldea-aqua
Mr. Rime             → mr-rime
Ninetales-Alola      → ninetales-alola

Alternate forms are separate entries with separate ids. The ranking really does list four Gourgeist sizes and six Rotom forms in different places.

A full response

GET /api/v1/pokemon/tauros-paldea-aqua.json — trimmed to the first item of each list.

{
  "version": 1,
  "game": "Pokémon Champions",
  "source": "in-game ranked ladder",
  "format": "doubles",
  "season": "M-5",
  "capturedAt": "2026-08-17T06:27:02.238Z",
  "comparedTo": "2026-08-16T14:01:20.495Z",
  "count": 235,
  "entry": {
    "id": "tauros-paldea-aqua",
    "name": "Tauros-Paldea-Aqua",
    "rank": 139,
    "previousRank": 137,
    "abilities": [{ "name": "Intimidate", "percent": 54.6 }],
    "items":     [{ "name": "Life Orb", "percent": 18.7 }],
    "moves":     [{ "name": "Protect", "percent": 77.2 }],
    "natures":   [{ "name": "Adamant", "percent": 60 }],
    "teammates": [{ "name": "Farigiraf", "percent": null }],
    "matchups": {
      "beats":     ["Sneasler", "Sylveon"],
      "beatsWith": [{ "name": "Earthquake", "percent": 48.2 }],
      "losesTo":   ["Basculegion", "Archaludon"],
      "beatenBy":  [{ "name": "Blizzard", "percent": 6.2 }]
    },
    "spreads": [{
      "statPoints": { "hp": 2, "atk": 32, "def": 0,
                       "spa": 0, "spd": 0, "spe": 32 },
      "percent": 29.1
    }],
    "confidence": {
      "formGuessed": false,
      "identifiedByElimination": false
    }
  }
}

Field reference

On every response

On an entry

Trainer ladder

/api/v1/ladder.json ranks players, not Pokémon. Same capture, same ranked doubles ladder, a different thing counted — so it carries its own capturedAt and its own comparedTo, and moves far more than the Pokémon ranking does: 789 of the thousand changed rank between two readings a day apart.

The game shows the top 300 in its own client. It downloads a thousand, and a thousand is what is published here.

{
  "version": 1,
  "source": "in-game ranked ladder",
  "format": "doubles",
  "ranks": "trainers",
  "capturedAt": "2026-08-19T08:16:09.000Z",
  "comparedTo": "2026-08-18T06:25:09.000Z",
  "count": 1000,
  "entries": [
    {
      "rank": 1,
      "previousRank": 4,
      "id": "biAcxGh7EW2hA1lfddc8abf5bd2cbbae",
      "name": "Nontaro",
      "rating": 2275.236,
      "wins": 262,
      "losses": 154,
      "draws": 0,
      "battles": 416,
      "winRate": 63.0,
      "country": { "code": 509, "name": "Thailand", "flag": "🇹🇭", "iso": "th" },
      "language": { "code": 20, "name": "English", "flag": "🇺🇸", "iso": "us" },
      "avatar": 22
    }
  ]
}

Three things that will catch you

Before you build on it

Four things that will cost you an afternoon if you meet them by surprise.

Where the data comes from

Pokémon Champions publishes no usage API. It does serve its own Battle Data to its own client, though, and that is what this is: a capture drives the game, records the ranking files it fetches, and decodes them. The numbers below are the ones the game published, not a reading of them — the ids it uses for moves, abilities and species turn out to be the canonical Pokémon indices, and the Stat Point spreads are hexadecimal.

Earlier readings were taken by photographing the Battle Data screens and running OCR over the frames, which is why confidence exists. It is kept, and reports false throughout, because a field that disappears breaks anyone reading it — but there is nothing left to be unsure about.

capturedAt is the moment the reading was taken. Captures run hourly and publish only when something has changed: the game rebuilds this data every fifteen minutes or so, but between two consecutive builds the rank order was identical and only decimals deep in the lists moved.

The ladder itself moves slowly. Over a full day, 98 Pokémon changed position and the largest move was five places.