Get current grade

curl -s "https://api.beliefsystems.xyz/v1/grades/polymarket/0x42945ea5657d6f6e77969a06661b29d6f6295083d1ef3479b42efd90647c9dfc/latest" \
  -H "Authorization: Bearer $BELIEF_API_KEY"

import os
import requests

resp = requests.get(
    "https://api.beliefsystems.xyz/v1/grades/polymarket/0x42945ea5657d6f6e77969a06661b29d6f6295083d1ef3479b42efd90647c9dfc/latest",
    headers={"Authorization": f"Bearer {os.environ['BELIEF_API_KEY']}"},
    timeout=10,
)
resp.raise_for_status()

payload = resp.json()
print(payload["data"])

const res = await fetch("https://api.beliefsystems.xyz/v1/grades/polymarket/0x42945ea5657d6f6e77969a06661b29d6f6295083d1ef3479b42efd90647c9dfc/latest", {
  headers: { Authorization: `Bearer ${process.env.BELIEF_API_KEY}` },
});
if (!res.ok) throw new Error(`Belief Systems API ${res.status}`);

const { data, meta } = await res.json();
console.log(data);

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.beliefsystems.xyz/v1/grades/{venue}/{market_id}/latest",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.beliefsystems.xyz/v1/grades/{venue}/{market_id}/latest"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.get("https://api.beliefsystems.xyz/v1/grades/{venue}/{market_id}/latest")
  .header("Authorization", "Bearer <token>")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.beliefsystems.xyz/v1/grades/{venue}/{market_id}/latest")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Get.new(url)
request["Authorization"] = 'Bearer <token>'

response = http.request(request)
puts response.read_body

{
  "data": {
    "asOf": "2026-10-23T00:00:00.000000Z",
    "calibrationVersion": "mg-cal-1.0",
    "caps": [
      {
        "binding": true,
        "cap_letter": "D",
        "lowered_letter": false,
        "source": "weakest_link"
      },
      {
        "binding": false,
        "cap_letter": "B+",
        "lowered_letter": false,
        "source": "evidence_tier"
      }
    ],
    "computationStatus": "candidate",
    "correction": null,
    "coverageClass": "full",
    "coverageShare": 0.999885,
    "dataStatus": "ok",
    "disclosureLines": [
      "Market Grades measure market quality, not the likelihood of any outcome.",
      "Market Grades are unsolicited: no graded party requests, pays for, or previews a grade. Belief Systems holds no positions in graded markets.",
      "A grade is not a recommendation to buy, sell, or hold any position, and is not a substitute for a user's own assessment."
    ],
    "evidenceTier": "T1",
    "firstObserved": "2026-09-23T10:25:05.936852Z",
    "gateFlags": [],
    "grade": "D",
    "gradeEpisodeId": "polymarket:0x42945ea5657d6f6e77969a06661b29d6f6295083d1ef3479b42efd90647c9dfc:1",
    "gradeSince": "2026-10-23T00:00:00.000000Z",
    "lastConfirmedAction": null,
    "lastFullData": "2026-10-23T00:00:00.000000Z",
    "lifecycleState": "active",
    "marketId": "0x42945ea5657d6f6e77969a06661b29d6f6295083d1ef3479b42efd90647c9dfc",
    "methodologyVersion": "mg-1.2",
    "observedDaysWindow": 30,
    "pillarGrades": {
      "integrity": {
        "letter": "B+",
        "since": "2026-10-23T00:00:00.000000Z",
        "trend": "stable"
      },
      "liquidity": {
        "letter": "F",
        "since": "2026-10-23T00:00:00.000000Z",
        "trend": "stable"
      }
    },
    "preLaunch": false,
    "question": "Will Ethereum reach $3,500 by December 31, 2026?",
    "revision": 0,
    "stateRevision": 0,
    "venue": "polymarket",
    "watch": null,
    "window": [
      "2026-09-23T00:00:00.000000Z",
      "2026-10-23T00:00:00.000000Z"
    ]
  },
  "meta": {
    "attribution": "Source: Belief Systems (beliefsystems.xyz)",
    "generatedAt": "2026-10-23T15:49:14.582224Z",
    "license": "https://beliefsystems.xyz/license",
    "termsUrl": "https://beliefsystems.xyz/terms"
  }
}

{
  "error": {
    "code": "invalid_api_key",
    "docsUrl": "https://docs.beliefsystems.xyz/api-reference/limits#invalid-api-key",
    "message": "This endpoint requires a Data API key. Create one free at https://beliefsystems.xyz/data ; programmatic or commercial licensing is at https://beliefsystems.xyz/license.",
    "requestId": "9f2c1ad4e6b74c0f8a3d5e1b7c904a26"
  }
}

{
  "error": {
    "code": "not_found",
    "docsUrl": "https://docs.beliefsystems.xyz/api-reference/limits#not-found",
    "message": "No Belief index 'NOPE'. GET /v1/indices lists the published catalog.",
    "requestId": "9f2c1ad4e6b74c0f8a3d5e1b7c904a26"
  }
}

{
  "error": {
    "code": "rate_limited",
    "docsUrl": "https://docs.beliefsystems.xyz/api-reference/limits#rate-limited",
    "message": "Rate limit exceeded: 60 requests per minute per key.",
    "requestId": "9f2c1ad4e6b74c0f8a3d5e1b7c904a26"
  }
}

{
  "error": {
    "code": "invalid_api_key",
    "docsUrl": "<string>",
    "message": "<string>",
    "requestId": "<string>"
  }
}