Belief Volatility
List volatility series
The Belief Volatility catalog: every published series with its tenors, headline tenor, units, and the publication gates in force.
An unlaunched surface returns an empty catalog rather than an error.
GET
/
v1
/
volatility
curl
curl -s "https://api.beliefsystems.xyz/v1/volatility" \
-H "Authorization: Bearer $BELIEF_API_KEY"import os
import requests
resp = requests.get(
"https://api.beliefsystems.xyz/v1/volatility",
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/volatility", {
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/volatility",
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/volatility"
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/volatility")
.header("Authorization", "Bearer <token>")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.beliefsystems.xyz/v1/volatility")
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": {
"count": 1,
"productFamily": "belief_volatility",
"series": [
{
"category": "elections",
"definitionLine": "Belief Volatility is a standardized estimate of how much prediction-market probabilities are expected to move over a stated horizon.",
"description": "How much the 2026 U.S. midterms balance-of-power distribution is expected to move.",
"gates": {
"arbMinDepthUsd": 500,
"arbToleranceMin": 0.01,
"arbToleranceTicks": 1,
"depthFloorUsd": 500,
"devigTolerance": 0.000001,
"identityTolerance": 0.000001,
"impactBudgetPts": 1,
"overroundFlagHi": 1.04,
"overroundFlagLo": 0.995,
"pythagoreanTolerancePts2": 0.01,
"retireAfterDegradedTicks": 12,
"snapshotMaxAgeSeconds": 900,
"snapshotMaxSkewSeconds": 300,
"spreadToMidMax": 0.5,
"suspendFailingBudgetShare": 0.1
},
"headlineTenorDays": 30,
"inceptionAt": "2026-08-06T00:01:51.828235Z",
"listed": true,
"methodologyUrl": "https://docs.beliefsystems.xyz/volatility/methodology",
"name": "Midterms Uncertainty Index",
"productFamily": "belief_volatility",
"relatedIndexTickers": [
"MIDR26",
"MIDD26"
],
"settlementDate": "2027-01-05",
"slug": "midvol",
"targetType": "partition_composite",
"tenorsDays": [
1,
7,
30
],
"ticker": "MIDVOL",
"units": "probability points"
}
]
},
"meta": {
"attribution": "Source: Belief Systems (beliefsystems.xyz)",
"generatedAt": "2026-08-31T14:01:22.277647Z",
"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": "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>"
}
}Authorizations
bearerAuthapiKeyAuth
Your Data API key as a Bearer token: Authorization: Bearer belief_live_.... This is the canonical form. Keys belong on a server, never in a browser.
⌘I
curl
curl -s "https://api.beliefsystems.xyz/v1/volatility" \
-H "Authorization: Bearer $BELIEF_API_KEY"import os
import requests
resp = requests.get(
"https://api.beliefsystems.xyz/v1/volatility",
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/volatility", {
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/volatility",
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/volatility"
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/volatility")
.header("Authorization", "Bearer <token>")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.beliefsystems.xyz/v1/volatility")
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": {
"count": 1,
"productFamily": "belief_volatility",
"series": [
{
"category": "elections",
"definitionLine": "Belief Volatility is a standardized estimate of how much prediction-market probabilities are expected to move over a stated horizon.",
"description": "How much the 2026 U.S. midterms balance-of-power distribution is expected to move.",
"gates": {
"arbMinDepthUsd": 500,
"arbToleranceMin": 0.01,
"arbToleranceTicks": 1,
"depthFloorUsd": 500,
"devigTolerance": 0.000001,
"identityTolerance": 0.000001,
"impactBudgetPts": 1,
"overroundFlagHi": 1.04,
"overroundFlagLo": 0.995,
"pythagoreanTolerancePts2": 0.01,
"retireAfterDegradedTicks": 12,
"snapshotMaxAgeSeconds": 900,
"snapshotMaxSkewSeconds": 300,
"spreadToMidMax": 0.5,
"suspendFailingBudgetShare": 0.1
},
"headlineTenorDays": 30,
"inceptionAt": "2026-08-06T00:01:51.828235Z",
"listed": true,
"methodologyUrl": "https://docs.beliefsystems.xyz/volatility/methodology",
"name": "Midterms Uncertainty Index",
"productFamily": "belief_volatility",
"relatedIndexTickers": [
"MIDR26",
"MIDD26"
],
"settlementDate": "2027-01-05",
"slug": "midvol",
"targetType": "partition_composite",
"tenorsDays": [
1,
7,
30
],
"ticker": "MIDVOL",
"units": "probability points"
}
]
},
"meta": {
"attribution": "Source: Belief Systems (beliefsystems.xyz)",
"generatedAt": "2026-08-31T14:01:22.277647Z",
"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": "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>"
}
}