> ## Documentation Index > Fetch the complete documentation index at: https://docs.beliefsystems.xyz/llms.txt > Use this file to discover all available pages before exploring further. # Get latest level > The current level for an index, undelayed, with the aggregate quality of the inputs behind it. `indexLevel` is an exact decimal string against a `baseIndexLevel` of 100 at inception, so a level reads on its own without a reference point. Parse it with a decimal type. Constituent compositions and the per-market panel are not on this surface. Composition membership and target weights are published in the free snapshot bundles. ## OpenAPI ````yaml /api-reference/openapi.json get /v1/indices/{ticker}/latest openapi: 3.1.0 info: contact: name: Belief Systems url: https://beliefsystems.xyz/data description: >- Rules-based benchmark data for prediction markets: Belief index levels and Belief Volatility series, read over HTTPS with an API key. The API is read-only. Every endpoint is a `GET`, every successful response is `{ data, meta }`, and every failure is a single `error` object with a stable `code`. Keys are free and take about a minute to mint at https://beliefsystems.xyz/data. Attribution is required on anything you publish from this data: "Source: Belief Systems (beliefsystems.xyz)". Production, redistribution, and commercial use require a license (https://beliefsystems.xyz/license). license: name: Belief Systems Data License url: https://beliefsystems.xyz/license termsOfService: https://beliefsystems.xyz/terms title: Belief Systems Data API version: '1.0' servers: - description: Production. There is no separate test host; the API is read-only. url: https://api.beliefsystems.xyz security: - bearerAuth: [] - apiKeyAuth: [] tags: - description: >- Belief indices are rules-based benchmarks of how prediction markets price a defined set of events. Levels are exact decimal strings based at 100 on the index's inception date. name: Indices - description: >- Belief Volatility measures how much prediction-market probabilities are expected to move over a stated horizon, in probability points. Always name the tenor when quoting a value. name: Belief Volatility - description: >- The service index, which reports your key's live quota, and pointers to the free point-in-time snapshot bundles. name: Service paths: /v1/indices/{ticker}/latest: get: tags: - Indices summary: Get latest level description: >- The current level for an index, undelayed, with the aggregate quality of the inputs behind it. `indexLevel` is an exact decimal string against a `baseIndexLevel` of 100 at inception, so a level reads on its own without a reference point. Parse it with a decimal type. Constituent compositions and the per-market panel are not on this surface. Composition membership and target weights are published in the free snapshot bundles. operationId: getIndexLatest parameters: - description: >- Ticker, case-insensitive. `GET /v1/indices` and `GET /v1/volatility` are the catalogs. example: CONFLICT in: path name: ticker required: true schema: type: string responses: '200': content: application/json: example: data: baseIndexLevel: '100.00000000' ceasedAt: null compositionVersion: 24ecfc71d2ddb86c computedAt: '2026-08-31T13:44:44.963697Z' dataQuality: freshDataPct: 100 freshMarketsCount: 24 staleMarketsCount: 0 totalMarketsCount: 24 inceptionAt: '2026-04-24T13:38:30.565565Z' indexLevel: '36.11697608' maturityType: PERPETUAL methodologyVersion: midprice-v1 name: Belief Global Conflict Risk Escalation Expectations Index publicStatus: active resolvedAt: null seriesFullyResolved: false seriesPartiallyResolved: true stale: false ticker: CONFLICT meta: attribution: 'Source: Belief Systems (beliefsystems.xyz)' generatedAt: '2026-08-31T14:01:22.277647Z' license: https://beliefsystems.xyz/license termsUrl: https://beliefsystems.xyz/terms schema: $ref: '#/components/schemas/IndexLatestResponse' description: Success. '401': content: application/json: example: 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 schema: $ref: '#/components/schemas/Error' description: Missing or unresolvable API key. '404': content: application/json: example: 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 schema: $ref: '#/components/schemas/Error' description: No index or volatility series matches that ticker on this surface. '429': content: application/json: example: 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 schema: $ref: '#/components/schemas/Error' description: >- Rate limited. Sleep for `Retry-After` seconds, which is exact on both windows. default: content: application/json: schema: $ref: '#/components/schemas/Error' description: Error. Every /v1 failure uses this shape. x-codeSamples: - label: curl lang: curl source: |- curl -s "https://api.beliefsystems.xyz/v1/indices/CONFLICT/latest" \ -H "Authorization: Bearer $BELIEF_API_KEY" - label: Python lang: python source: |- import os import requests resp = requests.get( "https://api.beliefsystems.xyz/v1/indices/CONFLICT/latest", headers={"Authorization": f"Bearer {os.environ['BELIEF_API_KEY']}"}, timeout=10, ) resp.raise_for_status() payload = resp.json() print(payload["data"]) - label: JavaScript lang: javascript source: >- const res = await fetch("https://api.beliefsystems.xyz/v1/indices/CONFLICT/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); components: schemas: IndexLatestResponse: properties: data: properties: baseIndexLevel: description: >- The level at inception, always 100. It is what makes a level readable on its own: 36.12 against a base of 100 is a 63.9% decline since inception. example: '100.00000000' type: string ceasedAt: format: date-time type: - string - 'null' compositionVersion: description: >- Fingerprint of the composition behind this level. Changes at each reconstitution. type: string computedAt: description: >- When this level was computed. UTC timestamp with microsecond precision, `Z`-suffixed. format: date-time type: string dataQuality: description: >- Aggregate input health behind this level. Counts only; the per-market panel is part of the licensed feed. properties: freshDataPct: description: Fresh constituents as a percentage of the total. type: number freshMarketsCount: description: Constituents priced within the freshness threshold. type: integer staleMarketsCount: description: Constituents whose last quote is older than the threshold. type: integer totalMarketsCount: description: Constituents in the current composition. type: integer type: object inceptionAt: description: First published level. format: date-time type: string indexLevel: description: >- Index level as an exact decimal STRING, not a JSON number. Parse it with a decimal type: floats lose the published precision on round-trip. example: '36.11697608' type: string maturityType: description: >- `PERPETUAL` for a series that reconstitutes, `FIXED` for one that runs to a settlement date. example: PERPETUAL type: string methodologyVersion: description: The calculation methodology in force. example: midprice-v1 type: string name: type: string publicStatus: example: active type: string resolvedAt: format: date-time type: - string - 'null' seriesFullyResolved: description: True once every constituent has resolved. type: boolean seriesPartiallyResolved: description: True once at least one constituent has resolved. type: boolean stale: description: True when the level rests on stale inputs. type: boolean ticker: example: CONFLICT type: string type: object meta: properties: attribution: description: >- The attribution line required on anything you publish from this data. Reproduce it verbatim. example: 'Source: Belief Systems (beliefsystems.xyz)' type: string generatedAt: description: >- When this response was generated. UTC timestamp with microsecond precision, `Z`-suffixed. format: date-time type: string license: description: Terms covering production, redistribution, and commercial use. format: uri type: string termsUrl: description: Terms of Service. format: uri type: string required: - attribution - license - termsUrl - generatedAt type: object required: - data - meta type: object Error: description: >- Every failure replaces `data` and `meta` with a single `error` object. Match on `code`, which is a stable contract. `message` is written for a person and may be reworded. properties: error: properties: code: description: Stable machine-readable error code. enum: - invalid_api_key - ip_rate_limited - rate_limited - daily_limit_reached - not_found - invalid_parameter - invalid_interval - invalid_window - method_not_allowed - internal_error - unavailable - error type: string docsUrl: description: Deep link to this code on the limits and errors page. format: uri type: string message: description: Human-readable explanation. Not a stable contract. type: string requestId: description: >- Correlation id, also returned as the X-Request-Id header. Quote it in support requests. type: string required: - code - message - docsUrl - requestId type: object required: - error title: Error type: object securitySchemes: bearerAuth: description: >- 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. scheme: bearer type: http apiKeyAuth: description: >- The same key sent as `X-API-Key` instead. Accepted everywhere the Bearer header is. Send one or the other, not both. in: header name: X-API-Key type: apiKey ````