# Crypto ETF Sentinel — XBRL Historical Time Series by CIK

> Crypto ETF Sentinel — XBRL Historical Time Series by CIK is a paid API for AI agents from api.cryptoetfsentinel.com, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-14).

Returns a quarterly historical time series for a single XBRL financial concept (AUM, NAV, shares outstanding, expense ratio, etc.) for one US spot crypto ETF issuer identified by SEC CIK.

## Facts

- Endpoint: GET https://api.cryptoetfsentinel.com/v1/xbrl/series
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-cryptoetfsentinel-com-125fd54f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0sA4J7LjX_siTQUYeWEGj

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability api-cryptoetfsentinel-com-125fd54f
```

Example prompt: Pull the quarterly historical AUM time series from Crypto ETF Sentinel for the issuer with SEC CIK 0001980994 — I want to see how their assets under management have changed over time.

## When to prefer this

Use this endpoint when you need multi-quarter trend data for a specific XBRL financial concept (AUM, NAV, shares outstanding, expense ratio) for a single US spot crypto ETF issuer identified by their SEC CIK. Prefer this over the snapshot endpoint when you need historical context or want to chart trends over time, rather than just the latest values.

## Known failure modes

- Invalid or non-existent CIK returns an error or empty result
- CIK does not correspond to a US spot crypto ETF issuer — no data found
- XBRL concept not reported by the issuer — empty series returned
- CIK format mismatch (non-numeric or too long) — schema validation error
- Payment not completed (x402 protocol) — 402 Payment Required response
- Issuer has not yet filed enough XBRL data — sparse or single-point series

## How this service works

Crypto ETF Sentinel — Historical quarterly time series for one XBRL concept (AUM, NAV, shares outstanding, etc.) on one US spot crypto ETF issuer. Use when charting a single fund's growth or checking a reported figure against its SEC filings. Pass the issuer's SEC CIK as cik; optional concept, unit, taxonomy.

## Output

A quarterly time series array of values for the requested XBRL concept (e.g. AUM, NAV per share, shares outstanding, expense ratio) for the specified issuer, sourced from SEC XBRL filings. Each data point includes the period date and the reported value.

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {
   "cik": "0001980994"
  }
 }
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "cik": {
       "type": "string",
       "pattern": "^[0-9]{1,10}$",
       "description": "Zero-padded SEC CIK identifier (e.g. ``0001980994``). Optional — pass one to target a specific issuer (discover CIKs via /v1/issuers); omit to get the largest issuer by AUM."
      },
      "unit": {
       "type": "string",
       "description": "Unit filter; auto-resolved from concept if omitted."
      },
      "concept": {
       "type": "string",
       "default": "InvestmentOwnedAtFairValue",
       "description": "XBRL TIER1 concept (e.g. InvestmentOwnedAtFairValue = AUM, NetAssetValuePerShare)."
      },
      "taxonomy": {
       "type": "string",
       "description": "Taxonomy filter; auto-resolved from concept if omitted."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "data"
     ],
     "properties": {
      "data": {
       "description": "The endpoint payload — type varies per route"
      },
      "meta": {
       "type": "object",
       "properties": {
        "limit": {
         "type": [
          "integer",
          "null"
         ]
        },
        "total": {
         "type": [
          "integer",
          "null"
         ]
        },
        "offset": {
         "type": [
          "integer",
          "null"
         ]
        }
       }
      },
      "error": {
       "type": [
        "string",
        "null"
       ]
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-cryptoetfsentinel-com-125fd54f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.cryptoetfsentinel.com](https://www.zero.xyz/host/api.cryptoetfsentinel.com/llms.txt)