# ECB Total Assets (USD) Time Series

> ECB Total Assets (USD) Time Series is a paid API for AI agents from darklyenergized.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-29).

Returns a time series of the European Central Bank's total assets converted to USD, with optional date filtering and statistical summary.

## Facts

- Endpoint: GET https://darklyenergized.com/api/v1/x402/series/cb_usd_ecbassetsw?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ecb-total-assets-usd-time-series-5629c9bd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_723UXdq_UrrSMe_7rNIvD

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 ecb-total-assets-usd-time-series-5629c9bd
```

Example prompt: Pull the ECB total assets time series in USD from January 2020 to December 2023, returning up to 500 data points, so I can analyze how the ECB balance sheet evolved during that period.

## When to prefer this

Choose this endpoint when you need ECB-specific total asset data converted to USD — especially useful when comparing across central banks in a common currency. Prefer this over general financial data APIs when you need pre-converted USD values with freshness metadata. Ideal for macro research, global liquidity tracking, or feeding into multi-central-bank composite indicators.

## Known failure modes

- Invalid date format (non-YYYY-MM-DD) returns a 400 error
- 'from' date after 'to' date results in empty or error response
- limit exceeding 10000 returns a validation error
- Payment not provided or insufficient funds triggers 402 Payment Required
- Requesting dates before data series begins returns empty data array
- Series temporarily stale if ECB source data not yet published

## How this service works

ECB Total Assets (USD) ($0.05): European Central Bank total assets converted to USD.

## Output

Returns a structured object containing the series ID, name, description, category, frequency, and unit, along with an array of time-indexed data points (date + USD value, nullable where unavailable). Also includes metadata covering total count, data range, freshness status (isStale, lastObservation, frequency), and optionally a statistical summary instead of raw data points.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "to": {
       "type": "string",
       "format": "date",
       "description": "End date (YYYY-MM-DD)"
      },
      "from": {
       "type": "string",
       "format": "date",
       "description": "Start date (YYYY-MM-DD)"
      },
      "after": {
       "type": "string",
       "format": "date",
       "description": "Return points after this date (meta.pagination.cursor)"
      },
      "limit": {
       "type": "integer",
       "default": 500,
       "maximum": 10000,
       "minimum": 1,
       "description": "Most data points to return, oldest first"
      },
      "summary": {
       "type": "boolean",
       "default": false,
       "description": "Return a statistical summary instead of the data points"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "oneOf": [
      {
       "type": "object",
       "required": [
        "data",
        "meta"
       ],
       "properties": {
        "data": {
         "type": "object",
         "required": [
          "id",
          "name",
          "description",
          "category",
          "frequency",
          "data"
         ],
         "properties": {
          "id": {
           "type": "string"
          },
          "data": {
           "type": "array",
           "items": {
            "type": "object",
            "required": [
             "time",
             "value"
            ],
            "properties": {
             "time": {
              "type": "string",
              "format": "date",
              "example": "2026-02-14"
             },
             "value": {
              "type": [
               "number",
               "null"
              ],
              "example": 1.23,
              "description": "Null where the series has no value on that date (for example while a computed series warms up)."
             }
            }
           }
          
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ecb-total-assets-usd-time-series-5629c9bd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from darklyenergized.com](https://www.zero.xyz/host/darklyenergized.com/llms.txt)