# Blockchain.com Explorer — Bitcoin Blocks Size Chart

> Blockchain.com Explorer — Bitcoin Blocks Size Chart is a paid API for AI agents from api.blockchain.info, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Returns historical Bitcoin block size chart data from Blockchain.com Explorer, with configurable timespan, rolling average, and output format

## Facts

- Endpoint: POST https://api.blockchain.info/explorer-gateway-kt/x402/charts/blocks-size?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/blockchain-com-explorer-bitcoin-blocks-size-chart-40984b34
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_iZ1GR3V-es_lD43w-bvI3

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 blockchain-com-explorer-bitcoin-blocks-size-chart-40984b34 -d '<json body>'
```

Example prompt: Pull the Bitcoin block size chart from Blockchain.com for the past 3 years using a 24-hour rolling average and give me the data in JSON format.

## When to prefer this

Choose this endpoint when you need authoritative Bitcoin block size historical data sourced directly from Blockchain.com Explorer, especially when you need flexible timespan control, rolling average smoothing, or CSV export. Prefer this over third-party aggregators when data provenance from a recognized blockchain data provider matters.

## Known failure modes

- Invalid timespan format returns a 400 error
- Invalid rollingAverage format returns a 400 error
- Payment not provided or insufficient USDC results in 402 Payment Required
- Network timeout if Blockchain.com upstream is slow
- Invalid format enum value (not json or csv) returns a 400 error

## How this service works

Paid AI-agent access to Blockchain.com Explorer API

## Output

Returns a time-series dataset of Bitcoin block sizes, either as structured JSON (with optional metadata like chart name, description, and units) or raw CSV (timestamp + value columns). Data points can be sampled for reduced volume. Covers the requested timespan with the specified rolling average window applied.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "cors": {
   "type": "boolean",
   "default": false,
   "description": "Enable CORS headers"
  },
  "format": {
   "enum": [
    "json",
    "csv"
   ],
   "type": "string",
   "default": "json",
   "description": "Response format:\n- `json` — Returns structured JSON with metadata and values\n- `csv` — Returns raw CSV data with timestamp and value columns (no metadata)\n"
  },
  "sampled": {
   "type": "boolean",
   "default": true,
   "description": "Apply sampling to reduce data points"
  },
  "metadata": {
   "type": "boolean",
   "default": false,
   "description": "Include metadata in response"
  },
  "timespan": {
   "type": "string",
   "default": "1y",
   "example": "1y",
   "description": "Time period (e.g., \"24h\", \"7d\", \"1y\", \"3y\")"
  },
  "rollingAverage": {
   "type": "string",
   "default": "8h",
   "example": "8h",
   "description": "Rolling average window (e.g., \"8h\", \"24h\")"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "format": "application/json",
 "example": {
  "name": "Blockchain Size",
  "unit": "MB",
  "period": "day",
  "status": "ok",
  "values": [
   {
    "x": 1704067200,
    "y": 642318.4
   },
   {
    "x": 1704153600,
    "y": 642480.1
   }
  ],
  "description": "The total size of all block headers and transactions. Not including database indexes."
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/blockchain-com-explorer-bitcoin-blocks-size-chart-40984b34/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.blockchain.info](https://www.zero.xyz/host/api.blockchain.info/llms.txt)