# Glassnode ETH2 Slot Height Metric

> Glassnode ETH2 Slot Height Metric is a paid API for AI agents from x402.glassnode.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).

Returns the cumulative total number of slots ever included in the Ethereum 2.0 beacon chain (slot height) as a time series.

## Facts

- Endpoint: GET https://x402.glassnode.com/v1/metrics/eth2/slot_height
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/glassnode-eth2-slot-height-metric-e3b86f7b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AXf9TxwS3XpqgLEg5263T

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 glassnode-eth2-slot-height-metric-e3b86f7b
```

Example prompt: Can you pull the Glassnode ETH2 slot height metric for Ethereum in JSON format with daily resolution so I can see how the total number of beacon chain slots has grown?

## When to prefer this

Use this endpoint when you need authoritative, time-series data on Ethereum 2.0 beacon chain slot height from Glassnode, particularly for on-chain analytics, blockchain research, or monitoring beacon chain progression. Prefer this over general blockchain explorers when you need structured, programmatic access to historical slot height data with consistent formatting.

## Known failure modes

- Missing required 'a' query parameter (asset) returns a 400 error
- Invalid asset symbol (non-ETH value) rejected since only ETH is supported
- Payment not included or insufficient USDC causes a 402 Payment Required response
- Invalid format parameter value causes a format error
- Rate limiting or upstream Glassnode data unavailability may cause 503 errors

## How this service works

Slot Height — The slot height, i.e. the total number of slots ever included in the main blockchain. Data by Glassnode.

## Output

Returns a time series array of objects, each with a Unix timestamp ('t') and the cumulative slot height value ('v') representing the total number of slots ever included in the Ethereum 2.0 beacon chain at that point in time.

## 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",
     "required": [
      "a"
     ],
     "properties": {
      "a": {
       "enum": [
        "ETH"
       ],
       "type": "string",
       "description": "Asset symbol, e.g. BTC, ETH"
      },
      "f": {
       "enum": [
        "csv",
        "json"
       ],
       "type": "string",
       "description": "Response format: json or csv"
      },
      "i": {
       "enum": [
        "24h"
       ],
       "type": "string",
       "description": "Time interval / resolution, e.g. 24h, 1w, 1month"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "array",
     "items": {
      "type": "object",
      "properties": {
       "t": {
        "type": "number"
       },
       "v": {
        "type": "number"
       }
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/glassnode-eth2-slot-height-metric-e3b86f7b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.glassnode.com](https://www.zero.xyz/host/x402.glassnode.com/llms.txt)