# SYNTHORA ERC-20 Token Holder & Transfer Counters

> SYNTHORA ERC-20 Token Holder & Transfer Counters is a paid API for AI agents from blockscout-token-holder-counters.hergertsynthora.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns holder count and cumulative transfer count for any ERC-20 or ERC-721 token contract address, sourced from public Blockscout APIs.

## Facts

- Endpoint: POST https://blockscout-token-holder-counters.hergertsynthora.com/service
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synthora-erc-20-token-holder-transfer-counters-d1248019
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Xw6U77JmyASq32M4fKbNv

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 synthora-erc-20-token-holder-transfer-counters-d1248019 -d '<json body>'
```

Example prompt: How many holders and total transfers does USDC (contract 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48) have on Ethereum right now — I want to check its adoption and concentration risk before including it in a portfolio strategy.

## When to prefer this

Choose this endpoint when you need fast, on-chain holder and transfer count data for any ERC-20 or ERC-721 token without running your own Blockscout node. It is ideal for autonomous agent workflows performing token screening, concentration risk assessment, or adoption analysis before a trade or investment decision. Prefer it over generalized blockchain explorers when you need a structured JSON response suitable for agent-to-agent due-diligence pipelines.

## Known failure modes

- Invalid or non-existent contract address returns an error or empty result
- Token not indexed by Blockscout returns no data
- Rate limiting or Blockscout API downtime causes lookup failure
- Non-ERC-20/ERC-721 contract addresses may return unexpected results
- Network mismatch (querying wrong chain for contract) returns null or error

## How this service works

Returns holder count and cumulative transfer count for any ERC-20/ERC-721 token via public Blockscout, plus circulating market cap, total supply and exchange rate on the token detail path. Feeds autonomous token-screening agents and agent-to-agent due-diligence flows that gauge holder distribution, concentration risk and token adoption before trading. First 3 calls FREE per wallet — send header X-WALLET: 0x<addr>. No charge on upstream failure.

## Output

A JSON object containing the token's total holder count (number of unique addresses holding the token) and cumulative transfer count (total number of on-chain transfer events), plus optionally circulating market cap, total supply, and exchange rate when queried via the token detail path.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "keys": {
   "type": "string",
   "description": "keys"
  },
  "caller": {
   "type": "string",
   "description": "caller"
  },
  "payload": {
   "type": "string",
   "description": "payload"
  },
  "provides": {
   "type": "string",
   "description": "provides"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "blockscout-token-holder-counters",
  "result": {
   "transfers_count": "336385388",
   "token_holders_count": "8204366"
  },
  "provenance": {
   "url": "https://eth.blockscout.com/api/v2/tokens/0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48/counters",
   "source": "ERC-20 Token Holder & Transfer Counters"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synthora-erc-20-token-holder-transfer-counters-d1248019/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from blockscout-token-holder-counters.hergertsynthora.com](https://www.zero.xyz/host/blockscout-token-holder-counters.hergertsynthora.com/llms.txt)