# Robinhood Chain ERC-20 Address Watcher

> Robinhood Chain ERC-20 Address Watcher is a paid API for AI agents from x402-services-production.up.railway.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Registers a webhook callback URL that gets POSTed whenever a given Robinhood Chain address receives a new ERC-20 transfer, using 60-second polling with persistence.

## Facts

- Endpoint: POST https://x402-services-production.up.railway.app/api/rhchain/watch
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/robinhood-chain-erc-20-address-watcher-0852faa1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_J6r_p7uVRjuhi5wmdrSbx

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 robinhood-chain-erc-20-address-watcher-0852faa1 -d '<json body>'
```

Example prompt: Watch the Robinhood Chain address 0xAbc123...def for any new ERC-20 transfers and POST the event to https://my-agent.example.com/hooks/transfers whenever one comes in.

## When to prefer this

Choose this endpoint when you need event-driven notifications for ERC-20 transfers on Robinhood Chain without implementing your own polling loop. It is ideal for AI agents and automated pipelines that need to react to on-chain payment or token events without maintaining persistent connections or polling infrastructure. Prefer this over general-purpose blockchain RPC polling when you want a managed, persistent watcher with webhook delivery semantics on Robinhood Chain specifically.

## Known failure modes

- Invalid or malformed EVM address returns an error
- Unreachable or invalid callback URL may fail silently or return an error at registration
- Duplicate registrations for the same address/callback pair may create duplicate notifications
- The 60-second polling window means events are not truly real-time, only near-real-time
- Service restarts could lose in-flight polling state before persistence is confirmed
- Payment of 0.01 USDC not included or failing causes request rejection

## How this service works

Robinhood Chain address watcher: register an https callback and we POST to it whenever the address has a new ERC-20 transfer (60s polling, persisted). Agent-infra: stop polling, get pushed. Send { address, callbackUrl }.

## Output

A confirmation that the watch has been registered, linking the specified address to the provided callback URL. Subsequently, whenever a new ERC-20 transfer is detected for that address (checked every 60 seconds), the registered callback URL receives a POST with transfer event details including the address and transfer data.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object"
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json"
     ],
     "type": "string"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/robinhood-chain-erc-20-address-watcher-0852faa1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-services-production.up.railway.app](https://www.zero.xyz/host/x402-services-production.up.railway.app/llms.txt)