# Base Address Chain Validator

> Base Address Chain Validator is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Validates whether a given address is a well-formed and recognized address on the Base blockchain network (chain ID 8453).

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/base_address_chain_validate/invoke
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-address-chain-validator-d2cbaeba
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rv18117bZunNN7195h809

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 base-address-chain-validator-d2cbaeba -d '<json body>'
```

Example prompt: Can you check if 0xAbC1234567890000000000000000000000000001 is a valid address on the Base mainnet network before I send funds to it?

## When to prefer this

Use this endpoint when you need a quick, cheap ($0.005 USDC) on-chain address format and chain compatibility check for the Base network specifically. Prefer this over general Ethereum validators when the target chain is Base mainnet (chain ID 8453) or Base Sepolia testnet (chain ID 84532). Ideal for pre-flight checks before sending transactions, onboarding user wallets, or storing addresses in a Base-specific context. Note: this does NOT verify ownership or account balance.

## Known failure modes

- Malformed address string returns validation failure or error
- Invalid JSON in request_json field causes parse error
- Network unavailable may return timeout or service error
- Address may be syntactically valid but warnings still issued (e.g. zero address)
- Does not verify account existence, ownership, or funded status — only format/chain compatibility

## How this service works

Explore 330 pay-per-call x402 API services and 27 agent-native digital products, with Base USDC pricing, secure Polar checkout, and free discovery.

## Output

Returns a JSON object indicating whether the address is valid on the Base network, including the chain ID (8453), network name (base_mainnet), OP Stack protocol context (accepted chain IDs, deposit transaction type, fee model), and any warnings (e.g. that validation does not prove ownership or account existence). The result also includes a status field (succeeded/failed) and a receipt with payment and execution metadata.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "request_json": {
   "type": "string",
   "maxLength": 65536,
   "minLength": 2
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Does not prove ownership, code, or account existence."
   ],
   "service_id": "base_address_chain_validate",
   "analysis_json": "{\"address\":\"0x0000000000000000000000000000000000000001\",\"chain_id\":\"8453\",\"network\":\"base_mainnet\",\"network_context\":{\"accepted_chain_ids\":[\"8453\",\"84532\"],\"deposit_transaction_type\":\"0x7e\",\"fee_model\":\"L2 execution plus caller-supplied L1 data/operator components\",\"protocol_family\":\"OP Stack\"},\"valid\":true}",
   "evidence_scope": "caller_supplied_data",
   "analyzed_network": "base"
  },
  "status": "succeeded",
  "receipt": {
   "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
   "usage": [],
   "status": "succeeded",
   "network": "eip155:8453",
   "artifacts": [],
   "endedAtMs": 0,
   "latencyMs": 0,
   "paymentId": "example-payment",
   "receiptId": "example-receipt",
   "requestId": "example-request",
   "serviceId": "base_address_chain_validate",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "5000",
   "resultSha256": "91aed55c8b162e51f15f2ccfd52cd0b98667514e8cd0582227cefd7a63fbec33",
   "serviceVersion": "1.0.0",
   "settlementReference": "0x0000000000000000000000000000000000000000000000000000000000000000"
  },
  "artifacts": [],
  "requestId": "example-request",
  "executionId": "example-execution"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-address-chain-validator-d2cbaeba/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from signalharness.ai](https://www.zero.xyz/host/signalharness.ai/llms.txt)