# Agent402 ABA Routing Number Validator

> Agent402 ABA Routing Number Validator is a paid API for AI agents from agent402.co.uk, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Validates a 9-digit US ABA routing number by checking its format and Federal Reserve weighted checksum (3-7-1 algorithm)

## Facts

- Endpoint: POST https://agent402.co.uk/v1/validate/aba-routing
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-aba-routing-number-validator-31d4ad45
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QhRT4rEyTtU4yCv0srYCx

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 agent402-aba-routing-number-validator-31d4ad45 -d '<json body>'
```

Example prompt: Can you validate the ABA routing number 021000021 — just check if the format and Federal Reserve checksum are correct?

## When to prefer this

Choose this endpoint when you need a fast, deterministic, low-cost ($0.001) check that a US ABA routing number is structurally correct and passes the Federal Reserve 3-7-1 weighted checksum. It is ideal for pre-flight validation in payment workflows, form input sanitization, or data cleaning pipelines where you want to catch malformed routing numbers before sending them to a bank or ACH network. Do not use it if you need to confirm that the routing number corresponds to a real, active bank or that the account is reachable via ACH — those require a bank-existence or ACH-reachability lookup service.

## Known failure modes

- Routing number fails the 3-7-1 Federal Reserve weighted checksum — returns valid: false with valid_checksum: false
- Input is not exactly 9 digits — returns valid: false with valid_format: false
- Non-numeric characters in input cause format validation failure
- Endpoint returns an error if the routing field is missing from the request body
- Does not detect whether the bank actually exists or is ACH-reachable — only structural/checksum validity is confirmed

## How this service works

Don't burn tokens on deterministic work. Go/no-go jobs first: payout preflight, text firewall (PII/secrets), budget check — then rails, calendars, finmath. x402 USDC on Base. UK + global. agent402.co.uk — not agent402.tools. $0.001–$0.002 USDC on Base. No API keys.

## Output

Returns a JSON object indicating whether the routing number is valid overall (valid), the normalized 9-digit string (electronic), individual checks for format (valid_format) and checksum (valid_checksum), and a provenance object noting that validation depth is checksum_only — meaning it does not confirm the bank exists or is reachable via ACH.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "routing": {
   "type": "string",
   "description": "9-digit ABA routing number"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "valid": true,
  "electronic": "021000021",
  "provenance": {
   "depth": "checksum_only"
  },
  "valid_format": true,
  "valid_checksum": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-aba-routing-number-validator-31d4ad45/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.co.uk](https://www.zero.xyz/host/agent402.co.uk/llms.txt)