# ABA Routing Number Validator

> ABA Routing Number Validator is a paid API for AI agents from bank-validators.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-11-02).

Validates a 9-digit US ABA routing number using the 3-7-1 weighted checksum and identifies the Federal Reserve district from the routing prefix.

## Facts

- Endpoint: GET https://bank-validators.x402tookit.com/aba-routing-check?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/aba-routing-number-validator-5f5e4a61
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tiM867ckLFHwNikDHFjhK

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 aba-routing-number-validator-5f5e4a61
```

Example prompt: Can you check whether the routing number 021000021 is valid — run the ABA checksum and tell me which Federal Reserve district it belongs to?

## When to prefer this

Use this endpoint when you need to structurally validate a US ABA routing number before initiating ACH transfers, wire payments, or direct deposit setups. It provides both checksum verification and Federal Reserve district identification in a single call. Prefer this over manual checksum logic or generic bank lookup services when you need authoritative format validation plus Fed district metadata without relying on a live bank directory.

## Known failure modes

- Non-9-digit input returns invalid verdict with format error reason
- Routing number failing 3-7-1 checksum returns invalid verdict with checksum failure reason
- Missing required 'routing' query parameter returns an error
- Network or service unavailability may return a degraded flag with partial results

## How this service works

Check a US ABA routing number: 3-7-1 weighted checksum and the Federal Reserve district from the prefix.

## Output

Returns a verdict (valid/invalid), the weighted checksum value, the normalized routing number, the 2-digit Federal Reserve district prefix, the prefix kind, the Federal Reserve district number and city, a human-readable summary, an array of reason strings explaining the result, and optional disclaimer and degraded-service flags.

## 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": [
      "routing"
     ],
     "properties": {
      "routing": {
       "type": "string",
       "description": "9-digit US ABA routing number, e.g. 021000021"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "prefix": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "normalized": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "prefixKind": {
       "type": [
        "null",
        "string"
       ]
      },
      "fedDistrict": {
       "type": [
        "null",
        "number"
       ]
      },
      "weightedSum": {
       "type": [
        "null",
        "number"
       ]
      },
      "fedDistrictCity": {
       "type": [
        "null",
        "string"
       ]
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/aba-routing-number-validator-5f5e4a61/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bank-validators.x402tookit.com](https://www.zero.xyz/host/bank-validators.x402tookit.com/llms.txt)