# US ABA Routing Number Checksum Validator

> US ABA Routing Number Checksum Validator is a paid API for AI agents from x402.agentindex.world, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-20).

Validates a 9-digit US ABA bank routing number using checksum verification

## Facts

- Endpoint: GET https://x402.agentindex.world/validate/routing?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/us-aba-routing-number-checksum-validator-c1bf8c2c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XUuaGDqeJjH-o0G4a1PbD

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 us-aba-routing-number-checksum-validator-c1bf8c2c
```

Example prompt: Can you check whether the routing number 021000021 is a valid US ABA routing number — does it pass the checksum?

## When to prefer this

Use this endpoint when you need a fast, cheap checksum-level validation of a US ABA routing number before processing payments, storing bank details, or accepting user input — particularly in ACH, wire transfer, or payroll contexts. Prefer this over full bank lookup services when you only need structural validity and cost is a concern.

## Known failure modes

- Non-9-digit input returns a pattern validation error
- Non-numeric characters cause rejection
- Missing routing_number parameter returns a 400 or schema error
- A structurally valid checksum does not guarantee the routing number is actively assigned to a bank — only that it is well-formed

## How this service works

Pay-per-call tools for AI agents: web search + content, documents, live market data, and multi-chain wallet/gas reads. Mainnet test from $0.000001 USDC on Base. Pay-per-call tools for AI agents in USDC on Base (x402/MPP): search, pdf, web-read, extract, summarize, fact-check, translate, jobs, discover. See GET /capabilities.

## Output

A validation result indicating whether the 9-digit ABA routing number passes the standard checksum algorithm, confirming if the number is structurally valid as a US bank routing number.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "title": "RoutingInput",
     "required": [
      "routing_number"
     ],
     "properties": {
      "routing_number": {
       "type": "string",
       "title": "Routing Number",
       "pattern": "^[0-9]{9}$"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "RoutingOutput",
     "required": [
      "valid"
     ],
     "properties": {
      "valid": {
       "type": "boolean",
       "title": "Valid"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "valid": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/us-aba-routing-number-checksum-validator-c1bf8c2c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.agentindex.world](https://www.zero.xyz/host/x402.agentindex.world/llms.txt)