# X402 Settlement Transaction Shape Validator

> X402 Settlement Transaction Shape Validator is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-20).

Validates a settlement transaction identifier against the expected on-chain structure for x402 payments, returning acceptance/rejection status and mismatch reasons without querying external providers.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/x402-settlement-tx-shape?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/x402-settlement-transaction-shape-validator-546f763a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2zXVCZ49yjn22jTH36Ce_

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 x402-settlement-transaction-shape-validator-546f763a -d '<json body>'
```

Example prompt: Before we accept this x402 payment, check if the settlement transaction '0xabc123...' on the 'base' network has the correct chain shape and structure — give me the acceptance status and any mismatch reasons.

## When to prefer this

Use this endpoint when you need to verify an x402 settlement transaction's on-chain shape before accepting or releasing resources in an x402 or agent delivery flow, especially when you want deterministic, in-memory validation without relying on an external blockchain RPC provider. Prefer this over generic transaction lookup services when you specifically need x402 protocol compliance checking with explicit acceptance/rejection output and mismatch diagnostics.

## Known failure modes

- Invalid or malformed transaction identifier returns rejection status with mismatch reasons
- Unsupported or unrecognized network string may yield inconclusive or error result
- Missing required fields (network or transaction) returns validation error
- Ambiguous transaction format may produce partial evidence with explicit rejection
- Input exceeds maxLength constraints causing request rejection

## How this service works

X402 Settlement Tx Shape: X402 Settlement Tx Shape checks a settlement transaction identifier for expected chain shape from bounded caller-supplied values without an external provider. Call X402 Settlement Tx Shape before paying for or accepting an x402 or agent delivery assembled from caller-supplied challenge and result metadata. Returns contract-specific checks, normalized evidence, mismatch reasons, and an explicit acceptance or rejection status for X402 Settlement Tx Shape as versioned det…

## Output

Returns contract-specific validation checks, normalized transaction evidence, a list of mismatch reasons if any, and an explicit acceptance or rejection status for the given settlement transaction, all computed in-memory from caller-supplied values without external provider calls.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "network": {
   "type": "string",
   "maxLength": 8192,
   "description": "Network supplied to X402 Settlement Tx Shape; used only for this bounded calculation and processed in memory without retention."
  },
  "transaction": {
   "type": "string",
   "maxLength": 8192,
   "description": "Transaction supplied to X402 Settlement Tx Shape; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "network": "eip155:8453",
   "shape_valid": true,
   "transaction": "0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
   "onchain_verified": false
  },
  "schema": "delx/util-x402-settlement-tx-shape/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "6b6686833b680e0e8c6f79699ebc9ae5179b0d0ffe3743085905a52387b0e70c",
   "external_calls": 0
  },
  "operation": "delivery_contract:x402_settlement_tx_shape"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-settlement-transaction-shape-validator-546f763a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)