# MioDio Meridian Tx Drift

> MioDio Meridian Tx Drift is a paid API for AI agents from workers.miodiollc.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-27).

Diffs a declared intent against an unsigned transaction or EIP-712 payload before signing, returning a match/drift/cannot_verify verdict with per-field diff and keccak hash

## Facts

- Endpoint: POST https://workers.miodiollc.com/v1/drift?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/miodio-meridian-tx-drift-147bccf3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Nz4BQb1iJeCf4sS7_Yw_n

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 miodio-meridian-tx-drift-147bccf3 -d '<json body>'
```

Example prompt: Before I sign this swap, check whether the actual unsigned tx matches my intent — I declared a USDC-to-ETH swap for 100 USDC on Base to recipient 0xAbC...123, max 0.5% slippage — run a drift check and tell me if anything has changed in the calldata.

## When to prefer this

Use this endpoint when an AI agent needs to verify transaction integrity immediately before wallet signing in a DeFi context — especially when using DeFi frontends where calldata could be manipulated. Prefer over manual inspection when dealing with EIP-712 Permit or Permit2 payloads, complex swap calldata, or any flow where front-end trust is uncertain. Not a replacement for full security audits, but the only per-call micropayment drift-check in the MioDio Meridian suite.

## Known failure modes

- 400 invalid_body — malformed or missing required fields in request
- 400 unsupported_chain — chain value not in ['base','ethereum']
- 402 payment required — x402 micropayment not provided or insufficient
- Unknown calldata returns cannot_verify instead of match — not an error but a safety default
- Partial or ambiguous intent fields may reduce diff precision without causing an error

## How this service works

MioDio Meridian parameter-drift check: diffs a declared intent against the exact unsigned tx or EIP-712 payload before you sign (~$0.005 USDC Exact on Base). Verdict match, drift or cannot_verify with a per-field diff and keccak of the bytes checked. Unknown calldata is cannot_verify, never match. A match is not a guarantee the intent was safe. Errors: 400 invalid_body or unsupported_chain, 402 payment required. MioDio x402 DeFi. Terms: https://workers.miodiollc.com/terms

## Output

A JSON verdict of 'match', 'drift', or 'cannot_verify'; a per-field diff showing exactly which fields diverged and by how much; a keccak hash of the bytes checked for auditability. Unknown or unparseable calldata always returns cannot_verify, never match.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "tx": {
   "type": "object",
   "description": "Exact unsigned transaction about to be signed: to, value, data, optional chainId/from."
  },
  "chain": {
   "enum": [
    "base",
    "ethereum"
   ],
   "type": "string",
   "description": "Target chain of the unsigned tx (default base). Independent of the USDC payment network."
  },
  "intent": {
   "type": "object",
   "description": "Declared intent: action, recipient/spender, token, amount, max slippage, expected contract."
  },
  "typed_data": {
   "type": "object",
   "description": "Optional EIP-712 payload (Permit, Permit2) when that is what will be signed."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/miodio-meridian-tx-drift-147bccf3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from workers.miodiollc.com](https://www.zero.xyz/host/workers.miodiollc.com/llms.txt)