# DDG x402 'upto' Metered-Settlement Fairness Verifier

> DDG x402 'upto' Metered-Settlement Fairness Verifier is a paid API for AI agents from agents.daedalusdevelopmentgroup.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-20).

Deterministically verifies x402 'upto' (capped) payment settlements for cap breaches, pricing math errors, and signed-authorization compliance, returning a signed pass/fail verdict.

## Facts

- Endpoint: POST https://agents.daedalusdevelopmentgroup.com/v1/x402/upto-verify?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ddg-x402-upto-metered-settlement-fairness-verifier-76b1437d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9naV5KYhog2Rh3cSJ0379

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 ddg-x402-upto-metered-settlement-fairness-verifier-76b1437d -d '<json body>'
```

Example prompt: Check whether this x402 'upto' settlement is fair: the cap was $0.50, the settled amount was $0.47, reported usage was 4700 tokens at $0.0001 per token, and the signed authorization covered up to $0.50 — run the fairness check and give me a signed verdict.

## When to prefer this

Use this endpoint when an AI agent needs deterministic, cryptographically-signed assurance that an x402 'upto' metered payment settled correctly — specifically when you need to catch cap overruns, pricing math discrepancies (per-token, per-byte, per-second), or signed-authorization violations before accepting a service result or releasing funds. Prefer this over manual math checks when you need a tamper-evident signed verdict for auditability.

## Known failure modes

- Settled amount exceeds cap — cap breach flagged, ok: false
- Calculated price from usage × unit rate does not match settled amount — over-charge or under-report flagged
- Signed authorization amount exceeds cap — authorization violation flagged
- Malformed or missing required fields in request body — 400 validation error
- Payment of $0.01 USDC not received — 402 payment required response blocking execution

## How this service works

x402 'upto' metered-settlement fairness check: cap breach (settled>cap), over-charge / under-report vs the reported usage math (per_token/per_byte/per_second unit price), and a signed-authorization amount<=cap check. Deterministic signed verdict. $0.01.

## Output

A deterministic signed verdict object with an 'ok' boolean indicating whether the settlement passed all checks (cap compliance, unit-price math correctness, and signed-authorization amount <= cap). On failure, the response indicates which check failed (cap breach, over-charge, under-report, or auth violation).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input",
  "output"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object"
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": true
  },
  "output": {
   "type": "object",
   "required": [
    "type",
    "example"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "ok": true
    }
   },
   "additionalProperties": true
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ddg-x402-upto-metered-settlement-fairness-verifier-76b1437d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agents.daedalusdevelopmentgroup.com](https://www.zero.xyz/host/agents.daedalusdevelopmentgroup.com/llms.txt)