# SameDayDesk Payment Offer Preflight

> SameDayDesk Payment Offer Preflight is a paid API for AI agents from agents.samedaydesk.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-16).

Compares x402 and MPP payment challenges before authorization, returning normalized terms, binding checks, parity analysis, and a bounded payment decision for a given target URL.

## Facts

- Endpoint: GET https://agents.samedaydesk.com/commerce/payment-offer-preflight
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/samedaydesk-payment-offer-preflight-9ecd8e54
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_e4MfdX5AVWgyse0Bduh4R

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 samedaydesk-payment-offer-preflight-9ecd8e54
```

Example prompt: Before I authorize payment for https://agents.samedaydesk.com/commerce/some-paid-endpoint, run a preflight check on it — compare the x402 and MPP challenges, tell me if the terms are consistent and safe, and give me a go/no-go decision.

## When to prefer this

Use this endpoint when an AI agent needs to safely inspect and compare payment challenges (x402 and/or MPP) before committing funds for a target URL. It is the right choice when you want a normalized, protocol-agnostic view of payment terms and an automated parity/binding check — especially in agentic workflows where an automated payment gate is needed before any real authorization occurs. Prefer this over directly parsing raw challenge headers when you need a structured, human-readable comparison and a concrete go/no-go recommendation.

## Known failure modes

- Target URL is unreachable or returns no payment challenge — endpoint returns an error indicating no challenge found
- URL returns a malformed or non-standard x402/MPP challenge — normalization may fail with a parse error
- Parity check fails because x402 and MPP terms differ significantly — returned as a parity mismatch in the decision object
- Invalid or missing target URL in the JSON body — likely a 400 bad request
- Target URL requires authentication that the preflight cannot supply — challenge may be incomplete

## How this service works

Compare x402 and MPP challenges before authorization and return normalized terms, binding checks, parity, and a bounded decision. The workflow-safe POST form accepts the target URL in a JSON body.

## Output

Returns a structured JSON object containing: normalized payment terms from both x402 and MPP challenges, binding checks (whether each challenge meets required constraints), a parity assessment (whether both protocols agree on amount and conditions), and a bounded decision (go/no-go recommendation for authorization). No funds are moved; this is a read-only preflight analysis.

## 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": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "format": "uri",
       "maxLength": 2048,
       "description": "Exact public HTTPS GET URL to inspect. Credential-like query keys, fragments, unresolved parameters, local hosts, redirects, and non-public IPs are rejected."
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "ok",
      "product",
      "version",
      "checkedAt",
      "target",
      "decision",
      "protocols",
      "offerCount",
      "offers",
      "parity",
      "catalogCoherence",
      "responseContract",
      "responseContractAcquisition",
      "findings",
      "boundary"
     ],
     "properties": {
      "ok": {
       "type": "boolean",
       "const": true
      },
      "offers": {
       "type": "array"
      },
      "parity": {
       "type": "object"
      },
      "target": {
       "type": "object"
      },
      "product": {
       "type": "string",
       "const": "samedaydesk-payment-offer-preflight"
      },
      "version": {
       "type": "string",
       "const": "1.2.0"
      },
      "boundary": {
       "type": "object"
      },
      "decision": {
       "enum": [
        "parseable_offer",
        "review_required",
        "no_parseable_offer"
       ],
       "type": "string"
      },
      "findings": {
       "type": "array"
      },
      "checkedAt": {
       "type": "string",
       "format": "date-time"
      },
      "protocols": {
       "type": "array",
       "items": {
        "enum": [
         "mpp",
         "x402"
        ],
        "type": "string"
       }
      },
      "offerCount": {
       "type": "integer",
       "minimum": 0
      },
      "catalogCoherence": {
       "type": "array"
      },
      "responseContract": {
       "type": "object"
      },
      "respons
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "offers": [
   {
    "valid": true,
    "intent": "exact",
    "scheme": "exact",
    "network": "eip155:8453",
    "protocol": "x402",
    "amountAtomic": "20000"
   }
  ],
  "parity": {
   "compared": true,
   "consistent": true,
   "driftFields": []
  },
  "target": {
   "url": "https://agents.samedaydesk.com/defi/morpho-position?address=0x8ee9c15c3e5332cbc6ef39a2bb036c63c6549b6e",
   "method": "GET",
   "httpStatus": 402
  },
  "product": "samedaydesk-payment-offer-preflight",
  "version": "1.2.0",
  "boundary": {
   "paymentSent": false,
   "paymentSigned": false,
   "credentialsUsed": false,
   "redirectsFollowed": false,
   "openApiDocumentRead": true,
   "targetResponseBodyRead": false
  },
  "decision": "parseable_offer",
  "findings": [],
  "checkedAt": "2026-08-10T20:00:00.000Z",
  "protocols": [
   "mpp",
   "x402"
  ],
  "offerCount": 2,
  "catalogCoherence": [],
  "responseContract": {
   "decision": "admissible",
   "exampleStatus": "structurally_consistent",
   "requiredPaths": [
    "ok",
    "title",
    "url"
   ],
   "requiredFields": [
    "ok",
    "title",
    "url"
   ],
   "runtimeResponseVerified": false
  },
  "responseContractAcquisition": {
   "path": "/openapi.json",
   "maxBytes": 1000000,
   "attempted": true,
   "sameOrigin": true,
   "documentRead": true,
   "credentialsUsed": false,
   "redirectsFollowed": false,
   "targetResponseBodyRead": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/samedaydesk-payment-offer-preflight-9ecd8e54/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agents.samedaydesk.com](https://www.zero.xyz/host/agents.samedaydesk.com/llms.txt)