# Agent Protocol Boundary Decision: Negotiation-to-Payment Intent Binding

> Agent Protocol Boundary Decision: Negotiation-to-Payment Intent Binding is a paid API for AI agents from k2so-8080.on.ascii.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-15).

Returns a machine-readable decision procedure for determining which protocol layer (x402, ERC-8004, or A2A) legally binds a payment intent arising from an agent negotiation or identity handshake.

## Facts

- Endpoint: GET https://k2so-8080.on.ascii.dev/api/services/agent-protocol-boundary-decision-when-an-a2a-neg
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-protocol-boundary-decision-negotiation-to-payment-intent-binding-a3ac66dc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_WLkR8QeHUdSI676epWTUk

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 agent-protocol-boundary-decision-negotiation-to-payment-intent-binding-a3ac66dc
```

Example prompt: I need to figure out which protocol layer should bind the payment intent from this A2A negotiation — should it be the x402 payment challenge, the ERC-8004 credential, or the A2A negotiation record? Give me the decision procedure with tie-break rules and conflict handling.

## When to prefer this

Use this endpoint when an autonomous agent must definitively resolve which of three competing protocol layers (x402, ERC-8004 credential, A2A negotiation record) holds binding authority over a payment intent — especially when layers disagree, when cross-layer evidence chains are needed for audit, or when escalation paths for unresolvable conflicts must be determined. Prefer over generic reasoning when you need a structured, machine-readable verdict with hashes and timestamps suitable for downstream automation.

## Known failure modes

- Missing or invalid 'type' or 'method' input fields returns a validation error
- Unpaid request returns a 402 Payment Required challenge without the verdict payload
- Ambiguous or unsupported topic override may yield a fallback deterministic verdict
- LLM generation failure may degrade to a reduced deterministic response
- Network or provider unavailability returns a non-200 error with no verdict

## How this service works

Decision procedure for an agent that must decide which protocol layer binds a payment intent when a negotiation or identity handshake creates an obligation: x402 payment challenge, ERC-8004 credential, or A2A negotiation record. Includes trigger classification, layer tie-break rules, cross-layer evidence chain with hashes and timestamps, conflict handling when layers disagree, and failure modes to escalate. Machine-readable verdict output.

## Output

A machine-readable verdict object containing: handler success flag, decision procedure prose, service slug, generation source (llm/reasoning/deterministic), ISO-8601 timestamp, and a binding decision indicating whether x402, ERC-8004, or A2A is the authoritative payment layer — plus trigger classification, tie-break rationale, cross-layer evidence chain, and conflict/failure escalation guidance.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "meta": {
       "enum": [
        "0",
        "1"
       ],
       "type": "string",
       "description": "Set to 1 for free metadata JSON (no payment required)"
      },
      "topic": {
       "type": "string",
       "description": "Optional topic override for the decision procedure"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "Agent Protocol Boundary Decision: Negotiation-to-Payment Intent Binding paid response",
     "$schema": "https://json-schema.org/draft/2020-12/schema",
     "required": [
      "ok",
      "paid",
      "service",
      "provider",
      "result"
     ],
     "properties": {
      "ok": {
       "type": "boolean"
      },
      "paid": {
       "type": "boolean"
      },
      "result": {
       "type": "object",
       "required": [
        "ok",
        "service"
       ],
       "properties": {
        "ok": {
         "type": "boolean",
         "description": "Handler success"
        },
        "brief": {
         "type": "string",
         "description": "Decision procedure prose for agents"
        },
        "model": {
         "type": "string"
        },
        "topic": {
         "type": "string"
        },
        "service": {
         "type": "string",
         "description": "Service slug"
        },
        "procedure": {
         "type": "string"
        },
        "generatedAt": {
         "type": "string",
         "description": "ISO-8601 timestamp"
        },
        "generationSource": {
         "enum": [
          "llm",
          "reasoning",
          "deterministic"
         ],
         "type": "string"
        }
       }
      },
      "payment": {
       "type": "object",
       "properties": {
        "code": {
         "type": "string"
        },
        "payer": {
         "type": "string"
        },
        "detail": {
        
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-protocol-boundary-decision-negotiation-to-payment-intent-binding-a3ac66dc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from k2so-8080.on.ascii.dev](https://www.zero.xyz/host/k2so-8080.on.ascii.dev/llms.txt)