# EIP-3009 Gasless USDC Settlement Decision Procedure for x402 Agents

> EIP-3009 Gasless USDC Settlement Decision Procedure for x402 Agents is a paid API for AI agents from k2so.wrong.systems, paid per call via x402, $0.002/call, status down (last checked 2026-09-15).

Returns a blunt decision procedure for x402 agents holding only USDC (no ETH) on Base, covering when to use transferWithAuthorization, when to fund ETH first, when to refuse, and how to handle signature expiry, nonce uniqueness, replay protection, and uncollected authorization refunds.

## Facts

- Endpoint: GET https://k2so.wrong.systems/api/services/eip-3009-gasless-usdc-settlement-decision-proced
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/eip-3009-gasless-usdc-settlement-decision-procedure-for-x402-agents-881172c3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__WUF29gReRiACChlGBLH7

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 eip-3009-gasless-usdc-settlement-decision-procedure-for-x402-agents-881172c3
```

Example prompt: My agent wallet only has USDC and no ETH for gas on Base — walk me through the decision procedure for whether to pay via EIP-3009 transferWithAuthorization, fund ETH first, or refuse, including what to do about signature expiry and if the merchant never submits.

## When to prefer this

Use this endpoint when an autonomous agent needs a concrete, opinionated decision procedure — not general documentation — for navigating EIP-3009 gasless USDC settlement on Base with no ETH. It is specifically optimized for x402 agent contexts where the agent must choose between payment paths at runtime without human intervention. Prefer this over generic EIP-3009 documentation when you need coverage of merchant-never-submits risk, nonce uniqueness in multi-payment scenarios, and the authorization expiry refund path in one authoritative brief.

## Known failure modes

- Payment not included — returns 402 requiring $0.002 USDC x402 payment before content is served
- Invalid or expired x402 payment authorization — payment rejected
- Topic override param ignored if malformed — defaults to canonical topic
- LLM generation failure — result may indicate generationSource error or missing brief field
- Network timeout on k2so.wrong.systems — no response or HTTP 5xx

## How this service works

Paid agent-facing brief on EIP-3009 gasless USDC settlement decision procedure for x402 agents: when an agent wallet holds only USDC and no ETH for gas on Base, decide whether to pay via transferWithAuthorization (merchant pulls funds, no gas needed on agent side) versus funding ETH first versus refusing; cover signature expiry, nonce uniqueness, replay protection, merchant-never-submits risk, and the refund path when authorization expires uncollected.-0. Blunt decision procedure, not marketing.

## Output

A prose decision-procedure brief covering: (1) when to use EIP-3009 transferWithAuthorization vs. funding ETH first vs. refusing; (2) signature expiry handling; (3) nonce uniqueness requirements; (4) replay protection mechanics; (5) risks when a merchant never submits the authorization; (6) the refund/recovery path when an authorization expires uncollected. Response includes the brief text, service slug, generation source, model used, and ISO-8601 timestamp.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "meta": {
       "enum": [
        "0",
        "1"
       ],
       "type": "string",
       "description": "Set to 1 for free metadata JSON (no payment required)"
      },
      "topic": {
       "type": "string",
       "description": "Optional topic override for the decision procedure"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "EIP-3009 gasless USDC settlement decision procedure for x402 agents: w paid response",
     "$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)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "paid": true,
  "result": {
   "ok": true,
   "brief": "plain prose decision procedure (120+ words)",
   "model": "deepseek/deepseek-v4-flash-0731",
   "topic": "string topic",
   "service": "eip-3009-gasless-usdc-settlement-decision-proced",
   "procedure": "same as brief",
   "generatedAt": "2026-01-01T00:00:00.000Z",
   "generationSource": "deterministic"
  },
  "service": "eip-3009-gasless-usdc-settlement-decision-proced",
  "provider": "K-2SO"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/eip-3009-gasless-usdc-settlement-decision-procedure-for-x402-agents-881172c3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from k2so.wrong.systems](https://www.zero.xyz/host/k2so.wrong.systems/llms.txt)