# Rubric Protocol x402 Spend Statement

> Rubric Protocol x402 Spend Statement is a paid API for AI agents from rubric-protocol.com, paid per call via x402, $0.5/call, status unknown (last checked 2026-09-15).

Generates a signed monthly x402 spend statement for a single agent, including payment totals, per-payment line items, and a Merkle root, returned as a signed ML document.

## Facts

- Endpoint: POST https://rubric-protocol.com/v1/x402/statement
- Price: $0.5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/rubric-protocol-x402-spend-statement-1d89ca13
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sxusBv8foCr3QKcX7QGqI

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 rubric-protocol-x402-spend-statement-1d89ca13 -d '<json body>'
```

Example prompt: Can you pull the signed monthly x402 spend statement for my agent, including the payment totals, all individual payment lines, and the Merkle root for this billing period?

## When to prefer this

Choose this endpoint when you need a cryptographically signed, Merkle-rooted monthly financial statement for a single AI agent's x402 payment activity — particularly for compliance reporting, cross-party billing verification, or auditable accounting records. Prefer it over generic payment logs when tamper-proof attestation and a structured ML document format are required.

## Known failure modes

- No payment records found for the specified agent in the given period — returns empty or error response
- Invalid or missing agent identifier — 400 bad request
- Billing period out of range or malformed — 422 validation error
- Payment processing failure for the $0.5 USDC service fee — request rejected before statement is generated
- Internal signing or Merkle computation failure — 500 server error

## How this service works

Signed monthly x402 spend statement for one agent: totals, per-payment lines, Merkle root. The statement is itself an ML

## Output

A signed monthly statement document (itself an ML artifact) containing the agent's total x402 spend for the period, individual per-payment line items, and a Merkle root that allows independent verification of the statement's completeness and integrity.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object"
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "format": {
     "type": "string"
    },
    "example": {}
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/rubric-protocol-x402-spend-statement-1d89ca13/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from rubric-protocol.com](https://www.zero.xyz/host/rubric-protocol.com/llms.txt)