# Rubric Protocol – Hedera Rubric Activity Facts (Attested)

> Rubric Protocol – Hedera Rubric Activity Facts (Attested) is a paid API for AI agents from rubric-protocol.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns attested Hedera network facts (HBAR exchange rate, gas fees, supply, node roster, throughput, topic state) for the 'rubric-activity' snapshot, each signed with an ML-DSA-65 post-quantum attestation ID.

## Facts

- Endpoint: GET https://rubric-protocol.com/v1/x402/hedera-facts/rubric-activity
- Price: $0.001/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-hedera-rubric-activity-facts-attested-08ff65f6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6wBCn7z-tWOfzetNb7X6_

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-hedera-rubric-activity-facts-attested-08ff65f6
```

Example prompt: Fetch me the latest attested Hedera network snapshot from Rubric Protocol — I need the HBAR exchange rate, current gas fees, and node roster, all with their ML-DSA-65 attestation ID so I can prove what the network state was when I made my decision.

## When to prefer this

Choose this endpoint when your agent or application needs cryptographically provable, tamper-evident Hedera network state — particularly for compliance, audit logging, or any use case where you must later prove what the network conditions were at a given moment. Prefer it over plain Hedera API calls when post-quantum attestation (ML-DSA-65) is required, or when regulatory or contractual obligations demand a signed reference datum. Use the bundle endpoint instead if you need all six facts in a single call.

## Known failure modes

- Payment not provided or invalid x402 payment header → 402 Payment Required
- Hedera network temporarily unavailable → upstream data fetch failure, 503 or error body
- Attestation signing service down → snapshot returned without attestation ID or error
- Malformed request → 400 Bad Request
- Rate limiting or quota exceeded → 429 Too Many Requests

## How this service works

Attested Hedera network facts: HBAR exchange rate, gas fees, supply, node roster, throughput, topic state. Each response

## Output

A JSON object containing the rubric-activity snapshot of Hedera network facts: HBAR/USD exchange rate, current gas fee schedule, total HBAR supply, active node roster, network throughput metrics, and HCS topic state — each snapshot accompanied by an ML-DSA-65 (post-quantum) attestation ID that cryptographically binds the data to the specific moment it was served, enabling agents to prove what they knew at decision time.

## 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"
    },
    "pathParams": {
     "type": "object",
     "required": [
      "fact"
     ],
     "properties": {
      "fact": {
       "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-hedera-rubric-activity-facts-attested-08ff65f6/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)