# AgentToolbox Quote Proof Verifier

> AgentToolbox Quote Proof Verifier is a paid API for AI agents from agi.agenttoolbox2026.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-27).

Verifies that specific text quotes genuinely appear in the content at given URLs, returning cryptographic proof of the verification outcome.

## Facts

- Endpoint: POST https://agi.agenttoolbox2026.workers.dev/v1/products/quote-proof/invoke?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agenttoolbox-quote-proof-verifier-c2598e09
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_E9nX6G91Sp8AR89Eodc0l

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 agenttoolbox-quote-proof-verifier-c2598e09 -d '<json body>'
```

Example prompt: Can you verify that the quote 'AI is transforming industries at an unprecedented pace' actually appears on this page: https://example.com/ai-report-2024? I need proof it's genuinely published there.

## When to prefer this

Choose this endpoint when you need cryptographically provable verification that specific text quotes appear in published web pages — particularly useful for AI agents that need to audit their own citations, validate research outputs, or confirm that claimed outcomes are genuinely published. Prefer this over simple web scraping when you need a trustworthy, paid proof artifact rather than just a raw page fetch.

## Known failure modes

- URL is unreachable or returns a non-200 status — verification cannot be completed
- Quote text not found in the page content — returns a negative verification result
- URL content requires JavaScript rendering and static fetch fails
- Rate limiting or access blocking by the target URL
- Invalid source_index referencing a URL outside the provided list
- Malformed quote string or empty quote content
- Payment not completed — x402 payment required error returned before invocation proceeds

## How this service works

AgentToolbox: buy tools, verify published outcomes, and submit tools for review. HTTP, x402 and MCP instructions for agents.

## Output

Returns a verification result indicating whether each submitted quote was found at its corresponding URL, along with a cryptographic proof token or signed outcome that can be used to demonstrate the verification was performed legitimately and paid for.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "input": {
   "type": "object",
   "$schema": "https://json-schema.org/draft/2020-12/schema",
   "required": [
    "urls",
    "quotes"
   ],
   "properties": {
    "urls": {
     "type": "array",
     "items": {
      "type": "string",
      "maxLength": 512
     },
     "maxItems": 5,
     "minItems": 1
    },
    "quotes": {
     "type": "array",
     "items": {
      "type": "object",
      "required": [
       "source_index",
       "quote"
      ],
      "properties": {
       "quote": {
        "type": "string",
        "maxLength": 512,
        "minLength": 1
       },
       "source_index": {
        "type": "integer",
        "maximum": 4,
        "minimum": 0
       }
      },
      "additionalProperties": false
     },
     "maxItems": 10,
     "minItems": 1
    }
   },
   "additionalProperties": false
  },
  "version": {
   "type": "string",
   "const": "0.1.1"
  },
  "agent_id": {
   "type": "string",
   "format": "uuid",
   "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$",
   "description": "Optional random UUID pseudonym (e.g. crypto.randomUUID()); not authenticated identity. Omit if unavailable."
  },
  "quote_id": {
   "type": "string",
   "format": "uuid",
   "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
  },
  "prepared_id": {
   "type": "string",
   "format": "uuid",
   "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$"
  },
  "referral_code": {
   "type": "string",
   "pattern": "^ref_[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$",
   "description": "Public referral code returned by registration. First-party tools only; preserve it in the original invoke body on every replay."
  },
  "review_secret_hash": {
   "type": "string",
   "pattern": "^[0-9a-f]{64}$",
   "description": "Optional SHA-256 hex of caller-kept atbr_ secret (32 random bytes). Bound to this paid request; never send the raw secret here."
  },
  "payment_amount_atomic": {
   "type": "string",
   "pattern": "^(0|[1-9][0-9]{0,77})$",
   "description": "Canonical decimal USDC atomic-unit string (6 decimals). Protocol uint25
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agenttoolbox-quote-proof-verifier-c2598e09/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agi.agenttoolbox2026.workers.dev](https://www.zero.xyz/host/agi.agenttoolbox2026.workers.dev/llms.txt)