# TrueCast API

> TrueCast API is a paid API for AI agents from true-cast-agent.vercel.app, paid per call via x402, $0.1/call, status down (last checked 2026-10-13).

Fact-checks and verifies claims or questions using real-time data from prediction markets, news, DeFi, and social sources, returning a truth assessment with confidence score.

## Facts

- Endpoint: POST https://true-cast-agent.vercel.app/api/trueCast?utm_source=zero.xyz
- Price: $0.1/call
- Payment: x402
- Status: down
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/truecast-api-cf1ef6fd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NZdYlwdC5w2eGugExdcLQ

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 truecast-api-cf1ef6fd -d '<json body>'
```

Example prompt: Can you fact-check this claim for me: 'Ethereum gas fees have dropped below 1 gwei for the first time in 2024' — I want to know if it's TRUE, FALSE, or PARTIALLY_TRUE with a confidence score?

## When to prefer this

Use TrueCast when you need real-time, multi-source fact-checking grounded in prediction market data alongside on-chain DeFi, crypto price, and social (Farcaster/X) signals — especially for claims in the crypto, Web3, or financial news space. Prefer over generic LLM fact-checking when you need a structured TRUE/FALSE/PARTIALLY_TRUE verdict with a confidence score.

## Known failure modes

- Missing required 'prompt' field returns validation error
- Ambiguous or unverifiable claims return UNVERIFIABLE assessment
- Payment failure (x402) prevents API access
- Rate limiting or upstream data source outages may degrade accuracy
- Guardrail rejection if content violates AWS Bedrock policies

## How this service works

TrueCast API - News aggregator and fact-checking service grounded by prediction markets. Real-time data sources include Perplexity, X AI, Tavily, Neynar, Pyth, DeFiLlama, Truemarkets, Zerion, Allora and more.

## Output

Returns the original query, a detailed fact-checked reply with analysis, a truth assessment enum (TRUE/FALSE/PARTIALLY_TRUE/UNVERIFIABLE/MARKET_SENTIMENT), a confidence score, metadata including sources used and processing time, and optionally IPFS storage details and guardrail validation results.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "prompt"
 ],
 "properties": {
  "prompt": {
   "type": "string",
   "description": "The statement, claim, or question to fact-check and verify"
  },
  "castHash": {
   "type": "string",
   "description": "Optional Farcaster cast hash for context-specific verification"
  },
  "runGuardrail": {
   "type": "boolean",
   "description": "Whether to run AWS Bedrock Guardrails validation (default: false)"
  },
  "storeToPinata": {
   "type": "boolean",
   "description": "Whether to store the response to IPFS via Pinata (default: false)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "query",
  "reply",
  "assessment",
  "confidenceScore",
  "metadata"
 ],
 "properties": {
  "ipfs": {
   "type": "object",
   "properties": {
    "hash": {
     "type": "string",
     "description": "IPFS hash of stored response"
    },
    "network": {
     "enum": [
      "public",
      "private"
     ],
     "type": "string",
     "description": "IPFS network used"
    },
    "gatewayUrl": {
     "type": "string",
     "description": "Public gateway URL for the stored response"
    },
    "paymentResponse": {
     "type": "object",
     "properties": {
      "payer": {
       "type": "string"
      },
      "network": {
       "type": "string"
      },
      "success": {
       "type": "boolean"
      },
      "transaction": {
       "type": "string"
      }
     },
     "description": "Payment transaction details if x402 was used"
    }
   },
   "description": "IPFS storage information (if storeToPinata was true)"
  },
  "query": {
   "type": "string",
   "description": "The original user query that was processed"
  },
  "reply": {
   "type": "string",
   "description": "The fact-checked response with analysis and conclusions"
  },
  "metadata": {
   "type": "object",
   "properties": {
    "timestamp": {
     "type": "string",
     "description": "ISO timestamp of processing"
    },
    "promptType": {
     "type": "string",
     "description": "Categorized type of the prompt"
    },
    "sourcesUsed": {
     "type": "array",
     "items": {
      "type": "string"
     },
     "description": "Names of data sources used"
    },
    "totalSources": {
     "type": "number",
     "description": "Total number of data sources queried"
    },
    "needsExternalData": {
     "type": "boolean",
     "description": "Whether external data was needed"
    },
    "processingTimeSec": {
     "type": "number",
     "description": "Time taken to process in seconds"
    }
   }
  },
  "guardrail": {
   "type": "object",
   "properties": {
    "input": {
     "type": "object",
     "description": "Input validation results"
    },
    "output": {
     "type": "object",
     "description": "Output validation results"
    }
   },
   "description": "AWS Bedrock Guardrails validation results (if runGuardrail was true)"
  },
  "assessment": {
   "enum": [
    "TRUE",
    "FALSE",
    "PARTIALLY_TRUE",
    "UNVERIFIABLE",
    "MARKET_SENTIMENT"
   ],
   "type": "string",
   "description": "The final truth assessment of the query"
  },
  
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/truecast-api-cf1ef6fd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from true-cast-agent.vercel.app](https://www.zero.xyz/host/true-cast-agent.vercel.app/llms.txt)