# Pulse Verity x402 Signed Crypto Price Feed

> Pulse Verity x402 Signed Crypto Price Feed is a paid API for AI agents from mcp.thepulse.markets, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-29).

Returns a cryptographically signed, multi-exchange USD price for a given cryptocurrency ticker, paid per-request in USDC via x402 with no API key required.

## Facts

- Endpoint: GET https://mcp.thepulse.markets/api/index/v1/x402/price?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pulse-verity-x402-signed-crypto-price-feed-1079c730
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BzSwgUVY5kdcDTglJg8Pa

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 pulse-verity-x402-signed-crypto-price-feed-1079c730
```

Example prompt: What's the current Pulse Verity signed price of BTC right now? I need the ECDSA signature too so I can verify it offline.

## When to prefer this

Choose this endpoint when you need a cryptographically verifiable, multi-exchange consensus crypto price that can be audited or validated offline without trusting the delivery channel — especially when no persistent API key or account setup is acceptable and pay-per-request micropayment billing in USDC is preferred. It is ideal for audit trails, smart contract price assertions, compliance workflows, or any context where tamper-evidence of the price matters more than raw speed or volume.

## Known failure modes

- Unsupported ticker symbol returns an error — only symbols listed in the Pulse Verity Index are valid
- Payment failure via x402 if the wallet has insufficient USDC or the payment flow is not completed
- Network timeout or service unavailability returns no data
- Stale or unavailable exchange data may lower confidence score or prevent a response
- Invalid query parameter format (e.g. missing symbol) returns a 400-level error

## How this service works

Signed crypto prices from the Pulse Verity Index, paid per request in USDC with x402, with no account or API key. Each price is a multi-exchange US dollar price signed with ECDSA P-256, and its signature can be checked offline against the public keys Pulse publishes.

## Output

A JSON object containing the ticker symbol, USD price as a number and text string, ISO 8601 timestamp, an ECDSA P-256 signature (v1 and v2), a signing key ID, a confidence score (0–1), and a grade (e.g. 'consensus') — all verifiable offline against Pulse's published public keys.

## 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",
     "required": [
      "symbol"
     ],
     "properties": {
      "symbol": {
       "type": "string",
       "description": "Crypto ticker, for example BTC"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "symbol",
      "price",
      "at",
      "signature",
      "kid"
     ],
     "properties": {
      "at": {
       "type": "string",
       "description": "ISO 8601 time of the price"
      },
      "v2": {
       "type": "object",
       "description": "Signature over the whole record: sig, canonical, signature, kid"
      },
      "kid": {
       "type": "string",
       "description": "Signing key id"
      },
      "sig": {
       "type": "string"
      },
      "grade": {
       "type": "string"
      },
      "price": {
       "type": "number",
       "description": "The price in US dollars"
      },
      "symbol": {
       "type": "string",
       "description": "The ticker, for example BTC"
      },
      "priceText": {
       "type": "string",
       "description": "The price as signed, as text"
      },
      "signature": {
       "type": "string",
       "description": "Signature over the print, checkable against the public keys Pulse publishes"
      },
      "confidence": {
       "type": "number"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "at": "2026-10-17T20:00:00.000Z",
  "v2": {
   "kid": "<signing key id>",
   "sig": "pulse-index-v2",
   "canonical": "<the exact signed text>",
   "signature": "<base64 signature>"
  },
  "kid": "<signing key id>",
  "sig": "pulse-index-v1",
  "grade": "consensus",
  "price": 65000.12,
  "symbol": "BTC",
  "priceText": "65000.12",
  "signature": "<base64 signature>",
  "confidence": 0.91
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pulse-verity-x402-signed-crypto-price-feed-1079c730/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mcp.thepulse.markets](https://www.zero.xyz/host/mcp.thepulse.markets/llms.txt)