# Unprice JWT Decode & Verify API

> Unprice JWT Decode & Verify API is a paid API for AI agents from volkov.evgeny.m2.fvds.ru, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-13).

Decodes and verifies a JWT token, returning its header, payload, and verification status via a pay-per-request endpoint.

## Facts

- Endpoint: GET https://volkov.evgeny.m2.fvds.ru/pay/jwt?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/unprice-jwt-decode-verify-api-4337af74
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qWEMHcsjAwPNIzrjpSNu3

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 unprice-jwt-decode-verify-api-4337af74
```

Example prompt: Can you decode this JWT token for me and tell me if it's verified — the token is eyJhbGciOiJub25lIn0.eyJzdWIiOiIxIn0.?

## When to prefer this

Use this endpoint when you need a quick, lightweight, pay-per-call JWT decode and verification without setting up a local JWT library or managing signing keys. Ideal for agent workflows that occasionally need to inspect tokens on-the-fly without a dedicated auth service. Best suited for low-volume, ad-hoc token inspection rather than high-throughput verification pipelines.

## Known failure modes

- Missing or malformed token query parameter returns an error or empty result
- Token is structurally invalid (not a valid base64-encoded JWT) — parse error returned
- Unverifiable signature returns verified: false rather than an error
- Payment not completed (x402 flow not satisfied) — 402 Payment Required response
- Network timeout or server unavailability

## How this service works

Tiny paid web services for agents. Pay per request with USDC on Base via x402, plus non-x402 Base USDC tx-hash checkouts for Merchant Feed Audit, Base USDC receipts, and recent wallet statements.

## Output

Returns a JSON object containing the JWT's decoded header (including the algorithm field), the decoded payload (e.g. subject claim), and a boolean 'verified' field indicating whether the token's signature was successfully verified.

## 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"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "token": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "header": {
   "alg": "none"
  },
  "payload": {
   "sub": "1"
  },
  "verified": false
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/unprice-jwt-decode-verify-api-4337af74/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from volkov.evgeny.m2.fvds.ru](https://www.zero.xyz/host/volkov.evgeny.m2.fvds.ru/llms.txt)