# Tenjin: x402 v2 vs v1 Discovery Vocabulary Changes

> Tenjin: x402 v2 vs v1 Discovery Vocabulary Changes is a paid API for AI agents from tenjin.blog, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-16).

Returns a pay-per-read article detailing what changed between x402 v1 and v2 in the discovery vocabulary on catalog surfaces, including header renames, challenge format changes, CAIP-2 naming, and Bazaar query vocabulary.

## Facts

- Endpoint: GET https://tenjin.blog/api/read/0xe4c16d163d80fd972e6e1e9b94bc71c5fbe5a9c5/x402-v2-vs-v1-what-changed-in-the-discovery-vocabulary-on-catalog-surfaces
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tenjin-x402-v2-vs-v1-discovery-vocabulary-changes-a472bd80
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jIJ0FLZFxK9xAP7e-BaX4

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 tenjin-x402-v2-vs-v1-discovery-vocabulary-changes-a472bd80
```

Example prompt: Can you pull up the Tenjin article on what changed between x402 v1 and v2 — specifically the discovery vocabulary, header renames, and how the payment challenge moved to the PAYMENT-REQUIRED header?

## When to prefer this

Choose this endpoint when you need authoritative, cited information about the x402 v2 specification changes for discovery/catalog clients, specifically covering header renames, challenge format migration, CAIP-2 naming, and Bazaar vocabulary — as a micropayment-gated article from an independent publisher rather than free documentation or a spec search.

## Known failure modes

- Payment not attached or insufficient — returns 402 Payment Required with challenge in PAYMENT-REQUIRED header
- Invalid or mismatched wallet address handle — returns 404 Not Found
- Slug not found for the given creator — returns 404 Not Found
- Network or upstream error — returns 5xx
- Using handle 'latest' without a wallet address (not payable) — may return error or wrong article

## How this service works

x402 v2 vs v1: what changed in the discovery vocabulary on catalog surfaces. As-of 2026-08-15: what a discovery/catalog client must change between x402 v1 and v2 — the header renames, the challenge moving from response body to PAYMENT-REQUIRED header, CAIP-2 network naming, Bazaar query vocabulary, and measured data on x402Version fragmentation from an open spec issue.

## Output

The full text of a pay-per-read article (unlocked for $0.01 USDC) covering the differences between x402 v1 and v2 as of 2026-08-15: renamed headers, the payment challenge moving from response body to the PAYMENT-REQUIRED header, CAIP-2 network naming conventions, updated Bazaar query vocabulary, and empirical data on x402Version fragmentation from an open spec issue.

## 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": [
      "handle",
      "slug"
     ],
     "properties": {
      "slug": {
       "type": "string",
       "description": "The article's URL slug, unique per creator. The reserved slug `latest` resolves to the creator's newest published piece; its stable scheduled-read form is the wallet-address URL /api/read/<0x-address>/latest (a handle `latest` is not payable)."
      },
      "handle": {
       "type": "string",
       "description": "The creator's handle, or their wallet address. The address form is REQUIRED for a durable `latest` alias (a handle `latest` is not payable), and is the only form for an unclaimed creator."
      }
     }
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {},
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tenjin-x402-v2-vs-v1-discovery-vocabulary-changes-a472bd80/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tenjin.blog](https://www.zero.xyz/host/tenjin.blog/llms.txt)