# Tenjin Knowledge Marketplace – Preserve HTTP 402 Payment Terms in LangChain Tools for Agent Souk

> Tenjin Knowledge Marketplace – Preserve HTTP 402 Payment Terms in LangChain Tools for Agent Souk is a paid API for AI agents from tenjin.sh, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).

Retrieves a verified, pre-researched knowledge article explaining how to preserve HTTP 402 payment terms when building LangChain tools for use in agent marketplaces.

## Facts

- Endpoint: GET https://tenjin.sh/api/read/0xe4f7077f75438e2d63a6112b854f1e666dc74f1b/preserve-http-402-payment-terms-in-langchain-tools-for-agent-souk
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tenjin-knowledge-marketplace-preserve-http-402-payment-terms-in-c1bc0b81
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_c7AkhOTVghRbaVAnIkZjp

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-knowledge-marketplace-preserve-http-402-payment-terms-in-c1bc0b81
```

Example prompt: Can you fetch the Tenjin article on how to preserve HTTP 402 payment terms in LangChain tools for Agent Souk? I want the verified research on how to wire up x402 payment handling correctly in a LangChain tool.

## When to prefer this

Choose this endpoint when you need a single, verified, human-authored research article on the specific topic of preserving HTTP 402 payment terms in LangChain tool construction for agent marketplaces. Prefer it over generic web search when you want a tested, citable answer rather than raw search results, and when you are operating in an x402-capable agent context that can handle microtransaction gating automatically.

## Known failure modes

- Payment not fulfilled (402): the caller has not paid the $0.05 USDC fee, no content returned
- Article not found (404): the slug or wallet address in the path is invalid or the article has been removed
- Facilitator unavailable: the x402 payment facilitator is down, blocking access
- Network timeout: the endpoint does not respond within expected latency window
- Malformed request: incorrect URL path structure results in a routing error

## How this service works

Tenjin is a knowledge marketplace for AI agents: buy verified answers and tested research, each finding on its own. Creators earn as their knowledge is used.

## Output

Returns a JSON object containing the article's unique ID, canonical URL, slug, tags (e.g. x402, langchain, agent-souk), price in micro-units, full title, creator handle and display name, a plain-language excerpt summarizing the key findings, and the publication timestamp.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "required": {
   "type": "string"
  },
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "id": "019f5e1d-3c0e-7b8d-824f-785faafd7bea",
  "url": "https://tenjin.sh/a/athoughts/x402-batch-settlement-how-the-protocol-s-payment-channel-voucher-scheme-actually",
  "slug": "x402-batch-settlement-how-the-protocol-s-payment-channel-voucher-scheme-actually",
  "tags": [
   "x402",
   "protocol",
   "batch-settlement",
   "payment-channels",
   "metering"
  ],
  "price": "100000",
  "title": "x402 batch settlement: how the protocol's payment-channel/voucher scheme actually works",
  "creator": {
   "handle": "athoughts",
   "displayName": "athoughts"
  },
  "excerpt": "A from-the-spec explainer of x402's batch-settlement scheme (a stateless unidirectional payment channel with cumulative signed vouchers) for anyone building a metered or streaming x402 service and deciding between exact and batch. Cadence knobs, the escrow deposit flow, and the facilitator-support gotcha. As-of 2026-07-13.",
  "publishedAt": "2026-07-14T00:53:22.064Z"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tenjin-knowledge-marketplace-preserve-http-402-payment-terms-in-c1bc0b81/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
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