multilingual knowledge search API for AI agent

$0.01 USDC per call on Base · No signup · No API key · x402 v2

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What it does

Multilingual knowledge search over 2,400 curated chunks. Full-text search over 2,438 curated knowledge chunks in 9 languages (vi, en, zh, th, id, ms, hi, ru, fr) covering Vietnam agriculture/enzyme guides and trade intelligence. $0.01/call via x402.

Data source: Curated knowledge base: 6 Vietnam agriculture/enzyme guides + 5 trade intelligence guides, SQLite FTS5

How to call (for AI agents)

No account. No API key. Every endpoint speaks x402 v2:

Call the endpoint → you get 402 Payment Required with the price
Pay $0.01 USDC on Base (eip155:8453)
Retry with the X-PAYMENT header → 200 with JSON

curl -X POST "https://api.mekongtradeintel.com/ksearch/api/ksearch" \
  -H "Content-Type: application/json" \
  -d '{\n  "query": "durian fertilizer schedule",\n  "lang": "en",\n  "limit": 3\n}'

Input

Param	Type	Description
`query`	string (body JSON)	Search query, e.g. 'durian fertilizer schedule'
`lang`	string (body JSON, optional)	Language code: vi, en, zh, th, id, ms, hi, ru, fr
`limit`	integer (body JSON, optional)	Max results, default 5

Example request & response

Request

{\n  "query": "durian fertilizer schedule",\n  "lang": "en",\n  "limit": 3\n}

Response

{\n  "query": "durian fertilizer schedule", "resultCount": 3,\n  "results": [{"source": "Vietnam Food Export Playbook", "section": "4.4 Lab Testing", "lang": "en", "excerpt": "..."}]\n}

Payment

x402 v2 · exact scheme · USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base (eip155:8453).
Facilitators: Coinbase CDP and PayAI (no API key needed for either).

FAQ

Which languages are supported?
9 languages: Vietnamese, English, Chinese, Thai, Indonesian, Malay, Hindi, Russian, French. Use the lang parameter to filter.

What is in the knowledge base?
2,438 chunks from 6 Vietnam agriculture/enzyme guides and 5 trade intelligence guides.

How is relevance ranked?
SQLite FTS5 full-text ranking over the curated corpus.

Do I need an API key?
No. This API uses x402: call the endpoint, receive a 402 Payment Required with the price, pay in USDC on Base, and retry with proof of payment. No signup, no API key, no account.

Which facilitators are supported?
Both Coinbase CDP and PayAI facilitators are supported for x402 v2 exact payments on Base (eip155:8453).

What if my payment is too low?
The facilitator verifies the on-chain amount against the price. If underpaid, you get 402 again; pay the full amount and retry.

More APIs for AI agents

Part of the x402 API Collection — 37 pay-per-call endpoints, $0.0008–$1.50/call. Full catalog: https://api.mekongtradeintel.com/.well-known/x402 · pricing