JSON Validator API
  
JSON validator with optional JSON Schema validation and structure stats. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.
Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.
Quickstart -- MCP
Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):
{
"mcpServers": {
"json-validator": {
"url": "https://json-validator.api.klymax402.com/mcp"
}
}
}Quickstart -- HTTP (x402)
curl -X POST "https://json-validator.api.klymax402.com/api/validate" \
-H "Content-Type: application/json" \
-d '{"json":"..."}'
# -> 402 Payment Required, with an x402 payment challenge in the response bodyAny x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.
Tools
| Tool | Method | Path | Price | Description | |---|---|---|---|---| | data_validate_json | POST | /api/validate | $0.003 | Validate JSON and optionally check against a JSON Schema |
data_validate_json
Use this when you need to validate JSON syntax or validate JSON data against a JSON Schema. Returns validity status, parse errors, formatted JSON, and structure stats (depth, key count, arrays, total size). Do NOT use for password checking — use security_check_password. Do NOT use for hash generation — use crypto_generate_hash. Do NOT use for cron expressions — use util_parse_cron.
Parameters
| Name | Type | Required | Description | |---|---|---|---| | json | string | yes | JSON string to validate | | schema | object | no | Optional JSON Schema to validate against |
Example agent prompts
- "Validate JSON syntax or validate JSON data against a JSON Schema"
Payment
- Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
- Network: Base L2 (
eip155:8453) - Asset: USDC
- Facilitator: Coinbase CDP (primary), PayAI (fallback)
Part of klymax402
100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.
- Catalog: https://klymax402.com/llms.txt
- Full API reference: https://klymax402.com/llms-full.txt
- Live stats: https://klymax402.com/stats
License
MIT
