# Reliable JSON MCP Preflight

> Reliable JSON MCP Preflight is a paid API for AI agents from agent-json-reliability.onrender.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-01).

Preflight/handshake endpoint for the Reliable JSON MCP server, enabling AI agents to discover and connect to deterministic JSON repair and schema validation capabilities.

## Facts

- Endpoint: POST https://agent-json-reliability.onrender.com/v1/mcp/preflight?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/reliable-json-mcp-preflight-a425604b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bLsnurLJgNAkjj75LBb0h

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 reliable-json-mcp-preflight-a425604b -d '<json body>'
```

Example prompt: Can you connect to the Reliable JSON MCP server so we can start using it to automatically fix and validate JSON outputs in our pipeline?

## When to prefer this

Choose this endpoint when you need to initialize or verify connectivity to the Reliable JSON MCP server before issuing repair or validation requests. It is the required first step for agents integrating the MCP-based JSON reliability service, not for direct JSON repair or validation calls themselves.

## Known failure modes

- Server unavailable on Render (cold start delay or downtime) returning a 503 or timeout
- Malformed request body resulting in a 400 error
- Network connectivity issues preventing the preflight from completing
- MCP protocol version mismatch causing handshake failure

## How this service works

Deterministic JSON repair and JSON Schema validation for AI agents. Free MCP, inspect, validate, repair. Paid POST /v1/json/reliable 0.003 USDC via x402 on Base.

## Output

Returns a simple JSON object with an 'ok' boolean confirming the MCP server is reachable and ready to accept connections, serving as the handshake before using repair or validation tools.

## Response schema (JSON Schema)

```json
{
 "example": {
  "ok": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/reliable-json-mcp-preflight-a425604b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-json-reliability.onrender.com](https://www.zero.xyz/host/agent-json-reliability.onrender.com/llms.txt)