# Universal A2A & MCP Tool Discovery, Safe-Proxy & Swarm Router

> Universal A2A & MCP Tool Discovery, Safe-Proxy & Swarm Router is a paid API for AI agents from json-repair.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-23).

Searches and discovers 500+ MCP servers and A2A agent tools by capability query, returning ranked results with token-compressed metadata through a prompt-guarded meta-router.

## Facts

- Endpoint: GET https://json-repair.agentdiet.dev/v1/mcp-gateway?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Provider: json-repair.agentdiet.dev
- Website: https://json-repair.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/json-repair-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-e8d28bc9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6YtTdscENP6lMiVpa388I

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 json-repair-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-e8d28bc9
```

Example prompt: Search the MCP tool index for any servers that handle 'SEC filings' and return up to 10 results — I want to find an agent-compatible endpoint I can wire into my financial research workflow.

## When to prefer this

Choose this endpoint when an agent needs to dynamically discover which MCP servers or A2A tools are available for a given capability, rather than hardcoding a specific tool URL. Ideal for meta-agents, swarm orchestrators, or autonomous planners that must self-assemble a tool chain at runtime. Prefer this over manual registry browsing when you need 500+ tools searchable in one call with built-in prompt-injection protection.

## Known failure modes

- Empty query string returns validation error
- No matching tools found returns empty results list
- Cursor expired or malformed returns pagination error
- Rate limit or payment required (HTTP 402) if quota exceeded
- Upstream MCP server index temporarily unavailable returns 503

## How this service works

Single-connection meta-router indexing 500+ MCP servers & A2A tools with 85% token compression and Prompt-Guard firewall. (Live x402 v2, IETF MPP & MCP endpoint at https://json-repair.agentdiet.dev/v1/mcp-gateway)

## Output

Returns a paginated list of matching MCP servers and A2A tools ranked by relevance to the query, including endpoint URLs, capability descriptions, token-compressed metadata, and an opaque cursor for fetching the next page. The response is filtered through a Prompt-Guard firewall to block malicious prompt injection from indexed tool descriptions.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "query"
 ],
 "properties": {
  "limit": {
   "type": "integer",
   "default": 20,
   "maximum": 100,
   "minimum": 1,
   "description": "Maximum number of items to return per page (1-100)"
  },
  "query": {
   "type": "string",
   "minLength": 1,
   "description": "Capability search query (e.g. 'context compression', 'github security', 'sec filings', 'company enrichment') or endpoint URL to verify"
  },
  "cursor": {
   "type": "string",
   "description": "Opaque pagination cursor for fetching the next page"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/json-repair-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-e8d28bc9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from json-repair.agentdiet.dev](https://www.zero.xyz/host/json-repair.agentdiet.dev/llms.txt)