# 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 defi-yield.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-23).

Searches and routes across 500+ indexed MCP servers and A2A tools via a single meta-gateway connection with 85% token compression and prompt-injection firewall protection.

## Facts

- Endpoint: GET https://defi-yield.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: defi-yield.agentdiet.dev
- Website: https://defi-yield.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/defi-yield-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-1e90cc53
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_51dPrZa_tvXxXtySvpwYI

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 defi-yield-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-1e90cc53
```

Example prompt: Search the MCP gateway for tools that do 'github security auditing' and return the top 10 results.

## When to prefer this

Choose this endpoint when an agent needs to dynamically discover which MCP server or A2A tool provides a specific capability without hardcoding individual server URLs. It is the right choice when operating in multi-agent swarm architectures where tool availability must be queried at runtime, or when you want a single connection point that indexes 500+ tools with built-in prompt-injection firewall protection and token-compressed responses.

## Known failure modes

- Empty or too-short query returns no results or validation error
- Cursor from a different session may be invalid or expired
- Limit exceeding 100 returns a validation error
- Unrecognized capability terms may return zero matches
- Payment not fulfilled (HTTP 402) blocks access
- Prompt-guard firewall may reject queries containing injection-like patterns

## 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://defi-yield.agentdiet.dev/v1/mcp-gateway)

## Output

Returns a paginated list of matching MCP servers or A2A tools with capability descriptions, endpoint URLs, and metadata. Each page contains up to 100 items and includes an opaque cursor for fetching the next page.

## 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/defi-yield-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-1e90cc53/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from defi-yield.agentdiet.dev](https://www.zero.xyz/host/defi-yield.agentdiet.dev/llms.txt)