# 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 2026-10-21).

Searches and routes to 500+ MCP servers and A2A tools via a single meta-router endpoint with token compression and prompt-injection firewall.

## Facts

- Endpoint: GET https://defi-yield.agentdiet.dev/v1/universal-mcp-gateway?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- 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-552f0b86
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9Whl4u6ejgR4WklCNm8B8

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-552f0b86
```

Example prompt: Search the MCP and A2A tool registry for anything that can do 'company enrichment' — I want to find the best available tool I can route to for that capability.

## When to prefer this

Use this endpoint when an agent needs to dynamically discover which MCP server or A2A tool to use for a given capability, rather than hardcoding a specific tool. Ideal for swarm architectures where agents must self-route to the best available tool across a large registry, or when building meta-agents that orchestrate other agents. Prefer this over manually curating tool lists when the required capability may be served by multiple providers.

## Known failure modes

- No matching tools found for the given query — returns empty result set
- Query string too vague — returns low-confidence or irrelevant tool matches
- Downstream MCP server unavailable — routing fails with connectivity error
- Prompt-Guard firewall blocks query flagged as potential injection attempt
- Payment not processed (x402) — request rejected before tool search executes

## 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/universal-mcp-gateway)

## Output

Returns a list of matching MCP servers or A2A tools ranked by relevance to the query, including tool metadata, endpoint URLs, and compressed capability descriptions, filtered through a Prompt-Guard firewall to prevent injection attacks.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "query"
 ],
 "properties": {
  "query": {
   "type": "string",
   "minLength": 1,
   "description": "Capability search query (e.g. 'context compression', 'github security', 'sec filings', 'company enrichment') or endpoint URL to verify"
  }
 }
}
```

## 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-552f0b86/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)