# 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 an index of 500+ MCP servers and A2A tools by capability query, returning compressed tool metadata through a prompt-guarded safe proxy

## Facts

- Endpoint: GET https://defi-yield.agentdiet.dev/v1/broker/execute?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-8a663ded
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8i5h7Q_HGufxaj6dwb5gf

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-8a663ded
```

Example prompt: Search the MCP tool index for any available servers that handle SEC filings or financial document retrieval — I want to see what's out there before I commit to one.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover which MCP servers or A2A tools are available for a given capability without pre-configuring each tool individually. It is especially useful in swarm orchestration scenarios where agents need to route tasks to the right sub-agent, or when you want a single connection point with built-in safety filtering and token-efficient responses across 500+ indexed tools.

## Known failure modes

- Empty query string returns validation error
- No matching tools found for obscure or highly specific queries
- Endpoint URL verification may return inconclusive results for unknown or private servers
- Rate limiting or payment failure (HTTP 402) if x402 payment header is missing or invalid
- Prompt injection attempts blocked by Prompt-Guard firewall may result in filtered or empty responses

## 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/broker/execute)

## Output

Returns a structured object containing matching MCP server or A2A tool entries filtered by the capability query, with compressed metadata (up to 85% token reduction) and Prompt-Guard firewall screening applied. May include tool names, descriptions, endpoint URLs, and compatibility signals.

## 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-8a663ded/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)