# 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 a meta-index of 500+ MCP servers and A2A tools by capability query, returning compressed results filtered through a prompt-injection firewall

## Facts

- Endpoint: POST https://defi-yield.agentdiet.dev/v1/web-rag-shield-dag?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-116dc0ad
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Vi2gjUyFUln3sLNYOPZUQ

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-116dc0ad -d '<json body>'
```

Example prompt: Search the MCP and A2A tool index for any servers that handle 'SEC filings' or 'company enrichment' — I need to find the best available agent tool for that capability.

## When to prefer this

Use this endpoint when an AI agent needs to dynamically discover which MCP server or A2A tool is best suited for a given capability at runtime, especially when you want firewall-protected, token-compressed results across a broad index of 500+ tools rather than hardcoding individual tool URLs.

## Known failure modes

- Empty results if query terms don't match any indexed capability
- Firewall rejection if query itself contains injection-like patterns
- Timeout if the meta-index is unavailable
- 400 error if query field is missing or empty string
- Payment required (402) if x402 micropayment is not completed

## 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/web-rag-shield-dag)

## Output

A compressed (up to 85% token reduction) list of matching MCP servers or A2A tool entries relevant to the query, each passing through a Prompt-Guard firewall to strip prompt-injection risks, along with metadata about each tool's capabilities.

## 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-116dc0ad/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)