# 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 a meta-index of 500+ MCP servers and A2A tools by capability query, returning matching endpoints with token-compressed results and prompt-injection firewall protection.

## Facts

- Endpoint: GET https://defi-yield.agentdiet.dev/v1/security-audit-dag?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-c3ed8e3e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Co7jgBbLH-B_Pr7NXbbOI

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-c3ed8e3e
```

Example prompt: Search the MCP tool index for any servers that handle SEC filings or company enrichment — I want to know what's available and get a compressed summary of matching endpoints.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover which MCP servers or A2A tools exist for a given capability, rather than hardcoding tool integrations. Especially useful for building swarm routers, agent orchestrators, or meta-agents that need to self-configure their tool stack at runtime. Prefer over manual tool registries when you need coverage of 500+ tools with built-in safety filtering and token budget management.

## Known failure modes

- Empty or vague query returns no meaningful matches
- Query string too short or missing causes validation error
- Indexed tool unavailable or stale metadata returned
- Prompt-Guard firewall may over-flag legitimate endpoints as unsafe
- Rate limiting or payment failure (x402) blocks access
- Returned endpoints may be offline or deprecated since last index crawl

## 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/security-audit-dag)

## Output

Returns a list of matching MCP servers or A2A tools relevant to the query, with capability descriptions and token-compressed metadata. Results are filtered through a Prompt-Guard firewall to flag potentially unsafe or injection-prone endpoints. May include endpoint URLs, tool names, and safety assessments.

## 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-c3ed8e3e/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)