# 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 email-verify.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, routing requests through a token-compressed proxy with a Prompt-Guard firewall.

## Facts

- Endpoint: POST https://email-verify.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: email-verify.agentdiet.dev
- Website: https://email-verify.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/email-verify-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-402c71aa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0SVaB_0sjlIzY2LX6Efci

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 email-verify-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-402c71aa -d '<json body>'
```

Example prompt: Search the agentdiet MCP and A2A tool registry for any available capabilities related to 'context compression' and tell me which servers and tools match.

## When to prefer this

Choose this endpoint when an agent needs to dynamically discover which MCP servers or A2A tools are available for a given capability without hard-coding individual service URLs, especially when token budget is limited (85% compression) or when prompt injection safety via the built-in firewall is a priority.

## Known failure modes

- Query too vague returns low-relevance or empty tool list
- Prompt-Guard firewall blocks a query flagged as adversarial, returning a rejection response
- Registry index may be stale if upstream MCP servers have gone offline
- Payment required (HTTP 402) if x402 micropayment header is missing or invalid
- Malformed query (missing or empty 'query' field) returns validation error

## 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://email-verify.agentdiet.dev/v1/web-rag-shield-dag)

## Output

Returns a structured list of matching MCP servers or A2A tools from a 500+ entry registry, including capability metadata, with 85% token compression applied and Prompt-Guard firewall screening on all proxied responses.

## 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/email-verify-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-402c71aa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from email-verify.agentdiet.dev](https://www.zero.xyz/host/email-verify.agentdiet.dev/llms.txt)