# 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 2026-10-21).

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

## Facts

- Endpoint: GET https://email-verify.agentdiet.dev/v1/b2a-router?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- 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-fd119870
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_f1SEHvvL0tbuJxYCVvTrV

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-fd119870
```

Example prompt: Search the A2A and MCP tool index for any servers that support SEC filings or financial document retrieval so I can wire one into my research agent.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover and route to specialized MCP or A2A tools at runtime rather than hardcoding integrations. Especially valuable when building agent swarms that need to self-assemble capabilities or when the right tool for a task is unknown in advance. The 85% token compression makes it efficient for agents with tight context budgets.

## Known failure modes

- Empty or vague query returns no results or generic matches
- Unknown or unindexed endpoint URL returns no verification match
- Query too broad causes high token output even with compression
- Rate limiting or payment failure returns HTTP 402 requiring x402 micropayment
- Firewall may flag legitimate queries containing prompt-like patterns

## 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/b2a-router)

## Output

Returns a token-compressed list of matching MCP servers or A2A tool endpoints relevant to the capability query, filtered through a Prompt-Guard firewall to prevent injection attacks, with metadata about each discovered tool.

## 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-fd119870/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)