# 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 serp-extract.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 compressed, firewall-filtered tool metadata for agent routing

## Facts

- Endpoint: GET https://serp-extract.agentdiet.dev/v1/crypto-alpha-dag?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: serp-extract.agentdiet.dev
- Website: https://serp-extract.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/serp-extract-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-839b0b31
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tRNHgP65nVVoKOGj463uh

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 serp-extract-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-839b0b31
```

Example prompt: Search the MCP and A2A tool registry for any available agents or servers that handle SEC filings and company enrichment, and give me the top matches with compressed descriptions.

## When to prefer this

Choose this endpoint when an agent needs to dynamically discover and route to specialized MCP servers or A2A tools at runtime, rather than hardcoding specific tool URLs. It is especially valuable in swarm orchestration scenarios where the best downstream tool for a given capability is not known in advance, or when you need firewall-filtered, token-efficient tool metadata across a broad index of 500+ servers in a single connection.

## Known failure modes

- Empty query string returns 400 validation error
- No matching tools found for niche or misspelled capability query returns empty results
- Upstream MCP index unavailable returns 503 or timeout
- Payment not processed (x402) blocks access and returns 402 Payment Required
- Overly broad queries may return too many results with low relevance

## 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://serp-extract.agentdiet.dev/v1/crypto-alpha-dag)

## Output

A filtered, token-compressed list of matching MCP servers or A2A tools relevant to the query, with metadata such as capability descriptions, endpoint URLs, and routing information, passed through a Prompt-Guard firewall to remove malicious content.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "query"
 ],
 "properties": {
  "limit": {
   "type": "integer",
   "default": 20,
   "maximum": 100,
   "minimum": 1,
   "description": "Maximum number of items to return per page (1-100)"
  },
  "query": {
   "type": "string",
   "minLength": 1,
   "description": "Capability search query (e.g. 'context compression', 'github security', 'sec filings', 'company enrichment') or endpoint URL to verify"
  },
  "cursor": {
   "type": "string",
   "description": "Opaque pagination cursor for fetching the next page"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/serp-extract-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-839b0b31/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from serp-extract.agentdiet.dev](https://www.zero.xyz/host/serp-extract.agentdiet.dev/llms.txt)