# 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 2026-10-23).

Meta-router that searches and proxies 500+ MCP servers and A2A tools by capability query, with token compression and prompt injection firewall.

## Facts

- Endpoint: POST https://serp-extract.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: 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-a34ad833
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oUx8qmwzpRfqrpOcmwUpb

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-a34ad833 -d '<json body>'
```

Example prompt: Search the MCP tool index for servers that handle 'SEC filings' and route my query through the safe-proxy — I want compressed, firewall-filtered results.

## When to prefer this

Choose this endpoint when you need a single connection point to discover and safely proxy across a large catalog of MCP servers or A2A tools, especially when token budget is constrained or when prompt injection safety is a concern. Prefer over direct MCP server calls when the right tool is unknown and needs to be searched first.

## Known failure modes

- Query too vague — returns low-relevance or empty tool list
- Queried endpoint URL not found in index — returns no match
- Prompt injection detected by firewall — request blocked
- Payment not processed (x402) — 402 response before results returned
- Downstream MCP server unavailable — proxy returns upstream 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://serp-extract.agentdiet.dev/v1/web-rag-shield-dag)

## Output

Returns a list of matching MCP servers or A2A tools relevant to the capability query, with compressed metadata (85% token reduction), safety-filtered through Prompt-Guard firewall, and routing details for direct use by an agent.

## 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/serp-extract-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-a34ad833/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)